不同药剂与施药时期对辣椒炭疽病防治效果的影响

Effects of Different Fungicides and Application Periods on the Control Efficacy of Pepper Anthracnose

【目的】探明贵州辣椒炭疽病的适宜防治药剂和防治时期,为辣椒炭疽病化学防控提供依据。【方法】选取已登记的15种辣椒炭疽病防治药剂单剂(25%咪鲜胺EC、80%波尔多液WP、50%肟菌酯WG、22.7%二氰蒽醌SC、70%代森锰锌WP、40%百菌清SC、30%琥胶肥酸铜WP、80%克菌丹WG、22.5%啶氧菌酯SC、85%三氯异氰尿酸SPX、40%苯醚甲环唑SC、500 g/L氟啶胺SC、50%咪鲜胺锰盐WP、250 g/L嘧菌酯SC和25%吡唑醚菌酯SC)和1个混剂(40%苯甲•吡唑酯SC)为药剂处理,选取贵州辣椒炭疽病的3个主要致病菌菌株(C.scovillei GL 17-25、C.gloeosporioides GL 17-42和C.fructicola GL 17-147)为防治对象,采用菌丝生长抑制法和离体果实接种法对药剂进行初筛,通过田间试验进一步验证适宜的药剂和防治时期。【结果】25%咪鲜胺EC、50%咪鲜胺锰盐WP、70%代森锰锌WP对3种辣椒炭疽病菌的菌丝生长抑制率均为100.00%;离体果实接种试验表明,除70%代森锰锌WP外,各药剂的平均预防效果均高于治疗效果,25%咪鲜胺EC对3个菌株的预防和治疗效果最好,平均值分别为72.48%和60.01%,其次为25%吡唑醚菌酯SC(43.53%和30.36%)。相比发病中期用药,发病初期用药的病情指数低、防效高,25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC的防效显著(P<0.05)高于25%咪鲜胺EC,前两者发病初期用药的防效分别为86.99%和88.59%,发病中期用药防效分别为50.87%和45.48%。【结论】25%吡唑醚菌酯SC和40%苯甲•吡唑酯SC能有效防治辣椒炭疽病,防治时期以发病初期为佳。

【Objective】The suitable control fungicides and application periods against pepper anthracnose in Guizhou were explored to provide a reference for the chemical control of pepper anthracnose.【Method】15 registered single fungicides(25%prochloraz EC,80%bordeaux mixture WP,50%trifloxystrobin WG,22.7%dithianon SC,70%mancozeb WP,40%chloroehalonil SC,30%copper succinate WP,80%captan WG,22.5%picoxystrobin SC,85%trichloroisocyanuric acid SPX,40%difenoconazole SC,500g/L fluazinam SC,50%prochloraz-manganese WP,250 g/L azoxystronbin SC and 25%pyraclostrobin SC)and 1 mixed fungicide(40%difenoconazole•pyraclostrobin SC)were selected as the agents.Three main pathogens(C.scovillei GL 17-25,C.gloeosporioides GL 17-42 and C.fructicola GL 17-147)of pepper anthracnose in Guizhou were screened as the control objects.The fungicides were preliminary screened by mycelial growth inhibition rate method and in vitro fruit-inoculation test,and the suitable fungicides and application periods were further verified by field experiment.【Result】The mycelial growth inhibition rates of 25%prochloraz EC,50%prochloraz-manganese WP and 70%mancozeb WP against three pepper anthracnose were 100.00%.In vitro fruit-inoculation test showed that the average preventive effect of all agents except 70%mancozeb WP was higher than that of treatment.The average preventive and therapeutic effects of 25%prochloraz EC against the three strains were 72.48%and 60.01%,respectively,followed by 25%pyraclostrobin SC(43.53%and 30.36%).Compared with the fungicides used in the efficacy was high.The control effect of 25%pyraclostrobin SC and 40%difenoconazole•pyraclostrobin SC was significantly higher than 25%prochloraz EC(P<0.05).The control effects of the first two fungicides were 86.99%and 88.59%,respectively,and 50.87%and 45.48%respectively in the middle stage of the disease.【Conclusion】25%pyraclostrobin SC and 40%difenoconazole•pyraclostrobin SC can effectively control pepper anthracnose,and the control period is better in the early stage of the disease.