What types of main pests and diseases affect orchids?

1) Southern blight: it mostly occurs during the plum rain season. Attention should be paid to ventilation and light transmission, and good drainage of the potting soil for prevention. After onset, the infected potting soil can be removed and pentachloronitrobenzene powder or lime can be sprinkled on.

(2) Anthracnose: it occurs year-round and is even more rampant in hot and rainy seasons. In addition to improving environmental conditions, during the onset period, spray with 50% thiophanate-methyl wettable powder at 800-1500 times dilution, once every 7-10 days, and then supplement with 1% Bordeaux mixture of equal amounts, once every half month.