Common diseases and prevention methods of wintersweet

Chimonanthus anthracnose

symptom

  The disease mostly occurs at the tip and edge of the leaves. The lesions are nearly oval, light red to grayish white, with reddish brown or brown edges, scattered black spots, and are easy to break. Anthracnose is a fungal disease caused by a fungus called Colletotrichum.  

Prevention and treatment methods  

Remove diseased fallen leaves and destroy them in a centralized manner to reduce sources of infection.  

Chemical control. When the disease is serious, spray 1000 times diluted 50% carbendazim wettable powder.

Chimonanthus chinensis leaf spot

symptom

The leaf spots are initially round and brown, then gradually expand into irregular shapes, with the centers of the spots turning light brown or grayish white and dark. In the later stage, small black spots appear in the center of the lesions. Leaf spot is caused by infection by a type of fungus, the shield mold.  

Prevention and treatment methods  

Remove diseased fallen leaves and destroy them in a centralized manner to reduce sources of infection.  

Chemical control. When the disease is serious, spray 1000 times diluted 50% carbendazim wettable powder.

Black spot of Chimonanthus

symptom

  On the infected leaves, the spots are nearly circular or fused together, forming irregular shapes. They are brown at first, then gradually fade to nearly white in the center, while the edges remain brown. There are sparse dark brown mold clusters on both sides of the lesions, mostly on the surface. Black spot is a fungal disease caused by the Alternaria alternata fungus, which overwinters on diseased fallen leaves.  

Prevention and treatment methods  

Remove diseased fallen leaves and destroy them in a centralized manner to reduce sources of infection.  

Chemical control. When the disease is serious, spray 1000 times diluted 50% carbendazim wettable powder.

Chimonanthus chinensis

symptom

It mainly occurs at the root base and root collar. In the early stage of the disease, the cortical tissue of the affected area becomes swollen and soft, and nearly circular brown spots appear. Afterwards, the diseased part begins to rot in a water-soaked state, reaching deep into the wood, and yellow-brown sap oozes out. In the later stage, the diseased tissue shrinks and cracks longitudinally, and the woody tissue dies and decays. The surface of the diseased part is wrapped with tender root-like cords, which are white at first and then turn into gray-brown or tan.

Prevention and treatment methods

Strengthen management, increase the application of organic fertilizer, improve the soil, control watering, and prevent waterlogging. Remove foreign matter (weeds, dead leaves) next to the plants in a timely manner.

Scrape off the lesions immediately if found, and disinfect the injured surface with 70% alcohol.