High temperature and high humidity weather cotton is easy to rotten

Cotton is rotten, and this happens almost every year to varying degrees. Therefore, on the basis of clarifying the conditions and causes of the occurrence of cotton rotten bells, comprehensive measures should be taken to prevent and control, and strive to minimize losses.

First, the conditions and causes of cotton rotten bells

Cotton rotten bells are caused by a variety of pathogens infesting cotton bolls. Especially in the rainy weather, the cotton field has a large humidity, severe canopy closure, poor ventilation and light transmission, suitable for pathogens to infest and infect, the disease is often serious, and the cotton rotten bell is also more serious. Cotton boll diseases mainly include blight, anthracnose, angular leaf spot, red rot, etc. Among them, the disease is the main type of rotten bell, accounting for 28.3% to 99.7% of bell disease. Extensive management of cotton fields, pruning or control measures are not timely, and plants are prosperous, which are beneficial to the disease.

Second, the prevention and control measures of cotton rotten bells

1. Rational fertilization. Add organic fertilizer and phosphorus and potassium fertilizer, use appropriate amount of nitrogen fertilizer to prevent cotton plants from growing, reduce cotton field stagnation, and improve ventilation and light transmission.

2. Timely drainage. For cotton fields with low topography, poor drainage and heavy water accumulation, the drainage ditch should be deepened to speed up the drainage. Eliminate the dark stains of cotton fields, improve the growth and development conditions of cotton, achieve cotton multi-peach, no premature aging, and reduce the risk of boll. In addition, for cotton field drainage and prevention of cotton lodging, soil cultivation before cotton flowering is also an effective agronomic measure and should be promoted.

3. Adjust the ringing. If there is too much pre-powder to make cotton or early-earning cotton, it can reduce the rotten bell by taking effective measures to adjust the bolling and ringing parts of cotton.

4. Reasonable pruning. For cotton fields with too narrow line spacing and premature sealing, in order to alleviate the excessive stagnation in the field and improve the light conditions and ventilation conditions in the middle and lower parts, the heart should be removed as soon as possible, thus reducing the bud buds and ringing.

5. Picking up the sick bell. When the bell period is more than 40 days, the bell shell has faded and turned yellow and the black spotted cotton peach has appeared. It is harvested before it is bad. The harvested cotton peach is dipped in a 1% ethylene solution and then air-dried to obtain a cotton with better boll opening.

6. Chemical control. Chemical control is an important measure to comprehensively control cotton rotten bells, and targeted disinfectant sprays are required. From August to September, when the weather forecast has rainy weather for several days, spray protection should be carried out in time. Spray should be concentrated in the middle and lower parts of the cotton plant. Commonly used agents are 50% carbendazim 1000 times solution, 58% metalaxyl manganese zinc wettable powder diluted 600~800 times liquid 70% chlorothalonil wettable powder diluted 500 times liquid.