To understand the methods of orchid seedling culture and orchid Phytophthora control.

Symptoms: it occurs all the year round, but in the plum rain season, the disease is the most serious when watering is too wet or poor ventilation, especially the seedlings just out of the bottle are the most vulnerable. The infected site produced brown disease spot, which expanded rapidly in high temperature and humidity, and finally showed black brown spot, and deciduous stem rot until the plant died.

Prevention and control methods:

(1) avoid excessive humidity, improve ventilation and adequate light.

(2) avoid partial use of nitrogen fertilizer and reduce plant overgrowth and weakness.

(3) spraying 1gram 800 carbendazim or 1gram 1000 Haoshengling liquid

(4) the wound removed by the diseased plant is smeared with large cornflour and then placed in a dry place without watering for a week, which can curb the spread of the disease.