Populus tomentosa scab disease

Half-known pathogens, subphyllospora, actinomycetes, Cephalosporium fungi

Harmful symptoms the scab of Euonymus tomentosa mainly harms leaves and branches. The leaf surface initially appeared round or nearly oval spots with a diameter of 1 mm to 2 mm, and later the diseased tissue dried up and fell off to form a perforation. When the new shoot is infected, there are dark brown round or oval slightly raised spots on the surface, such as scab-like, gray-white in the center. In the later stage, one to two small black spots were produced in the center of the lesion, namely the conidial disk. In serious cases, it causes the leaves to fall off and eventually leads to the death of the branches.

The pathogen usually overwinters in the soil and spreads infection under suitable conditions. Mole cricket, kowtow worm, nematode and so on can spread the pathogen and enlarge the damage. In addition, running water and maintenance operations can also spread diseases. Overdense plants, poor growth, extensive management, wind and rain are conducive to the occurrence and transmission of diseases. The conditions of high temperature, more Rain Water and high humidity are easy to aggravate the disease.

Prevention and cure method

1. Strengthen the management, enhance the growth potential of seedlings and reduce the conditions of disease.

2. combined with pruning, cut off some diseased leaves and burn them.

3. Improve the planting environment, control the plant density, promote ventilation and light transmission, especially the cutting seedbed.

4. During the prevention period, 100 times of Bordeaux solution or Baume 5-degree stone-sulfur mixture can be sprayed.

5. During the occurrence of the disease, 65% Dysen zinc 500-800 times solution, or 50% carbendazim, 50% carbendazim 700 times to 1000 times solution, chlorothalonil 1000 times solution, methyl topiramate 1200 times solution, sprayed once in 7 days to 10 days, continuously sprayed 3 to 4 times, the control effect was good.