Orchid snow mildew

Distribution: there are also greenhouses in Asia and America.

Pathogen: some species of the genus Ptychogaster.

Hosts: Vanda and other close relatives without pseudobulbs.

Symptoms: the white powder appears on the culture medium or soil, even at the base of the plant stem or extending to other parts.

Prevention and treatment: this pathogen is not parasitic on orchids, but lives on cultured soil, consumes nutrients and water, affects air circulation, and thus harms orchids. Therefore, it is necessary to remove the culture soil with bacteria, and mix 40% pentachloronitrobenzene or 50% carbendazim 5~6g/ square meters with fine soil and then mix it into the soil. Plants should also be drenched. (Chen Xinqi, Ji Zhanhe)