PUMPKIN PRODUCTION
Site Selection
Pumpkins should be grown on soils that have good water infiltrationrates and good water-holding capacity. If pumpkins aregoing to be grown on sandy soils, access to irrigation is important
to obtain optimum plant growth, uniform fruit set, anddevelopment. Soil pH should be in the 5.8–6.6 range with minimumsoil compaction. Pumpkins are very sensitive to coldtemperatures (below 50°F) and plants and fruit will exhibitinjury from even a slight frost. The best average temperaturerange for pumpkin production during the growing season isbetween 65 and 95°F; temperatures above 95°F or below 50°Fslow growth and maturity of the crop. Pumpkins require aconstant supply of available moisture during the growing season.Water deficiency or stress, especially during the blossom
and fruit set periods, may cause blossoms and fruits to drop,resulting in reduced yields and smaller-sized fruits.
Planting and Fertilization
Pumpkins are generally seeded in the field during the firstcouple weeks of July. Since they are a warm-season crop, theyshould not be seeded until the soil temperature reaches 60°Fthree inches beneath the soil surface. Pumpkins seeded in coolsoils may suffer from seed corn maggot injury. No-till pumpkinscan be seeded with a no-till planter or transplanted in aminimally prepared bed with only secondary tillage such as ans-tine cultivator or in a previously tilled field without any tillagetreatment, saving both time and labor. Because pumpkinseed germinates and develops optimally when soil temperaturesare at least 60°F, early pumpkin production using no-tillis difficult because of the cold soil temperatures. However, bymid- to late June, soil temperatures in a no-till field are warmenough for rapid pumpkin seed germination and growth. Inaddition, no-till reduces soil moisture loss early in the seasonand has more water available for pumpkin plant growth laterin the season. If considering no-till pumpkin production, thefollowing factors must be considered to be successful: variety,planting date, soil fertility practices, insect pressure and control,planting equipment, cover crop type and stand, and weedspecies and population distribution in the field.Because pumpkins are a warm-season crop, they can alsobe grown as transplants on raised beds with black or silverplastic mulch and drip irrigation for optimum plant growthand yields. The use of plasticulture in the production ofpumpkins will:
1) Increase soil temperature 8–12 degrees warmer than
bare soil
2) Maintain soil water availability
3) Reduce weeds
4) Improve soil tilth
5) Reduce fertilizer and pesticide leaching under the bedUse of drip irrigation also allows for fertilizer application(injection) throughout the growing season. Growing pumpkinsusing plasticulture will double the yield of pumpkinsgrown on bare soil or in no-till production.
Fertilizer recommendations are based on soil test results,and soil tests should be taken every year. In absence ofsoil test results, recommended N-P-K application rates are80-150-150 broadcast or 40-75-75 banded at planting. Soilcalcium levels should be checked; if soils are testing low orlow to medium in calcium and have not received any calcitic(calcium-based) lime applications, apply gypsum to the fieldin bands where rows will be planted prior to planting pumpkins.Gypsum will supply calcium to the soil without changingsoil pH.
Seeding and Spacing
Seed in the field between June 15 and July 5 in coolerareas, and between June 15 and July 15 in warmer, southernareas.
Base plant spacing on vine habit and average fruit size ofthe variety. Note. Fruit size may be decreased at closerspacings.
Large vine with fruit over 30 pounds: Rows 10 to 12 feet
apart with 5 to 6 feet between plants in the row.
Large vine with fruit 12 to 25 pounds: Rows 7.5 to 9 feet
apart with 4 feet between plants in the row.
Large/medium vine with fruit 8 to 15 pounds: Rows 6 to
7.5 feet apart with 3 to 4 feet between plants in the row.
Small vine/bush with fruit less than 8 pounds: Rows 5 to
6 feet apart with 2 feet between plants in the row.
Planting depth is 1 -2 inches.
Porcelain Doll Notes
Porcelain Doll is a full vine variety requiring 25 to 30 square feet of planting space. It needs 120 days to mature, and should be planted as early in the season as possible.
Pollination
Honey bees are important for proper, complete pollinationand fruit set. One hive per acre is the recommended populationof honey bees for maximum fruit production. Populationsof pollinating insects may be adversely affected byinsecticides applied to flowers or weeds in bloom.
Pest Control
Control of weeds can be achieved with a good crop rotationsystem and herbicides. Pumpkins can be competitive withweeds once they develop their mature canopy, if they areplanted at high plant populations, or if they are planted onplastic mulch. There are several pre-transplant and post-emergenceherbicides labeled for pumpkins, depending onspecific weed problems requiring control and stage of pumpkingrowth. In addition, under mild infestation levels, earlycultivation (if possible prior to vine running) can minimizeweed problems.Insects can be a major problem in pumpkin production.Cucumber beetles, aphids, squash vine borer, seed corn maggot,
squash bug, and spider mites have the potential to causea reduction or loss of the marketable crop in any given year.Monitoring insect populations through scouting will helpgrowers determine when they should start and stop sprayingpumpkins and the intervals between applications.Several diseases of pumpkin can cause a reduction in cropyields, especially bacterial wilt, viruses (powdery mildew,downy mildew), and scab. Optimum crop yields and fruit colormay only be possible if a scheduled fungicide program is usedto prevent leaf loss from mildews. Crop rotation, good soil and
air drainage, and use of resistant varieties (where possible) canhelp reduce problems from these diseases in the field.Many of the pesticides required for pumpkin productionare restricted-use pesticides and require a pesticide license topurchase. Pesticide applicator tests are usually administeredat county extension offices, so you should contact your localoffice for dates and times of these examinations. When usingany pesticides in your enterprise, remember to follow all labelrecommendations regarding application rates and personalprotection equipment (PPE) requirements. Also rememberthat any Worker Protection Standards (WPS) apply to theowner as well as to employees.
Harvest and Storage
Pumpkins are hand-harvested at their mature stage, color(orange or white), and size. Because fruit are pollinated atdifferent times, multiple harvests over the field are quite common.Grading pumpkins for size, maturity, and pest damagebefore marketing is necessary to ensure a high-quality product.Maintaining pumpkin fruit in a dry, cool environment(a barn, for example) will help extend the shelf life of the cropand help maintain a non-shrunken fruit appearance.Placing pumpkins in a well-ventilated storage area, preferablyprotected from rain, maintains healthy fruit for processing
(pumpkin pie mix) or late sales of Jack-O-Lantern types.Pumpkins will retain good quality for approximately 2–3months if stored at the appropriate relative humidity (50–70percent) and temperature (50–55°F).