Toxicity of 26 Fungicides against and Synergistic Effects of Binary Mixtures on Oidium heveae

26种杀菌剂对橡胶粉孢的毒力测定及二元复配增效作用研究（英文）

[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was determined in vitro and in vivo by calculating EC50 values.Horsfall＇s toxicity rate was preliminarily employed to predict the type of joint action of 180 two-way mixtures,based on which the interaction level of the potentially synergistic mixtures was validated by Sun and Johnson＇s co-toxicity coefficient.[Result] Triflumizole,pyraoxystrobin,flufenoxystrobin,epoxiconazole,pyrametostrobin,flusilazole,pyraclostrobin and tetraconazole were the most potent inhibitors of both spore germination and mycelial growth.An ‘in vitro-in vivo＇ integrated strategy is proposed for screening the inhibitors of O.heveae,according to the fact that data obtained in germination experiment are able to reflect to some extent the effectiveness of fungicide confirmed by pot experiment.Results achieved by Horsfall＇s were in line with that validated by Sun and Johnson＇s,the Horsfall＇s seems to be a convenient means to assess rapidly the potential interaction type and level of fungicides in a binary mixture.Nineteen mixtures interact synergistically：epoxiconazole ＋ pyraclostrobin at the mixing ratio of 6：4,8：2;tetraconazole ＋ flufenoxystrobin at 1：9,2：8,3：7 and 4：6;triadimefon ＋ flufenoxystrobin at 9：1;triflumizole ＋ flufenoxystrobin at 8：2;flusilazole ＋pyrametostrobin at 7：3,8：2 and 9：1;tetraconazole ＋ pyrametostrobin at 6：4;triadimefon ＋ pyrametostrobin at 5：5,8：2;triflumizole ＋ pyrametostrobin at 7：3,8：2;tetraconazole ＋ pyraoxystrobin at 9：1;triflumizole ＋ pyraoxystrobin at 8：2,9：1.[Conclusion] The single fungicides and their binary mixtures are expected to serve as the alternatives to triadimefon and the alternate use of them could delay the buildup of resistant O.heveae isolate.

[目的]测定26种杀菌剂对橡胶粉孢的毒力及二元复配增效作用。[方法]利用离体和活体试验测定了26种杀菌剂对橡胶树白粉病菌的毒力,以Horsfall法对不同类型杀菌剂的大量复配组合进行增效作用定性分析,再以孙云沛的共毒系数法验证增效配比的增效程度。[结果]氟菌唑、唑菌酯、氟菌螨酯、氟环唑、唑胺菌酯、氟硅唑、吡唑醚菌酯、四氟醚唑8种杀菌剂可作为防治橡胶树白粉病的备选药剂。孢子萌发试验结果在一定程度上反映了盆栽试验测出来的药剂杀菌活性,据此提出了离体试验与活体试验相结合的策略来筛选橡胶树白粉病防治药剂。Horsfall法的增效作用定性分析与孙云沛的共毒系数法验证增效程度的结果较一致。19个复配配比具有增效作用:氟环唑和吡唑醚菌酯配比6:4、8:2,四氟醚唑和氟菌螨酯配比1:9、2:8、3:7、4:6,三唑酮和氟菌螨酯配比9:1,氟菌唑和氟菌螨酯配比8:2,氟硅唑和唑菌酯配比7:3、8:2、9:1,四氟醚唑和唑菌酯配比6:4,三唑酮和唑菌酯配比5:5、8:2,氟菌唑和唑菌酯配比7:3、8:2,四氟醚唑和唑胺菌酯配比9:1,氟菌唑和唑胺菌酯8:2、9:1。[结论 ]筛选出的单剂及其二元复配剂有望作为对三唑酮的替代药剂,以延缓橡胶树白粉病菌抗药菌株的积累。