What to Do When Bean Leaves Turn Yellow? Cause Analysis and Control Methods

Beans are one of our common vegetables, and spring and summer are the season when they hit the market. However, during the bean growing period, many farmers have reported yellowing bean leaves, which seriously affects the growth of beans. So what causes bean leaves to turn yellow? How should they be controlled? Let's take a look.

1. Symptoms

Yellow leaves on beans generally fall into two situations. One is yellowing of the lower leaves, which drop off very easily and then spread upward, followed by plant death. The other is yellowing of the new leaves at the top, accompanied by flower and pod drop. There is also a relatively rare phenomenon in which the plants do not die, but the leaf veins turn yellow.

2. Causes

There are three main causes of yellowing bean leaves. One is infection by root rot, a soil-borne disease in which the pathogen attacks the root system early on, causing poor plant growth and gradual yellowing of the lower leaves; the plant wilts during the high-temperature, strong-light period at noon, recovers in the morning and evening, and eventually dies. The second is a lack of trace elements: yellowing of the top leaves is caused by iron and zinc deficiency, while yellowing of the new top leaves is caused by sudden clearing after rain or changes between cold and warm weather. Yellowing of the leaf veins is caused by poor plant growth; this condition does not cause plant death and is mainly caused by excessively high temperatures, poor root growth, and insufficient fertilizer and water.

3. Control Methods

For bean root rot, a combination of physical control and chemical control can be used. When planting, soil should be disinfected and sterilized along with land preparation to eliminate the pathogen. When the disease occurs, drenching the roots with carbendazim gives good results. For trace element deficiency, organic fertilizer can be applied as a base fertilizer to increase the soil organic matter content, improve soil structure, and supply the plant with various trace elements. Later, foliar spraying can supplement the trace elements the plant lacks and can alleviate leaf yellowing. For yellowing leaf veins, watering and fertilizing should be done reasonably to enhance the plant's resistance and make the root system grow strong, so as to prevent yellowing of the leaf veins and premature leaf aging.

The above is an introduction to the causes of yellowing bean leaves and control methods. We hope it helps you. To learn more related knowledge, please stay tuned to us.