Symptoms: the disease is mainly manifested in the leaves. At the beginning, the leaves turn green, and then yellow spots appear. In the later stage, it will become more and more serious, which will make the whole leaves scorch and fall off.
Prevention and control: first of all, we should change from the source and not water too much. When pruning, we should cut off the diseased branches and leaves in time. If the disease occurs, we can spray some Bordeaux liquid.
Symptoms: this disease is also concentrated on the leaves, mainly small spots on the leaf surface or on the edge of the leaves. With the continuous deterioration in the later stage, the spots will be concentrated together, and then the whole leaves will turn yellow.
Prevention and control: cut off the source of disease in time, and then destroy it intensively. It was observed that after the onset of the disease, it is necessary to start spraying, and carbendazim solution can be used. Pay attention to the concentration of the mixture. It is difficult to eradicate with one kind of medicine, but also with tobuzin, captan, mancozeb, etc., which can be used in turn.
Symptoms: the longicorn will gather on the trees and bite the trunk and rhizome. In serious cases, it may lead to the death of Magnolia.
Prevention and control: if sawdust and insect dung are found, they should be treated in time, and insect holes should be found. Then dip a cotton ball in dichlorvos and plug it into insect holes, which can be plugged outside, so as to smoke and kill longicorn.
