What if the bean leaves turn yellow?

Many farmers will encounter the problem of yellowing of bean leaves, whether it is the yellowing of new leaves or the yellowing of old leaves at the bottom, there are many reasons for yellowing of leaves. If effective measures are not taken in time, it will even lead to the loss of production. The following is aimed at the yellowing of bean leaves under different conditions, recommend several effective measures to you.

First, the new leaves turn yellow

If the bean plant is in cloudy and rainy weather for a long time, the root system is weak or the fruiting amount is too large, it is easy to cause the new leaves near the growth point at the top of the plant to yellowing and whitening, which is mainly caused by iron deficiency and zinc deficiency.

Prevention and control measures: once the yellowing of new leaves is caused by the lack of trace elements, trace element fertilizer must be sprayed on the leaves in time to alleviate the symptoms quickly and effectively; at the same time, it is suggested that farmers should pay attention to the supplement of organic matter and trace elements when planting the next crop, so as to avoid the adverse effects of soil on the next crop due to the lack of available trace elements.

Second, yellowing between veins.

The middle and lower old leaves are prone to yellowing between veins, which is mainly characterized by yellowing between veins, but it will not cause the phenomenon of dead trees. The yellowing between leaf veins is mainly caused by two reasons, one is the lack of available magnesium in soil, the main symptom of magnesium deficiency is chlorosis between leaf veins, and because magnesium ions are highly mobile in plants, they mostly occur in the middle and lower leaves of the plant. Another reason is that weak plant growth, premature senescence, high greenhouse temperature, poor root growth, unscientific fertilizer and water supply will lead to weak plant growth, resulting in yellowing between leaf veins.

Prevention and control measures: for the chlorosis of leaf veins caused by magnesium deficiency, magnesium foliar fertilizer should be sprayed in time, and attention should also be paid to the supplement of organic fertilizer and magnesium fertilizer when applying base fertilizer; plants with poor growth can apply Kim Jong-da / Waft / ophosphates fertilizer to promote plant rooting and regulate their growth, fertilize water reasonably during topdressing period, and prevent the occurrence of chlorosis between leaf veins through comprehensive management.

Third, the bottom leaves are yellowing

Cause analysis

1. Bean root rot, commonly known as "red root disease". This is a soil-borne disease, the early pathogen infects the root system, the plant is malnourished, the bottom leaves turn yellow, the plant wilts at noon, recovers sooner or later, and finally leads to death.

two。 Lack of trace elements. The leaves at the top growing point appear yellow and white, which is caused by iron and zinc deficiency. The yellowing of the new leaves at the top generally occurs when it is sunny after the shade, poor root growth, the weather changes from cold to warm, and there are too many plants bearing in the early stage.

3. The plant is not growing well. This situation will not cause the death of the plant, mainly because of the poor growth of the plant, which leads to the yellowing of the middle and lower leaves and veins, which is easy to cause premature senescence. For example, high temperature in the greenhouse, root dysplasia, root injury, unscientific fertilizer and water supply and so on can cause a similar situation.

Prevention and cure method

1. Bean root rot can be irrigated with medicament. You can choose agents: salvation, Jinmianwei, Xiumiao, dripping shark, etc., together with fine sweeping, fine brake, chlortrimazole, must green, etc.

two。 In bad weather and in the middle and later stages of plant growth, foliar spray can be used: fine brake, golden trimazole, must green, fungus shark with withered yellow and skillful green, Wandai red, Biao, etc., can effectively alleviate the yellow and white of the new leaves at the top.

3. Enhance plant resistance, cultivate strong roots, reasonable watering fertilizer, (can choose green source balanced fertilizer, big 20-20-20, Miaoguo, one mu gold, etc.) to prevent yellowing in the middle of leaf veins, resulting in premature senescence of leaves. Can be combined with the use of retrogradation liquid + special excellent root, flushing for 2-3 times.

All right, these are the reasons and solutions for the yellowing of bean leaves. Farmers who find that bean leaves are yellow must find out the cause in time and prevent it as soon as possible, so as not to cause the death of the whole plant. Some of the above prevention and control measures are aimed at the analysis of leaf yellowing in unused parts, and we can prescribe the right medicine to the case.