苹果轮纹病和炭疽病发生规律的研究

Studies on Occurrences of Apple Perennial Canker and Apple Anthacnos

苹果轮纹病和炭疽病均引起苹果烂果 ,本研究发现轮纹病是导致苹果烂果的主要原因。采收期病果中轮纹病占 82 .99%～ 91 .0 8% ,炭疽病占 6.87%～ 9.4 8%。贮藏期病果轮纹病占 78.50 %～ 80 .56%。两病均具有前期侵染、后期发病、潜伏期长的特点。苹果轮纹病菌的侵染初期在 5月 ,侵染盛期在 7～ 8月 ;苹果炭疽病菌的侵染盛期为 6～ 8月。果园内 4～ 9月均有孢子活动。孢子散发初盛期为 5～ 6月 ,盛期在 7～ 8月 ,田间孢子散发盛期与病菌侵染盛期相吻合。果实感病率幼果期至果实膨大期高于成熟期。采收前 3 0d和贮藏 3 5d内为果实发病高峰期。降雨是决定两病当年发病早晚和发生程度的决定性因素。病菌孢子释放、侵染及田间果实发病均与降雨密切相关。温度只影响孢子散发的初始期 ,而对病情发展无明显影响。

Apple perennial canker (Physalospora piricola Nose) and apple anthacnos (Gomerella cigulata Schr & Spauld) were the main apple fruit diseases, the apple perennial canker was the main cause of apple fruit rot. The rates of apple perennial canker and apple anthacnos among the rotted fruits were 82.99%～91.08% and 6.87%～9.48% respectively at the harvest stage.The rate of apple perennial canker was 78.50%～80.56% among all rotted fruits during the storage period. The incubation period of these diseases was very long. The beginning of infection stage of the apple perennial canker was in May and the high infection occurred from July to August. The high infection stage of apple anthacnos was from July to August.The spores of two pathogens appeared from April to September, beginning in May or June, climaxing in the period of July to August. The high spread stage of the spores coincided with the high infection of pathogen.The rate of infection during the growth stage of the fruit was higher than during the ripe stage. The disease of fruit climaxed 30 days before the picking and 35 days after storing. Rainfall was the decisive factor which affected the occurring date and severity in one year. Rainfall contributed to the spread of spores,the disease infection and the disease development of fruit in the orchard. The temperature only affected the beginning of the spore spread ,playing a minor role in the disease development.