How to prevent and treat sooty mold on orchids?

OrchidsSooty mold is also known asOrchidsmold stain disease. This disease causes sooty mold-like material to appear on the affected parts of the plant, affecting the plant's photosynthesis.

Symptoms: The affected parts of the infected plant are covered with a layer of black mold, which is the mycelium of the pathogen. This pathogen grows on the secretions of aphids, scale insects and whiteflies, rather than directly parasitizing the orchid plant, and it does not absorb nutrients from the plant.

Pathogen: The pathogen is Capnodium citri Berk. et Desm., belonging to the subdivision Ascomycotina, class Loculoascomycetes, order Dothideales, genus Capnodium.

Control: ① Scattered mold on the leaves can be brushed off, or the diseased leaves can be cut off and destroyed. ② Chemical pest control: Spraying 40% omethoate at 1000 times dilution can control aphids, red spiders and thrips. To control scale insects, spray 25% phosmet emulsifiable concentrate at 1000 times dilution, or 50% malathion emulsifiable concentrate at 1000 times dilution, during the peak period of egg hatching.