How To Prevent Tree Peony From Gray Mould？

                                                                                      How to Prevent Tree Peony from Gray Mould？
Cardinal symptom: There are two kinds of pathogenic bacteria: the first is Botrytis paeoniae Oudem, the spot on the leaf is nearly round or irregular, most of which occur in the tip and thin leaves, brown or purple brown, with irregular wheel lines, and grow gray mildew when the air humidity is high. When infecting the stem, the diseased spot is brown. The flowers are brown, soft rot, gray, mildew and the black granular sclerosomes are sometimes produced at the lesion. The second pathogen is Botrytis cinerea, which not only harms herbaceous peony, but also infects peony, chrysanthemum, cyclamen and so on.It causes brown rosette wrinkle at the edge of the leaf. Petiole and pedicel soft rot, outer coat rotting, pedicel killed, often affecting seed maturity.
The onset of conditions: The above two pathogens overwintering in the soil by sclerotinia. The incidence of multiple continuous cropping plots was serious. High temperature and rain were beneficial to the formation and transmission of conidia, conidia were in contact with the host. Under the condition of water and humidity, the bud tube germinates and invades the host body, excessive application of nitrogen fertilizer, the plants too close, high humidity, lack of light, plants with weak growth are vulnerable to bacteria.
Prevention and control methods:
1. Avoid continuous cropping and plant in aseptic soil.
2. Use aseptic seedling and use 65% wettable zinc powder 300 times solution before planting, soak for 10 minutes.
3. Pay attention to ventilation, light transmission, proper application of nitrogen fertilizer, timely drainage after the rain, and remove the diseased leaves and diseased plants at any time.