Causes of Yellowing Leaves and Seedling Death in Soybeans and the Latest Control Methods

In the process of growing soybeans, farmers often encounter yellowing leaves and seedling death, which seriously affect soybean yield and cause huge economic losses to growers. So what are the causes of yellowing leaves and seedling death in soybeans? How should they be controlled? Let's take a look at the detailed introduction below.

1. Diseases

When soybeans are infected with top rot during the seedling stage, their cotyledons develop brown ring spots, the growing points necrosis, and in severe cases the entire plant withers and dies. In plants infected before flowering, the internodes lengthen, the terminal buds turn brown, and the plants become brittle and prone to lodging. In plants infected after flowering, the leaves drop easily, fewer pods are set, the pods and seeds develop poorly, maturity is delayed, and the plants remain green before harvest.

Control measures: When plants become infected, promptly pull out the diseased plants to prevent the disease from spreading. For lightly infected plants, spraying with dufulan and chlorothalonil gives good results.

2. Pests

Soybean cyst nematode causes seedling death. When seedlings are damaged, the leaves change, development is slow, and in severe cases the plants wither and die. When adult plants are affected, they grow poorly and become dwarfed, the leaves turn yellow from bottom to top, flowering is delayed, and the pods and seeds grow underfilled with a darker color. Pulling out the diseased plants will reveal poorly developed root systems, few root nodules, and many soybean cyst nematodes attached to the roots.

Control methods: Apply more organic fertilizer to improve soil fertility and promote soybean growth. Water in a timely manner to keep the soil moist; a dry soil environment is extremely favorable for the reproduction of soybean cyst nematode. For affected fields, a low-concentration omethoate emulsion can be sprayed on the stem base.

3. Nutritional imbalance

In fields that lack fertilizer, are given excessive amounts of a single fertilizer, or are severely drought-stricken, the plant leaves show various yellowing and wrinkling phenomena, and plant growth is also slow; in severe cases the plants die from fertilizer deficiency.

Control methods: Fertilize scientifically and reasonably to ensure sufficient soil fertility and promote soybean growth. For fields lacking fertilizer, a low-concentration potassium dihydrogen phosphate solution can be sprayed to relieve or eliminate the symptoms and allow soybeans to grow normally.

4. Herbicide damage

During weed control, problems such as improper timing of herbicide use, excessive dosage, improper herbicide combinations, and repeated spraying can all cause herbicide damage, leading to yellowing leaves in soybean plants and, in severe cases, seedling death.

Control methods: The use of herbicides must be strictly standardized. After herbicide damage is found, water promptly to reduce the chemical concentration, and spray foliar fertilizer and plant growth regulators to alleviate the damage.

The above is an introduction to the causes of yellowing leaves and seedling death in soybeans and the control methods. We hope it helps you. For more related knowledge, please stay tuned to us.