MySheen

Leaf spot of Euonymus tomentosa

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, The symptom is harmful to the young and old leaves of Euonymus tomentosa, with yellow-brown spots on the front, expanding into nearly round or irregular shape, 4mm~14mm in diameter, gray-white in the center, light brown concentric lines, dark brown margin slightly raised, and dense small black mildew spots in the disease spot. The spot passes through the back, but the color on the back is slightly lighter than that on the front. After the disease spot dried up, it split with the healthy part until the perforation was formed. Often cause early defoliation. Pathogenic fungus, half-known fungus, subphyllospora, cercosp

The symptom is harmful to the young and old leaves of Euonymus tomentosa, with yellow-brown spots on the front, expanding into nearly round or irregular shape, 4mm~14mm in diameter, gray-white in the center, light brown concentric lines, dark brown margin slightly raised, and dense small black mildew spots in the disease spot. The spot passes through the back, but the color on the back is slightly lighter than that on the front. After the disease spot dried up, it split with the healthy part until the perforation was formed. Often cause early defoliation.

Pathogenic fungus, Cercospora cercosporadestructivarav.

The pathogen overwintered in the diseased leaves on the tree and on the ground, produced conidia in spring for initial infection, and then produced a large number of conidia for multiple re-infection in the whole growing season. When it is rainy, wet, frozen in spring or the plants are too dense and poorly ventilated, the disease is often serious, resulting in fallen leaves.

Prevention and cure method

Do a good job in the sanitation of green land, clean up diseased and fallen leaves in winter and spring, and concentrate on burning.

At the initial stage of the disease, the patients were sprayed with 1, 2, 200 Bordeaux solution or 1000 times of methyl thiophanate wettable powder or 65% zinc wettable powder, and then sprayed again for 1 time or 3 times according to the condition.

 
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