Effects of Fungicides on Fruit Diseases and Pre-harvest Fruit Drops of Chestnuts in Long'an County

【Objective】The objective is to identify the cause of fruit diseases and pre-harvest fruit drop of Chinese chestnuts in Long’an and select the effective fungicides for the diseases and drop in order to provide a scientific basis for the prevention of fruit diseases and pre-harvest fruit drop of chestnuts.【Method】Through field investigation of 14-yearold chestnuts, the effects of different fungicides on fruit diseases and pre-harvest fruit drop of chestnuts in Long’an County were carried out in response to the phenomenon of fruit drop and diseases of chestnuts. Clear water was used in the control group. Five fungicides, including Carbendazim, Kasugamycin, Diphenoxazole, Kasugamycin + Diphenoxazole and Thiodiazole-copper were sprayed, individually or in combination, on the chestnuts for 3 times one month before harvest, with the last spraying performed about 15 days before harvest. And the rates of pre-harvest fruit drop and diseases were investigated.【Result】The five fungicides, sprayed individually or in combination, could reduce the fruit drop before harvest. The average rate of fruit drop was between 10.60% and 34.24%, with the best control effect found in carbendazim (10.60%). In addition, the rate of fruit diseases ranged from19.69% and 33.49%, with an overall average of 27.16%. The average rate of fruit drop was 19.69% for those sprayed with carbendazim. Three fungi strains that caused the fruit diseases of chestnuts were finally identified through a pathogenic bacteria separation, purification and pathogenicity test.【Conclusion】For the fruit protection measures of chestnuts, in-depth research should mainly focus on the rational spraying and scientific management of the fungicide carbendazim to reduce the fruit drop and diseases and improve economic benefits and yield.