How to strengthen cultivation and management during the cotton bud stage? Keep these technical key points in mind

After cotton transplanting this year, continuous drought and little rain, unstable temperatures, and a long seedling-hardening period seriously affected plant development. In addition, large populations of aphids and red spider mites caused severe damage, leading to a second seedling-hardening in cotton seedlings, with a few seedlings showing red stems all the way to the top and true leaves drying up and falling off. Recent rainfall has alleviated the drought, and seedling conditions have begun to improve. Transplanted cotton now has 7-9 true leaves and has begun to form buds, and cotton after wheat (rapeseed) has also begun to develop, but overall seedling conditions are not as good as in previous years. The bud stage is the most important period in the life of cotton, and the following cultivation and management measures should be emphasized.

Supporting ditch systems: During the plum rain period, there are many rainy days and heavy rainfall, which easily causes waterlogging and hidden waterlogging in cotton fields. The "three ditches" inside and outside the cotton field should be dug and cleared to drain water and reduce waterlogging, promoting root growth.

Strengthen cultivation and management: Rainfall easily causes soil compaction, yellowing of cotton seedling roots, and waterlogged stunted seedlings. After rainfall, cultivation and management of cotton fields should be strengthened, with comprehensive loosening and hilling of soil, and clearing ditches and regulating soil moisture to promote cotton seedling growth.

Apply bud fertilizer steadily: Bud fertilizer, also called development fertilizer, is mainly used for the development and framework building of late-developing, thin and small cotton seedlings, and for balanced nutrient supply to normally growing cotton seedlings. Generally, per mu, apply 20 kg of special compound fertilizer, 20 kg of potassium chloride, and 200 kg of decomposed organic fertilizer by deep application. Special attention should be paid to applying sufficient potassium fertilizer to meet the needs of cotton flowering and boll setting in the middle and late growth stages.

Promote or control according to seedling condition: For weak waterlogged stunted seedlings, the method of "spraying on the leaves and topdressing in the soil" can be adopted to promote development and framework building, that is, on the basis of soil fertilization, combined with pest control, spray foliar fertilizer. Because most cotton seedlings are relatively thin and weak due to the earlier drought, chemical control is not necessary at present. After the weather clears and cotton seedlings enter normal growth, for individual cotton fields where seedlings grow too vigorously, leaves are too large, and the red stem ratio is too small (with 3-4 fruiting branches and plant height above 35 cm), spray mepiquat chloride for chemical control. Most local cotton fields have low transplanting density. In order to fully give play to individual growth advantages and promote vegetative branch growth, chemical control is not recommended for cotton seedlings growing normally at the bud stage.

Select and retain vegetative branches: As early as possible, select and retain 1-2 dominant vegetative branches extending toward the rows to increase the number of bolls per plant. The principle for selecting and retaining vegetative branches is to keep the large and remove the small, keep the high-position and remove the low-position, and keep those extending toward the rows and remove those extending toward the plants. When a vegetative branch has 4-5 secondary fruiting branches, remove its terminal bud (around July 20).

Prevent and control pests and diseases: Excessive rain often worsens the occurrence of pests and diseases in cotton fields. The appropriate control period should be grasped, the right pesticides should be used, and pests such as plant bugs should be controlled at the right time. After a sudden shift from drought to flood, Fusarium wilt and Verticillium wilt are prone to occur. While strengthening cultivation and management of cotton fields, pesticides should be used promptly for control, and diseased plants should be pulled out. (Contributed by the Rudong County Crop Cultivation Station)