At the beginning of the disease, there will be many irregular brown spots on the leaves with fine lines. With the aggravation of the disease, there will be many black molds. Usually, multiple spots are linked together to form larger patches. When the disease is serious, the whole plant will die.
Once the brown spots are found, they should be cleaned up in time and sprayed with carbendazim or chlorothalonil solution in time. In the growing season, carbendazim should be sprayed properly for prevention.
At the onset of the disease, there were cyan plaques on the edge of the leaves, which would gradually form into a piece and expand inward, gradually turning brown. When the lotus root rots, the central part will turn brown and gradually extend upward, and the node and stem of lotus root will gradually necrosis.
Spray carbendazim solution in time for prevention and treatment, once every 3-5 days and 3-5 times. In other cases, spray once a month for prevention and control.
This kind of pest will gnaw the mesophyll, leave the vein and surface layer of the leaf, the leaf will be like the screen window, showing gray white. When the larva becomes larger, it will not only bite the leaves, but also damage the flower buds and flowers. From June to October every year, Spodoptera litura has a high incidence.
The diseased leaves can be removed manually, insects have been found, and the diseased leaves can be scraped or destroyed in time. In the larva gathering area, spraying methamidophos 1000 times solution for control.
Aphids have strong adaptability to the environment and are widely distributed. It mainly damages the stems and leaves of plants, especially the young shoots.
Aphids have been found to be hard to cure because of their strong reproduction. Therefore, it needs long-term maintenance and regular spraying of chemicals. The West diluted DDV emulsifiable concentrate was sprayed once a month, and the frequency of spraying was increased appropriately.
