How to cultivate plastic-mulched watermelon for high yield? Detailed explanation of key planting techniques

Most watermelons on the market now are plastic-mulched watermelons, so how do plastic-mulched watermelons prevent premature aging? What should be noted when fertilizing?

High-yield cultivation techniques for plastic-mulched watermelon

1. Select good varieties.

According to market demand and the characteristics of our county's soil and climate, choose varieties with high yield, good quality and strong resistance, such as Xinong No. 9, Zhonghua Guobao, Kenong No. 9, Kangbing Jianong, Shinong Bawang, etc.

2. Land preparation and fertilization.

Choose fields or plots with fertile soil, deep soil layers, loose texture, convenient drainage and irrigation, and where cucurbit crops have not been previously planted. When preparing the land, deep plowing is required, and the soil must be plowed evenly and harrowed fine. During plowing, apply 2000-2500 kg of farmyard manure, 50 kg of superphosphate, and 30 kg of compound fertilizer as base fertilizer.

3. Sowing and rational close planting

1. Sowing. The sowing method for watermelon generally uses direct sowing of dry seeds.

2. Rational close planting and film covering. Ridge cultivation is required, with a ridge width of 200 cm and a ditch width of 30-40 cm. Plant 1 row per ridge, with a row spacing of 240 cm and a plant spacing of 40-60 cm. Plant 400-600 plants per mu. After planting, cover with film and ensure it is pulled tight and pressed firmly on all sides to prevent air leakage and being blown away by wind.

4. Field management

1. Breaking the film. After watermelon seedlings emerge, the film must be broken in time to prevent seedling scorching. When breaking the film, the opening should not be too large. Carefully pull out the seedlings and seal the opening well with fine soil.

2. Watering and topdressing. Watermelon grows quickly and has large fruits, so it has high fertilizer and water requirements. Throughout the entire growth period, keep the soil alternately dry and moist. Generally, topdress 3 times. At the first topdressing, when the seedlings have 3-4 leaves, apply 5-10 kg of urea and 10 kg of superphosphate per mu, diluted with water; at the second, when the vines are 15-20 cm long, apply 20-25 kg of ternary compound fertilizer (15:15:15) per mu to promote stem and vine elongation; at the third, when young fruits grow to the size of a duck egg, apply 30-40 kg of ternary compound fertilizer per mu or 10-15 kg of urea, 40 kg of superphosphate, and 20-30 kg of potassium sulfate.

3. Pruning and fruit setting. When the main vine grows to more than 30 cm, select 2-3 strong side vines at the base and remove all other side vines; keep one normal fruit per branch. When the fruits have basically reached their final size, turn and expose them to the sun two to three times so that the fruit surface receives light evenly, the color is uniform, and the fruit shape is regular, improving yield and quality.

What should be noted when fertilizing plastic-mulched watermelon?

First, do not apply a large amount of nitrogen fertilizer alone. When fertilizing watermelon, special attention should be paid to the combination of nitrogen, phosphorus, and potassium. If a large amount of nitrogen fertilizer is applied alone, the plants are very prone to excessive vegetative growth, which is unfavorable for flowering, fruit setting, and fruit development; second, do not apply chlorine-containing fertilizers. Watermelon is a chlorine-sensitive crop. Applying chlorine-containing fertilizers will affect sugar accumulation and make the fruit taste bland; third, do not fertilize on the surface soil layer. Topdressing watermelon should be done deeply, and soil should be covered promptly after application. This is especially true for nitrogen fertilizer. If applied on the surface, nitrogen is likely to volatilize and produce ammonia gas, harming the leaves and at the same time reducing fertilizer efficiency; fourth, do not fertilize on cloudy and rainy days. On cloudy and rainy days, air humidity is high and soil moisture content is high. Fertilizing at this time not only makes nutrients easy to lose, but also easily causes excessive vegetative growth of watermelon; fifth, do not place the fertilization site too close to the roots. For watermelon, the fertilization site is generally required to be about 10 cm from the main root. If it is too close, it is easy to burn the roots; sixth, do not topdress during drought. When the weather is dry and soil moisture content is low, applying chemical fertilizer at this time will cause the cytoplasmic solution of root cells to seep outward, leading to physiological water loss and death of the plants.