小麦白粉病重发原因及综合防治对策OA

To reduce yield losses caused by wheat powdery mildew,this paper summarized the occurrence characteristics of the disease in Qishan County,Shaanxi Province,analyzed the causes of its severe epidemic,and proposed integrated control strategies.The occurrence characteristics of wheat powdery mildew in the study area were early infection before winter,an average disease incidence of 18.5%at the peak occurrence stage,an average disease incidence of 3.67%in dense and vigorous wheat fields,and an average disease incidence in dryland that was 0.4 percentage points higher than that in the tableland irrigation area.Analysis of the occurrence causes indicated that warm winters,relatively high temperatures in early spring and abundant precipitation favored the survival and spread of wheat powdery mildew;the cultivation of wheat varieties with weak disease resistance increased the incidence of powdery mildew to a certain extent;pathogen inoculum accumulated in the soil due to the retention of diseased straw in fields;excessively early sowing dates and excessively high planting densities tended to trigger the outbreak of wheat powdery mildew;compared with the tableland irrigation area,the relatively low level of refined cultivation and management by dryland farmers exacerbated the occurrence and damage degree of wheat powdery mildew in dryland;and uneven fungicide spraying reduced the control efficacy.Accordingly,integrated control measures were proposed,including predicting disease development trends based on meteorological forecasts,selecting resistant varieties such as Xinong 226 according to local production conditions,adopting late sowing at an appropriate date,increasing phosphorus and potassium fertilizer application,and conducting chemical seed dressing and field control with suitable fungicides,so as to ensure safe wheat production and sustainable development.