Identification of the peach leaf black spot pathogen and evaluation of the biocontrol effects of biological agents in the field
Peach black spot is one of the main leaf diseases of peach trees in Hebei province,which is caused by diverse pathogens.And the early symptoms of peach perforation and peach black spot are easily confused.Therefore,it is necessary to identify the main pathogens infected leaves of peach trees in Hebei Province.In this study,the diseased peach leaves in the main peach growing areas of Hebei Province were collected to isolate the pathogens whose pathogenicity were verified using Koch's postulates.The pathogens were identified by morphological characteristics combined with multi-gene sequence analysis including rDNA-ITS,EF-1α,Alt-al and RPB2.The Alternaria alternata was identified from 39 isolated strains as the pathogen causing black spot disease of peach leaves in Hebei Province.The virulence of the eight fungicides against Alternaria alternata was determined by the mycelial growth method.43％tebuconazole showed the best fungicide effect with EC50 of 17.661 mg/L.The EC50 of the biological agents including 16％polyoxin and 80％ethylicin were 61.613,87.518 mg/L,respectively.The field evaluation of 43％tebuconazole against peach black spot was 76.86％,while the efficacy of 80％allicin and 0.3％tetramycin in the field was 70.13％and 64.93％,respectively.Taken together,biological agents are safer,greener and more suitable for use in peach orchard disease control.This study provides a basis for using effective biological agents to guide production in the peach industry and to construct green control systems for different commercial peach orchards.
peach treeleaf black spotpathogen identificationpathogenicitybiological agentsfield efficacy
万方数据
维普
