Preliminary study on the epidemic regularity of apple scab in the cool areas of south-west China and screening of control fungicides
Since 2021,apple scab was outbreak in some apple producing areas in the cool highlands of south-west China.In order to explore the occurrence regularity of apple scab and screen out effective prevention and control fungicides,five-year-old Ruixue apple was used to investigate the occurrence regularity of apple scab and its relationship with the climate change,and effect of 11 fungicides on apple scab was tested with field test.The results showed that the overwintering spores of apple scab began to germinate and infect the plants in mid-late March in Zhaotong areas,and the primary symptom on leaves was observed at the end of April and the beginning of May,then the rate of infected leaves increased exponentially with the increase of rainfall and reached the peak at the end of June,finally became stable with the decrease of rainfall and the maturation of leaves.Among the 11 fungicides,40%pyrimethanil SC(1,000 times liquid),20%pydiflumetofen SC(3,500 times liquid),50%kresoxim-methyl WG(2,500 times liquid)and 40%flusilazole EC(6,000 times liquid)showed the best control effects.After 20 days of the last spray,the control effect remained above 93%.The control effects of 30%pyraclostrobin SC(2,500 times liquid),30%triflumizole WP(3,000 times liquid),10%difenoconazole WG(2,000 times liquid),40%mefentrifluconazole SC(1,500 times liquid)and 50%Fluopimomide WG(3,500 times liquid)were moderate,from 68%and 79%at 20 days after the last spray.The control effects of other fungicides were lower.
apple scabepidemic regularitythe cool highland of southwest Chinafungicide screening
万方数据
维普
