Effect of Meteorological Factors on Production of Conidia of Helminthosporium sp. and Alternaria sp., the Incidents of Foliar Blight of Wheat

The present investigation on the epidemiology of foliar blight diseases of wheat caused by Helminthosporium sativum and Alternaria triticina was conducted considering the effect of several atmospheric parameters on the air borne conidia of the fungi. With the increase of minimum temperature up to 15°C and maximum temperature up to 28–29°C, the concentration of conidia remained almost at same level or increased very slowly, with the increase of both minimum and maximum temperatures, the prevalence of air borne conidia increased at a very high rate and was more abrupt in case of Alternaria triticina. Wind speed was a very important factor to influence the number of air borne conidia and was positively correlated with the average number of air borne conidia. Highest viability of conidia was observed during February and early March at a maximum temperature of around 28°C.