What are the causes of yellowing leaves in yardlong beans and the control methods
Many farmers often encounter the phenomenon of yellowing leaves when growing yardlong beans, whether it is new leaves turning yellow or old leaves at the bottom. If measures are not taken in time to prevent and control it, it will cause a reduction in yield, and may even lead to total crop failure. Let's take a look below at the causes of yellowing leaves in yardlong beans and the control methods.
I. Causes of yellowing leaves in yardlong beans
1. New leaves turning yellow
Continuous rainy days leading to excessively high air humidity, weak root systems, or an excessively large fruit load and other reasons can all cause the new leaves at the top of the plant to turn yellow or whitish. At the same time, this is also greatly related to a deficiency of iron and zinc elements, so spraying foliar trace element fertilizer in time and promptly maintaining iron and zinc can effectively alleviate this symptom in the plant.
2. Yellowing leaf veins
The old leaves in the middle and lower parts of the plant can also develop yellowing of the leaf veins, but the plant will not die. The main cause of this kind of yellowing is magnesium deficiency, or weak plant growth, premature aging, and improper fertilizer and water management. If it is magnesium deficiency, it can be solved by spraying magnesium fertilizer on the leaves, while if the growth is poor, it is necessary to improve and adjust fertilizer and water management to solve it.
3. Bottom leaves turning yellow
Generally, when the bottom leaves turn yellow, it may be caused by root rot of yardlong beans. The early symptoms of root rot are not obvious, and it usually begins to show signs only at the flowering and pod-setting stage. It appears as stunted plants, with the lower leaves beginning to turn yellow and dry from the leaf margins, but generally they do not fall off.
⟦NL>II. Control methods
Attention should be paid to the application of base fertilizer. The base fertilizer should be mainly organic fertilizer, and it is necessary to ensure the supplementation of organic matter and trace elements, especially the three of iron, zinc, and magnesium. Once they are deficient, they will cause yellowing leaves in the plant. During management, the environmental temperature should be controlled within a suitable range and should not be too high, to ensure root development and regulate root growth. This is a point that needs attention. When root rot occurs, 99% hymexazol can be used at 3000-4000 times dilution as a root drench for control.
The above is an introduction to the causes of yellowing leaves in yardlong beans and the control methods. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.