What are the control methods for cotton boll rot?

The cause of cotton boll rot is basically too much rain in summer and poor ventilation, which allows various pathogens to invade the cotton and cause cotton boll disease. Cotton boll rot is the most common symptom of cotton boll disease, appearing to some degree every year, and it seriously affects the quality and yield of cotton. So let us learn together below how to prevent and control cotton boll rot.

1. Drain water promptly

When planting cotton, you must choose good land and prepare it well. Cotton has fairly strong drought resistance but is greatly affected by moisture, so when preparing the land we must set up a good drainage system, and during the cotton growing period we must promptly control and regulate the moisture in the field. That is to say, when there is a lot of heavy rain in summer, go to the field and clear the drainage system, drain the rainwater out of the cotton field, improve the cotton growing environment through manual means, and promptly prevent cotton boll disease caused by moisture.

2. Scientific density

When planting cotton, you must reasonably arrange the distance between rows and between plants. When cotton grows for a certain time it will spread out, so avoid planting too densely, with cotton branches and leaves all gathered together, causing stuffiness from lack of ventilation, or a humid and unventilated situation after rain, which can also cause cotton boll rot. So the general planting density is about 50 cm between rows and 30 to 40 cm between plants.

3. Loosen the soil and fertilize

To prevent and control cotton boll rot, you can also carry out intertillage and fertilizing. The purpose of intertillage is to let air into the soil and evaporate the moisture in the soil; the best time for intertillage is generally chosen on a sunny day. Fertilizing cotton fields generally uses organic fertilizer, phosphate fertilizer, potassium fertilizer and an appropriate amount of nitrogen fertilizer. This keeps the cotton from growing especially luxuriantly, reduces the heaviness in the cotton field, and lets it get sunlight and achieve a ventilating effect.

4. Scientific crop rotation

Another cause of cotton boll rot may be that the cotton field is often left without other crops and is only used to grow cotton, so the soil's capacity is insufficient, and many diseases occur. If rotation is carried out, it can regulate the soil's fertility and pH, and can effectively prevent the symptoms of cotton boll rot.

5. Chemical control 

Chemical control is the spraying of chemicals against the comprehensive factors of cotton boll rot. In the period of July and August in summer and September in autumn, there is more rain, so chemical spraying is needed to protect the cotton. When spraying, it is generally applied to the middle and lower parts of the cotton. Commonly used chemicals include carbendazim 1000-fold solution, 58% metalaxyl·mancozeb wettable powder diluted 600-800-fold, 80% pencozeb wettable powder diluted 500-600-fold, 70% chlorothalonil wettable powder diluted 500-fold, etc.

6. Pruning and boll regulation

Actually, the purpose of pruning is to reduce the heaviness in the cotton field and help the cotton get light and ventilation. Boll regulation mainly means regulating the cotton's boll-setting period and boll-setting position. The usual regulation method is to remove the flower buds on the first to fourth fruiting branches of the lower part of the cotton plant, or remove the first and second fruiting branches, which can reduce cotton boll rot.

The symptoms of cotton boll rot are very likely to appear in cotton planting, so preventive measures must be taken during the cotton growing period. The above is the control methods for cotton boll rot brought to you by Qinnong Net. Of course, there are certainly some other prevention and control methods, but the most commonly adopted measures are basically all here.