How to prevent the three major hazards during the cotton seedling stage? A detailed explanation of the latest measures

In the process of cotton cultivation, because there are many types of pests and diseases, prevention and control measures need to be taken well, and in the cotton process, there are also “three hazards,” which are cold damage, waterlogging damage, and fertilizer damage. So how should their harm be prevented? Follow the editor to take a look at the prevention methods.

1. Symptoms of cold damage

Cold damage mainly shows as delayed seedling development, small true leaves, cotyledons that fall off very easily, and shriveled young leaves, resembling aphid damage; in severe cases, stems and leaves wilt and die in patches. There are mainly three causes: first, sowing blindly too early, so that after emergence the seedlings encounter a cold wave and the temperature drops sharply; second,

removing the plastic insulating film too early; third, removing the film during the day and not covering it again at night in time.

Prevention methods: prevent blind sowing, understand the temperature requirements for cotton emergence, and sow at the right time. The minimum temperature for cotton germination is 10.5 degrees, and the emergence temperature is above 12 degrees; second, understand the local climate conditions. Generally, in the Yangtze River basin in early April, the temperature is above 13 degrees, so trial sowing can be carried out before large-scale sowing. At the same time, after emergence, pay attention to uncovering the film early and covering it late, so that when nutrient bowl seedlings are not transplanted, the film cannot leave the seedbed.

2. Symptoms of waterlogging damage

First, cotton seedlings turn from white to brown, and finally become brown, and the seedlings grow excessively; second, the seedling stems develop poorly and have poor toughness, making them very prone to damping-off in patches, and they are also easily infected by diseases such as Rhizoctonia solani. The main causes are poor drainage, inability to drain water in time after rain, and seedbed soil that is relatively sticky and heavy with poor permeability.

Prevention methods: finely prepare the cotton seedbed soil, and the seedbed site should not be continuous cropping, to prevent infection by residual pathogens; also, the drainage system should be kept unobstructed. It is best to increase the application of organic fertilizer, improve the soil structure, and ensure that spring rain can fall and filter through, and that the seedbed dries after the rain stops.

3. Symptoms of fertilizer damage

Fertilizer damage can cause cotton seeds to rot after sowing and fail to emerge, and after sprouting it can also cause scorching of the radicle and plumule, resulting in a very low emergence rate; even after emergence, it can cause root scorching, scorched leaf margins on young leaves, and in severe cases leaf drop and plant death. There are many causes of fertilizer damage: first, applying a large amount of urea in the base fertilizer, causing dehydration of cotton seed cells and inhibiting seed germination; second, applying too much base fertilizer, making the soil solution concentration too high and producing reverse osmosis that damages the seedlings; third, applying undecomposed organic fertilizer, which generates high temperature during fermentation and burns the seedlings.

Prevention methods: in response to the possibility of fertilizer damage, take targeted preventive measures. First, the organic fertilizer in the base fertilizer must be fully decomposed, which can both prevent high-temperature seedling burning and also prevent weeds from competing with seedlings for water and nutrients. Second, do not use urea as seedbed base fertilizer, so as to avoid seed dehydration and suffocation. When applying chemical fertilizer, control it at about 0.75 kg per 10 sq m.

The above is an introduction to preventive measures for the three major hazards during the cotton seedling stage. I hope it can help you. To learn more related knowledge, please continue to follow us.