How to prevent seedlings from being killed by heat in high temperature weather?

Shade and cool to prevent seedlings from burning. The weather is changeable in spring, and the temperature changes greatly. Pay more attention to weather forecast. When the average temperature of the day reaches above 20℃ and the time for uncovering the film is less than 20℃, the plastic film must be covered with straw. Keep the temperature in the film below 35℃ to prevent high temperature from burning seedlings. Uncover the film in time to prevent green seedlings and dead seedlings. 5-7 days after sowing, when the first complete leaf is unfolded, it is beneficial to cultivate strong seedlings, enhance the stress resistance of seedlings, and reduce or prevent green seedlings and dead seedlings. The time to uncover the film should be determined according to the weather conditions, and the film should be uncovered at night on a sunny day. Be sure to water it once in time after uncovering the film. It is best to water at the same time, and uncover the film before 10: 00 in cloudy morning, which can effectively prevent the occurrence of green seedlings and dead seedlings.

Control pests and diseases. It is mainly used to control underground pests and early blight. Before sowing, phoxim EC 1000 times per mu, about 250kg evenly. When the temperature difference is large after the film is uncovered, spraying 2000 times of diuron solution in advance can effectively prevent rice sheath blight. At high temperature, the filling duration of rice is obviously shortened, that is, the so-called high temperature ripening, which leads to poor grain plumpness and rice quality and increased yield. From booting stage to heading and flowering stage, 5-8 cm water layer should be left in the field to reduce the ear layer temperature and increase the humidity in the field. If conditions permit, the microclimate of the population can be adjusted by daily irrigation and night row. Irrigation should be carried out as soon as possible in fields that are short of water and drought to prevent drought and high temperature and heat damage from overlapping.

In order to maintain and promote root activity, rice should not be damaged by waterlogging, but should grow and develop normally. Don't cut off water prematurely in the later growth period, keep the field moist, and prevent premature aging and yield reduction. In the middle and late stage of rice growth, the temperature is high and the air humidity is high, and the leaf area of the population reaches a large value. The microclimate in the field is very suitable for the occurrence of various diseases and insect pests. Therefore, it is necessary to strengthen the prevention and control of pests and diseases, especially the drug control of rice planthopper and rice leaf roller, while cooling rice fields. Single application of chemical fertilizer, topdressing by stages, combined application of phosphorus, potassium and zinc fertilizers, application of full panicle fertilizer in the middle growth stage and application of nitrogen fertilizer in the later stage can maintain the stable growth of rice and enhance the high temperature resistance of plants to some extent.