Prevention and control of orchid anthracnose

The most common disease of orchids is anthracnose. The disease is harmful to orchid leaves and often occurs at the tip and edge of orchid leaves. Leaf disease, the initial round or oval black spot, and then gradually expanded, in the later stage, the center of the spot was light brown or the edge of the dark brown or dark brown, the boundary between the disease and the healthy part was clear. The expansion of the disease spot is often limited by the leaf vein, and the disease spot on the leaf tip is often triangular, spreading downward from the leaf tip. The disease spot on the edge of the leaf is often semicircular, the disease part is brittle, and sometimes ruptured longitudinally. The size of disease spot varies with the width of orchid leaves.

Harm to the situation. The disease mainly harms many kinds of orchids, such as Chunlan, Jianlan, Huilan and so on. A large number of diseased spots appeared in the leaves of the diseased plants, which affected the growth and ornamental.

The pattern of occurrence. The pathogen of the disease is a semi-known fungus that overwinters with mycelium in the host residue or soil. The next spring produced conidia, spread by wind and rain, invaded from the wounds of orchid leaves, and spread repeatedly in the same way, causing damage. The disease is prevalent between July and September.

Prevention and control methods:

1. Cut off the diseased leaves and burn them in time.

two。 Strengthen the cultivation management, maintain the ventilation and light transmission of the orchid cultivation environment, watering should be injected from the edge of the flowerpot to avoid leaf watering.

3. In the early stage of the disease, 50% carbendazim wettable powder 500 times 600 times, or 70% methyl topiramate 1000 times, or equivalent 100 times 200 times Bordeaux solution was sprayed 2 times for 3 times.