What is the cause of garlic yellowing? What should I do?

Garlic is an indispensable condiment at home. Garlic leaves don't have the same strong taste as garlic cloves, and you don't have to worry about "bad breath". For people who have experienced growing garlic, what is the reason for the yellowing of garlic leaves? What should I do?

Garlic is yellow, which is mainly caused by improper management of fertilizer and water, soil acidification and so on. But in fact, the yellow garlic is more likely to be caused by diseases and insect pests, especially the root-knot nematode disease which is particularly serious in recent years. Root-knot nematode disease is caused by nematodes infecting crops, and there are many kinds of crops harmed by root-knot nematodes. If trees, melons, eggplant fruits, legumes and other crops are affected by nematodes, garlic is no exception.

According to experts, with the adjustment and upgrading of China's agricultural structure in recent years, and affected by factors such as traditional planting patterns and limited arable land, the multiple cropping index of crops is generally on the high side. The host plants of nematodes such as vegetables and melons planted in some plots for a long time, and root-knot nematode disease is serious, leaving more insect sources in the soil, while garlic is mostly intercropped with these host plants. This led to the occurrence of garlic root-knot nematode disease, especially in greenhouses, greenhouses and protected areas.

According to the observation, when the second instar larvae of garlic root-knot nematode harm garlic, it will pierce the tender part of the fibrous root (root tip) through a sharp needle, and the root knot will hinder the absorption of nutrition and water by the root system, and the growth of the root system is hindered and the phenomenon of not growing new roots often occurs. However, the symptoms of aboveground diseased plants were not obvious at the initial stage, but with the development of the disease, the growth was weak, the leaves were yellowish green, and the leaves were scattered, which was similar to the symptoms of lack of water and fertilizer. With the development of the disease, the diseased plants gradually yellowed, wilted, and even withered and died.

Thus it can be seen that the prevention of garlic yellowing is inseparable from the prevention and control of garlic root-knot nematode. Experts say that the prevention and control of root-knot nematodes should be focused on prevention rather than treatment. Preventive measures can take agricultural and physical control methods, while the control of root-knot nematodes needs to be combined with chemical agents to achieve the best control effect.