Control techniques of Leaf spot of Cymbidium

First, the main symptoms: occur in the leaves, mostly from the edge of the leaves to start the disease. The initial stage of the disease spot is grayish brown, surrounded by a yellow halo; after expansion, the disease spot is nearly oval to irregular, inside grayish brown, the edge is dark brown, and the surrounding yellow; in the later stage, scattered black particles appear on the disease spot.

Second, the cause of the disease: fungal diseases. The pathogen lives on the diseased body of the plant and spreads with the help of wind and rain, watering and human activities, and mostly infects and harms from the edge wound of the leaf where the plant growth is weak. Plant growth is weak and the damage caused by shell insects is easy to induce diseases. The disease is serious during the period of high temperature drying.

Third, prevention and control methods: ⑴ timely removal of diseased and residual leaves, centralized destruction. ⑵ Cymbidium prefers high air humidity, so it should often spray water on the leaves during high temperature drying to cool down and moisturize. In the early stage of ⑶, mancozeb and thiram fungicides were sprayed with 800x solution.