apple blight的意思|示意

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Apple blight is a disease which affects apple trees, as well as other fruit-bearing trees and shrubs. It is caused by the fungus Noylella mucronata, which affects the leaves, petioles, and twigs of apple trees. The fungus penetrates the host plant's tissues and then develops a mycelium which produces spores. These spores are spread to other plants, and when they come into contact with the host plant, they cause infection.

Apple blight appears as a dark brown or black circular lesion, which is often surrounded by a yellowish halo. It can also cause leaf spots, petiole necrosis, and growth of stunted shoots. The disease can also cause premature defoliation of the tree and reduced fruit production.

Apple blight can be controlled by several cultural and chemical practices. These include pruning diseased branches, removing dead material, and trimming infected shoots. Pruning should be done in the winter, when the spores are least active. Chemical control may include the use of fungicides, such as Benomyl, which can be applied to the tree foliage and the soil around it.

In order to better control apple blight, it is important to practice good cultural practices. This includes pruning and fertilizing the trees regularly, and following a spray schedule that includes a preventive fungicide application. It is also important to take note of weather conditions and make sure to prune or spray on days when the humidity is low and there is no chance of rain. Regular monitoring is also important, as this helps to detect early signs of infection.