The latest causes of yellow leaves and dead seedlings of soybean and their control methods

Farmers often encounter the phenomenon of yellow leaves and dead seedlings in the process of planting soybean, which seriously affects the yield of soybean and causes huge economic benefits to growers. So what are the reasons for the yellow leaves and dead seedlings of soybeans? How to prevent and cure it? Let's take a look at the detailed introduction.

1. Disease

In the seedling stage of soybean infected with top blight, its cotyledons will appear brown ring spots, growth node necrosis, in serious cases, the whole plant will die; pre-anthesis infected planting, its internodes will be prolonged, the terminal bud will turn brown, the plant will become brittle and easy to fold; infected plants after anthesis, the leaves are easy to fall off, pods are less, pods will be stunted, maturity will be delayed, and will remain green before harvest.

Control measures: when the plant is infected, pull out the diseased plant in time to avoid the spread of the disease. For lightly infected planting, you can spray disinfectant alum and chlorothalonil, the effect is better.

2. Insect pests

Soybean cyst nematode will cause the death of seedlings, when the seedlings are damaged, the leaves will change, develop slowly, and wither and die in serious cases; the occurrence of adult plants is that the plants grow poorly and dwarf, the leaves turn yellow from the bottom up, and the flowering period is postponed. Pods do not grow full and dark in color. When the diseased plant is removed, it will be found that the root system is underdeveloped, the root nodule is few, and the root system attaches a lot of soybean cyst nematode.

Control methods: increase the application of organic fertilizer, improve soil fertility, promote the growth of soybean, timely watering, keep the soil moist, dry soil environment is extremely conducive to soybean cyst nematode reproduction, for the diseased fields can be sprayed with low concentration omethoate emulsion on the base of the stem.

3. Malnutrition

When there is a lack of fertilizer or a certain kind of fertilizer is applied to the land, or when the land is seriously dry, the plant leaves will appear different yellowing and shrinking phenomena, and the plant will grow slowly and die because of losing fat in serious cases.

Prevention and control methods: scientific and reasonable fertilization to ensure adequate soil fertility and promote the growth of soybeans. For fields lacking fertilizer, low concentration of potassium dihydrogen phosphate solution can be sprayed to alleviate or disappear symptoms and make soybeans grow normally.

4. Herbicide damage

When weeding, if the use of herbicides is inappropriate, the dosage is too high, the herbicides are mismatched, repeated spraying and other problems, it will cause herbicide damage, which will lead to the phenomenon of yellow leaves in soybean plants and dead seedlings in serious cases.

Prevention and control methods: the use of herbicides must be on a strict scale, watering in time after finding drug damage, reducing drug concentration, spraying foliar fertilizer and plant growth regulators to alleviate drug damage.

The above is the introduction of soybean yellow leaves, dead seedlings and control methods, hope to help you, want to know more related knowledge, please pay attention to us.