To modernize the traditional cultivation of bitter gourds, it's essential to adopt more advanced techniques, especially for winter greenhouse production. Unlike high-temperature methods, which can be challenging in colder seasons, grafting has become a popular solution in recent years. By grafting bitter gourd onto a compatible rootstock, such as black-seeded pumpkin, farmers have improved disease resistance, ensured safer winter growth, and achieved earlier harvests. This technique allows yields of up to 3,000 kilograms per mu, significantly boosting economic returns. Below are the detailed cultivation techniques.
The Blue Mountain Bitter Gourd variety is commonly selected, with black-seeded pumpkin used as the rootstock due to its strong cold tolerance and high yield potential. Seed treatment begins in early October. Bitter gourd seeds are soaked in 50–55°C water for 15–20 minutes, then left to soak at room temperature for 12 hours. Germination occurs at 30–35°C. Pumpkin seeds are soaked for 6–8 hours and germinate at 25–30°C. The pumpkin is sown 1–2 days after the bitter gourd, and once the pumpkin has sprouted, grafting is performed when the true leaves appear.
Grafting is done using the planting method, and after grafting, the small arch cover is immediately closed to maintain humidity above 95% and temperatures between 30–32°C during the day and 20°C at night. For the first three days, shading is necessary, except on cloudy days. From day 3 to 6, partial shading is applied from 10:00 AM to 3:00 PM, while allowing light at other times. After about 10 days, the grafts typically survive, and the rootstock is cut off. Temperatures are then adjusted to 25°C during the day and 15°C at night. Before planting, the night temperature is gradually reduced to around 10°C for hardening off. Planting usually takes place in early December.
Soil preparation involves deep plowing and adding 10,000 kg of organic fertilizer per acre, along with 100–150 kg of cake fertilizer and 25 kg of diammonium phosphate. The planting density is 80 cm between rows and 30 cm within rows, totaling about 2,800 plants per acre. Mulch is used to cover the soil.
Temperature management is crucial for winter and spring crops. After planting, the greenhouse is kept closed to raise temperatures and promote seedling growth. Daytime temperatures should reach 30–35°C, and nighttime temperatures should not drop below 12–15°C. Once seedlings are established, temperatures are gradually lowered to normal levels—20–25°C during the day and 15°C at night. These principles are similar to those used for cucumbers.
For watering and fertilization, after the seedlings are stable, water is applied along the furrows. During winter and spring, one or two irrigation sessions are carried out. After seedlings establish, a thorough watering is done, followed by a period of drying to encourage root development. Fertilization is controlled initially, then increased gradually. The first fertilizer application occurs after male flowers appear, and the second after fruit setting. Fertilizer use is approximately 15–20 kg per acre. In spring, when the weather warms, 2–3 flushes of diluted human excrement (1,000–1,500 kg per acre) are applied.
Vine training begins when vines reach about 30 cm, using trellises for support. Vines are trained to grow upward in an S-shape. Pruning is essential—side shoots below 50 cm from the ground are removed, and dense or excessive lateral branches are trimmed to ensure the main vine grows strong. When the main vine reaches the top of the trellis, it is pinched back. 3–5 side vines are left in the lower part, with 1–2 fruits per side.
Pollination is done manually by collecting male flowers the day before they open, drying them at 25°C, and using them to pollinate female flowers the next morning. One male flower can pollinate 3 female flowers without damaging the stigma. Harvesting occurs 12–15 days after flowering, when the fruit starts to shine and the skin turns bright green.
Pest and disease control follows the principle of prevention, integrated management, accurate diagnosis, and timely treatment. Common diseases include Fusarium wilt, bacterial blight, and downy mildew, while pests like fruit flies and aphids are prevalent. Prevention measures include crop rotation, using resistant varieties, and applying bio-protectants like "Shiloji" seed coating. Fungicides like "Cola-Hui Shi" and bactericides like "Shigao" are used for disease control. For fruit flies, yellow sticky traps and insecticides like "Kung Fu" are effective. Thrips and leaf miners are managed with products like "Aktai" and "Coulomb."
Overall, these techniques not only improve yield and quality but also enhance sustainability and profitability in bitter gourd cultivation.
Frozen Handcrafted Fish Balls,Instant Fish Ball,Fish Ball Snack,Frozen Fish Ball Snack
Zhejiang Industrial Group Co., Ltd. , https://www.xingyeseafood.com