Spraying procymidone 1 time before and after pollination.

After the results, spraying calcium-boron foliar fertilizer 1 time can improve the toughness of pericarp.

After entering the fruit expansion period, spraying water-soluble fertilizer with high phosphorus and high potassium twice can make the peel develop better and improve the sweetness of pulp.

Irrigation with melon water and 10- 15 kg high-potassium compound fertilizer per mu have obvious effects on preventing melon cracking.

First, the watermelon anti-crack formula

1, pharmaceutical formula

(1) Spray procymidone 1 time on watermelon before and after pollination.

(2) Spraying 1 times of calcium boron foliar fertilizer before and after fruiting. Spraying in the early stage can improve the fruit setting rate of watermelon, and spraying in the later stage can improve the peel toughness, thus preventing fruit cracking.

(3) After entering the fruit expansion period, spraying high-phosphorus and potassium water-soluble fertilizers on the leaves twice in a row can make the peel develop better and supplement phosphorus and potassium elements for watermelon. In addition, it can make the roots grow healthily and improve the sweetness of watermelon.

(4) Irrigation of melon water combined with application of high-potassium compound fertilizer 10- 15kg/ mu has obvious effects on preventing melon cracking and increasing sugar.

(5) In the greenhouse with the second crop of melons, after picking the first crop of melons, ternary compound fertilizer 10- 15 kg (15- 10-20) can be applied per mu, which can obviously improve the air permeability of the soil and increase the yield of the second crop of melons.

2. Other methods

(1) Generally speaking, 1- 1.5 cm is suitable for planting watermelon varieties with appropriate peel thickness.

(2) Planting watermelon varieties with strong crack resistance, such as Xin Jing, Hao Yunjing Xin, Xi Nong Da Ba Wang, Yongfeng 1.

(3) Spread straw on the edge of the border, leave enough leaves before and after fruit setting, and cover with leaves to prevent watermelon from being exposed to direct sunlight. In order to prevent fruit cracking caused by sudden rainstorm after continuous drought, a large amount of nutrients can be properly controlled to flow into the fruit.

(4) For varieties with small fruit type and easy to crack, 65,438+0-2 vines can be reserved appropriately to reduce the transport of nutrients only into the fruit and prevent the melon from cracking due to the rapid expansion of the single melon.

(5) Appropriate furrow irrigation, judging the degree of water shortage according to the wilting degree of leaves, and combining with the local weather forecast, furrow irrigation should be carried out for 3-4 days on the premise of ensuring no rainstorm in the near future, and the irrigation should be uniform.

(6) On the basis of watering watermelons with sole water, properly water watermelons before sitting to prevent the soil from being too dry during the melon swelling period. Water should be balanced during the expansion period to avoid sudden increase in water volume in the short term, and stop watering after picking for 7 days.

(7) Select two small bamboo sticks with the width of 1/3 and the diameter of the stem and vine, and insert them vertically into the melon and vine; Insert the pin vertically into the fruit handle instead of the bamboo stick; Twisting vines or fruit stalks by hand can reduce the probability of fruit cracking.

(8) For varieties that are prone to fruit cracking, you should choose to pick melons in the afternoon, and minimize vibration and knocking when picking to avoid artificial damage to watermelons.

(9) Strengthen site management, collect fresh air in time, reasonably control the temperature difference in the shed to avoid temperature fluctuation. Spraying foliar fertilizer in time and applying trace element fertilizer can improve the crack resistance of watermelon.

(10) If cracked melons have appeared in the field, you can squeeze the vines of Wanggua in front of 3-4 leaves of the melons, or cut a short section along the vines to disperse nutrients and transport them to young melons. If the functional leaves have strong growth potential, some leaves can be removed to reduce the accumulation of nutrients and prevent young melons from cracking due to short-term growth.

Second, the causes of watermelon cracking

1. Some varieties have high melon cracking rate, and some watermelon varieties with thin skin, crisp quality or small fruit are easy to crack melon.

2. Before sitting on the melon, the soil was in a state of drought for a long time, and a large amount of water (or heavy rain) suddenly caused the melon to crack during the melon expansion period.

3. In the early stage of fruit development, the fruit develops slowly at low temperature, and expands rapidly after the temperature rises, resulting in melon cracking.

4. Partial or excessive application of nitrogen fertilizer during the expansion period of melon, the growth of melon skin is slower than that of melon meat, which leads to melon cracking.

5. Some inferior fertilizers contain more plant growth regulators (such as sodium nitrophenolate), and long-term accumulation in the field will lead to watermelon cracking.