Tobacco mildew of orchids

Orchid tobacco mildew, also known as orchid mildew, causes tobacco mildew in the diseased part of the plant and affects the photosynthesis of the plant.

Symptoms: the disease part of the susceptible plant is covered with a black mold layer, and the black mold layer is the mycelium of the pathogen. The pathogen is born on the secretions of aphids, shell insects and whiteflies, rather than parasitic directly on orchid plants and does not absorb plant nutrients.

Pathogen: the pathogen is CapnodiumcitriBerk.etDesm. It belongs to Ascomycetes subphylum, Coleoptera, Coleoptera and Fungi.

Prevention and treatment: sporadic mildew layer on ① leaves can be brushed off, or diseased leaves can be cut off and destroyed. ② insecticides against insects: spraying 1000 times of omethoate can control aphids, red spiders and thrips. The control of scale insects should be carried out by spraying 1000 times of 25% imidophos emulsion or 1000 times of 50% malathion emulsion during the peak egg hatching period.