Jornal de Patologia Vegetal e Microbiologia

Abstrato

Prediction of Potato Late Blight Disease Based upon Environmental Factors in Faisalabad, Pakistan

Nadeem Ahmed, Muhammad Aslam Khan, Nasir Ahmad Khan and Muhammad Asif Ali

Potato late blight (PLB) caused by Phytophthora infestans (Mont.) de Bary, is an important and serious threat to successful potato production in the world. It spreads through seed and soil residual material. In Pakistan, PLB disease can induce 100% yield losses under epidemic condition. Due to lack of resistance in indigenous potato germplasm, disease is managed through fungicides by the growers of Pakistan. Excessive use of fungicides causes resistance in the pathogen and creates fatalistic effect on the environment. Disease predictive model under such situation may be effective tool to predict early onset of disease. A disease predictive model was developed on two years data of PLB disease severity and epidemiological factors using stepwise regression analysis. Model explained upto 80% disease variability. Maximum and Minimum temperature, relative humidity, rainfall and wind speed appeared to be most significant factors in the PLB disease development. The environmental conditions conducive for the development of PLB disease were characterized. Maximum and minimum temperatures in the range of 16-20°C and 1-6°C were found favourable for potato blight disease. Similarly, relative humidity, rainfall and wind speed in the range of 63-71%, 1.5-3.75 mm and 1-5.5 Km/h, respectively, were conducive for PLB disease which are helpful in disease development.