Comprehensive Evaluation about Control Effect of Various Fungicides on Pepper Southern Blight
WANG Junying1，2☆，ZHU Chunhui3☆，YI Xi4，LUO Meng4，PENG Yue1，2，LI Xuefeng2，MA Yanqing1，2，ZHENG Jingyuan1，2，4*
1College of Horticulture，Hunan Agricultural University，Changsha 410128，Hunan，China；2Hunan Vegetable Reaserch Institute，Changsha 410125，Hunan，China；3Hunan Institute of Plant Protection，Changsha 410125，Hunan，China；4Longping Branch，Graduate School of Hunan University，Changsha 410125，Hunan，China
Abstract：In order to evaluate the bactericidal effect of chemical fungicides for controlling pepper southern blight，this experiment carried out comprehensive evaluation on 7 fungicide prodrugs，14 fungicide preparations and compound combinations，and control effects of potted and field plants．The results of indoor bioactivity measurement showed that the antibacterial effects of single original drug of 97% prochloraz powder，98% fludioxonil powder and 96% pyraclostrobin powder on pepper southern blight were more obvious，with EC50 values of 0.000 6-24.488 4 mg · L-1. The mixed prodrugs of 97% hymexazol powder +96% pyraclostrobin powder had obvious synergistic effect. The EC50 values of 8 preparations，including 42% trifloxystrobin-tebuconazole suspension，25% pyraclostrobin suspension，15% triazolone wettable powder，etc. were lesser，which could significantly inhibit mycelial growth．6 kinds of mixed preparations including 25% pyraclostrobin suspension + 42% trifloxystrobin-tebuconazole suspension，etc. showed better inhibiting effect on pepper southern blight fungus and obvious synergistic effect. 3 preparations with better control effect of 42% trifloxystrobin-tebuconazole suspension，15% triazolone wettable powder and 25% pyraclostrobin suspension and 2 kinds of compound combinations with the best control effect of 25% pyraclostrobin suspension + 42% trifloxystrobin-tebuconazole suspension，43% tebuconazole suspension + 40% pentachloronitrobenzene were screened out through pot culture experiment. The control effect was 97.58%-100.00%. Field trials validated that 15% triazolone wettable powder and the combination of 25% pyraclostrobin suspension + 42% trifloxystrobin-tebuconazole suspension had obvious control effect．Their control efficacy was 85.81% and 82.02%，respectively．In this experiment，the optimal type of fungicide for controlling pepper southern blight were methoxyacrylates and triazole fungicide. Among them，15% triazolone wettable powder，the combination of 25% pyraclostrobin suspension + 42% trifloxystrobin-tebuconazole suspension could be used for comprehensive control of large areas pepper southern blight．
