What are the main diseases of onions in the latest

Onion appears on everyone's table as an ingredient, it is most famous for its smell and its lethality is amazing, but in fact, the onion itself is indeed very fragile and vulnerable to some diseases. Let's follow in the footsteps of the pro-farm network to learn about some common diseases of onions.

1. Downy mildew

Diseases such as mildew are unavoidable diseases in plants, and downy mildew is common in onions. Such symptoms are mostly concentrated in the pedicel, that is, closer to the soil. At the beginning of the disease, there will be white mildew spots, with the deepening of the disease will slowly become purple, and finally lead to plant collapse. In addition to the harm of bacteria, it is also related to high humidity, which can be prevented and treated with 75% chlorothalonil wettable powder 600 times.

2. Purple spot

Purple spot disease occurs when more concentrated with the leaves, and then slowly expand, the time is more concentrated in the rainy season, so we must do a good job of drainage. At the beginning of the disease, there will be some lavender spots on the top of the leaves, with the spread of purple as the core, brown withered around, and finally the whole plant withered and died. The prevention and treatment can be sprayed with more than 2% antimycin 30ppm agents, and the leaf tip should be emphatically sprayed once a week, about an hour before nightfall for a month.

3. Yellow dwarf disease

This is a disease caused by bacteria, the incidence of the phenomenon is obvious, mostly concentrated in the early stage of growth. The disease spread from the leaves to the whole, first, the leaves began to turn yellow, the new leaves became smaller and smaller, and finally the whole plant stopped developing and slowly withered. After the disease is stable, the serious diseases can be removed directly to avoid infection, and those with mild diseases can be prevented and treated with 1.5% Zhiyanling emulsion 1000 times, once a week for two weeks.

4. Onion deformity

Onions are generally caused by excessive nitrogen fertilizer leading to nutritional imbalance and ground maggots, of course, there will be environmental and other factors, but the more common are these two. The symptom is that the onion grows irregularly, and the rhizome can be observed on the outside. If the rhizome is thicker than other Mandarin, it may be abnormal growth. Daily fertilization must be proportional release, not a single release, for maggots can be poured into the soil 50% dimethoate 1000 times liquid, must be combined with water irrigation effect is good.

These are some common diseases of onions. I think this is more common for other diseases. Once we find that the above situation must be paid attention to, we should pay more attention to the daily management of the field to avoid greater losses.