嘧菌酯对马铃薯早疫病最低有效防控剂量的研究

由茄链格孢霉[Alternaria solani(Ell.et Mart.)Jones et Grout.]引致的马铃薯早疫病是世界马铃薯产区普遍发生的病害,喷施杀菌剂是防治马铃薯早疫病的常用手段。为探索减少杀菌剂嘧菌酯施用剂量对马铃薯早疫病防治效果,2018~2019年进行了嘧菌酯对马铃薯早疫病最低有效防控剂量的田间试验。试验在3个地理区域(乌兰察布市凉城县、临汾市蒲县、呼伦贝尔市扎兰屯市)完成,分别代表了不同气候、栽培和耕作特点。每个地点的2次施药分别在7月末和8月初进行,间隔7~10 d。250 g/L嘧菌酯悬浮剂有效剂量112.5 g/hm2处理,在第2次施药后14 d的防效达80%以上,此施药量为嘧菌酯对马铃薯早疫病最低有效防控剂量,比该农药登记推荐剂量(有效剂量150.0~187.5 g/hm²)减少用药25.00%~40.00%。研究结果可指导马铃薯早疫病防治农药减施和精准施药。

Minimum Effective Dosage of Azoxystrobin for Control of Potato Early Blight

Potato early blight,caused by[Alternaria solani(Ell.et Mart.)Jones et Grout.],is a word-wide disease occurring in the potato-producing regions,and fungicide application is common strategy of the disease control.In order to explore the effect of reducing the dose of Azoxystrobin on the control efficiency of potato early blight,the field experiments were conducted in 2018-2019 to determine the minimum effective dosage of Azoxystrobin application.These experiments were carried out in the three geographic locations(Liangcheng County,Wulanchabu City;Pu County,Linfen City;and Zhalantun City,Hulunbeir City),representing different climatic,cultural,and potato cropping systems.In each site,the application was carried out in late July and early August,respectively,with an interval of 7-10 days.When applying 250 g/L Azoxystrobin SC at 112.5 a.i.g/ha,its efficacy reached to over 80%on the 14th day after the second spraying.This concentration is the minimum dosage that still demonstrated the efficacy for disease control and was 25.00%-40.00%lower than that recommended(150.0-187.5 a.i.g/ha)by pesticide registration.The result could be used to guide the disease management with reduction and precision of this fungicide application.