Key points of emergency management of cotton after being flooded

The summer rainfall is heavy, the rainfall is concentrated, and the rainfall time is long. At this time, cotton is in the most critical period of transformation from vegetative growth to reproductive growth, and it is also the most critical period for cotton bud and boll increase. In order to reduce the loss of cotton production and strive for a bumper cotton harvest, the following emergency management measures must be taken immediately after cotton is flooded.

First, dig three trenches deeply. Quickly remove open water, reduce stagnant water in cotton fields, and dig three ditches deeply, not only to ensure that open water can be drained, but also to reduce groundwater level and soil water content to remove dark stains in cotton fields and dredge the trenches in time; waist trench is strictly required according to the standard of 60 cm wide, 30 cm wide and 50 cm deep, and the waist groove must be unblocked and deep, so that all water can flow into the branch ditch. Branch ditches should remove drainage obstacles in time to ensure unimpeded drainage.

Second, look at the fields and fertilize. Cotton is generally in two states: one is waterlogged water control type, the other is multi-Rain Water hairstyle. The state of being flooded must be strictly distinguished and remedial measures should be taken.

⑴ waterlogging water control type. Mainly refers to three types of seedling cotton fields and cotton fields that have been flooded for more than 36 hours, where stiff seedlings do not form water control, and quick-acting nitrogen fertilizer should be applied to these cotton fields, applying 10 kg urea or 15 kg diammonium phosphate per mu. ⑵ has more than Rain Water hairstyle. As cotton is often in a critical period of transformation from vegetative growth to reproductive growth during the period of flooding, long-term heavy rain suppresses the reproductive growth of cotton, resulting in excessive vegetative growth of cotton, excessive growth of cotton plants and serious shedding of buds and bolls. For watery cotton, it is necessary to reduce the amount of fertilizer application, especially the amount of available nitrogen fertilizer. Flower and boll fertilizer must be applied when cotton growth weakens and each plant sits on 1-2 big peaches. Due to the serious loss of nitrogen, potash and micro-fertilizers in long-term flooded cotton fields, peach fertilizer must be re-applied. Peach fertilizer per mu buried urea 20-25 kg, potassium chloride 15 kg, boron fertilizer, zinc fertilizer 1 kg each, mixed and ditched deep application. Combined with fertilization for cultivation.

Third, due to the chemical control of seedlings. Waterlogged water-controlled cotton should not be chemical controlled during the period of water control. After the transformation of fertilization, chemical control should be light, and a small amount should be carried out many times. The chemical control of multi-Rain Water hairstyle cotton should be used early and multi-purpose, so that the plant height should be controlled at about 50cm when flowering, and 1.2g / mu should be used for chemical control during the interval of rain.

Fourth, extra-root topdressing. The root system of cotton is seriously damaged by waterlogging, and the absorption of nutrients is hindered. Topdressing outside the root can quickly supplement cotton nutrients, enhance cotton waterlogging resistance and reduce cotton bud and boll shedding. Specific methods: per mu with 200 grams of urea, 100 grams of potassium dihydrogen phosphate, 100 grams of boron fertilizer mixed with 50 kilograms of water for foliar spray. Foliar fertilizer spraying should be carried out in the morning and evening on cloudy or sunny days, and the concentration must not be too high.

Fifth, ploughing and cultivation. After a long period of flooding, the foundation of cotton is very weak and easy to lodge. At this time, we must quickly straighten the cotton plant and cultivate it. When soil moisture permits, ploughing and deep cultivation should be carried out quickly. Mid-tillage is beneficial to break soil consolidation, promote root respiration and accelerate root growth.

Sixth, prevent diseases and insects. To timely control the third generation of cotton bollworm, the second generation of red bollworm, corn borer, aphids, red spiders and other pests. Targeted prevention and control of cotton wilt and Verticillium wilt and prevention of cotton boll disease in advance.

For fields that have lost their harvest, do not wait and see, but should quickly change to short-season crops such as autumn corn, buckwheat and vegetables, so as to minimize losses.