Detailed Guide to Bitter Melon Cultivation Techniques: From Sowing to Field Management
I. Timely Sowing
The planting period for autumn-planted bitter melon is generally July-August. The climate during this period is suitable, management is easy, the harvest period is long, and yields are high. The planting period for winter-planted bitter melon is November-December. Because winter temperatures are low, film mulching should be used when planting, with integrated water and fertilizer irrigation under the film. This not only preserves fertilizer and moisture, raises soil temperature, promotes normal growth and development of seedlings, and increases yield, but also saves labor and costs.
II. Land Selection and Preparation
Bitter melon is not strict about soil requirements and can be grown in various soils. However, its root system is relatively developed, with many lateral roots and a wide root mass. It is tolerant of fertilizer but not of poor soil, prefers moisture, and avoids waterlogging. Therefore, it is best to choose land near a water source with deep, loose soil and good drainage. Before planting, the land should be plowed, sun-bleached, composted, and raked fine, so that it reaches a state of depth, looseness, fertility, fineness, and levelness, laying the foundation for high yield.
III. Trellis Building and Vine Training
When the seedlings grow to 5-6 true leaves, bamboo should be inserted promptly to build a trellis. The trellis frame is generally built in a "∏" shape, allowing the branches and vines to distribute evenly over the trellis. When the melon seedlings grow to 50-60 cm, the vines can be trained onto the trellis. Generally, the main vine is trained straight up along the support (rope), and the lateral vines are trained horizontally to the left and right of the support. Vine training is best done on sunny afternoons. Bitter melon has especially strong branching ability and many lateral vines, and some lateral vines do not bear fruit. After the vines are trained onto the trellis, the lateral vines on the lower part of the main vine below 50 cm from the ground, as well as the short, weak, overly dense, aged, and diseased branches and leaves on the upper part that do not bear female flowers, should be removed promptly, so that the population can have good ventilation and light transmission, improve photosynthesis and light energy utilization, reduce nutrient consumption, and favor flowering and fruit setting.
IV. Fertilizer and Water Management
Fertilization and watering for bitter melon should follow integrated water and fertilizer management, and fertilization should follow the principle of "light application at the seedling stage, heavy application at the flowering and fruiting stage." This can both ensure normal growth and development of vines and leaves and meet the nutrient demands of continuous flowering and fruiting. In integrated water and fertilizer management, application should be flexible according to seedling condition and weather changes. Per mu topdressing: before 5 leaves, apply dilute manure water or high-concentration formulated fertilizer water for cucurbits 1-2 times; before flowering and fruiting: apply 15-20 kg of superphosphate once, 12-18 kg of urea, and 8-10 kg of potassium chloride, applying once every 7-10 days in 2-3 split applications; after flowering and fruiting: apply 20-35 kg of urea and 15-20 kg of potassium chloride, applying once every 7-10 days in 4-6 split applications, and spray trace element foliar fertilizer 3-4 times.
Bitter melon prefers moisture and avoids waterlogging. Water use can be determined according to soil moisture conditions. Generally, on sunny days with strong sunlight and high evaporation, moisture disappears quickly, so irrigation should be done promptly to ensure its physiological water requirements and avoid drought wilting, which affects plant growth and development and flowering and fruiting. If heavy rain occurs, drainage should be done promptly to avoid waterlogging in the field, which can cause root rot and disease. Li Wei, Feng Zhaojing