【摘要】 为了有效防治由多主棒孢霉〔Corynespora cassiicola(Berk.&Curt.)Wei〕引起的烤烟叶斑病,调查研究了气候、品种、土壤类型等对吉安烤烟棒孢霉叶斑病发生流行的影响;采用含毒介质培养法测定了咪鲜胺(ME)、菌核净(WP)、氟环唑(SC)、苯醚甲环唑(WG)、戊唑醇(SC)、啶酰菌胺(WG)、腐霉利(WP)、异菌脲(SC)、吡唑醚菌酯(EC)、多抗霉素B(WP)等10种药剂对烤烟棒孢霉菌的毒力,其中6种药剂开展了烤烟棒孢霉叶斑病田间防治试验。结果表明,吉安烤烟棒孢霉叶斑病在5月底6月初开始发病,且旱地发病较早,6月下旬高温多雨气候有利于其暴发流行,烤烟品种K326耐病性相对较好,而鳝泥田、麻沙泥田、紫泥田和潮沙泥田4种水田土壤类型均可发生该病;咪鲜胺、菌核净和啶酰菌胺对烤烟棒孢霉菌显示较好的抑制菌丝生长作用,EC50值分别为1.012、1.085、1.503 mg/L,其余7种药剂的EC50值在3.542~7.650 mg/L之间;田间试验显示菌核净对烤烟棒孢霉叶斑病防治效果较好,达66.94%~72.91%,其次为啶酰菌胺和氟环唑,防效可达68.62%和63.93%。提出防治烤烟棒孢霉叶斑病要结合气象因素,依据往年流行规律,在病害发生初期用药,并应进一步研究该病害的防治药剂。更多还原

【Abstract】 In order to prevent and control the leaf spot of flue-cured tobacco caused by Corynespora cassiicola(Berk. & Curt.) Wei,the occurrence of this Corynespora leaf spot in different climates,breeds,soil types,cultivation and management conditions was investigated and researched,and the regular epidemic pattern of this disease in Ji’an was analyzed. The toxicities of 10 fungicides including Prochloraz ME,Dimethachlon WP,Epoxiconazole SC,Difenoconazole WG,Tebuconazole SC,Boscalid WG,Procymidone EC,Iprodione SC,Pyraclostrobin EC,Polyoxin B WP were determined by the radical growth rate of poison of medium culture method. And above six fungicides were used to control flue-cured tobacco leaf spot in the field trial. The results showed that Corynespora leaf spot of flue-cured tobacco attacked in end of May and early June in Ji’an,and especially early indry farmland. High temperature and raininess in late June was better for epidemic outbreak. The disease resistance of Breed K326 was relatively good,but in 4 kinds of soil types,such as eel mud,hydromorphic alluvial sandy mud,purple mud and hydromorphic tide sandy mud,it was attacked by this disease. Prochloraz,Dimethachlon and Boscalid showed good inhibition on the growth rate of C. cassiicola,the values of EC50 were 1.012,1.085 and 1.503 mg/L respectively. The values of EC50 of other seven fungicides were between 3.542 mg/L and 7.650 mg/L. Field trial results showed that Dimethachlon had better effect on flue-cured tobacco leaf spot,the control effects was 66.94%-72.91%,and the control effects of Boscalid and Epoxiconazole were 68.62% and 63.93%. The results suggest that preventing and controlling flue-cured tobacco leaf spot need to combine weather factors and use fungicides at early stage according to the epidemic regularity. And the further study of fungicides of this disease should be needed.更多还原