Effect of nitrogen fertilizer on fusarium sheath rot in rice

The effect of nitrogen at 25, 50, 75 and 100 Kg/acre was studied in rice cultivar PR-116 during kharif 2002. Spore suspension of Fusarium moniliforme (1x10⁶ spores/ml) was sprayed in each plot at boot stage of the crop. Sheath rot incidence (plant and tiller basis) and severity was maximum in treatments with 100 Kg N/acre and minimum where nitrogen dose was 25 Kg/acre. The trend in loss of yield was in correspondence with the infection. Maximum yield (83.2 q/ha) was obtained at 25 Kg N/acre and minimum (78.3 q/ha) at 100 Kg N/acre. Similar trend was observed in 1000-grain weight whereas, per cent chaffiness and discoloration was higher at higher doses (100 Kg N/acre) and was low at lower doses (25 Kg N/acre).