Rhoda Mojisola, Olanrewaju2019-10-182019-10-1820041115-960Xhttp://hdl.handle.net/123456789/2834Out break of downy mildew has been a menace to maize production in Ilorin and its environ. This paper has identified the most crucial climatic parameters for the outbreak- of downy mildew, a disease of maize. A comparative analysis of years with and without outbreak was carried out and also tile weather before, during and after the outbreak was examined. Climatic data were broken into three sets of March - June, June - October and November - March based on the length of time it takes for each season of planting maize (early, late and dry) to mature ill the field. Monthly mean of climatic variables (rainfall, relative humidity, wind run, evaporation, maximum and minimum temperatures and soil temperature) were calculated for five years with outbreak and for five years without outbreak of do wily mildew disease. Simple regression analysis was employed to investigate the relationship. The results of the analyses showed a variation ill outbreak severity with mean rainfall, relative humidity, wind run and evaporation. However based on the results (If correlation analysis only relative humidity, wind run, evaporation and maximum temperature are significant at 95 confidence level. Relative humidity displayed strongest positive relationship followed closely by wind run (+ 0.722 and + 0.711) while evaporation exhibited strongest negative relationship of - 0.642 followed by maximum temperature (-0.574). The weather patterns preceeding, during and after the outbreak is described as hot and slightly humid, warm and humid. hot and dry respectively. The paper suggests application of technology to control outbrettk of downy mildew disease.enClimateDowny MildewHumiditytemperatureArticle