Effect of Date of Sowing and Nitrogen Levels on Spot Blotch Disease of Wheat Caused by Bipolaris sorokiniana

In India, wheat is grown in the Rabi season mostly under irrigated condition. The main constraints responsible for less yield of wheat in comparison to other country seem to non-availability of seeds of improved high yielding varieties to farmers, poor fertility, unirrigated land and other inputs. Experimental findings clearly indicates that yield loss due to spot blotch varied between 7 to 30 per cent and loss in 1000-grain weight between 3 to 23 per cent, depending upon the levels of disease. Delayed sowing favored incidence of spot blotch irrespective of nitrogen level and more disease developed at higher nitrogen level in all the three date of sowing. Higher levels of nitrogen at all the three date of sowing increased yield and 1000-grain weight and with delay in sowing, yield and 1000-grain weight decreased significantly at all the three nitrogen level.