Detection Of Fungicide Resistance In Botrytis Cinerea In Shangdong Province And Selection Of The Fungicides Against Cucumber Gray Mold By Dipping Flowers

In recent years,with the growth of greenhouses in China,gray mold has been one of the most important diseases,seriously hindering the further development of crops in greenhouses.Currently,applying fungicides remain the primary approach to decrease the occurrence of gray mold.However,with the extensive fungicides use,the resistance of Botrytis cinerea has been standing out obviously,due to its characteristics of wide host,fast reproduction and genetic variation,and airflow spread,so it is necessary to determine the sensitivity of B.cinerea to the common fungicides in the study.In addition,in the agricultural production,farmers usually improve the fruit-set rate and control gray mold by dipping flowers with the mixture of hormone and fungicide.This treatment has many problems,including pesticides screening,optimal dose,safety,so its feasibility assessment is necessary.85 B.cinerea,collected from different areas of Shandong Province,were determine the sensitivities to commonly used fungicides by the mycelium growth rate method.We have studied the control efficacy of ten kinds of fungicides and their feasibility,providing a scientific basis on cucumber gray mold by dipping flowers.1.The highly resistance frequency of B.cinerea from Shandong province to carbendazim was 84.71%,and do not be determined the sensitive isolate in 85 B.cinerea.Resistance frequency to procymidone was 92.94%,and highly resistant isolates accounted for 10.59%.Resistance frequency to iprodione was 89.41%,and lowly resistant isolates accounted for74.12%.Resistance frequency to diethofencarb was 96.47%,and highly resistant isolates accounted for 21.18%.Resistance frequency to pyrimethanil was 98.82%,and highly resistant isolates accounted for 94.12%.Sensitivity frequency to pyrisoxazole was 98.82%,and lowly resistant isolates accounted for 1.18%.Resistance frequency to fluopyram was 64.71%,and moderate resistant isolates accounted for 44.71%.Sensitivity frequency to boscalid was 77.65%,and highly resistant isolates accounted for 5.26%.Sensitivity frequency to fludioxonil was 87.06%,and highly resistant isolates accounted for 1.18%.There was not the resistant isolate to triflumizole determined in 85 B.cinerea.Sensitivity frequency to isopyrazam,lowly resistant isolates accounted for 1.18%.2.With the low dose of five fungicides,Gary mold was effectively controlled by dipping flowers in field trails.Compared with the control,the control efficacy of fluopyram at 20μg m L-1,isopyrazam at 30μg m L-1,boscalid at 30μg mL-1,fludioxonil at 30μg mL-1,pyrisoxazole at 30μg m L-1,were 80.04%,81.31%,83.95%,87.12%,83.27%,respectively,had no bad influence on the rate of commodity fruit and the weight of single fruit.