Preliminary Study On Peony Gray-mold And Root Rot In Greenhouse In Beijing

Herb peony (Paeonia lactiflora Pall.) is a traditional flower in China. To extend commercial season for peony production, people began to study and use facility cultivation techniques. The prevention and control of diseases has always been a problem in greenhouse. In order to get to know the incidence of peony diseases in greenhouse, the author has conducted a survey and carried out identification and biological characteristics study of the pathogen of two main peony diseases. Effective fungicides and resistant peony varieties for main diseases have been screened out. The results are as follows:1,Through the survey,19 peony diseases in open field and 12 in greenhouse have been found in Beijing, statistical table and a disease map displaying the incidence of peony diseases have been made. The results show that the resistance of peony is different between two cultivation environments.2,The main diseases in greenhouse are peony gray mold and peony root rot, whose pathogen are Botrytis cinerea Pers. and Fusarium solani (Mart.) Sacc.3,The optimum growth condition for Botrytis cinerea is 20℃, pH 3-5, light and dark alternating.Continuous light can not produce spores; Fusarium solani need higher temperature and relative humidity.is its optimum condition is 25-30℃, pH 6-10. The change of light has no significant effect on its mycelial growth and sporulation. The need of RH for conidia germination of both pathogens is higher than 85%.1% glucose is conductive to spore germination.4,The Botrytis cinerea-resistance identification of 15 peony varieties with mycelium agar disk inoculation method on the detached leaves and on live stem showed that the resistance of peony leaf was significantly correlated with stem.3 resistant peony varieties was screened out with'Da Fu Gui' 'Sheng Tao Hua','Dong Jing Nv Lang'as the examples. 5,Isolated root inoculation method can't be used in Fusarium solani resistance identification of peony varieties. Live inoculation result and natural incidence of peony root rot shows 2 resistant peony varieties with'Tao Hua Fei Xue','Dong Fang Hong' as the examples.6,Laboratory toxigenicity testing of 12 fungicides shows that 70% Mancozeb,45% Prochloraz,40% pyrimethanil,50% iprodione are effective fungicides for controlling peony greymold, 70%Mancozeb,45% Prochloraz are effective for controlling peony root rot. Within a certain range, concentration has little effect on its controlling effect.The research is the first time to use artificial inoculation to screen for resistant peony varieties.The results provide disease resistant parents for breeding new varieties, and offer reference for growing resistant peony varieties. The effective fungicides to specific disease have been screened out so we can control peony diseases more effectively.