Key Cultivation Techniques for Western Pumpkin in Spring Greenhouses
Pumpkin is a nutritious and healthy vegetable, and the Western pumpkin introduced from abroad is deeply loved by consumers because its fruit has low water content, high solids, high non-reducing sugars and starch, a starch/total sugar ratio exceeding 1, low crude fiber, and high crude protein, giving it excellent taste and mouthfeel, with quality far surpassing domestic local pumpkins...
Pumpkin is a nutritious and healthy vegetable, and the Western pumpkin introduced from abroad is deeply loved by consumers because its fruit has low water content, high solids, high non-reducing sugars and starch, a starch/total sugar ratio exceeding 1, low crude fiber, and high crude protein, giving it excellent taste and mouthfeel, with quality far surpassing domestic local pumpkins. Since 1999, our institute has successively introduced 7 new Western pumpkin varieties from Taiwan Nongyou Seed Company and Thailand Chia Tai Group Seed Company for trial planting, all of which showed characteristics of early maturity, high yield, labor and cost savings, and high economic benefits. In the spring of 2001, in Huangnong Village, Lixin Township, Lishui City, 40 mu of fresh fruit production was organized, with yields per mu all above 1000 kg. Among them, farmer Xu Jinfu's 0.8 mu acceptance results showed an average yield per mu of 1950 kg. In the same year, our institute's greenhouse planting achieved an average yield per mu of 2325 kg. The spring greenhouse cultivation techniques for Western pumpkin are introduced as follows:
1. Varieties
At present, there are many Western pumpkin varieties. According to the comparative trial results of varieties introduced by our institute, "Dongsheng" and "Yipin" selected by Taiwan Nongyou Seed Company; and the "Juhong" series and "Lübao" selected by Thailand Chia Tai Group Jiangsu Chia Tai Seed Co., Ltd. showed relatively good comprehensive traits. The fruit colors of the above varieties are mainly divided into two types: golden red and dark green. Each region can select corresponding varieties according to market demand.
2. Cultivation Techniques
(1) Sowing period: Western pumpkin is suitable for cool climates and is not heat-tolerant (it is prone to viral diseases during high-temperature periods). The full growth period for spring greenhouse planting is generally about 115 days, 65 days from emergence to flowering, and generally 40-50 days from fruit set to harvest. Trial results, combined with local meteorological data, suggest that the optimal sowing period for spring greenhouse planting in the Lishui plain area is from late December to early January.
(2) Seedling raising: ① Preparation of seedling shed and seedbed: Use double-layer greenhouses with an added small arch tunnel for seedling raising. Seedbed preparation: Generally, a 7 m wide greenhouse is divided into four beds, with a seedbed width of 1.2 m and a ditch width of 0.7 m. First, level the ground inside the greenhouse, dig a ground trench 1.2 m wide and 0.30 m deep, lay 15 cm thick rice straw in the trench, cover with soil, then lay heating wires, cover with soil again, and lay plastic film. ② Preparation of nutrient soil: Use 3 parts paddy soil, 1 part burnt mud ash, and an appropriate amount of calcium magnesium phosphate fertilizer, mix thoroughly. The soil moisture content should be about 70%. Testing method: Grab the nutrient soil and squeeze it into a ball; it is suitable if it naturally breaks apart when dropped. Use 10 cm x 10 cm plastic pots filled with nutrient soil, arrange them on the seedbed, then spray with 500x carbendazim and wait for sowing. ③ Seed soaking and germination: Western pumpkin seeds have already been disinfected before sale, so no further disinfection is needed. Soak seeds in clean water for one day, remove, drain the water, wrap in a wet cloth, and place under a constant temperature of 30-32°C for about 2 days to germinate. Seeds can be sown once the radicle emerges. ④ Sowing: On the prepared nutrient pots, use tweezers to make a small hole, place the seed radicle (pointed end) downward into the small hole, one seed per pot. After sowing, cover with about 1 cm of burnt mud ash, spray once with 800x thiophanate-methyl, finally cover the nutrient pots with a layer of plastic film, and then build a small arch tunnel. ⑤ Seedling stage management: Remove the plastic film 3-5 days after sowing. For spring seedling raising, adopt the temperature management principle of higher at the front and lower at the back. From sowing to full emergence, control the greenhouse temperature at around 25°C; if the nighttime temperature is below 15°C, heat in time. From true leaf expansion to the three-leaf stage, control the temperature at around 20°C. Stop heating and harden seedlings 10 days before transplanting (generally no more heating). Generally, no fertilization is needed during the seedling stage. Water management is very important; better dry than wet. Watering should be done on sunny days, preferably around 11 AM; never water during rainy days or when affected by cold air. Whether cloudy, rainy, or sunny, the greenhouse should be opened for ventilation; on rainy days at 1-2 PM; on sunny days generally open at 9 AM and close before 4 PM. During the seedling stage, attention should also be paid to the prevention and control of damping-off and Rhizoctonia rot. Seedling age is 30-35 days.
(3) Transplanting: ① Land preparation: Use greenhouse plus plastic film with trellis-style planting. The greenhouse width is mostly 7-8 m, divided into 4 beds, bed width 1.0 m, ditch width 0.8 m. ② Base fertilizer: Fertilizer is mainly base fertilizer, accounting for about 60%. Open a ditch in the middle of the bed and apply 40 loads of barn manure and 50 kg of ammonium bicarbonate, cover with soil and level, lay 1.2 m wide plastic film and wait for planting. ③ Transplanting: Before transplanting, spray the seedbed with 600x chlorothalonil, and select disease-free strong seedlings for transplanting. Transplanting spacing is about 0.5 m between plants and 0.7 m between rows. Use single-row zigzag transplanting. Generally, plant 700 plants per mu. After transplanting, water to settle the seedlings, and build a small arch tunnel above.
(4) Management after transplanting: ① Topdressing and ventilation for warmth: Apply topdressing once 3-4 days after transplanting and once when vines begin to run. After transplanting, because temperatures are relatively low, the main focus is on heat preservation, but ventilation is still necessary. Specific operation requirements refer to the seedling shed. ② Pruning: Western pumpkin has strong growth vigor, and generally the three-vine pruning method is used, that is, one main vine with two side vines retained, and other excess side vines and sub-vines growing from side vines should be removed in time. ③ Artificial pollination and fruit setting: For early spring cultivation, male flowers are later than female flowers and there are fewer male flowers, so artificial supplementary pollination should be adopted, that is, use a brush to collect some pollen from male flowers and apply it to the stigma of female flowers. Western pumpkin has very good fruit-setting ability, and each node can produce a female flower. Generally, all female flowers within 70 cm from the base of the plant should be removed, with one fruit retained per side vine and two fruits retained on the main vine. Letting fruits set at positions beyond 70 cm is conducive to the formation of large fruits. ④ Heavy application of fruit swelling fertilizer: When the fruit develops to the size of an egg, dig a pit 25 cm from the base of the plant and apply 20 kg/mu of compound fertilizer.
(5) Harvesting: About 1 month after pollination and fruit setting, when the fruit color changes from light yellow to orange-red, it can be harvested for market. At this time, the market price is relatively good, but the quality is not the best. Harvesting should wait until the fruit color is darker, that is, mature fruit (about 50 days). Harvesting should generally be done on a sunny morning, leaving about 2 cm of the fruit stalk.