PESTS & DISEASE

Squash are susceptible to several pests and diseases. The most prevalent diseases are wilt, mildew and rot. Good crop rotation and weeding is important to mitigate disease. Planting early, before virus-carrying insects arrive, or later in the season also reduces diseases and crop defects such as fruit rot and streaking.

Pests include aphids, pickleworms, cucumber beetles, squash bugs, and squash vine borers. Soil-based pests, such as beetle grubs, wireworms, and other larvae, can damage young plants by depriving the soil of nutrients and feeding on the roots. Squash are most vulnerable to pests as seedlings and during flowering, and most susceptible to disease after bearing fruit.

Squash plants produce male and female flowers, which must be pollinated to bear fruit. Pest control should avoid destroying good insects, such as bees, that are needed for pollination. In addition, squash flowers are less attractive sources of pollen and nectar to bees than other flowers. Therefore, avoid planting competing flowering plants in the vicinity of squash.

References: Alabama Cooperative Extension, Clemson University Cooperative Extension Service, University of Georgia Cooperative Extension.

CULTIVATION, STORAGE & PACKAGING

Preharvest:
All squash need warm weather to grow and should not be planted until the risk of frost has passed and ground temperatures are at least 60°F at a depth of 4 inches, preferably 70 to 90°F. Squash is best planted from seed (transplants are very fragile) and prefer well-drained, sandy and loamy soils, rich in organic matter with a pH level of 6.0 to 6.5. Crops should be rotated on an annual basis.

Winter squash takes 80 to 120 days to mature. Two pounds of seed will yield an acre of vining winter squash spaced 2 to 5 feet between plants and 5 to 8 feet between rows. Summer squash yields fruit in 40 to 50 days, can be planted every two weeks for continuous production, and up to 60 days before the last frost. Four pounds of seed will yield one acre of summer squash at a spacing of 12 to 18 inches between plants, and 3 to 4 feet between rows. All squash require adequate water and good drainage. A barrier used to keep fruit off of the earth can prevent rot and pest damage.

Postharvest:
At maturity, winter squash (and pumpkins) should be cut from the vine and allowed to cure for 2 weeks at warmer temperatures (at least 70°F). The curing process will reduce weight by about 10 percent due to water loss, but healthy fruit will heal and the skin will harden. Exposure to cold at this stage will damage squash and reduce shelf life. Windrowing crops can reduce risk of rot or damage from pests and diseases. Caution should be used to prevent rough handling or pressure from packaging, as this will cause bruising. A healthy butternut squash—not exposed to chilling injury— can be stored for 3 to 4 months.

Summer squash should be harvested before it goes to full maturity and develops hard seeds. It can be harvested several times per week from staggered plantings, and should be delivered to the fresh market immediately. If necessary, summer squash can last 3 to 4 days at 45 to 50°F and 85 to 90% humidity, but will quickly breakdown afterward.

References: Clemson University Cooperative Extension Service, Michigan State University Extension, Texas A&M Agrilife Extension, University of Georgia Cooperative Extension, Virginia Cooperative Extension.

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