Cotton bolls rot should be checked and treated on high temperature and humidity days for planting cotton

At present, cotton is in the flower and boll stage and immediately enters the boll opening stage, which is the exuberant period of cotton reproductive growth, the key period of peach growth and yield formation, and the key period of prevention and control of rotten bolls. From late July to early August this year, the rainfall is abnormally more than usual, and rotten bolls are easy to occur.

The symptom of diseased peach is blackened and immersed in water, with long sparse white erect hyphae, non-cracking and stiff peach. Due to weak light, poor ventilation, high humidity, Rain Water leaching or insect bite, the lower part of cotton plant is easy to be infected by bacteria and rot bolls. The main reason for the occurrence of rotten bell this year is Rain Water. After field investigation, rotten bolls were found on August 5, 3-5 days earlier than in previous years, and the rate of diseased plants was 5-15%.

Prevention and control methods:

First, ventilation and light. Prune and fork in time, go to the tip of the group, push the plant and ridge. In the early stage of boll disease, old leaves should be beaten in time, empty fruit branches and leaf branches should be removed, empty plants should be pulled out, ventilation and light transmission conditions among cotton plants should be improved, field humidity should be reduced, and the occurrence of boll disease should be reduced.

Second, drainage and dehumidification. On the basis of leveling the land, eradicating weeds, drainage and irrigation, timely opening ditches to cultivate soil is beneficial to rapidly discharge stagnant water, reduce field water content, and timely ploughing and dispersing soil moisture.

The third is to reduce the source of bacteria. Pick the rotten fruit in time and take it out of the field.

The fourth is to control insects in time. Control the third and fourth generation of cotton bollworm, prevent insect bite wound, reduce the chance of infection.

Fifth, chemical prevention and control. In the early stage of boll disease, 1000 times of 50% methyl topiramate or 75% chlorothalonil wettable powder or 50% carbendazim wettable powder were sprayed on the middle and lower cotton bolls per mu.