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Contents

Edited by William Terry Kelley


FOREWORD

This publication is the result of a joint effort among the seven disciplines that make up the University of Georgia Extension Vegetable Team. It is the first and most comprehensive production guide ever assembled for squash and cucumbers in Georgia. The 12 topics covered in this bulletin are all integral parts of successful squash or cucumber management programs. Each topic focuses on a particular aspect of production and provides the latest management technology for that phase of production. The information in this publication is designed to help growers improve profitability in squash and cucumber production. Chemical pest control recommendations are subject to change from year to year and are not specifically mentioned in this publication. Growers are urged to consult the current Georgia Pest Management Handbook or check with their local county Extension agents regarding the most recent chemical recommendations. Mention of trade names in this publication is neither an endorsement of a particular product nor a lack of endorsement for similar unmentioned products.


ORIGINS, CLASSIFICATIONS AND USES
William Terry Kelley, Darbie M. Granberry and George E. Boyhan, Extension Horticulturists

Cucumbers and squash are both members of the cucurbit family, Cucurbitaceae. Many other vegetables belong to this family of vining crops: watermelon, muskmelon, pumpkin and gourd. They are all warm-season tender annuals. Generally, they have a spreading growth habit and have tendrils at the leaf axes. Botanically, the fruit is called a pepo � a type of fruit in which the ovary wall and receptacle tissue are fused to form a hard (or semi-hard) rind. Both cucumbers and squash have a long history of cultivation for human consumption, although they originated on separate sides of the globe.

Most squash produced in Georgia are summer squash, although smaller acreages of hardshell winter squash are produced in the state. The majority of cucumbers produced in Georgia are fresh-market slicing cucumbers. Some pickling cucumber production occurs in the state, although it remains a small portion of the total acreage. Although this publication focuses primarily on summer squash and slicing cucumber production, many of the practices described herein are also applicable to winter squash and pickling cucumber production.

Cucumber

Cucumbers, Cucumis sativus, are indigenous to an area of India between the Himalayas and the Bay of Bengal. One of the oldest cultivated vegetables, they were grown in western Asia as early as 1000 B.C. Cucumber is one of the plants specifically mentioned in the Bible. Cultivation migrated to Greece, Italy and China before arriving in Europe as early as the 9th century. Cultivation in England began around 1550. Columbus is known to have planted cucumbers in Haiti, and Native Americans were growing them in Florida by 1539. Early American colonists also planted cucumbers in Virginia by 1539, and the first permanent settlements in Massachusetts planted them in 1629.

Both the slicing and pickling varieties are members of the same species. Cucumbers are consumed as immature fruits. Slicing varieties are usually eaten raw in salads or as snacks. Pickled cucumbers are processed and used in numerous ways, including salad ingredients, relishes, sandwich slices and spears.

Slicing and pickling types of cucumbers can be differentiated primarily on the basis of the fruit appearance. Slicing types have long fruit, are generally dark green from stem to tip and have white spines that often are not visible. Pickling types are shorter and blockier and may have white or black spines. Fruit of pickling types are often dark green at the stem end and may be almost white at the blossom end.

Squash

Summer squash, Cucurbita pepo, has its origin in the areas of Mexico and Central America. Before Columbus� arrival in the New World, summer squash were cultivated in much of what is now the southwestern, midwestern and eastern United States by Native Americans. Seafarers returned with the crop to Europe, where it quickly gained popularity.

Summer squash are consumed as immature fruit and can be cooked in numerous ways or eaten raw. Winter squash are generally consumed as mature fruit and are usually used for baking or in pies. Four common types of summer squash exist; all are produced in Georgia.


SOILS AND FERTILIZER MANAGEMENT
William Terry Kelley and Darbie M. Granberry
, Extension Horticulturists

Soil requirements and fertilizer management are similar for squash and cucumbers whether they are grown for fresh market or for processing. Both crops will perform well on most soil types found in Georgia. Neither crop can be grown in poorly drained areas. Both crops will produce good yields with proper management when grown on any fertile, well-drained soil. Medium-textured soils with enough organic matter to hold moisture and keep the soil loose for proper root growth are ideal for both squash and cucumbers. Coarse, sandy soils are preferred for early spring production because they tend to dry out and warm up more quickly. However, these soils also require more intense fertilizer and irrigation management.

Crop Rotation

Proper crop rotation is essential in squash and cucumbers to reduce potential problems from diseases, nematodes and herbicide carryover. Never grow squash or cucumbers on land that has been planted with any other cucurbit crop such as watermelons, cantaloupes, pumpkins, etc, within the last three years. Land planted with squash or cucumbers in the same time frame should also be avoided. Proper rotation with non-cucurbit crops will help prevent potential problems from carryover of disease organisms on plant material. Rotation with crops that discourage nematode increases is also beneficial. A good crop rotation program could include corn, rye or other small grains. Other well-fertilized vegetable crops not in the cucurbit family, such as fresh-market tomatoes or peppers, can be good crops to use in a squash or cucumber rotation. Residual fertilizer and organic matter help develop early growth.

Always be aware of any herbicide material that has been used in the last 12 to 18 months that might create a potential carryover problem on land intended for squash or cucumbers. Check labels of herbicides previously used for carryover restrictions.

Land Preparation

Squash and cucumbers both produce moderately deep root systems. However, most of the roots are in the top 8 inches of soil. Therefore, plan soil preparation in order to produce good soil tilth to a depth of at least 8 inches. Work the soil when moisture is adequate, but avoid wet soils. Chop litter from previous crops and work it into the soil by disking prior to plowing to speed up breakdown of organic matter.

In Georgia, optimal yields for both crops have been obtained with deep turning to bury the litter at the bottom of the furrow. Smooth the soil with something other than a disk harrow, which can cause undesirable soil compaction. A tine harrow with a smoothing board or a Rototiller will do a nice job of smoothing the beds. Smoothing operations should be in the same direction as rows, leaving tire tracks exposed so that all future trips can be in the same tracks to prevent further compaction.

Both squash and cucumber can benefit from subsoiling, particularly if a hard pan is present in the field. This allows crop roots to obtain water and nutrients from a greater volume of soil. This can be particularly beneficial in drought situations. When planting on bare ground, it is advisable to plant on a bed raised at least 4 inches high and tapered to the edges to provide good surface drainage, enhance warming of the soil and reduce damage to vines during spraying. The seedbed should be firm and have a uniform texture before planting. When plastic mulch is to be used (see "Production on Plastic Mulch"), the ground should be tilled deeply enough to form a good bed and worked to minimize clods on heavier soils.

Liming and Fertilization

As with any vegetable production system, a recent soil test forms a basis for fertilizer and lime requirements. Check with you local county Extension office or crop consultant regarding proper procedures for soil sampling and interpretation of results. Take the soil test several months before crop establishment to determine lime requirements and to make necessary applications in a timely manner.

A pH of between 6.0 and 6.5 is best for squash and cucumber production. If soil tests reveal a need for lime, apply and disk in dolomitic lime at least three months before planting. Many nutrient deficiencies detected during the growing season, such as calcium or phosphorous deficiencies, can be traced to excessive soil acidity. Foliar applications often can overcome calcium deficiencies. Generally, phosphorous is in the soil but unavailable at low pH; this can be difficult to correct during the season.

Cucumbers and squash are fast-growing crops but are medium to light feeders of major nutrients. On Coastal Plain soils, nitrogen requirements for squash and cucumbers will range from 80 to 120 pounds per acre. On Piedmont, Mountain and Limestone Valley soils, 80 to 100 pounds of nitrogen per acre will be sufficient. Apply potassium and phosphorous based on soil test results. Table 1 summarizes the recommended potassium and phosphorous applications based on the soil test rating for each. For example, if a soil test revealed a low potassium rating and a medium phosphorous rating, 120 pounds of potassium and 80 pounds of phosphorous would be required.

Preplant fertilizer application rates will vary with the natural fertility and past history of the soil. If soil test magnesium is low and lime is recommended, apply dolomitic limestone. If magnesium tests low and lime is not recommended, apply 25 pounds of elemental magnesium per acre. Other nutrient elements also are essential for good crop growth and yield. Boron, sulfur and zinc can be applied in preplant fertilizer if soil tests reveal a need. Apply 1 pound of boron, 10 pounds of sulfur or 5 pounds of zinc per acre if needed. A complete fertilizer with minor elements will provide most other required nutrients. A fine line lies between adequate and toxic amounts of micronutrients. Apply them only when needed and in precise amounts. Watching for nutrient deficiencies is very important in times of high rainfall or frequent irrigation.

Correcting deficiencies of major nutrients is not feasible through foliar nutrient applications. Therefore, an adequately managed soil fertility program is required to maintain proper growth and development. Some deficiencies of minor elements can be remedially corrected through foliar applications. However, it is always best to supply adequate amounts of these nutrients via your basic soil fertility program.

Apply all phosphorous, micronutrients and 30 percent to 50 percent of nitrogen and potassium before planting. Because phosphorous is relatively immobile in the soil, it should be placed in close proximity to the rooting zone. For best results on bare ground, band base fertilizer applications 3 inches to the side and 3 inches below the seed level. If plastic mulch will be used, incorporate fertilizer into the bed before laying the plastic.

Sidedress squash with 30 pounds of nitrogen and 30 pounds of potassium per acre when plants are 8 to 10 inches high. Apply another 30 pounds after the first fruit flush is over to maintain production. For cucumbers, sidress with 30 pounds each of nitrogen and potassium per acre when vines begin to run. Additional nitrogen applications may be needed in areas of high rainfall or in areas where leaching may be a problem. When plastic mulch with drip irrigation is used, additional applications will be injected (see "Production on Plastic Mulch").

Over-the-top applications of dry fertilizer are potentially hazardous because particles may become lodged in the foliage and cause burns. If over-the-top applications become necessary, use less caustic materials such as sodium nitrate and irrigate immediately after application to reduce the chances of fertilizer burn. Always make these applications on dry foliage. All nitrogen fertilizer used for squash and cucumber fertilizer programs should contain at least 50 percent of the nitrogen in the nitrate form.

To reduce the chances of fertilizer burn, never apply more than 40 pounds of nitrogen or potassium to squash or cucumber at any one time. Also avoid overfertilizing cucurbits with nitrogen; excessive nitrogen can delay maturity, reduce fruit set and reduce shipping quality of fruit.

Plant Tissue and Petiole Sap Analysis

Plant tissue and petiole sap analyses are excellent tools in evaluating crop nutrient status. Periodic tissue analysis or sap tests can be used to determine if fertility levels are adequate or if supplemental fertilizer applications are needed. Both tests are useful in detecting nutrient deficiencies that may have developed during the growing season.

Table 1. Recommended potassium and phosphorous applications based on soil test ratings of each nutrient (pounds of N-P2O5-K2O per acre)

Potassium Rating
Low
Medium
High
Very High
Phosphorous Rating

Low

*-120-120

*-120-90

*-120-60

*-120-30

Medium

*-80-120

*-80-90

*-80-60

*-80-30

High

*-40-120

*-40-90

*-40-60

*-40-30

Very High

*-0-120

*-0-90

*-0-60

*-0-30

* Recommendations for nitrogen:
Coastal Plain � 80-120 pounds per acre
Piedmont, Mountain and Limestone Valley � 80-100 pounds per acre

Table 2. Plant tissue analysis critical values for cucumbers and summer squash

 

Nutrient

N (%)

P (%)

K (%)

Ca (%)

Mg (%)

S (%)

Fe (ppm)

Mn (ppm)

Zn (ppm)

B (ppm)

Cu (ppm)

Mo (ppm)

Cucumber

Deficient

<2.5

0.25

1.6

1.0

0.3

0.3

40

30

20

20

5

0.2

Adequate

2.5-5.0

0.25 -0.6

1.6-3.0

1.0-3.5

0.3-0.6

0.3-0.8

40-100

30-100

20-50

20-60

5-10

0.3-1.0

High

>5.0

0.6

3.0

3.5

0.6

0.8

100

100

50

60

20

2.0

Toxic (>)

 

 

 

 

 

 

 

900

950

150

 

 

Summer Squash

Deficient

<3.0

0.25

2.0

1.0

0.3

0.2

40

40

20

25

5

0.3

Adequate

3.0-5.0

0.25 -0.5

2.0-3.0

1.0-2.0

0.3-0.5

0.2-0.5

40-100

40-100

20-50

25-40

5-20

0.3-0.5

High

>5.0

0.5

3.0

2.0

0.5

0.5

100

100

50

40

20

0.5

Adapted from Vegetable Production Guide for Florida, Pub. No. SP 170. Univ. of Florida Cooperative Extension Service. July, 1996.


Table 3.
Sufficiency ranges for petiole sap testing in cucumbers and squash

Crop Development Stage

Fresh petiole sap concentration (ppm)

NO3-N

K

Cucumber

First blossom

800-1000

NR

Fruit three inches long

600-800

NR

First harvest

400-600

NR

Squash

First blossom

900-1000

NR

First Harvest

800-900

NR

NR-No recommended ranges have been established.
Adapted from Vegetable Production Guide for Florida, Pub. No. SP 170. Univ. of Florida Cooperative Extension Service. July, 1996.


The most recently mature leaves of the crop are the subjects for plant tissue analysis. A sample of 20 to 30 leaves should be taken from the area(s) in question. Check with your local county Extension office or crop consultant on proper tissue analysis techniques and for location of analytical laboratories and interpretation of results.

Petiole sap analysis is a more recently developed method. Fresh sap pressed from leaf petioles is analyzed for nitrogen and potassium concentrations. Sap analysis kits are available from a number of sources. Tables 2 and 3 show critical ranges for nutrient concentrations in squash and cucumbers for tissue analysis and petiole sap analysis, respectively.


VARIETIES AND CULTURE
William Terry Kelley and George E. Boyhan, Extension Horticulturists

Climatic Requirements

Both cucumbers and squash are warm-season crops that are sensitive to frost and cold injury. These short-season crops can grow at various times of the year in all areas of Georgia. In the warmer, longer season of South Georgia, two crops per year are common.

Planting and Spacing

Because squash and cucumbers are warm-season crops, planting should be delayed until probability of frost is sufficiently low. Cucumber and squash plantings in South Georgia occur fairly early in the spring, with successively later plantings in the middle and northern sections of the state. Local frost and freeze data should be taken into account when selecting proper planting dates. Cucumbers and squash are almost exclusively direct seeded. Transplanting is not recommended.

Planting early yields little advantage because germination will be slowed by cool soils. In cool, wet soils, germination may be delayed and seeds may decay. Successive plantings can be made every 10 to 14 days for a continuous harvest. Always make the last planting at least 60 days before the first expected frost.

A variety of plant populations can be used for both crops. Cucumbers are generally planted in rows 36 inches apart with an in-row spacing of 9 to 12 inches. Bush type squash are usually planted in rows 36 inches apart with 12 to 18 inches between plants.

In recent years, the development of precision seeders has made more accurate planting feasible. This type of planter can save seed and reduce the need for thinning. If thinning is necessary, pinch the excess plants off at ground level rather than pulling them up, which disturbs the roots of other plants. Precision planters can often cut seed used per acre by 20 percent to 40 percent over traditional methods and eliminate the need for thinning. Precision seeding can greatly enhance uniformity in plant spacing and planting depth, which usually translates into more uniform production and harvest.

Always use quality treated seed from a reputable source. A windbreak of small grain strips placed periodically throughout the field will reduce sandblasting injury and mechanical damage (twisting, etc.) to young seedlings from spring winds.

Maturity dates for squash and cucumber will depend primarily on the variety and the environment. Temperature, soil type and moisture regime can have a significant impact on the number of days from planting to maturity. See Table 4 for a summary of planting and seeding recommendations.

Table 4. Summary of planting and seeding recommendations for cucumber and squash in Georgia

Cucumber

Squash

Planting Dates

South Georgia

Spring

March 1-May 1

March 1-May 1

Fall
August 1-September 15
August 1-September 15

Middle Georgia

Spring

March 15-May 15

March 15-May 15

Fall
August 1-September 1
August 1-September 1

North Georgia

Spring

April 15-June 15

April 15-June 15

Fall
NR
NR

 

Bush

Vining

Seeding Recommendations

Distance Between Rows (in)

36-48

36-48

60-72

Distance Between Plants (in)

6-18

12-24

30-60

Seeding Depth (in)

2-1

1-12

12-2

Seed per Acre (lbs)*

2-3

2-4

1-2

Seed per Pound

17,000-18,000

1900-6500

1600-4800

Days to Maturity

45-65

40-55

75-110

Plant Population per Acre

14,000-21,000

8,000-15,000

1,500-3,000

Optimum Soil Temperature

75�-80�F

70�-80�F

70�-80�F

Minimum Soil Temperature
60�F
60�F
60�F
Optimum Air Temperature

75�-85�F

75�-85�F

75�-85�F

*Based on use of conventional planters, precision seeders will use less. NR=not recommended.


Variety Selection

Base variety selection of squash and cucumbers on criteria similar to that used for other vegetables. Obviously, yield is of primary concern to the grower; however, other factors such as horticultural characteristics, disease resistance and adaptability should also be considered. Varieties should produce a competitive yield compared with standard varieties currently produced. Quite often buyers will prefer certain varieties. Therefore, it is a good idea to check with the buyer for preferences before making your selection.

When selecting varieties, find out as much as you can about adaptability of particular varieties to see if they perform well in your area. If possible, consult local growers familiar with the variety regarding their experience. If using a new variety, consult your county Extension office for information regarding its performance in variety trials in your area. Well-adapted varieties will perform well over a wide range of environmental conditions.

Horticultural characteristics such as color, shape and skin texture are also important in variety selection. Summer squash should have a skin color and texture that is acceptable to the market. They should develop seed slowly and maintain a glossy appearance as they mature. Slicing cucumbers should be uniformly smooth and dark green. They should have small seeds that do not harden early, have a desirable flavor and have an appropriate length to diameter ratio.

Recent advances in squash varieties have resulted in varieties that are resistant to some viruses that affect squash (see "Squash and Cucumber Diseases"). Although these varieties may be resistant to certain viruses, they may not be resistant to all viruses present in your field. Therefore, a consistent oil spray program will still be necessary in seasons of high virus pressure. Also, because virus pressure is greater during summer and fall production, you may benefit from using resistant varieties for these plantings and the less expensive non-resistant varieties for early spring production.

Other disease resistance characteristics may also be present in some varieties. Cucumber varieties, in particular, often possess a number of resistance characteristics. Any time disease resistance combines with good yield and good horticultural quality, the variety is that much more appropriate if it is adaptable and acceptable to the market.

Fresh market cucumbers should be more attractive in appearance and have a darker green skin than pickling varieties. They are also longer than most pickling cucumbers. Average length/diameter ratio (LDR) is an important characteristic of cucumber varieties. The LDR varies according to growing conditions, environment and position on the vine. Fruit at the crown of the plant will have lower LDR than those at the more distal ends of the vines. Conditions favorable to growth will increase LDR. Average LDR for slicing cucumbers varies between 3.0 and 4.5.

New squash and cucumber varieties are developed and introduced yearly. Therefore, any list of varieties will soon be outdated as new varieties hit the market. Tables 5 and 6, however, list some of the varieties that have been popular in Georgia or have performed well in experimental trials.

Sex Expression

Advances in plant breeding of cucumbers have resulted in varieties of cucumbers that exhibit various combinations of flower types. These fall into several groups that are explained below. Growers will need to be familiar with this terminology in selecting varieties and versed in the ramifications that environmental conditions have on the various types.

Gynoecious

All plant flowers are female. Only female flowers produce fruit, so these types increase the incidence of female flowers in the field. They must however, be interplanted with a male pollinator to produce fruit. Most gynoecious varieties are blended with a small percentage of pollinator seed by the seed company. Make sure that pollinators are present, because without them yields will be drastically reduced.

Predominantly Female

Plants are usually produced from crossing gynoecious and monoecious (see below) lines. These plants, as the name implies, generally produce mostly female flowers under normal conditions. Terminals and laterals of PF varieties usually produce continuous female flowers. Unstable varieties, cool temperatures and crowding of plants can increase the incidence of male flowers in these types.

Monoecious

Plants produce numerous male flowers and infrequent female flowers. These plants usually begin by producing only male flowers then go through a period of mixed flowering (producing both male and female flowers) and end with a period of only female flowers.

Hermaphroditic

Plants produce perfect flowers or flowers that have both male and female parts in the same flower. These are mostly experimental at this time.

The environment can have a marked influence on sex expression in cucumber and squash plants. Climatic conditions often radically change the ratio of male to female flowers. High temperatures and long days induce male flower development; low temperatures and short days cause predominantly female flower development. For this reason, early spring crops often produce numerous female flowers before the first male flowers. Almost any type of stress � light intensity, fertility, moisture, temperature, plant population, etc. � can result in more male flowers.

Table 5. Varieties of squash that have performed well under Georgia conditions and are acceptable on various markets

Variety

Maturity (Days)

Color

Plant Type

Virus Resistance

Crookneck

Dixie

41

Lemon Yellow

Open

 

Enterprise

41

Yellow

   

Gentry

43

Yellow

Open bush

 

Goldie

43

Bright Yellow

Open bush

 

Medallion

52

Bright Yellow

Open bush

 

Prelude II

41

Lemon Yellow

Semi-open

ZYMV, WMV

Supersett

50

Yellow

Bush

Precocious

Straightneck

Enterprise

41

Yellow

Vigorous

 

Goldbar

43

Bright Yellow

Open, upright

 

Lemondrop L

41

Lemon Yellow

Open

 

Multipik

50

Yellow

Bush

Precocious

Superpik

50

Yellow

Bush

Precocious

Zucchini

Ambassador

51

Med.-Dk. Green

Open bush

 

Declaration II

40

Medium Green

Open bush

ZYMV, WMV

Independence II

41

Medium Green

Open

ZYMV, WMV

Revenue

44-47

Medium Green

Bush

 

Spineless Beauty

43

Medium-dark green

Open

 

Senator

41

Medium Green

Open

 

Tigress

49

Medium Green

Bush

ZYMV, WMV-2

Precocious indicates the variety carries the precocious yellow gene that masks virus symptoms but is not resistant. ZYMV=Zuchinni Yellows Mosaic Virus, WMV=Watermelon Mosaic Virus.


Table 6. Varieties of slicing cucumbers that have performed well under Georgia conditions and are acceptable on various markets

Variety

Maturity (Days)

Color

Shape

L:D Ratio

Sex

Centurion

59

Dark Green

Cylindrical

 

PF

Dasher II

58

Dark Green

Tapered

3.2

GYN

Harvestmore

63

Dark Green

Cylindrical

 

MON

Lightning

Early

Dark Green

Blocky

4.1

PF

Thunder

Early

Dark Green

Blocky

4.3

PF

Speedway

56

Dark Green

Blocky

 

GYN

Slice Nice

 

Dark Green

Blocky

4.2

GYN

Supersett

60

Dark Green

Cylindrical

3.8

GYN

Turbo

67

Dark Green

Blocky

4.0

GYN

L:D Ratio = Length to diameter ratio
PF=predominantly female; GYN=gyneocious; MON=moneocious


Pollination

Because most squash and cucumber plants produce separate male and female flowers, pollen transfer from the male to the female flower is essential to the production of good yields of high quality fruit. Bees are the most common agent of pollination for cucurbit crops. Therefore, an ample supply of honeybees should be introduced into production fields to enhance and ensure pollination. Poorly pollinated fruit will be misshapen and have poor development, which usually results in unmarketable fruit.

Native honeybee populations have declined in recent years; although bumblebees are excellent pollinators, they are generally not plentiful enough to be effective. Therefore, recommendations for numbers of hives per acre have changed. As a general rule, you should place one hive of honeybees for every acre of squash and one to two hives for each acre of cucumbers.

Squash and cucumber flowers are generally open in the morning hours until early afternoon, which coincides with the hours that honeybees are most likely to be working. Schedule spraying and irrigation around these times to avoid disrupting pollination. Other important factors to consider in hive management include:

  1. supplying a good clean source of water for bees;
  2. grouping hives within 500 feet of one another, which increases competition so bees are more apt to forage further into the field;
  3. removing competing sources of pollen near production fields;
  4. placing hives in fields just before or just after the onset of blooming; and
  5. avoiding pesticides with high toxicity to bees.

Bees often make several visits (7-10) to a flower to complete pollination. The use of chemical attractants is one option that many growers consider. Although these attractants may be of use in marginal situations, there is no substitute for a good supply of bees. For more information on pollination and bee maintenance, consult University of Georgia Cooperative Extension Service Bulletin 1106, Bee Pollination of Georgia Crop Plants.

Periods of cloudy, cool, windy or wet weather also can hinder bee activity. Some evidence shows that the application of 0.2 pounds of boron two or three times beginning at first bloom can enhance pollination in some cucurbits. These applications can be made in conjunction with regular spray programs and are most effective in boron deficient soils.

Cross-pollination of squash with other cucurbit crops is often a concern of growers. In most cases this is not a problem. However, plants of the same species will cross-pollinate and some cross-pollination occurs between some other species. By knowing the genus and species of the crops in question you can determine the potential for cross-pollination. Unless you are going to save seed from the crop, which is not recommended, cross-pollination will rarely be a problem for the commercial grower. However, these are the combinations that can cross-pollinate between species:


PRODUCTION ON PLASTIC MULCH
Darbie M. Granberry,
Extension Horticulturist

In Georgia, vegetable acreage on plastic has been increasing since the late 1980s. By 1994, approximately 10 percent of the total vegetable acreage in the state was grown with plastic mulch. This acreage was expected to continue increasing throughout the 1990s.

A production system using plastic mulch and drip irrigation, commonly referred to as "plasticulture," offers many benefits. However, the extent to which benefits are actually achieved depends on how effectively production is managed. Plasticulture has the potential for increasing profitability of many vegetable crops. On the other hand, poor management of crops on plastic usually results in greater losses (disasters) than poor management of production on bare ground.

Among other things, plastic mulch and drip irrigation:

  1. enhance earliness during spring production,
  2. increase yield and quality,
  3. help control weeds,
  4. improve irrigation efficiency by application of water directly to the root zone and
  5. facilitate more effective fertilizer management by fertigation through the drip system.

Disadvantages can include increased costs of production and disposal of used plastic mulch.

In any given situation, the degree of earliness and increase in yield depends on the specific vegetable being grown; the average temperatures during the production season, especially in early spring; and soil productivity. However, on the average, vegetables grown on plastic mulch are ready for harvest one to two weeks earlier and frequently yield 50 percent to 100 percent more marketable product.

Because of larger size, fewer defects, reduced contamination with soil and increased shelf life, plasticulture improves the quality of most vegetables. However, environmental factors, especially rainfall and temperature; the severity of insect and disease problems; and soil characteristics affect the overall degree to which plastic improves quality.

Reducing weed pressure is an important advantage. Plastic mulches that block light transmittance � black, white-on-black and certain wavelength-selective plastic mulches � prevent germination or growth of most weeds except nutsedge. See "Weed Control in Cucumbers in Squash" in this bulletin.

Considerations for Producing Vegetables on Plastic

For technology to be a good investment, economics dictates it must increase profitability. Plastic mulch and drip irrigation can substantially increase production costs. Will you make more money by growing cucumbers or squash on plastic? That depends on how much it costs you to use the technology relative to the added income it generates. For current estimates of production costs and expected returns, see the "Production Costs" section of this publication.

Multiple Cropping with Plastic Mulch and Drip Irrigation

The anticipated increased income from the use of plastic with some crops, especially high-value crops such as fresh-market tomato and pepper, readily justifies the costs of plastic mulch and drip irrigation. Plasticulture may or may not increase the value of low-value crops enough to justify its cost.

To help spread the costs of mulch and drip irrigation over several seasons or crops, multiple cropping on plastic (growing a second or even third crop immediately after the previous crop) has become a common practice. Proper installation of a good quality plastic mulch and drip tape is absolutely necessary for successful multiple cropping. Consult your county Extension agent or plastic mulch/irrigation dealer to ensure the materials you select will adequately meet your needs.

Processing Cucumbers

Processing cucumbers are not high-value products. The increase in their value when grown on plastic may not cover the cost of the plastic and drip tube. Except where processing cucumbers fit into double or triple cropping, in which a previous crop pays for the plastic and drip tube, growing them on plastic does not seem economically feasible.

Growing Cucumbers and Squash on Plastic

Fresh-market cucumbers or squash can be profitably grown on plastic. They may be the only crop grown on the plastic or the first, second or third crop in a multicropping system. Cucumbers do well as a second or third crop behind a fall, early spring or summer crop. However, planting cucumber behind a late spring crop may reduce yields. Yields of cucumbers planted between early June and late July commonly are reduced because of heat stress. Squash may be planted on plastic from early spring until early fall. For fall production, cucumber and squash should be planted early enough to allow time for a sufficient number of harvests before frost.

For spring production, especially early spring, cucumber and squash should be planted on black plastic because it will warm the soil and enhance early growth. For production during summer and fall, these crops should be planted on white-on-black plastic to help prevent excessive heating of the plastic and soil when temperatures are high. If black plastic from a previous spring crop is to be used for summer or fall production, paint the top surface with a 2:1 dilute of white latex paint to water.

Cucumbers can be seeded in a single row on the mulched bed. However, if beds are on 4- to 6-foot centers and the top surface of the plastic mulched bed is at least 28 inches wide, yield potentials can be increased by planting two rows per bed. Where one row exists, preferably centered on the bed, a final stand of single plants 6 inches apart in the row is recommended. For two rows, preferably centered on the bed, the rows should be 12 to 16 inches apart with plants offset and spaced 8 to 10 inches apart in the row. Whether one row or two rows are planted to a bed, the drip tape should be located no more than 6 to 8 inches from the row(s).

Squash, both bush and vine types, should be planted in a single row, preferably centered on the mulched bed. For early spring plantings and for most cultivars, plants should be spaced 18 inches apart. Very vigorous cultivars, especially when grown during seasons conducive to maximum growth, should be spaced 24 inches apart.

In general, rows should be centered on the beds. However, when establishing a cucumber or squash crop on previously used plastic, ensuring that the drip tape is not damaged during planting/transplanting and that the location of the row or rows is such that the drip tape will effectively irrigate/fertigate plants takes priority over centering rows on the bed.

Cucumber or squash can be seeded or transplanted into the plastic mulch. Compared with seeding on plastic, transplanted cucumber or squash can usually be harvested about two weeks earlier. Will it pay you to invest in transplants? That depends on how much more value an earlier harvest adds to your crop.

"Plasticulture for Commercial Vegetable Production"

Plastic mulch with drip irrigation is a relatively new technology for Georgia vegetable growers. It is more complicated and requires a much higher level of management than production on bare ground. Limited space in this publication does not permit coverage of all the information needed for successfully growing vegetable crops on plastic. However, University of Georgia Extension Bulletin 1108, Plasticulture for Commercial Vegetable Production, is available from your local county Extension office. Please refer to Bulletin 1108 for additional information. This bulletin covers the benefits of drip irrigation and fertigation in detail and thoroughly discusses effective management of plasticulture technology and how it affects crop growth and productivity.


SQUASH AND CUCUMBER DISEASES
David B. Langston, Jr., Extension Plant Pathologist

Squash and cucumber are subject to many diseases that cause serious losses throughout the state each year. Both crops share several common diseases; however, each has unique diseases affecting it. A clear understanding of the diseases and the disease management strategies are necessary for successful squash and cucumber production.

Cucumber Diseases

Alternaria Leaf Spot

Alternaria leaf spot, caused by Alternaria spp., can cause serious damage under extended periods of wet weather. The occurrence of this disease in Georgia is sometimes sporadic but can be devastating if left unchecked.


Figure 1

Symptoms

The disease causes tiny brown leaf spots, which enlarge and cause a target spot with concentric rings (Figure 1). Older lesions will develop a dark color in the concentric pattern. Spore production, which causes the dark color, can infect new sites if no protective measures are followed.

Disease Management

Most fungicides used in disease management will suppress Alternaria leaf spot. No resistant cultivars are available.


Angular Leaf Spot

Angular leaf spot, a bacterial disease caused by Pseudomonas lachrymans, attacks cucumber leaves, stems and fruit. The bacterium that causes angular leafspot overwinters on old plant debris and on cucumber seed. During rains it splashes from the soil to the stems, leaves and later to the fruit. Once infection takes place, the organism spreads over the field on the hands of workers or by cucumber beetles. Angular leafspot is most severe during extended rainy periods when temperatures are between 70� and 80�F.


Figure 2

Symptoms

Spots on the foliage are straw colored to light brown and angularly shaped (Figure 2). Affected areas first seem water soaked, then gradually dry and split. After the diseased tissue splits open, portions of it tear out, leaving irregularly shaped holes in the leaves. Small, circular spots develop on the fruit. These diseased areas later crack open and turn white.

Disease Management

The primary disease prevention tool is disease-free seed. Angular leaf spot resistant cucumber varieties are available. A two-year rotation behind crops other than cucurbits and cultivating the soil when it is dry will decrease the ability of the bacterium to survive and infect upcoming cucumber crops. During warm, moist periods, when disease development is favorable, copper sprays may reduce the spread of the disease.


Anthracnose

Anthracnose, caused by the fungus Colletotrichum lagenarium, attacks all above-ground parts of the cucumber plant. The fungus causing anthracnose overwinters locally on old cucurbit vines and may appear any time during the growing season. It may reach epidemic proportions when rainfall is above average and temperatures are between 70� and 80�F.

Anthracnose
Figure 3

Symptoms

The first symptom of anthracnose is observed on the oldest leaves as round, reddish-brown spots. The centers of some spots fall out, giving the leaf a shot-hole appearance (Figure 3). Often the leaves at the center of the plant die first, leaving the crown of the plant bare.

Light brown to black elongated streaks develop on stems and petioles. Round, sunken lesions may appear on the fruit. These lesions first appear water-soaked and then turn a dark green to brown. The pinkish ooze often noticed in the center of the lesion is a mass of spores of the fungus.

Disease Management

A one-year rotation and deep turning infected debris immediately after harvest are effective cultural practices for reducing inoculum levels in subsequent crops. Using disease-free seed produced from areas not known to have anthracnose is an essential disease-prevention measure. Cucumber varieties resistant to anthracnose races 1, 2 and 3 are available. Several protectant fungicide options, which can be found in the Georgia Pest Management Handbook, are available.


Gummy Stem Blight

Gummy stem blight, caused by Didymella bryoniae, attacks only the leaves and stems of cucumbers and is one of the most destructive diseases of cucumbers in the state. This disease is driven by cool, moist periods, especially extended periods of leaf wetness. The gummy stem blight fungus can easily be brought into a new area on or in the seed. Once the disease becomes established, it produces millions of sticky spores. These spores spread over the field as humans, other animals and machines move through wet vines.

Gummy stem blight
Figure 4

Symptoms

It is noticeable when an individual runner or an apparently healthy plant suddenly dies. Vine cankers are most common near the crown of the plant (Figure 4). This disease is usually identified by finding elongated, water-soaked areas on the stem. These areas become light brown cracks in the vine and usually produce a gummy ooze. On the older leaves, this disease may produce brown to black spots. It spreads from the center of the hill outward, as does anthracnose and downy mildew.

Disease Management

Choosing high quality, disease-free seed and transplants should be the first line of defense in preventing losses to gummy stem blight. A two-year rotation with crops other than cucurbits is another appropriate disease-management tool. Protective fungicide sprays can offer the most effective disease suppression if applied in a timely manner. Consult the Georgia Pest Management Handbook for details concerning protective fungicides.


Target Spot

Target spot, caused by the fungus Coryneospora cassiicola, can defoliate and destroy an entire crop if left unchecked. It occurs very sporadically and can be confused with downy mildew and other leaf spotting diseases.

Target spot
Figure 5

Symptoms

Target spot begins on leaves as yellow leaf flecks becoming angular with a definite outline (Figure 5). Later spots become circular with light brown centers surrounded by dark brown margins. Lesions join together and produce large dead areas with dead and shedding leaves.

Disease Management

Most protective fungicides used to control other foliar pathogens will suppress target spot. Destroying infected debris or sanitizing greenhouse areas will greatly aid in reducing the spread of the disease. Several cucumber varieties have resistance to target spot and are the best assurance against severe disease losses when combined with sanitation and fungicide applications.


Belly Rot

Belly rot has been a common problem in cucumber plantings in Georgia. The two fungi primarily responsible for belly rot are Pythium (also called cottony leak) and Rhizoctonia. Belly rot can occur on fruits at any stage of growth; however, it is most noticeable when cucumbers are mature.

Cottony mycelium Figure 6

Belly rot
Figure 7

Symptoms

Symptoms may vary from small, yellow sunken areas to large rotted spots on the undersides of fruit. Pythium causes a water-soaked lesion that develops into a watery soft rot. White, cottony mycelium is also generally associated with Pythium lesions (Figure 6). Rhizoctonia belly rot typically appears as dry, sunken cracks on the underside of cucumber fruit (Figure 7).

Disease Management

Rotation and deep turning are cultural practices that can reduce the amount of disease inoculum near the soil surface. Practices that ensure good drainage can also reduce losses to these fungi. Systemic fungicides may aid in suppression of Pythium; fungicides have proven inconsistent in dealing with Rhizoctonia belly rot.


Bacterial Wilt

The bacterium Erwinia tracheiphila causes bacterial wilt. The bacterium affects only cucurbits, except for watermelon, which is almost completely immune. The pathogen overwinters in the godies of the spotted and striped cucumber beetles. It then hibernates in the beetle�s digestive tract and in the spring finds its way through the feces of the carriers to the young plant. The bacterium enters the plant tissue only through deep wounds produced by beetles when feeding.

Bacterial wilt
Figure 8

Symptoms

The most typical symptom associated with bacterial wilt is individual runners or whole plants wilting and dying very quickly (Figure 8). Affected runners usually will turn dark green before becoming necrotic as the wilt becomes irreversible. Long strands of bacterial slime can be observed if wilted runners are cut and the cut ends are pressed together and then pulled apart.

Disease Management

The most effective tool for managing bacterial wilt in cucumber is controlling the cucumber beetle. This can be achieved by using contact or soil applied insecticides. The use of resistant varieties is also recommended.

 

Diseases Affecting Both Cucumber and Squash

Nematodes

Nematodes are slender microscopic roundworms that live in the soil. The root-knot nematode is the most common type attacking cucurbits. If not controlled, this pest can completely destroy a squash crop, especially in sandy soil.

Nematode evidence
Figure 9

Symptoms

Root-knot nematodes enter young squash feeder roots during their common feeding process, causing the roots to swell. The most common below-ground symptom is the formation of galls or knots on the roots (Figure 9). Nematode injury interferes with the uptake of water and nutrients, thus giving the top portion of the plants an appearance resembling a lack of moisture or a fertilizer deficiency. Stunting, yellowing, irregular growth and rapid decline are also above-ground symptoms of nematode injury.

Control

Rotating squash with a grass crop, such as rye or corn, is somewhat beneficial in managing root-knot nematodes, but this practice is no substitute for soil fumigation. In the light soils of South Georgia, where root-knot nematodes are widespread, the use of soil fumigants is essential in most fields to maximize yields. Fumigant nematicides are most effective against nematodes and must be applied three weeks before planting. Materials, rates and methods of application can be found in the Georgia Pest Management Handbook.



Squash Diseases

Squash production is hindered by severe disease losses. Diseases such as mosaic and scab destroy at least 50 percent of the squash crop in many areas each year. To produce squash successfully, a working knowledge of the diseases and their management is needed. Commercial squash growers in Georgia must be prepared to apply fungicides on a regular schedule for adequate disease management.

Scab

Squash scab, caused by the fungus Cladosporium cucumerinum, inflicts severe losses on the crop in all areas where moisture is high and temperature is relatively low (70� to 75�F). Most damage occurs in North Georgia, where weather conditions are more favorable for disease development. However, damage to fall squash in South Georgia is not uncommon. The fungus causing scab lives over winter in old squash and cucumber vines and on infected seed. Early spring infection may come from either of these sources. Sptos are produced soon after the fungus begins to sporulate and are spread by insects, humans or tools, or are blown long distances in moist air.

Scab
Figure 10

Symptoms

Although scab can attack any above-ground portion of the plant, injury to the fruit is most noticeable. Fruit can be infected at all stages of growth. Spots first appear as gray, sunken areas about 1/8 inch in diameter (Figure 10) from which a sticky substance may ooze. The spots grow darker with age and gradually sink into the squash until a cavity forms. Several areas may run together, forming lesions 2 inches in diameter.

The presence of pale green water-soaked areas is the first sign of disease on the foliage. These spots gradually turn gray to white and become angularly shaped. The dead leaf tissue usually splits open and falls outs, leaving a ragged hole in the leaf. Under favorable weather conditions, scab can deform young leaves by shortening the internodes.

Disease Management

Losses to this disease can be effectively and economically reduced through a complete disease control program. The critical steps are as follows:

  1. Disease Free Seed: Always use high quality, western grown seed obtained from a reputable seed source. Seeds obtained from this source are grown in disease-free arid conditions and must meet high standards of the trade and the government.
  2. Crop Rotation: Never grow squash on land where cantaloupes, cucumbers, pumpkins or squash has been grown within the past three years.
  3. Use Clean Wash Water: Many growers wash their squash in a tub of water soon after harvest. If one diseased squash passes through the wash water, every squash being washed thereafter will be inoculated with the scab-causing fungus and will most likely rot soon after reaching the market. Squash should always be washed under running water or in water containing HTH (65 percent chlorine) at 2 ounces per 100 gallons of water or sodium hypochlorite at a rate to make a similar concentration. Exact amounts of HTH or sodium hypochlorite will depend on temperature and pH of water.
  4. Fungicide Sprays: Several fungicides can reduce the severity of scab if applied on a schedule after first bloom. Consult the Georgia Pest Management Handbook.

Crown Rot

Crown rot, caused by the fungus Phytophthora capsici, may inflict serious damage once established. The fungus infects all above-ground parts of cucurbits. This disease became established in 1994 after hurricane Alberto. Spores of the fungus were apparently deposited over the entire state by the hurricane. The major damage occurred in squash and pepper the first year. Because of a relatively wide host range, the disease is now causing problems in watermelons, cantaloupes, cucumbers and eggplant. Entire plantings of these crops were affected in 1998.

Crown rot
Figure 11

Symptoms

Symptoms on squash appear as constricted, water-soaked lesions near the base of stems close to the soil (Figure 11). Infected fruit may have circular, sunken, water-soaked lesions that may contain a pasty or powdery sporulation of the fungus.

Disease Management

Rotation with a non-susceptible crop has been highly effective in disease prevention. Planting a susceptible crop in an infested field is inadvisable for two years. Measures that ensure good field drainage, such as utilizing crowned beds, subsoiling and avoiding overirrigation, will decrease the severity of the disease. Preventive applications of some fungicides have shown some promise in suppressing this disease in the field.

 

Mildews

Mildews on squash are a common occurrence in commercial squash plantings, causing growers to spray on a regular basis. This practice will result in increased yields (10 percent to 15 percent). This is especially true in large fields and where several harvests are desired. Two distinct mildew diseases exist; each favored by a different weather pattern, and each requiring different materials for control. Unfortunately, the symptoms and occurrence of these diseases overlap considerably.

Powdery Mildew

Powdery mildew, caused by the fungi Sphaerotheca fuliginea and Erysiphe cichoracearum, is much more widespread on squash than downy mildew, especially during dry hot periods.

Powdery mildew
Figure 12

Symptoms

This disease is characterized by a white or brownish, mealy growth found on the upper and lower sides of the leaves and young stems (Figure 12). If plants are severely attacked, the leaves and young stems may wither and die. In less severe cases, the plant may be weakened or stunted. Early defoliation resulting from the disease may cause premature ripening or sun scald.

Disease Management

The use of preventive fungicide applications is the most effective means of suppressing powdery mildew. However, several squash varieties have been released that demonstrate significant levels of resistance to this disease. Fungicides used in conjunction with resistant varieties offer the most complete disease management program for powdery mildew on squash.


Downy Mildew

Downy mildew, caused by the fungus Pseudopernospora cubenis, has not been a serious problem on squash in recent years. During wet, cool weather, however, it can cause considerable damage.

Downy mildew
Figure 13

Symptoms

This disease produces irregular to angular, yellow to brownish areas on the upper sides of diseased leaves (Figure 13). The undersides of the leaves may show a pale grayish-purple mold after damp weather. The mold may vary from white to nearly black in color. The diseased spots may enlarge rapidly during warm, moist weather, causing the leaves to wither and die. This damage may resemble frost injury because the entire vine dies. The fruit from diseased plants is usually small and has poor flavor.

Disease Management

Follow the same spray program recommended for scab control. Fungicides containing mefenoxam are the most effective for control of downy mildew. However, fungal insensitivity to these fungicides has been observed. When this occurs, alternative fungicides should be used.

 

Viral Diseases

Mosaic

This disease is caused by one or more of five major viruses. The most prevalent are cucumber mosaic virus (CMV), papaya ringspot virus (PRV), watermelon mosaic virus II (WMVII), zucchini yellow mosaic virus (ZYMV) and squash mosaic virus (SMV). The most common virus in cucumbers is CMV. One or a combination of these viruses may affect squash. Aphids transmit all of these viruses with the exception of squash mosaic, which is seed transmitted. Surveys have indicated that only about 2 percent of all squash virus infections are caused by squash mosaic. Aphids must acquire the virus from a host reservoir and are capable of transmitting it for 10 to 15 minutes in most cases.

Mottling
Figure 14

Strapping
Figure 15

Discolored, bumpy fruit
Figure 16

Symptoms

Symptoms of virus disease are mottling, strapping and vein distortion (Figures 14-15). One virus may cause mild symptoms, while additional viruses in the same plant cause much more dramatic symptoms. In some cases the symptoms may appear to be phytotoxic chemical damage. Fruit from infected plants may be discolored or have raised bumps or mottles (Figure 16).

Disease Management

Resistant varieties are available for avoiding losses to some virus diseases but cultivars with true resistance to all of the squash viruses are not available as of yet. Stylet oil sprayed on a two- to three-day schedule has been shown to delay the spread of virus, particularly in the fall (see "Insect Management"). Viral diseases are much worse in late summer and fall plantings because aphid populations are much higher and virus-carrying host plants are more available. Early spring plantings usually have less virus; however, control measures are recommended to delay virus infection. Yield losses are directly related to time of infection. The later the infection occurs, the less damage observed.

 


INSECT MANAGEMENT
David B. Adams, Extension Entomologist

Squash and cucumber are subject to attack by a variety of insect pests. These attacks do not always result in economic injury, so certain insect management practices can be used to ensure cost-effective control decisions. Indiscriminate use of insecticides often creates more favorable conditions for the development of harder-to-control insect pests, thus increasing the cost of production.

Insects cause injury to the leaves, stems, roots and fruit. The developmental stage of the plant at the time of attack often governs which plant part different insect pests may injure. However, some insects feed specifically on one plant structure; others may feed on several structures. The first step in control is to identify the insect.

Certain cultural practices may have a dramatic affect on the potential for economic injury by certain insects. Planting during optimal growing conditions ensures rapid seedling emergence and subsequent growth. This reduces the amount of time that plants are susceptible to injury from seedling insect pests.

Spring plantings that are harvested by early July often escape the period of time that certain insect pests pose their greatest economic threat. Migratory species not indigenous to Georgia do not build large populations until July or later. Disease-vectoring species, even though present in the spring, are often a more serious threat to later plantings.

Most insect problems can be treated as needed if detected early, but no one insecticide will adequately control all the insects that may attack squash and cucumber. Scouting for insects is the most efficient way to determine what problems may exist and what action should be taken.

Preventive treatments may be necessary for certain insect pests. Preventive treatments are used against insects that are certain to cause economic injury if they are present. Preventive treatment decisions are influenced by field history, harvest dates and insect pressure in nearby production areas.

Root Maggot

Root maggot
Figure 17. Root maggots

The seedcorn maggot, Hylemya platura, is the predominant species of root maggot found in Georgia's major production areas. The seedcorn maggot adult is a fly similar to the housefly, only smaller. It has many bristles on the body. The larvae or maggot is creamy white, � inch long at maturity and legless. The body tapers sharply from rear to head.

The maggot is the damaging stage. Root maggots tunnel into the seeds or the roots and stems of seedlings. Seeds usually succumb to secondary rot organisms and fail to germinate following attacks. Seedlings often wilt and die from lack of water uptake. Seedlings that survive are weakened and more susceptible to other problems.

Cool, wet conditions favor the development of root maggot infestations. Early plantings are therefore most subject to attack. Egglaying adults are attracted to soils with high organic matter. Even though soils in Georgia are characteristically low in organic matter, it still presents problems. Dead or dying organic matter such as weeds or previous crop residue attracts the flies.

Greenhouse grown transplants are grown in high organic soil mixtures that attract the flies in the greenhouse environment. Eggs may be laid on the soil while the plants are in the greenhouse. The eggs may hatch after the transplants are placed in the field and the maggots attack and kill the seedlings.

Several practices may be used to help control maggots. Previous crop litter and weeds should be turned deeply several weeks prior to planting so there is adequate time for decomposing. Plant during optimum conditions for rapid germination and seedling growth. Early plantings should be preceded by incorporation of a recommended soil insecticide. Plants should be maintained stress free until they are beyond the seedling stage. (Figure 17)

Wireworms and Whitefringed Beetle Larvae

Wireworm WFB

Figure 18. Wireworm (top), whitefringed beetle larvae

Wireworms, mostly Conoderus spp., and whitefringed (WFB) beetle larvae, Graphognathus spp., can reduce stands dramatically if present in even moderate numbers (one per square yard). Wireworms are less likely to affect early planting because they are relatively inactive during the early spring.

The WFB adults, weevils, are not important in squash or cucumber. Larvae are creamy white and legless. They grow to about 2 inches long and are C-shaped grubs. The mouthparts are dark brown, pincherlike structures that are highly visible. The head capsule is slightly recessed and blends so well with the rest of the body that it appears headless.

Whitefringed beetle larvae pass the winter in the larval stage and may be active even during the milder winter months. Presently, no effective insecticides are labeled for control of this insect. If one WFB larva per square yard is found during land preparation, do not plant field in squash or cucumber. (Figure 18)

Cucumber Beetles

Spotted cucumber beetle

Striped cucumber beetle

Foliage damage

Figure 19. Spotted cucumber beetle (top), striped cucumber beetle and stem damage (middle), cucumber beetles and foliage damage

Several species of cucumber beetles may attack squash and cucumber. The most common species found in Georgia are the spotted cucumber beetle, Diabrotica undecimpunctata, and the striped cucumber beetle, Acalymma vittata. The banded cucumber beetle, Diabrotica balteata, is occasionally found.

Cucumber beetles are sometimes mistaken for lady beetles, which are beneficial predators. Cucumber beetles are more oblong than lady beetles, which are nearly circular. The spotted cucumber beetle adult is about � inch long with 11 black spots on its yellowish-green to yellow wing covers. The striped cucumber beetle is slightly smaller than the spotted cucumber beetle. The striped cucumber beetle is yellow with three black stripes on the back. The banded cucumber beetle is the least significant of the three species.

The larvae of the different cucumber beetles are very similar and live underground. Larvae are creamy, yellowish-white, soft-bodied worms with three pairs of inconspicuous legs. Mature larvae of the spotted cucumber beetle may be from � to � inch long. The striped cucumber beetle larvae are slightly smaller. Both larvae have a dark brown head and a dark brown plate on the last body segment.

Beetles and larvae may damage squash and cucumber. The beetles have been responsible for most economic damage. Beetles feed on the stems and foliage of the plant. Beetles feed on the stems until the plants become less attractive because of hardening, after which more foliage damage will be apparent. Feeding begins on the undersides of the cotyledons, or true leaves. If beetle populations are high during the seedling stage, stand reductions can occur. The beetle may also transmit bacterial wilt disease in cucumbers. This disease does not affect squash. Larvae may feed on all underground plant parts and usually cause insignificant amounts of damage.

Cucumber beetles can be controlled with foliar applications of insecticides when 10 percent or more of the seedlings are infested. In squash, insecticide applications may be terminated once plants are bearing fruit. In cucumbers, the beetles should be controlled throughout the growing season. Beetles should be controlled if they are found infesting more than 20 percent of the cucumber plants. The natural feeding behavior of cucumber beetles leads to their avoidance of insecticidal sprays during the seedling stage, so thorough spray coverage is imperative. The most cost-effective application method is to band over-the-top and direct sprays to the base of the plant. There are no recommendations for control of the larvae (Figure 19).

Aphids

The melon aphid, Aphis gossypii, and the green peach aphid, Myzus persicae, are common in Georgia squash and cucumber. Aphids are soft-bodied, oblong insects that rarely exceed 3/32 inch long. Adults may be winged or wingless, most often wingless. Aphids have two exhaustpipe-like structures called cornicles located on the rear of their abdomens. Immature aphids are wingless and look like the adults, only smaller.

Aphids are slow-moving insects that live in colonies on the undersides of leaves. Aphids feed on the leaves with their piercing-sucking mouthparts. As they remove plant sap, the leaves curl downward, giving them a puckered appearance. Heavy populations cause plants to yellow and wilt. Aphids secrete a substance known as honeydew, which collects on the surface of the lower leaves. Under favorable conditions the honeydew provides the sustenance for the growth of sooty mold, a fungus that blackens the leaf surface. This reduces photosynthesis; thereby reducing quality, yield or both.

The greatest damage caused by aphids is indirect. Aphids vector several viruses that can reduce fruit marketability. For this reason, aphid populations should be kept to a minimum. Winged aphids are the primary vectors of such diseases and should be monitored two to three times per week throughout the season, especially in squash.

In Georgia, squash may become infected with as many as four aphid-vectored viruses (see "Squash and Cucumber Diseases"). The green peach aphid is one of the most common vectors.

The aphid acquires the viruses while feeding on infected weed or crop host plants. Virus particles from infected cells contaminate the aphid�s needlelike sucking mouthpart called the stylet. Transmission occurs when the contaminated aphid flies to and feeds on squash plants. This feeding must occur almost immediately because the mosaic viruses are very unstable and become inactivated within a few minutes to an hour after removal from cells of infected host plants.

After primary infection sites have been established, secondary infection occurs from movement of aphids within the field. The highest populations of aphids carrying the viruses occur in the fall. When primary infection occurs early (as the cotyledons break through the soil), 100 percent infection may be expected by the time squash is ready for first harvest. Fall squash production without an oil spray program is questionable.

Control of aphids on squash is not difficult, but controlling aphids has very little impact on the final incidence of mosaic. The use of foliar or at-planting systemic insecticides to kill aphids before they are able to successfully vector the viruses has failed more often than not. Aphids usually feed long enough to transmit the viruses before receiving a lethal dose of insecticide.

How Oils Work

The theory underlying mosaic suppression with oil sprays is to prevent transfer of virus particles from the aphid�s stylet into the leaf cells punctured during the feeding process. The oil is sprayed on the squash foliage much like an insecticide, but more complete coverage of the lower leaf surface is necessary because this is where the aphids feed. As the aphid�s stylet penetrates the leaf cell, the virus particles are removed in the oil barrier. Because the virus is very unstable outside the leaf cell, it dies very shortly after being removed from the stylet.

The use of oils is not a panacea for virus control. The objective is to delay early primary and secondary infection within the field so that marketable squash is produced over a longer period of time.

One of the first oils for mosaic suppression was JMS Stylet Oil from JMS Flower Farms Inc. Both JMS Stylet Oil and Saf-T-Side from the ClawEl Division of Brandt Chemical Co. have been tested with success since 1987 in Georgia on-farm research. Test results in 1990 showed that the incidence of mosaic reduced significantly, but in fall plantings virus infection will occur eventually.

In using oils, the method of application has been the key to on-farm success. In most of the research in Georgia, we have modified the procedures for application from the JMS Stylet Oil label:

Other air-assisted sprayers also have been effective in delaying virus transmissions.

Application Timing

The final and most important ingredient is the timing of applications. The first few applications are the most important, and delays in early sprays have been the most common cause for field failures. The first application should be made by the time 25 percent emergence is expected. Even though much of the first application may be to bare ground, it is not uncommon to find winged aphids on the cotyledons of squash, even during the late cracking stage.

Subsequent applications should be made twice per week on a regular schedule. An insecticide should be used during the first week and as needed thereafter to prevent the development of aphid colonies that will increase the potential for secondary, in-field spread of the viruses. Oil sprays may be discontinued within two weeks of final harvest because expression of mosaic in individual plants requires about 14 to 21 days after inoculation.

Interest in using oils has increased in recent years. The greatest limiting factor to widespread use of this technology is that many growers do not have application equipment suited for delivering oils under high pressure. However, the advantages of using a sprayer of this type for insect and disease control on vegetables can be justified economically.

Reflective mulches

Highly reflective mulches have been shown to give increased yields by reducing the incidence of mosaic virus infections. However, at this time, oil sprays are less expensive and growers will have to evaluate the cost effectiveness of mulches vs. oil sprays. Also, reduced oil sprays may be necessary in conjunction with reflective mulch.

Silverleaf Whitefly

Figure 20. Silverleaf whitefly

The silverleaf whitefly, Bemesia argentifolii, may infest both squash and cucumber; however, silverleaf is only induced in squash. Because of this, whitefly control is more important in squash that in cucumber. Infestations of small numbers of immature whiteflies can induce silverleaf in squash. The foliage turns silver and the fruit becomes very pale and unmarketable.

Fortunately, the oil sprays used to delay mosaic virus transmission by aphids also gives excellent prevention of silverleaf. The whitefly also should be controlled with insecticides tank-mixed with the oil sprays. Insecticides are not needed in every oil application but rather used as needed to suppress whitefly development (Figure 20). However, in late summer plantings of squash, special efforts are required to reduce transmission of mosaic virus diseases.

Thrips

Thrips damage

Thrips damage

Figure 21. Thrips damage, seedling (top); thrips damage, mature leaf

Several species of thrips may inhabit squash and cucumber fields, but they are not very well understood as pests. Thrips are very small, spindle-shaped insects 1/10 inch or less long. Immature thrips are wingless; the adults have wings with hairlike fringe.

The thrips that cause early foliage damage are often different from those present during the period of heavy fruit set in spring plantings. The most noticeable damage is to the foliage. Narrow bronze lesions appear on the leaf surface. The entire field may have silvery appearance from heavy feeding. This damage is caused by the thrips rasping the leaf surface before its expansion. The most severe damage occurs during the periods of slow growth. Damage is quickly outgrown during periods of rapid growth, and usually no treatment is required.

The western flower thrips (WFT), Frankliniella occidentalis, is the species most common during rapid fruit set. WFT is a large species two to three times larger than the common onion and tobacco thrips often found infesting early plantings. Whether WFT or any other species causes any significant damage to squash or cucumber is not very well known. Thrips mechanically damage plants during the feeding process. If thrips fed on prepollinated fruit, the damage would not be noticeable until the fruit were larger. Physical damage of this type would appear as catfacing, light russeting or other deformities on the surface of the fruit.

Thrips can be controlled with foliar insecticide applications. There are no treatment thresholds developed for thrips. As a rule of thumb, treatments generally are not necessary if thrips are damaging only the foliage. Treatments for thrips during early fruit development should be initiated when a majority of the blooms are found infested with large numbers of thrips, 75 or more per bloom. (Figure 21)

Cutworms

Cutworms
Figure 22. Cutworms

The granulate cutworm, Feltia subterranea, is the predominant species found in the Coastal Plain of Georgia. The adult is a nondescript moth. Larvae are greasy-looking caterpillars that may be 1� to 1� inches long at maturity. Young larvae may be pinkish-gray; older larvae are usually dingy gray. A series of chevron-shaped markings, slightly lighter gray than the body, run along the back.

Cutworms feed at night and remain inactive during the day, either on the soil surface or below ground. Cutworms may attack all plant parts, but the most severe damage occurs when they feed on young seedlings. Cutworms damage young plants by chewing on the stem slightly above or below ground. Stand reductions may occur.

Cutworms can be difficult to control, but understanding their behavior can help. Cutworms pass the winter months in the larval stage. This means that the larvae may be present at the time of planting. In these cases, stand reductions will likely occur. Inspect fields during land preparation and just before and during the planting operation. If cutworms are found, treatments should be made either by incorporation of a soil insecticide prior to planting or by a directed spray if plants are already present. Foliar sprays should be made as late in the day as possible to coincide with the greatest larval activity. (Figure 22)

Pickleworm and Melonworm

Young pickleworm Mature pickleworm

Melonworm Figure 23. Pickleworm, young larva (above left); pickleworm, mature larva (above); melonworm (left)

The pickleworm, Diaphania nitidalis, is a migratory insect that overwinters in areas from southern Florida to South America. Squash and cucumbers are two of their preferred hosts in the cucurbit group. Plantings of cucurbits that are harvested by early July are unlikely targets. Extremely late plantings are subject to attack and should be monitored for developing infestations. Preventive treatments to late plantings should begin during early bloom and continue during fruit development. Close monitoring will help in making spray-scheduling decisions. (Figure 23)

Fruitworms

[Photo missing]
Figure 24. Fruitworm

Any worm that feeds directly on the fruit may be called a fruitworm. The most common worms that may fit this description are cutworms, corn earworms, loopers, and beet and fall armyworms. When the fruit is attacked, the insect must be identified correctly because no one insecticide will control all of the aforementioned species. (Figure 24)

Miscellaneous Insect Pests

Some insects become pests of squash or cucumber only if a preferred host is not available, populations are very high or environmental conditions are just right for rapid development. Flea beetles, spider mites, leaf miners, stink bugs, leafhoppers, squash bugs and grasshoppers are just a few. These problems can be addressed on a case-by-case basis. Contact the local county Extension agent if you have questions on the treatment of these insects.

Honeybees

Honeybees are necessary to ensure adequate pollination; because most insecticides are toxic to honeybees, certain practices should be followed to prevent bee kills. Honeybees may be active from dawn to dusk. Insecticide applications should be made late in the day, after sunset if possible, after bee activity has ceased. If it is necessary to spray large acreages during the day, hives should be removed from the field on the preceding day. If these precautions are followed, bee kills will be kept to a minimum. Once dried on the leaf surface, the toxic effects of most insecticides are dramatically reduced.


WEED CONTROL IN CUCUMBERS AND SQUASH
Greg MacDonald
, Extension Weed Scientist

Successful weed management is vital to the production of quality cucumbers and squash. Weeds compete with the crop for light, space, nutrients and water. Weed growth promotes disease problems and can harbor deleterious insects and diseases. Weeds also impair the ability to harvest effectively, reducing the quantity of marketable fruit and increasing labor costs. Cucumbers and squash, as with most crops, require early season weed control to ensure a quality crop. In addition, the spreading nature of cucumbers makes weed control difficult once the vines begin to run.

Factors Affecting Weed Control

One of the most important factors to consider when growing cucumbers and squash is site or field selection. Fields heavy in Texas panicum, sicklepod, cocklebur and other hard-to-control species should be avoided. In addition, perennial weeds such as nutsedge or Bermuda grass will cause problems and can be extremely difficult to control. With perennial weeds such as these, frequent disking or mechanical disturbance prior to planting may reduce the severity of these species. Non-selective herbicides may also be used to reduce perennial weed infestations. Weed identification is also important, especially seedling weeds. Seedling weeds are generally easier to control; in many cases, control can only be obtained at the seedling stage. Another important factor is the growth of the crop. Generally, an aggressive, healthy crop will outcompete and exclude many weeds. Proper fertilization, disease, nematode and insect management will promote crop growth and aid in weed suppression.

Methods of Weed Control

Several methods of weed control exist for cucumbers and squash. Selection of the method best suited for an individual grower will depend on several factors including: weed species, crop species and variety, stage of crop and/or weed development, and labor costs and availability.

Hand weeding provides very effective weed control and is very safe to the crop. Weeding should be performed when the crop and weeds are small to reduce crop damage and to allow hoeing. Removal of large weeds with extensive root systems may damage crop roots or vines.

Rotation with crops that have good weed-control methods for predominant weed species in a field allows the grower to control weeds more effectively in the alternate crop years. This helps suppress populations in successive years and enhances weed control in the cucurbit crop.

Mechanical cultivation provides effective weed control but is limited to small weeds that can be easily uprooted or covered. More importantly, mechanical cultivation should not be performed once the plants have begun to vine. These vines are very tender and are easily damaged by tractor wheels or cultivators. Mechanical control must be supplemented with chemical or hand weeding to remove those weeds in the rows or after the plants produce vines.

Chemical weed control is currently limited to herbicides recommended by the University of Georgia Cooperative Extension Service (see Georgia Pest Management Handbook). This publication collectively includes cucumber and squash herbicide use, and tolerance varies among these crops. Furthermore, some differing tolerance has been noted between varieties of the same crop (e.g., yellow vs. zucchini squash).

Weed control utilizing the stale seedbed technique involves chemical weed control of emerged weeds before crop emergence. A nonselective, contact material is used. The stale seedbed method often is coupled with a preplant-incorporated herbicide treatment. If the crop is transplanted, this method may be used to kill emerged weeds before transplanting. On direct-seeded plantings, apply the herbicide to those weeds that have emerged after planting but before the crop has emerged.

Fumigation will provide substantial weed control but is expensive and dangerous and must be performed by trained personnel. To ensure proper fumigation, the soil is covered with a nonporous material such as plastic. The fumigant is placed under the plastic, and the edges are sealed with soil. The length of time needed for the cover to remain in place varies with fumigants but is generally three days. After this time, remove the cover and allow the soil to breathe for seven to 10 days before planting to avoid crop injury. Most small-seeded broadleaves and grasses will be controlled, but larger seeds and nutsedge tubers will not. Unless fumigation is needed for disease or nematode control or is used in the preceding rotational crop, this method is generally impractical for weed control.

Plastic mulch with drip irrigation is a very effective method of weed control. Black or non-light-transmitting plastic is preferred, eliminating light required for weed germination and growth. This will eliminate most weeds except nutsedge. The tightly folded and pointed leaves of this species will penetrate the plastic and emerge. Plastic covers the plant beds; it should fit tightly and be sealed along the edges to prevent wind disturbance. Once covered, a small hole is made in the plastic, and the transplant or seeds inserted. The smallest hole possible is advantageous to eliminate weed emergence from the hole. Those areas between the beds should be treated with a herbicide registered for the crop, because the crop roots may extend into the row middles and contact the treated soil.


SPRAYERS
Paul E. Sumner
, Extension Agricultural Engineer

Two types of sprayers, boom and air assisted, are used for applying insecticides, fungicides, herbicides and foliar fertilizers. Air-assisted sprayers (Figure 25) use a conventional hydraulic nozzle. Air forces the spray onto the plant foliage. Boom sprayers (Figure 26) get their name from the arrangement of the conduit that carries the spray liquid to the nozzles. Booms or long arms on the sprayer extend across a given width to cover a swath as the sprayer passes over the field.

Air-assisted sprayer Boom sprayer
Figure 25. Air-assisted sprayer Figure 26. Boom sprayer

Pumps

Three factors to consider in selecting the proper pump for a sprayer are:

  1. Capacity. The pump should be of proper capacity or size to supply the boom output and to provide for agitation (5 to 7 gallons per minute (gpm) per 100-gallon tank capacity). Boom output will vary depending upon the number and size of nozzles. Also, 20 percent to 30 percent should be allowed for pump wear when determining pump capacity. Pump capacities are given in gallons per minute.
  2. Pressure. The pump must produce the desired operating pressure for the spraying job to be done. Pressures are indicated as pounds per square inch (psi).
  3. Resistance to corrosion and wear. The pump must be able to withstand the chemical spray materials without excessive corrosion or wear. Use care in selecting a pump if wettable powders are to be used because these materials will cause pump wear.

Before selecting a pump, consider factors such as cost, service, operating speeds, flow rate, pressure and wear. For spraying vegetable crops, a diaphragm pump is preferable because of serviceability and pressures required.

Nozzles

Nozzle tips are the most neglected and abused part of the sprayer. Because clogging can occur when spraying, clean and test nozzle tips and strainers before each application. When applying chemicals, maintain proper ground speed, boom height and operating pressure. This will ensure proper delivery of the recommended amount of pesticide to the plant canopy.

Herbicides

Figure 27. A broadcast spray pattern is used for herbicide applications.

The type of nozzle used for applying herbicides is one that develops a large droplet and has no drift (Figure 27). The nozzles used for broadcast applications include the extended range flat fan, drift reduction flat fan, turbo flat fan, flooding fan, turbo flooding fan, turbo drop flat fan and wide angle cone nozzles. Operating pressures should be 20 to 30 psi for all except drift reduction and turbo drop flat fans, flooding fans and wide angle cones. Spray pressure more than 40 psi will create significant drift with flat fans nozzles. Drift reduction and turbo drop nozzles should be operates at 40 psi. Flooding fan and wide angle cone nozzles should be operated at 15 to 18 psi. These nozzles will achieve uniform application of the chemical if they are uniformly spaced along the boom. Flat fan nozzles should overlap 50 percent to 60 percent.

Insecticides and Fungicides

Hollow cone nozzles are used primarily for plant foliage penetration for effective insect and disease control, and when drift is not a major concern. At pressures of 60 to 200 psi, these nozzles produce small droplets that penetrate plant canopies and cover the underside of the leaves more effectively than any other nozzle type. The hollow cone nozzles produce a cone-shaped pattern with the spray concentrated in a ring around the outer edge of the pattern. Even fan and hollow cone nozzles can be used for banding insecticide or fungicides over the row.

Nozzle Material

Various types of nozzle bodies and caps, including color-coded versions, and multiple nozzle bodies are available. Nozzle tips are interchangeable and are available in a wide variety of materials, including hardened stainless steel, stainless steel, brass, ceramic and various types of plastic. Hardened stainless steel and ceramic are the most wear-resistant materials. Stainless steel tips, with corrosive or abrasive materials, have excellent wear resistance. Plastic tips are resistant to corrosion and abrasion and are proving to be very economical for applying pesticides. Brass tips have been common but wear rapidly when used to apply abrasive materials such as wettable powders. Brass tips are economical for limited use, but other types should be considered for more extensive use.

Water Rates (GPA)

The grower who plans to spray materials at the low water rates should follow all recommendations carefully. Use product label recommendations on water rates to achieve optimal performance. Plant size and condition influence the water rate applied per acre. Examination of the crop behind the sprayer before the spray dries will give a good indication of coverage.

Agitation

Most materials applied by a sprayer are in a mixture or suspension. Uniform application requires a homogeneous solution provided by proper agitation (mixing). The agitation may be produced by jet agitators, volume boosters (sometimes referred to as hydraulic agitators) and mechanical agitators. These can be purchased separately and installed on sprayers. Continuous agitation is needed when applying pesticides that tend to settle out, even when moving from field to field or when stopping for a few minutes.

Nozzle Arrangements

When applying insecticides and fungicides, it is advantageous to completely cover both sides of all leaves with spray. When spraying cucumbers, use one or two nozzles over the top of the row (up to 12 inches wide). As the plants start to spread, place nozzles on 10- to 12-inch centers for broadcast spraying. For squash, the nozzle arrangement should be adapted for the various growth stages of plants (figures 28 and 29). When plants are small (up to 12 inches), one or two nozzles over the top are sufficient. As the plant starts to bush or branch, drop nozzles should be added. Opposing nozzles should be rotated clockwise slightly so that spray cones do not collide. This will guarantee that the spray is applied from all directions into the canopy. As the plant increases in height, add additional nozzles for every 8 to 10 inches of growth. In all spray configurations, the nozzle tips should be 6 to 10 inches from the foliage. Properly selected nozzles should be able to apply 25 to 125 gallons per acre when operating at a pressure of 60 to 200 or higher psi. Usually, more than one size of nozzle will be needed to carry out a season-long spray program. Generally larger volumes are used when the crop is in the earlier growth stages.

One nozzle Drop nozzles
Figure 28. One or two nozzles over the row for small plants Figure 29. Use drop nozzles as plants grow.

Calibration

The procedure below is based on spraying 1/128 of an acre per nozzle or row spacing and collecting the spray that would be released during the time it takes to spray the area. Because there are 128 ounces of liquid in one gallon, this convenient relationship results in ounces of liquid collected being directly equal to the application rate in gallons per acre.

Calibrate with clean water when applying toxic pesticides mixed with large volumes of water. Check uniformity of nozzle output across the boom. Collect from each nozzle for a known time period. Each nozzle should be within 10 percent of the average output. Replace with new nozzles if necessary. When applying materials that are appreciably different from water in weight or flow characteristics, such as fertilizer solutions, etc., calibrate with the material to be applied. Exercise extreme care and use protective equipment when an active ingredient is involved.

  1. From Table 7, determine the distance to drive in the field (two or more runs suggested). For broadcast spraying, measure the distance between nozzles. For band spraying, use band width. For over-the-row or directed, use row spacing.
  2. Measure the time (seconds) to drive the required distance with all equipment attached and operating. Maintain this throttle setting!
  3. With sprayer sitting still and operating at same throttle setting or engine RPM as used in Step 2, adjust pressure to the desired setting. Machine must be operated at same pressure used for calibration.
  4. For broadcast application, collect spray from one nozzle or outlet for the number of seconds required to travel the calibration distance.
    For band application, collect spray from all nozzles or outlets used on one band width for the number of seconds required to travel the calibration distance.
    For row application, collect spray from all outlets (nozzles, etc.) used for one row for the number of seconds required to travel the calibration distance.
  5. Measure the amount of liquid collected in fluid ounces. The number of ounces collected is the gallons per acre rate on the coverage basis indicated. For example, if you collect 18 ounces, the sprayer will apply 18 gallons per acre. Adjust applicator speed, pressure, nozzle size, etc., to obtain recommended rate. If speed is adjusted, start at Step 2 and recalibrate. If pressure or nozzles are changed, start at Step 3 and recalibrate.

Table 7. Distance to measure to spray 1/128 acre. One ounce discharged equals one gallon per acre.

Nozzle Spacing (inches)

Distance
(feet)

Nozzle Spacing (inches)

Distance
(feet)

6

681

20

204

8

510

22

186

10

408

24

170

12

340

30

136

14

292

36

113

16

255

38

107

18

227

40

102

To determine a calibration distance for an unlisted spacing, divide the spacing expressed in feet into 340. Example: Calibration distance for a 13" band = 340 13/12=313 feet.

Sprayers should be calibrated at 2� to 4 miles per hour. Calibration should be conducted every 8 to 10 hours of operation to ensure proper pesticide application.


IRRIGATION
Anthony W. Tyson and Kerry A. Harrison, Extension Agicultural Engineers

Water is a critical component in the production of cucumbers and squash. These are all fleshy fruits that consist of 90 percent to 95 percent water. Thus an adequate water supply is critical to produce profitable yields and to maintain marketable quality.

Cucumbers and summer squash are typically shallowly rooted (12- to 18-inch effective root zone). Actual rooting depths will vary considerably depending on soil conditions and cultural practices. The shallow rooting depth and the fact that these crops are often grown in sandy soils with a low water-holding capacity make irrigation necessary for consistently high yields of quality cucumbers and squash in Georgia.

Inadequate water during crop establishment may result in inconsistent stands and may delay maturity, which can have adverse effects on marketing. Water stress in the early vegetative stage results in reduced leaf area and reduced yield. The most serious yield reductions result from water stress during flowering and fruit development. Water stress at this time may also result in small and/or misshapen fruit.

Several types of irrigation systems may be used successfully on squash and cucumbers in the Southeast. Ultimately, the decision about system type will be based on one or more of the following factors:

  1. availability of existing equipment,
  2. field shape and size,
  3. amount and quality of water available,
  4. labor requirements,
  5. fuel requirements, and
  6. cost.

Sprinkler Irrigation

Currently, most vegetables in Georgia are irrigated with some type of sprinkler irrigation. These systems include center pivot, linear move, travelling big gun, permanent set and portable aluminum pipe with sprinklers. Any of these systems are satisfactory if used correctly. However, they have significant differences in initial cost, fuel cost and labor requirements.

Any sprinkler system used on cucumbers or squash should be capable of delivering at least an inch of water every three days. In addition, the system should apply the water slowly enough to prevent run-off. With most soils, a rate less than 2 inches per hour safely prevents runoff.

Sprinkler systems with a high application uniformity (center pivot and permanent set) can apply fertilizer. This increases the efficiency of fertilizer utilization by making it readily available to the plant and by reducing leaching.

Drip Irrigation

Drip irrigation is gaining popularity. It is usually used with plastic mulch. One of the major advantages of drip irrigation is its water-use efficiency. Studies in Florida have indicated that 40 percent less water was required for drip irrigated vegetables than for those sprinkler irrigated. Weeds are also less problem because only the rows are watered; the middles remain dry. Some studies have indicated that drip also enhances earlier yields and fruit size.

Drip tubing may be installed on the ground surface or buried 2 to 3 inches deep. When used in conjunction with plastic mulch, the tubing can be installed at the same time the plastic mulch is laid. Offsetting the tubing slightly from the center of the bed is usually dsirable. This prevents the tubing from being damaged during the hole punching and the planting operation.

Typically, one line of tubing is installed beside each row. A field with 6-foot row spacing will require 7,260 feet of tubing per acre.

The tubing is available in various wall thicknesses ranging from 3 mils to 25 mils. Most growers use thin wall tubing (less than 10 mils) and replace it every year. Heavier wall tubing can be rolled up at the end of the season and reused; however, care must be taken in removing it from the field. Labor costs are high.

Drip systems can be adapted easily for fertilizer injection. This allows plant nutrients to be supplied to the field as needed. This method also eliminates the need for heavy fertilizer applications early in the season, which tend to leach beyond the reach of root systems or cause salt toxicity problems. Only water-soluble formulations can be injected through the drip systems. The system should be thoroughly flushed after each injection.

Water used in a drip irrigation system should be well filtered to remove any particulate matter that might plug the tubing. The water should be tested for minerals that might cause plugging problems. For more detailed information on drip irrigation and injection, consult University of Georgia Cooperative Extension Service bulletins 1108, Plasticulture for Commercial Vegetable Production, and 1130, Drip Chemigation: Injecting Fertilizer, Acid and Chlorine.

Scheduling Irrigation

The water used by a crop and evaporated from the soil is called evapotranspiration (ET). ET rates for cucumbers and squash may be as high as 0.25 inches per day. Factors that affect ET are stage of crop growth, temperature, relative humidity, solar radiation, wind speed and plant spacing.

These crops should be planted in moist soil. If transplants are used, you should apply about � inch of water immediately after planting to settle the soil and to ensure good soil-root contact. During germination or transplant establishment, the primary objective is to keep the top few inches of soil moist with light applications of water (� to � inch) as needed. The soil should not become waterlogged.

Generally, during dry weather, you should irrigate two or three times a week after root system establishment if using sprinklers. Net application amounts will typically be in the range of � to 4/5 inches per irrigation. The actual amount applied should be 10 percent to 20 percent higher than the desired net amount to account for evaporation losses and wind drift. Sandy soils will require more frequent light applications; heavier soils can be watered less frequently with heavier applications.

Irrigation can best be managed by monitoring the amount of moisture in the soil. Tensiometers or electric resistance blocks can be used to measure soil moisture. For best results, maintain soil moisture between 10 and 30 centibars tension depending on soil type. Consult Univeristy of Georgia Cooperative Extension Service Bulletin 974, Irrigation Scheduling Methods, for more detailed information.

Drip irrigation systems need to be operated more frequently than sprinkler systems. Typically, they are operated every day or every other day. Do not overwater, especially when using plastic, because the plastic will keep the soil from drying out.

Soil moisture should be maintained at adequate levels until harvest.


GOOD AGRICULTURAL PRACTICES IN THE HARVEST, HANDLING AND PACKAGING OF FRESH MARKET SQUASH AND CUCUMBERS
William C. Hurst, Extension Food Scientist

Introduction

Outbreaks of foodborne illness caused by microbial contaminants on consumed produce are rare. However, several recent and highly publicized outbreaks have drawn attention to the fresh produce industry. As a result, the FDA and the USDA have jointly published the first ever safety guidance document, The Guide to Minimize Food Safety Hazards for Fresh Fruits and Vegetables. It delineates safe agricultural practices for growing, packing, shipping and selling fresh produce. Cucumber and squash growers/shippers should begin to implement these production and handling practices designed to minimize potential hazards in their crops.

Quality and Safety

Produce quality and safety are often perceived by consumers to mean the same thing. Good quality produce may be visually appealing and delicious, yet may contain pathogens or toxins that can cause illness to the consumer. Safe produce, in contrast, may be discolored, over mature and unappealing, yet present no hazard to the consumer. Unfortunately, the safety of fresh produce cannot be determined by its outward appearance or condition.

Field Sanitation Program

Raw Product Safety

Ensuring fresh cucumber and squash safety begins with preventing hazards in the field. The best guarantee of a safe raw product is a proactive food safety program that has been designed and implemented to identify and prevent hazards during production and postharvest handling of these vegetables. Growers/shippers should familiarize themselves with safe production practices so they might be viewed as qualified suppliers among potential buyers. Some issues of concern during fresh production are summarized in Table 8.

Land-use History

Grazing animals on or near cropland can introduce to the soil bacteria that are pathogenic to humans. Growers should ensure that land has not been used for animal husbandry and that it is not in proximity to animal feedlots or water runoff from grazing lands. Past improper use of pesticides can result in hazardous residues on raw products. Buyers might insist on letters of guarantee from grower/shippers that the land is suitable and safe for the crops being produced. Before planting, soil residue levels of pesticides and heavy metals should be determined.

Fertilizer Use

Incompletely composted organic fertilizers may contain bacteria pathogenic to humans derived from animal or human feces. If organic fertilizers are used, they must be certified that they have been completely composted so no pathogens are present. Composted sewage sludge should not be used because it may contain pathogens as well as heavy metals.

Irrigation

Natural surface water (e.g., canal, lake, pond) provides enough organic matter to support the growth of bacterial pathogens. Surface water may be used but should be tested for the presence of the bacterium Escherichia coli (E. coli), which is an indicator of fecal contamination. Groundwater is less likely to harbor human pathogens but should be analyzed for heavy metal and pesticide contamination.

Overhead irrigation is more likely to spread contamination to above-ground plant parts than is root zone irrigation. Growers must be able to document answers to the following questions:

Pesticide Usage

Inspection, monitoring and documentation of proper use of pesticides will prevent unsafe or illegal pesticide residues from contaminating the raw product. Growers must be able to answer the following questions:

Harvesting

Mechanical harvesting can wound produce, encouraging contamination from the soil. Hand harvesting may lead to pathogen contamination if field workers practice poor hygiene. Field crews must be trained and monitored for personal hygiene, and portable bathroom and hand-washing facilities must be provided in the field.

Field Containers (boxes, buckets, bins, etc.)

Containers for harvesting fresh cucumbers and squash should be nontoxic, easy to clean and free of extraneous materials (e.g., nails, wood splinters) that can carry over into processing. They must be approved by the U.S. Department of Agriculture (USDA) or the Food and Drug Administration (FDA) for field use. After detergent cleaning, field bins, buckets, etc., can be sanitized using a strong sodium hypochlorite solution dispensed from a high-pressure sprayer.

Table 8. Potential hazards during cucumber and squash production

Production Factor

Potential Hazard

Prevention

Documentation

Land use

Fecal contamination (source of pathogens) from animals

No grazing animals or feedlots on/near production land

Grower certification of no recent animal husbandry on land used

Toxic pesticide residues in soil Review pesticide history for plant back restrictions Pesticide selection/application records

Fertilizers

Pathogenic bacteria from organic fertilizers

Use inorganic fertilizer

Credible test results

Heavy metal toxicity from sewage sludge Use certified organic fertilizers or tested and approved sludge Credible test results

Irrigation water

Pathogenic bacteria from surface water

Test/monitor water supply

Water test results

Heavy metal/pesticide residues in ground and suface water Test/monitor water supply Water test results

Pesticide use

Illegal/hazardous residues on product

Employ only professional, licensed applicators and monitor pesticide use

Examine applicator records; test for residues if contamination suspected

Hand harvesting

Fecal contamination of product

Field worker personal hygiene; field washing/sanitizing facilities available

Training programs on worker hygiene

Field containers

Soil and human pathogens

Use plastic bins; clean/sanitize all containers

Field sanitation records

 

Harvest Quality

Summer squash (both yellow and green types) and cucumbers are harvested at the same physiological maturity, as immature fruits. Optimum maturity for squash harvest is best judged by size and succulence of skin. Desired squash is 1� to 2 inches in diameter. At this stage, young fruit has a tender skin, glossy appearance, slightly sweet taste; seeds have not begun to enlarge and harden. Toughening of the rind and seeds can be expected in zucchini and yellow straightneck types when sizes increase beyond about 6 inches in length.

Generally, cucumber fruit are harvested at a slightly immature stage, near full size but before seeds fully enlarge and harden. A glossy dark to medium green color with no yellowing and firm texture are indicators of optimum harvest quality. At proper harvest maturity, a jelly-like material has begun to form in the cucumber seed cavity.

Harvesting

Cucumbers and squash should be picked at frequent intervals to optimize quality and avoid losses from overmaturity. Harvest of both crops is done by hand at intervals of one to three days in Georgia, depending on environmental conditions. Wet fruit should not be picked because surface moisture increases field heat accumulation in the load and enhances disease development. Crews must exercise extreme care to minimize fruit damage during harvest.

Polyethylene 5-gallon pails are the preferred picking containers for squash because they inflict less physical damage and are easy to clean. These containers must be cleaned and sanitized daily to minimize decay spread between harvest periods. Wash buckets with a soapy solution first to remove soil, rinse and then sanitize with a solution consisting of 3� ounces of 5.25 percent sodium hypochlorite (household bleach) mixed in 7� gallons of water.

Because of its thin, tender skin, summer squash is more easily damaged than any other vegetable during harvest. The most prevalent types of damage are puncture by fingernails, sand abrasion, scratches inflicted by abrasion from the harvesting container and bruising because of impact or compression damage. Every puncture, abrasion or bruise is a potential site for latent decay development. Harvesters must keep their fingernails closely clipped or perhaps wear soft cotton gloves during harvest. Squash should be cut from the plant with a knife (also sanitized between harvest periods) leaving about � inch of the stem attached to the fruit. In harvesting, the worker should grasp the fruit lightly because they are easy to break and bruise with too much external pressure.

Research has shown that summer squash with intact stems are more resistant to bacterial soft rot. Decayed, off-grade and overmature squash should be removed from the plant to initiate new fruit set. Picking pails of squash should not be stacked or excessive bruising and damage will occur during transport from the field to the packing shed.

In the harvest of cucumbers, workers should never pull the fruit from the vine. This may tear the fruit and damage the vine, either of which increases decay and disease. When properly picked, the stem is pushed off the fruit with the thumb. Although squash are transported in picking pails, cucumbers are emptied into pallet bins for transport to the packinghouse. Physical damage may occur during bulk bin loading as cucumbers split or become bruised when striking hard wooden bottoms. Field demonstration research has shown that padding bin bottoms with insulated carpet reduced splitting and bruising by more than 20 percent.

Field Packing

The trend toward field packing is increasing for summer squash. It offers some advantages over a packinghouse operation:

  1. The grower needs less capital investment.
  2. Culled and decayed fruits are left in the field.
  3. Less handling is involved; thus, damage decreases and pack-out yields increase.
  4. Harvesting and packing can be more closely coordinated.

Containers of squash are dumped into a vat of water on a flatbed trailer. This water should be kept clean by chlorinating (3� ounces bleach to 7� gallons water) and changing it frequently, because dirty squash will use up the chlorine strength rapidly. Squash should be hand agitated to remove sand, dirt, etc., and off-grade fruit should be removed. Care should be taken to remove blossoms at the flower end. These are a source of enzymes, which if left intact, can cause squash softening. The fruit should be stacked carefully in a box so they lie close together and do not move around during handling of the carton. Care should be used in washing and packing to avoid skin damage.

Packinghouse Operations

At the packinghouse, summer squash is dumped into a tank of water for cleaning. This water should be kept clean by frequent changes and chlorination. Dump tank water should be chlorinated at a rate of 150 ppm free chlorine. After squash washing, excess water should be removed by sponge rollers or air blowers. Fruit is then graded, ensuring flower removal, sized and packed into a variety of containers. Packing line workers should wear plastic gloves when packing fruit to avoid gouging its tender surface.

Cucumbers may be dumped into a chlorinated tank of water or into a holding pit. This area should be padded with hard foam to help break the fall during unloading and to reduce bruising or splitting. Once dumped, cucumbers are elevated from the holding pit past spray washers to remove field debris. This water should be chlorinated at 75 to 100 ppm free chlorine and monitored regularly using test kits. Soft brushes remove excess water. Fruit may or may not move through a waxer depending on market preference. Food grade waxes are applied to inhibit water loss and to enhance appearance. Approved fungicides may be added to waxes to extend shelf life. Cucumbers proceed down the packing line, where they are graded, mechanically sized and packed into either wirebound or fiberboard boxes according to buyer specification. Graders should remove blossoms, which produce enzymes that can lead to fruit softening.

Quality Defects and Pack Specifications

Summer squash quality is based on uniform shape, rind tenderness, glossy skin color and the absence of growth or handling defects (discoloration, bruises, pitting, etc.). U.S. grades are No. 1 and No. 2. Most buyers will accept only the equivalent of U.S. No. 1 Grade or higher. Size consistency is not a part of federal grade standards but may be contractually specified as minimum or maximum diameter, length or both. Tolerance by count for U.S. No. 1 Grade should not exceed 10 percent total defects, including 2 percent decay.

The U.S. Department of Agriculture�s standards for summer squash say: " �U.S. No. 1� consists of squash of one variety or similar varietal characteristics, with stems or portions of stems attached, which are fairly well formed, firm, free from decay or breakdown, and from damage caused by discoloration, cuts, bruises and scars, freezing, dirt or other foreign material, disease, insects, mechanical or other means." U.S. No. 2 is similar except for having fruit "which are not old and tough."

Winter squash falls into two grades: U.S. No. 1 and U.S. No. 2. " �U.S. No. 1� consists of squash of one variety which are well matured, not broken or cracked and which are free from soft rot or wet breakdown, and from damage caused by scars, dry rot, freezing, dirt, disease, insects, mechanical or other means," according the USDA standards for fall and winter type squash. U.S. No. 2 is similar except for fruit "which are at least fairly well matured."

The most common package for Georgia yellow squash is the � bushel (30 pound) carton. The most common package for Georgia zucchini squash is the � or 5/9 bushel (21 pound) carton. The most common package for Georgia winter squash is the 1 1/9 bushel (50 pound) carton. A plastic liner should be used in all wooden containers to prevent abrasion of the squash and retard water loss from the product. Shipping containers should have the size/count, weight, grade and packer clearly marked on the package.

Cucumber quality is primarily based on uniform shape, firmness, a medium to dark green skin color and an absence of growth and handling defects (no yellow streaks, cracks, pitting, etc.). Size uniformity is most important to buyers. They prefer the industry grade called "super select," which has a maximum diameter of 2 3/8 inches and minimum length of 6 inches. Other grades include select, small super, small, large and carton. Super select should be 76 to 80 count packed in a 1 1/9 bushel fiberboard box with a net weight of 55 pounds. U.S. grades are Fancy, Extra No. 1, No. 1, No. 1 Small, No. 1 Large and No. 2. Tolerances by count for U.S. No. 1 should not exceed 10 percent total defects, including 1 percent decay.

" �U.S. Fancy� consists of cucumbers which are well colored, well formed, not overgrown, and which are fresh, firm, and free from decay, sunscald and from injury caused by scars and from damage caused by yellowing, sunburn, dirt or other foreign material, freezing, mosaic or other disease, insects, cuts, bruises, mechanical or other means. The maximum diameter shall not be more than 2 3/8 inches and the length shall not be less than six inches," USDA standards for cucumbers say. U.S. No. 1 is similar to Fancy except that "fairly" qualifies the terms "well colored" and "well formed." Well colored means that not less than three-fourths of the surface is of a medium green or darker color. Well formed means that the cucumber is practically straight and not more than slightly constricted or more than moderately tapered or pointed. Most buyers will accept only the equivalent of U.S. No. 1 Grade or higher.

Cooling and Storage

Summer squash is a highly perishable commodity that will display shriveling (dehydration) quickly if not cooled promptly after harvest. Cucumbers, although not as perishable, should be promptly cooled to prevent water loss and extend shelf life. Forced air cooling is the most efficient type of precooling to remove field heat. To prevent dehydration of these vegetables during cooling, the refrigeration system used should be designed with a large evaporator coil surface to maintain high relative humidity (90 percent to 95 percent). Summer squash should be cooled to 45�F and held at 95 percent relative humidity. Under these ideal conditions, yellow varieties have a shelf life of 10 days; green varieties, 14 days. Cucumbers, which should be stored at a slightly higher temperature, 50�F, and 95 percent relative humidity, have a shelf life of 14 days. Both commodities are subject to chilling injury if held for more than three or four days below their optimal storage temperatures. Chilling manifests itself in summer squash as water-soaked skin, pitting, browning and decay and in cucumber as pitting and accelerated decay. Because growers/shippers normally use the same cold storage facility for both crops, to compensate for these differences, hold squash in the rear of the facility (coldest at 45�F) and cucumbers in the front of the facility (warmest at 50�F) near the door.

Mixed Load/Storage Compatibility

Chilling injury, which begins at 31�F, and dehydration are the two most common physiological disorders affecting summer squash. Chilling injury is exhibited by water-soaked patches of the soft rind becoming brown and gelatinous over time. Dehydration causes loss of firmness and shriveling. Summer squash have similar shipping and storage requirements as cucumbers, eggplant, okra, peppers, snap beans and watermelons. Therefore, these vegetables can be safely stored together without detrimental effects. Ice, however, should never make contact with these commodities. Summer squash is sensitive to low to moderate (0.1 to 10 ppm) ethylene depending on variety. Accelerated yellowing of green varieties can be caused by long term ethylene exposure. Recent USDA research has demonstrated that temperature preconditioning can prevent chilling injury and double the shelf life of zucchini squash. Temperature preconditioning involves holding squash at 59�F for two days before being stored at 41�F.

Cucumbers are highly sensitive to ethylene exposure (0.1-1), causing skins to undergo premature yellowing. Chilling injury is initiated at 31�F. Cucumbers should never be stored with ethylene-producing commodities such as bananas, cantaloupe or tomatoes. Cucumbers are compatible with eggplant, potatoes, pumpkins, watermelons, grapefruit and limes.

Postharvest Decay

Diseases are an important source of postharvest loss for both cucumbers and summer squash, especially in combination with physical injury and chilling stress. Summer squash and cucumbers are subject to the same types of marketing diseases. For example, bacterial soft rot is a common disorder on both vegetables. Bacterial and fungal decay pathogens do not normally enter healthy exterior tissue. However, when mechanical damage (caused by physical injury) or weakening of tissue (caused by chilling stress) occurs, these organisms penetrate core tissue. Pathogens in contaminated water may also enter through natural openings in the skin. Proper handling, grading and temperature management will minimize occurrence of these diseases.

Sanitary Guidelines for Packinghouse Operations

Receiving Incoming Product

Harvest crews should remove as much dirt and mud from the product as is possible before the produce leaves the field. An area should be set aside in the receiving yard so pallets can be cleaned before dumping in bins or cooling.

Water Sanitation

Water used in cleaning and cooling should be chlorinated at a concentration of 75 to 150 ppm of free chlorine. Chlorination can be accomplished using a gas injection system, adding bleach or using calcium hypochlorite tablets. Chlorination levels in the water should be monitored frequently during operation through the use of chlorine litmus paper or, more accurately, with a chlorine test kit. Water pH should be maintained between 6.5 and 7.5 to avoid having to use excess chlorine in order to maintain recommended free chlorine levels. Excessive use of chlorine causes gassing off � objectionable chlorine odor, irritating to skin, corrosive to equipment and inflationary to sanitation cost.

Employee Hygiene

Good employee hygiene is essential. Employee training, health screening and constant monitoring of packinghouse sanitation practices (hand washing, personal hygiene) are important in reducing contamination by employees.

Packinghouse Equipment

Packinghouse equipment should always be maintained in clean condition. The remnants of product left on belts, tables, lines and conveyors could provide a source for microbial growth; therefore, cleaning by scrubbing to remove particles should be part of the cleaning procedure.

If it is deemed appropriate, sanitizing with a chlorine solution could be accomplished, especially on belt conveyors and equipment, by spot spraying with hand sprayers. Knives, blades, boots, gloves, smocks and aprons should be cleaned or replaced as needed.

Pest Control

A pest control program should be in place to reduce, as much as possible, the risk of contamination by rodents or other animals. In an open or exposed packinghouse operation, the best control is constant vigilance and elimination of any discovered animals and their potential nesting locations. Product and/or product remnants will attract pests; therefore, the daily cleaning of the packinghouse to eliminate the attractive food source should help reduce pest activity.

Facility Sanitation

Packinghouse facilities have the potential for developing microbial growth on walls, tunnels, ceilings, floors, doors and drains. Scheduled wash down and/or sanitizing of the facility will reduce the potential for microbial growth. The cooling system should be monitored and cleaned as necessary depending on the type of system.

Temperature Control

Maintenance of proper holding room temperature could affect product quality and could be a factor in reducing microbial growth. Temperature should be monitored to ensure maintenance at established product temperature parameters.


MARKETING CUCUMBERS AND SQUASH
William O. Mizelle, Jr., Extension Ag Economist

Marketing is more than selling. Marketing includes production, distribution and pricing. To be successful, marketing must be responsive to consumers' demands. Consumers demand quality, freshness, and reasonable prices.

Production

Production data for most vegetables are not available. Thus, other types of data must be used to substitute for production estimates. The USDA collects market arrival data for fresh fruits and vegetables in the major markets in the United States.

Data showed that 26 states and seven foreign countries were supplying cucumbers to the major U. S. markets at some time during 1996. The top three sources of cucumbers were Mexico, Florida and California. Georgia was the fourth leading supplier of cucumber shipments to the major U.S. markets (Table 9). Georgia accounted for 7 percent to 8 percent of the annual volume.

The U.S. monthly volume of cucumbers was lowest in February and peaked in July. Volume to the major markets ranged from about 35 million to 55 million pounds per month. Georgia had about 7.5 percent of the annual volume but had about 25 percent of the market during its biggest months, June and October. Florida and North Carolina were Georgia�s primary competitors.

Twenty-eight states and four foreign countries supplied squash some time during the year. However, four states accounted for nearly 60 percent of the annual volume shipped to the 22 major U. S. markets (Table 10). California and Florida were the leading squash-producing states. Georgia and New Jersey followed in annual volume.

Squash volume was fairly consistent throughout the year but peaked in June. Monthly volume was about 20 million pounds per month shipped to the 20 major markets. Georgia's volume peaked during June and October. Georgia accounted for 7 percent of the annual volume but had about 25 percent of the market in June and 18 percent in October.

Distribution

Population locations, tastes and preferences determine the demand for any product. For most vegetables, the top three markets are the three largest cities: New York, Los Angeles and Chicago.

The top three cucumber markets were New York, Los Angeles and Chicago (Table 11). New York, Chicago and Boston were Georgia's largest markets, receiving nearly 50 percent of Georgia's shipments to the major markets. Slightly more than 20 percent of Georgia's shipments went to the Southern markets. The Southern markets received less than 17 percent of all shipments.

The top three squash markets were Los Angles, Chicago and San Francisco (Table 12). The top markets for Georgia's squash were Boston, Chicago and Atlanta. Nationally, the West received the largest share of all squash, 36 percent. However, data for squash were not separated by type of squash, so one area might have been consuming a higher proportion of one type when compared with other areas. The Southern cities received more than one-fourth of Georgia's squash.

Pricing

Supply and demand determine the general price level. The competing states' production determines the supply. Consumers' willingness to buy different quantities at different prices determines the demand.

Arrivals chart
Figure 30. Cucumber and squash arrivals

Consumption data were reported for cucumbers but not for squash. Per capita consumption for cucumbers was 2.7 pounds in the early 1970s, 4.5 pounds in the early 1980s and 4.7 pounds in the early 1990s. Arrival data for the past decade shows an upward trend for cucumbers, squash and pumpkins. Cucumber arrivals for 1995-96 were up 17 percent (429 million to 505 million pounds) from the 1985-86 period. For this same period, squash arrivals were up 19 percent (237 million to 284 million pounds). Pumpkin arrivals more than doubled: 17 million to 40 million pounds.

Arrival data for Georgia's spring and fall seasons have been on an upward trend for both cucumbers and squash (see volume trends in Figure 30). Georgia's cucumber volume to the major markets doubled from the mid-1970s to the mid-1980s and doubled again by the early 1990s � a fourfold increase in 15 years. Squash volume has grown less dramatically, but it shows a threefold increase in the 15-year period

Cucumbers and squash prices (figures 31 and 32) vary greatly within a season and between years. Weather effects on production cause most of the price variation within season. Changes in acreage and weather cause price variations among years. Demand changes cause very little of the price variation. Demand changes are slight from year to year.

Cucumber prices chart

Figure 31. Cucumber prices, medium size, 1 1/9 bushel

 

Squash prices chart
Figure 32. Squash prices, small size, 3/4 bushel

Figure 31 shows the average price data for cucumbers from 1988 through 1997. During the period, spring prices for Georgia cucumbers ranged from $6.40 to $10.70 per 1 1/9 bushel carton and averaged $8.85 per carton. Fall cucumber prices have ranged between $5.90 and $12.70 per carton and averaged $7.25 per carton.

Spring yellow squash prices have ranged between $4.35 and $9.00 per carton and averaged $6.40 per carton. Fall squash prices have ranged between $6.00 and $13.50 per carton and averaged $8.00 per carton. For recent prices, see Extension agricultural economics publication Vegetable Economics � A Planning Guide.

Summary

Nationally, annual cucumber supplies have increased slightly during the past 10 years � up 14 percent � while Georgia's volume has doubled. Seasonal average prices have ranged from $5.00 to $12.00 and with most years, prices are above break-even costs. As a result, Georgia volume has doubled. Cucumbers seem profitable for Georgia growers, especially when a competing area experiences adverse weather. Squash are experiencing a similar favorable marketing environment. Most seasons� average prices are above estimated costs. Volume data increases are not as impressive as cucumbers possibly because of more volume going to nonreporting markets.

Even with recent years� favorable price/cost situation, cucumber and squash growers will have to continue to adjust to changing market conditions. For these highly competitive commodities, the better marketers will be the ones most likely to survive.

Table 9 . Monthly cucumber arrivals in 20 U. S. cities, in 1996 (million pounds)

Source

Jan.

Feb.

March

April

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

Total

1995

California

0.2

0.7

1.0

1.6

5.7

6.6

7.8

6.3

6.6

6.4

2.6

1.0

46.5

39.2

Florida

9.8

5.8

4.5

11.4

27.2

10.3

0.6

0

0

4.0

13.2

11.8

98.6

129.1

Georgia

0

0

0

0

3.0

12.3

5.0

0.4

0.7

10.8

4.3

0

36.5

39.8

Michigan

0

0

0

0

0

0

3.6

8.9

8.9

2.2

0

0

23.6

24.4

New Jersey

0

0

0

0

0

1.6

10.7

5.7

5.6

2.3

0

0

25.9

30.1

New York

0

0

0

0

0

0

1.9

6.1

5.4

1.4

0

0

14.8

14.1

North Carolina

0

0

0

0

0

7.4

6.7

0.5

0.4

1.1

0

0

16.1

19.5

Virginia

0

0

0

0

0.1

0.8

6.5

1.6

1.8

1.7

0

0

12.5

12.1

Mexico

26.3

29.4

33.0

30.7

16.0

4.9

1.7

0.6

0.8

4.3

13.9

24.7

186.3

154.6

Other

0.2

0.1

0.7

1.5

3.9

5.7

10.0

12.3

9.0

5.0

2.3

0.5

51.2

44.3

Total

36.5

36.0

39.2

45.2

55.9

49.6

54.5

42.4

39.2

39.2

36.3

38.0

512.0

507.2

Georgia�s Percentage of Total

0

0

0

0

5.4%

24.8%

9.2%

0.9%

1.8%

27.6%

11.8%

0

7.1%

7.8%

Source: Fresh Fruit and Vegetable Arrival Totals, FVAS-3 Calendar Year 1996


Table 10 .
Average monthly squash arrivals in 20 U. S. cities (million pounds)

Source

Jan.

Feb.

March

April

May

June

July

Aug.

Sept.

Oct.

Nov.

Dec.

Total

1995

California

0.4

0.3

0.3

0.8

4.6

6.3

8.8

8.2

6.8

8.5

3.7

1.3

50.0

47.7

Florida

5.2

4.1

4.5

7.9

9.6

2.3

0

0

0

1.2

4.9

6.0

45.7

59.3

Georgia

0

0

0

0

3.5

5.3

2.9

0.5

1.2

4.6

1.9

0.1

20.0

20.5

New Jersey

0.7

0.5

0.5

0.2

0.1

1.8

4.9

2.1

2.3

1.4

1.0

0.2

15.7

20.9

North Carolina

0

0

0

0

0

2.8

1.6

0.4

0.4

0.4

0.1

0

5.7

8.8

Mexico

18.2

17.1

17.0

16.1

8.2

1.9

1.1

0.4

0.3

3.1

9.7

14.6

107.7

83.1

Other

0.7

0.5

0.3

0.3

0.7

1.8

6.4

9.9

9.4

5.8

4.0

1.3

41.1

42.3

Total

25.2

22.5

22.6

25.3

26.7

22.2

25.7

21.5

20.4

25.0

25.3

23.5

285.9

282.6

Georgia�s Percentage of Total

0

0

0

0

13.1%

23.9%

11.3%

2.3%

5.9%

18.4%

7.5%

0.4%

7.0%

7.3%

Source: Fresh Fruit and Vegetable Arrival Totals, FVAS-3 Calendar Year 1996


Table 11.
Cucumber arrivals in 20 major U.S. cities, 1996

 

From Georgia

To City

Market

Million Pounds

Percent of Total

Million Pounds

Percent of Total

Atlanta

3.1

8.5%

20.1

3.9%

Baltimore

2.8

7.7%

32.9

6.4%

Columbia

0.1

0.3%

6.5

1.3%

Dallas

1.4

3.8%

15.3

3.0%

Miami

1

2.7%

8.3

1.6%

New Orleans

0

0

0

0

South

8.4

23.0%

83.1

16.2%

Boston

5.7

15.6%

57.3

11.2%

Buffalo

0

0

0

0

New York

6

16.4%

90

17.6%

Philadelphia

1.8

4.9%

25.2

4.9%

Pittsburgh

2.4

6.6%

22.9

4.5%

Northeast

15.9

43.6%

195.4

38.2%

Chicago

5.9

16.2%

64.2

12.5%

Cincinnati

0

0

5.5

1.1%

Detroit

3.7

10.1%

28.7

5.6%

St. Louis

2.3

6.3%

21.4

4.2%

Midwest

11.9

32.6%

119.8

23.4%

Los Angeles

0.3

0.8%

70.8

13.8%

San Francisco

0

0

29

5.7%

Seattle

0

0

13.9

2.7%

West

0.3

0.8%

113.7

22.2%


Table 12. Squash arrivals in 20 major U.S. cities, 1996

 

From Georgia

Total to City

Market

Million Pounds

Percent of Total

Million Pounds

Percent of Total

Atlanta

2.5

12.5%

10.1

3.5%

Baltimore

1.2

6.0%

13.5

4.7%

Columbia

0.1

0.5%

3.4

1.2%

Dallas

1.1

5.5%

10.7

3.7%

Miami

0.3

1.5%

3.4

1.2%

New Orleans

0

0

0

0

South

5.2

26.0%

41.1

14.4%

Boston

4.7

23.5%

36.7

12.8%

Buffalo

0
0
0
0

New York

2.2

11.0%

31.5

11.0%

Philadelphia

1.3

6.5%

9.7

3.4%

Pittsburgh

0.5

2.5%

3.8

1.3%

Northeast

8.7

43.5%

81.7

28.6%

Chicago

4.2

21.0%

40.4

14.1%

Cincinnati

0

0

2.6

0.9%

Detroit

1.4

7.0%

13.1

4.6%

St. Louis

0.5

2.5%

4.4

1.5%

Midwest

6.1

30.5%

60.5

21.2%

Los Angeles

0

0

51.5

18.0%

San Francisco

0

0

38.1

13.3%

Seattle

0

0

13

4.5%

West

0
0

102.6

35.9%

 


PRODUCTION COSTS
William O. Mizelle, Jr. and George O. Westberry, Extension Ag Economists

Cucumber and squash growers can use enterprise budgets to estimate production costs and break-even prices. Budgets include cost estimates for those inputs necessary to achieve the specified yields over a period of years. Because production practices vary among growers, each grower should adapt budget estimates to reflect his or her individual situation. Detailed printed and computerized budgets are available from your county Extension offices.

Types of Costs

Total costs of producing any crop include both variable and fixed costs. The variable or operating costs vary with the cultural practices used. Common variable costs include seed, fertilizer, chemicals, fuel and labor. Fixed costs include items such as equipment ownership (depreciation, interest, insurance and taxes) management and general overhead costs. You incur most of these costs even if little production takes place. Consider these costs when planning your production.

Variable costs are further broken down into preharvest and harvest operations in the budgets. This provides you an opportunity to analyze the costs at different stages of the production process.

Land cost may either be a variable or a fixed cost. Even if you own the land, there is a cost. Land is in the fixed cost in these budgets. If land is double-cropped, charge each enterprise half the annual rate.

A fixed cost per hour of use shows ownership costs for tractors and equipment (depreciation, interest, taxes, insurance, and shelter). Overhead and management are 15 percent of all preharvest variable expenses. This figure pays for management and farm costs that cannot be allocated to any one specific enterprise. Overhead items include utilities, pick-up trucks, farm shop and equipment, and fees.

Cost Per Unit of Production

The cost categories (tables 14-19) are broken down in cost per unit at the bottom of the budget. The preharvest variable costs and the fixed costs decline with increases in yields.

Table 13. Costs per carton from the 1998 Extension budget

 
Bare ground
Plastic
Cucumbers
Preharvest cost
$1.67
$2.49
Harvest & marketing cost
$4.51
$4.55
Fixed cost
$0.70
$0.68
Total cost
$6.88
$7.72
Yellow squash
Preharvest cost
$1.18
$1.53
Harvest & marketing cost
$3.11
$3.35
Fixed cost
$0.52
$0.42
Total cost
$4.81
$5.30
Zucchini squash
Preharvest cost
$0.63
$1.23
Harvest & marketing cost
$2.98
$3.19
Fixed cost
$0.28
$0.34
Total cost
$3.98
$4.76
For current cost estimates, see most recent extension vegetable budgets


Budget Uses

In addition to estimating the total costs and break-even costs for producing cucumber and squash, the budgets have other uses.

Estimates of the cash costs (out-of-pocket expenses) provide information on how much money needs to be borrowed. The cash cost estimates are helpful in preparing cash flow statements.

In the instance of share leases, the cost estimates by item can be used to determine more accurately a fair-share arrangement by the landlord and tenant.

Risk Rated Net Returns

Because yields and prices vary from year to year, an attempt has been made to estimate the riskiness of producing cucumber and squash. The Extension agricultural economics department uses five different yields and prices to calculate risk. The median values are those prices and yields a particular grower would anticipate exceeding half the time. Half the time, he would anticipate not reaching below these prices and yields. Optimistic values are those prices and yields a grower would expect to reach or exceed one year in six. The pessimistic values are poor prices and yields that would be expected one year in six. The best and worst values are those extreme levels that would occur once a lifetime (1 in 48).

The risk rated section (Table 14) for cucumber shows a 75 percent chance of covering all costs. Over a period of years, this hypothetical grower would anticipate average or expected returns of $362 per acre. One year out of six he would expect to make more than $898 per acre or to lose more than $178 per acre.

The risk rated section (Table 15) for yellow squash shows a 78 percent chance of covering all costs. Over a period of years, this hypothetical grower would anticipate average or expected returns of $594 per acre. He would be expected to net $594 or more about half the time and $594 or less half the time. One year out of six he would expect to make more than $1,395 per acre or to lose more than $180 per acre.

The risk rated section (Table 16) for zucchini squash shows a 77 percent chance of covering all costs. Over a period of years, this hypothetical grower would anticipate average or expected returns of $494 per acre. He would be expected to net $494 or more 51 percent the time and net $494 or less 49 percent of the time. One year out of six he would expect to make more than $1,150 per acre or to lose more than $205 per acre.

Table 14. Cucumbers, Bareground Fresh Market

Best

Optimistic

Median

Pessimistic

Worst

*Yield (carton)

500

325

250

175

0

*Price per carton

11.40

9.80

8.35

6.80

5.25

Item

Unit

Quantity

Price

Dollar Amount per Acre

Variable Costs

Seed1

Lb.

3.00

38.00

114.00

Lime, applied

Ton

.50

26.00

13.00

Fertilizer

Cwt.

10.00

8.50

85.00

Sidedressing

Acre

1.00

33.00

33.00

Insecticide2

Application

4.00

6.90

27.60

Fungicide

Application

10.00

2.78

27.80

Nematicide

Acre

1.00

34.60

34.60

Herbicide

Acre

1.00

24.26

24.26

Machinery

Acre

1.00

18.75

18.75

Labor

Acre

1.00

15.25

15.25

Land Rent

Acre

1.00

.00

.00

Irrigation

Application

3.00

4.26

12.78

Interest on Operating Capital

$

406.04

10.5%

10.66

Preharvest Variable Costs

 

   

416.70

Harvest and Marketing Costs

Picking and Hauling

Carton

250

1.50

375.00

Grading and Packing

Carton

250

1.00

250.00

Container (1 1/9 bushel)

Carton

250

1.30

325.00

Marketing

Carton

250

.71

177.50

Total Harvest and Marketing

 

 

4.51

1127.50

Total Variable Costs

 

 

 

1544.20

Fixed Cost

Machinery

Acre

1.00

42.06

42.06

Irrigation

Acre

1.00

30.46

30.46

Land

Acre

1.00

40.00

40.00

Overhead and Management

Dollar

416.70

0.15

62.50

Total Fixed Costs

 

 

 

175.02

Total Budgeted Cost per Acre

 

 

 

1,719.22

Costs Per Carton

Preharvest Variable Cost per Carton

 

1.67

 

Harvest and Marketing Cost per Carton

 

4.51

 

 

Fixed Costs per Carton

 

0.70

 

 

Total Budgeted Cost per Carton

 

6.88

 

 

1 Price is for hybrid. Open pollinated are about $8 per lb.
2 Late plantings may require more applications.

Risk-Rated Bareground Cucumber Returns Over Total Costs
Net return levels (top row), the chances of obtaining this level or more (middle row) and chances of obtaining this level or less (bottom row)

Optimistic

Expected

Pessimistic

*Returns

$1,167
$898
$630
$362
$92
$-178
$-448

Chances

7%

16%

31%

50%

 

 

Chances

 

 

 

50%

31%

16%

6%

Table 15. Squash, Bareground Fresh Market

Best

Optimistic

Median

Pessimistic

Worst

*Yield (� bushels)

725

525

325

125

.00

*Price per � bushel

9.00

8.50

6.75

5.25

3.50

Item

Unit

Quantity

Price

Dollar Amount per Acre

Variable Costs

Seed

Lb.

4.00

33.50

134.00

Lime, Applied

Ton

.50

26.00

13.00

Fertilizer

Cwt

8.00

8.50

68.00

Sidedressing

Acre

1.00

18.00

18.00

Insecticide1

Application

4.00

4.15

16.60

Fungicide

Application

4.00

3.90

15.60

Nematicide

Acre

1.00

45.00

45.00

Herbicide

Acre

1.00

16.50

16.50

Machinery

Acre

1.00

16.27

16.27

Labor

Acre

1.00

14.40

14.40

Land Rent

Acre

1.00

.00

.00

Irrigation

Application

4.00

4.26

17.04

Interest on Operating Capital

Dollar

374.41

10.5%

9.83

Preharvest Variable Costs

 

 

 

384.24

Harvest and Marketing Costs

Picking and Hauling

Bushel

325

1.00

325.00

Washing and Packing

Bushel

325

.25

81.25

Container

Bushel

325

1.30

422.50

Marketing

Bushel

325

.56

182.00

Total Harvest and Marketing

 

 

3.11

1,010.75

Total Variable Costs

 

 

 

1,394.99

Fixed Costs

Machinery

Acre

1.00

42.06

42.06

Irrigation

Acre

1.00

30.46

30.46

Land

Acre

1.00

40.00

40.00

Overhead and Management

Dollar

384.24

0.15

57.64

Total Fixed Costs

 

 

 

170.16

Total budgeted cost per acre

 

 

 

1,565.15

Costs Per Bushel

Preharvest Variable Cost per Bushel

 

1.18

 

Harvest and Marketing Cost per Bushel

 

3.11

 

 

Fixed Costs per Bushel

0.52

Total Budgeted Cost per Bushel

4.81

1 Planting after July 1 will require twice as many applications.


Risk-Rated Bareground Yellow Squash Returns Over Total Costs
Net return levels (top row), the chances of obtaining this level or more (middle row) and chances of obtaining this level or less (bottom row)

Optimistic

Expected

Pessimistic

*Returns

$1,795
$1,395
$994
$594
$207
$-180
$-567

Chances

7%

16%

30%

50%

 

 

 

Chances

 

 

 

50%

31%

16%

7%

Table 16. Zucchini, Bareground Fresh Market

Best

Optimistic

Median

Pessimistic

Worst

*Yield (carton)

1,000

800

600

350

.00

*Price per carton

6.70

5.85

5.00

4.10

3.25


Item

Unit

Quantity

Price

Dollar Amount per Acre

Variable Costs

Seed

Lb.

4.00

32.00

128.00

Lime, Applied

Ton

.50

26.00

13.00

Fertilizer

Cwt.

8.00

8.50

68.00

Sidedressing

Acre

1.00

18.00

18.00

Insecticide1

Application

4.00

4.15

16.60

Fungicide

Application

4.00

3.90

15.60

Nematicide

Acre

1.00

45.00

45.00

Herbicide

Acre

1.00

16.50

16.50

Machinery

Acre

1.00

16.27

16.27

Labor

Acre

1.00

14.40

14.40

Land Rent

Acre

1.00

.00

.00

Irrigation

Application

4.00

4.26

17.04

Interest on Operating Capital

Dollar

368.41

10.5%

9.67

Preharvest Variable Costs

 

 

 

378.08

Harvest and Marketing Costs

Picking and Hauling

Carton

600

1.00

600.00

Washing and Packing

Carton

600

.25

150.00

Container (5/9 bushel)

Carton

600

1.30

780.00

Marketing

Carton

600

.43

258.00

Total Harvest and Marketing

 

 

2.98

1,788.00

Total Variable Costs

 

 

 

2,166.08

Fixed Costs

Machinery

Acre

1.00

42.06

42.06

Irrigation

Acre

1.00

30.46

30.46

Land

Acre

1.00

40.00

40.00

Overhead and Management

Dollar

378.08

0.15

56.71

Total Fixed Costs

 

 

 

169.23

Total Budgeted Cost per Acre

 

 

 

2,335.31

Costs Per Carton

Preharvest Variable Cost per Carton

 

0.63

 

 

Harvest and Marketing Cost per Carton

 

2.98

 

 

Fixed Cost per Carton

 

0.28

 

 

Total Budgeted Cost per Carton

 

3.89

 

 

1 Planting after July 1 will require twice as many applications.

Risk-Rated Bareground Cucumber Zucchini Squash Returns Over Total Costs
Net return levels (top row), the chances of obtaining this level or more (middle row) and chances of obtaining this level or less (bottom row)

Optimistic

Expected

Pessimistic

*Returns

$1,479

$1,150

$822

$494

$144

$-205

$-554

Chances

6%

16%

32%

51%

 

 

Chances

 

 

 

49%

30%

16%

6%

Table 17. Cucumbers on Plastic, Fresh Market

Best

Optimistic

Median

Pessimistic

Worst

*Yield (carton)

800

600

500

400

200

*Price per carton

11.90

10.35

8.85

7.30

5.75

Item

Unit

Quantity

Price

Dollar Amount per Acre

Variable Costs

Seed1

Lb.

3.00

37.00

111.00

Lime, Applied

Ton

1.00

26.00

26.00

Fertilizer

Cwt.

10.00

8.50

85.00

Sidedressing

Gal.

200.00

.95

190.00

Insecticide2

Application

4.00

6.70

26.80

Fungicide

Application

10.00

2.70

27.00

Herbicide

Acre

1.00

6.00

6.00

Fumigation

Lb.

200.00

1.00

200.00

Plastic

Roll

2.80

68.50
191.80

Plastic Removal

Acre
1.00
85.00
85.00

Machinery

Acre

1.00

21.38

21.38

Labor

Acre

1.00

45.00

45.00

Land Rent

Acre

1.00

.00

.00

Irrigation

Acre

1.00

197.11

197.11

Interest on Operating Capital

Dollar

1212.09

10.5%

31.82

Preharvest Variable Costs

 

 

 

1,243.91

Harvest and Marketing Costs

Picking and Hauling

Carton

500

1.50

750.00

Grading and Packing

Carton

500

1.00

500.00

Container (1 1/9 bushel)

Carton

500

1.30

650.00

Marketing, 8.5% Gross

Carton

500

.75

375.00

Total Harvest and Marketing

 

 

4.55

2,275.00

Total Variable Costs

 

 

 

3,518.91

Fixed Costs

Machinery

Acre

1.00

45.09

45.09

Irrigation

Acre

1.00

67.89

67.89

Land

Acre

1.00

40.00

40.00

Overhead and Management

Dollar

1,243.91

0.15

186.59

Total Fixed Costs

 

 

 

339.57

Total Budgeted Cost per Acre

 

 

 

3,858.48

Costs Per Carton

Preharvest Variable Cost per Carton

 

2.51

 

Harvest and Marketing Cost per Carton

 

4.55

 

Fixed Costs per Carton

 

0.68

 

Total Budgeted Cost per Carton

 

7.72

 

1 Price is for hybrid. Open pollinated seed are about $8.00 per pound.
2 Late planting may require more applications.

Cucumbers on Plastic Risk Rated Returns Over Total Costs
Net return levels (top row), the chances of obtaining this level or more (middle row) and chances of obtaining this level or less (bottom row)

Optimistic

Expected

Pessimistic

*Returns

$1,956

$1,490

$1,024

$558

$90

$-378

$-846

Chances

7%

16%

31%

50%

 

 

Chances

 

 

 

50%

31%

16%

7%

Table 18. Squash on Plastic, Fresh Market

Best

Optimistic

Median

Pessimistic

Worst

*Yield (carton)

1,200

1,000

800

550

300

*Price per carton

9.60

8.30

7.00

5.75

4.50

Item

Unit

Quantity

Price

Dollar Amount per Acre

Variable Costs

Seed

Lb.

4.00

33.50

134.00

Lime, Applied

Ton

1.00

26.00

26.00

Fertilizer

Cwt.

8.00

8.50

68.00

Sidedressing

Gal.

200.00

.95

190.00

Insecticide1

Application

4.00

4.15

16.60

Fungicide

Application

4.00

3.90

15.60

Herbicide

Acre

1.00

6.00

6.00

Fumigation

Lb.

200.00

1.00

200.00

Pastic

Roll
2.80
68.5
191.80

Pastic Removal

Acre
1.00
85.00
85.00

Machinery

Acre

1.00

21.38

21.38

Labor

Acre

1.00

45.00

45.00

Land Rent

Acre

1.00

.00

.00

Irrigation

Acre

1.00

197.11

197.11

Interest on Operating Capital

Dollar

1,196.49

10.5%

31.41

Preharvest Variable Costs

 

 

 

1,227.90

Harvest and Marketing Costs

Picking and Hauling

Bushel

800

1.00

800.00

Washing and Packing

Bushel

800

.45

360.00

Container

Bushel

800

1.30

1,040.00

Marketing, 8.5% Gross

Bushel

800

.60

480.00

Total Harvest and Marketing

 

 

3.35

2,680.00

Total Variable Costs

 

 

 

3,907.90

Fixed Costs

Machinery

Acre

1.00

45.09

45.09

Irrigation

Acre

1.00

67.89

67.89

Land

Acre

1.00

40.00

40.00

Overhead and Management

Dollar

1,227.90

0.15

184.18

Total Fixed Costs

 

 

337.16

Total Budgeted Cost per Acre

 

 

 

4,245.06

Costs Per Bushel

Preharvest Variable Cost per Bushel

 

1.53

 

Harvest and Marketing Cost per Bushel

 

3.35

 

Fixed Costs per Bushel

 

0.42

 

Total Budgeted Cost per Bushel

 

5.30

 

 

1 Planting after July 1 will require twice as many applications.

Squash on Plastic Risk Rated Returns Over Total Costs
Net
return levels (top row), the chances of obtaining this level or more (middle row) and chances of obtaining this level or less (bottom row)

Optimistic

Expected

Pessimistic

*Returns

$3,109

$2,473

$1,837

$1,200

$550

$-101

$-751

Chances

7%

16%

31%

50%

 

 

 

Chances

 

 

 

50%

31%

16%

7%

Table 19. Zucchini on Plastic, Fresh Market

Best

Optimistic

Median

Pessimistic

Worst

*Yield (carton)

1,500

1,250

1,000

650

300

*Price per carton

6.90

6.00

5.20

4.35

3.45


Item

Unit

Quantity

Price

Dollar Amount per Acre

Variable Costs

Seed

Lb.

4.00

33.50

134.00

Lime, Applied

Ton

1.00

26.00

26.00

Fertilizer

Cwt.

8.00

8.50

68.00

Sidedressing

Gal.

200.00

.95

190.00

Insecticide1

Application

4.00

4.15

16.60

Fungicide

Application

4.00

3.90

15.60

Herbicide

Acre

1.00

6.00

6.00

Fumigation

Lb.

200.00

1.00

200.00

Plastic

Roll
2.80
68.50
191.80

Plastic Removal

Acre
1.00
85.00
85.00

Machinery

Acre

1.00

21.38

21.38

Labor

Acre

1.00

45.00

45.00

Land Rent

Acre

1.00

.00

.00

Irrigation

Acre

1.00

197.11

197.11

Interest on Operating Capital

Dollar

1,196.49

10.5%

31.41

Preharvest Variable Costs

 

 

 

1,227.90

Harvest and Marketing Costs

Picking and Hauling

Bushel

1,000

1.00

1,000.00

Washing and Packing

Bushel

1,000

.45

450.00

Container

Bushel

1,000

1.30

1,300.00

Marketing, 8.5% gross

Bushel

1,000

.44

442.00

Total Harvest and Marketing

 

 

3.19

3,190.00

Total Variable Costs

 

 

 

4,417.90

Fixed Costs

Machinery

Acre

1.00

45.09

45.09

Irrigation

Acre

1.00

67.89

67.89

Land

Acre

1.00

40.00

40.00

Overhead and Management

Dollar

1,227.90

0.15

184.18

Total Fixed Costs

 

 

 

337.16

Total Budgeted Cost per Acre

 

 

 

4,755.06

Costs Per Bushel

Preharvest Variable Cost per Bushel

 

1.23

 

Harvest and Marketing Cost per Bushel

 

3.19

 

Fixed Costs per Bushel

 

0.34

 

Total Budgeted Cost per Bushel

 

4.76

 

 

1 Planting after July 1 will require twice as many applications.

Zucchini on Plastic Risk Rated Returns Over Total Costs
Net return levels (top row), the chances of obtaining this level or more (middle row) and chances of obtaining this level or less (bottom row)

Optimistic

Expected

Pessimistic

*Returns

$1,605

$1,120

$634

$148

$-359

$-867

$-1,375

Chances

6%

16%

31%

51%

 

 

Chances

 

 

 

49%

30%

16%

7%


ACKNOWLEDGMENTS

The authors would like to express their gratitude to the following people without whose help this publication would not have been possible: Dr. Danny Gay, former UGA Extension plant pathologist; Mr. James M. Barber, Mr. Paul Colditz and Dr. Charles S. Vavrina, former UGA Extension horticulturists; Dr. Wayne J. McLaurin, Extension horticulturist; Mr. Willie O. Chance, Houston County Extension agent and former Extension horticulturist; Mrs. Jan Howell and Mrs. Priscilla Dolney, Agricultural Engineering Department; Mrs. Kay Dunn, Horticulture Department; Mrs. Soccoro Seela, Entomology Department; Mrs. Alice Pitts, Department of Agricultural and Applied Economics; and Mrs. Machelle Clements, Plant Pathology Department.


The University of Georgia and Ft. Valley State University, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service, the University of Georgia College of Agricultural and Environmental Sciences offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability.

An Equal Opportunity Employer/Affirmative Action Organization Committed to a Diverse Work Force

Bulletin 1178, April 2000

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating. Gale A. Buchanan, Dean and Director

 

 

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