Back to top

Chapter 18: Cucurbits: Cucumber, Melon, Pumpkin, Squash, and Watermelon

18.1 Varieties

Tables of Disease Resistant Varieties for pickling cucumber, slicing cucumber, muskmelons, pumpkin, specialty melons, watermelon, yellow summer squash, and zucchini squash

18.2 Planting Methods

Cucumber and Melon

Cucumbers for early harvest are started as transplants while later plantings are direct seeded in pots or cell-type containers. Melons do not grow well and may suffer chilling damage when air or soil temperatures are below 50°F. Typically in upstate New York, transplants are set in the field between June 1 and 10 for harvest in mid-August to early September. In warmer regions of the state and when row covers are used, the transplanting date may be two to four weeks earlier.

Wind, combined with low air temperatures (32°to 50°F), can severely damage vine crops, retarding maturity and reducing yields. Soil temperatures below 50°F also slow growth and impair water uptake by roots. For these reasons, plastic mulch and row covers are often used, especially for early-season production of melons. Black, clear, or infrared-transmitting (IRT) mulches can be used. Remember that row covers enhance daytime temperatures and growth but provide at best only a few degrees of frost protection at night. Compared to other crops, melons have had the most consistent, positive response to plastic or spunbonded fabric row covers for increased early-season production. The covers are applied at transplanting and removed at flowering to allow bee pollination.

Another means of wind protection is to plant rye strips between every second or third row of the crop. Site selection is also important for wind protection and optimal soil temperature. Light textured soils that warm quickly in the spring are preferable to heavier soils that remain cool. Good drainage, fertility, and high organic matter are other soil features that will improve the potential for good yield and quality.

Summer Squash

Container grown plants may be used for the early crop and are planted into plastic mulch. Early plantings should be protected from cold and winds with row covers or hot caps and windbreaks. See discussion under Cucumber and melon for details.

Watermelon

Watermelons should not be transplanted to the field until daily mean temperatures are above 55°to 60°F. Many varieties require over 100 days to mature, so season extension techniques are important.

Transplants should be produced in a greenhouse with temperatures between 75° and 85°F. Each transplant should have at least a two inch by two inch space. Seedless watermelon seed should be planted with the point up to facilitate growth. Overseeding may be appropriate if the germination test is low. Transplants from seed typically take about three weeks to grow in the greenhouse.

Table 18.2.1 Recommended spacing

Crop Row In-row
Cucumber    
Slicers 5-6' 10-15"
Pickles 2-5' 3-8"
Melon 5-6' 2-3'
Pumpkin    
Bush 4-6' 18-24"
Vining 6-8' 24-36"
Squash    
Bush 4-6' 18-24"
Vining 6-8' 24-36"
Watermelon 6-8' 3-4'
Seedless Watermelon 6-8' 3-4'

18.3 Fertility

Use lime to maintain a pH of 6.0 to 6.5. See Table18.3.1 and Table 18.3.2 for the recommended rates of nitrogen, phosphorus, and potassium.

Table 18.3.1 Recommended nutrients based on soil tests for seeds and transplants in bare ground.

If the pH is between 5.5 and 6.0, apply 5 pounds of magnesium per acre in the fertilizer band. If the pH is below 5.5, apply 10 pounds of magnesium

N pounds/acre P2O5 pounds/acre   K2O pounds/acre Comments
  Soil Phosphorus Level   Soil Potassium Level  
  low med. high   low med. high  
100-120 120 80 40   120 80 40 Total recommended.
                 
40 80 40 0   80 40 0 Broadcast and disk-in.
30-40 40 40 40   40 40 40 Band place witd planter or sidedress one week after transplanting.
30-401 0 0 0   0 0 0 Sidedress when plants begin to run.
1: If nitrogen deficiency is likely because of leaching or waterlogged soil, increase nitrogen sidedressings by 30 pounds.

 

Table 18.3.2 Recommended nutrients based on soil tests for transplants in plastic mulch with fertigation.

If plastic mulch is used without fertigation, broadcast and incorporate all fertilizer before laying plastic mulch.

N pounds/acre P2O5 pounds/acre   K2O pounds/acre Comments
  Soil Phosphorus Level   Soil Potassium Level  
  low med. high   low med. high  
100-120 120 80 40   120 80 40 Total recommended.
                 
40 80 40 0   40 40 0 Broadcast and disk-in.
15-20 20 20 20   20 20 20 Fertigate 1 week after planting.
15-20 20 20 20   20 20 20 Fertigate 3 weeks after planting.
15-20 20 0 0   20 20 20 Fertigate at fruit set.1
15-20 20 0 0   20 0 0 Fertigate 2 weeks before harvest.

18.4 Harvesting

Cucumber

Both fresh-market and pickling cucumbers are picked by hand four to five days apart depending on temperature and moisture. A field can generally be picked ten to 15 times.

Populations of 40,000 plants or more per acre concentrate yields sufficiently for mechanical harvesting of pickles. Success of machine harvest depends on establishing a uniform stand, harvesting when ten percent of the fruit are two inches in diameter or larger, and moving the fruit quickly from the field to the processing plant.

Melon

Melons should be harvested at "full slip" when the fruit slips easily from the vine. The ground color under the net starts to turn yellow at full slip, and the soluble solids (determined with a handheld refractometer) are greater than eight percent. Eastern melons are bruised easily during harvest, and this can shorten shelf life.

The winter or honeydew-type melons do not slip when ripe. Harvest is based on experienced observations of the change in color of the ground spot and amount of softening of the blossom end at optimal ripeness.

Eating maturity of melons occurs one to three days after harvest, and the best flavor is attained if melons are held near 70°F for this final ripening, then chilled for serving. If melons are to be stored longer, they should be held at 50° to 55°F and 85 to 90 percent relative humidity. Eastern melons will seldom maintain quality when stored longer than one week. Winter melons such as honeydew can be stored for two to four weeks, at 45° to 50°F and 90 percent relative humidity. All melons are subject to chilling damage if held at temperatures lower than those indicated.

Pumpkin and Squash

In fields where pumpkins are turning orange, it is worthwhile to cut and windrow and bring them in out of the field. This will allow the handles to cure and protect fruit from insects, vertebrate pests, and diseases. For best color development, day temperatures in the 70's to 80°F and night temperatures no lower than 65°F is best. If you need to leave pumpkins in the field for pick-your-own, cut handles from the vine to save them from advancing disease.

Store only mature fruit that is free of disease. Harvest and place the fruit under shelter before it can be damaged by chilling or freezing. Fruits subjected to temperatures below 50°F for two weeks or more may break down and rot.

Desirable storage conditions are 50° to 55°F at a relative humidity of 50 to 75 percent with good air circulation to maintain uniform temperature and humidity throughout the storage period. During a long storage period, fruit will lose less moisture if humidity is maintained near 70 to 75 percent.
Acorn-type squash can be stored ten to 15 weeks after which quality deteriorates rapidly. Other squash may be kept up to six months under good conditions.

Watermelon

Watermelons should be harvested when the tendril on the vine at the juncture between the fruit and stem turns brown; the ground color under the melon turns yellow; and "thumping" produces a dull, hollow sound. In some varieties, a slight bumpy surface develops when the watermelon is ready to be harvested.

Watermelons are best stored at 55°F and 90 percent relative humidity. If handled gently, they should store two to three weeks under these conditions. Some seedless varieties may have a slightly longer storage life. Holding at temperatures less than 50°F causes the red color to fade quickly to pink.

Table 18.4.1 Nonpathogenic disorders

Disorder Affected Crop(s) Cause/Guideline
Oedema Pumpkin/winter squash Provide a consistent level of moisture to help reduce this moisture-stress related problem.
Poor fruit set All Related to poor pollination. Also, weather dependent. Provide hives at a rate of 1 hive per 2 acres.
No female flowers Cucumber/squash Variety or weather related.
Fruit cracking Melon Due to excessive rainfall or irrigation.
Misshapen fruit Cucumber Poor pollination or water management during fruit enlargement.
Fruit hollows Cucumber/watermelon Water management during fruit enlargement is essential.

18.5 Disease Management

18.5.1 Alternaria Leaf Blight
18.5.2 Angular Leaf Spot and Bacterial Leaf Spot
18.5.3 Anthracnose
18.5.4 Bacterial Wilt
18.5.5 Belly Rot
18.5.6 Choanephora Blossom Blight and Fruit Rot
18.5.7 Cottony Leak
18.5.8 Virus Diseases of Cucurbits
18.5.9 Damping-Off and Root Rot
18.5.10 Downy Mildew
18.5.11 Fusarium Wilt, Fusarium Crown and Foot Rot, and Verticillium Wilt
18.5.12 Gummy Stem Blight and Black Rot
18.5.13 Nematodes
18.5.14 Phytophthora Blight
18.5.15 Plectosporium Blight
18.5.16 Powdery Mildew
18.5.17 Scab
18.5.18 Sclerotinia White Mold
18.5.19 Seedborne Diseases and Seed Decay
18.5.20 Septoria Leaf Spot
18.5.21 Storage Rots
18.5.22 Ulocladium Leaf Spot

 

Table 18.5.1 Importance of each disease for a particular cucurbit

Disease Cucumber Melon Pumpkin Summer squash Winter squash Watermelon
Angular leaf spot L, R L M L M L
Bacterial leaf spot L - M L M -
Bacterial wilt H M M, V M L NA
Alternaria leaf blight L M L L L M
Anthracnose L, R M L L L M
Choanephora - - L H L -
Fusarium crown and fruit rot L L H M M L
Fusarium wilt - H, R - - - -
Damping-off M L L L L L
Downy mildew H, R H, R H H H L
Gummy stem (Black rot) L M M L M M
Phytophthora blight H L H H H H
Powdery mildew M, R M, R H, R H, R M,R M
Plectosporium blight - - M M - -
Scab L, R L L L L L
Septoria leaf spot - L L - L -
Sudden wilt - H - - - -
Ulocladium Leaf Spot M, R - - - - -
Viruses L, R H M H, R M L

R = resistant varieties exist exhibit reduced susceptibility which varies with the type and number of genes); Pathogens have evolved (ie. DM in cucumber) which can overcome resistance genes, which renders resistant varieties less effective at suppressing disease development; ; L = low (occurs, but not in damaging levels); M = moderate; H = high level of susceptibilty to pest; V = variable susceptibility among varieties; When disease tolerance for a particular variety is unknown, line is left blank.

18.6 Insect Management

18.6.1 Aphids
18.6.2 Striped Cucumber Beetle and Spotted Cucumber Beetle
18.6.3 Seedcorn Maggot
18.6.4 Squash Bug
18.6.5 Squash Vine Borer
18.6.6 Spider Mites
18.6.7 Springtails

 

18.7 Weed Management

Websites

Maintained by Abby Seaman, New York State IPM Program. Last modified 2019.