Brown spot, caused by Helminthosporium oryzae (Breda de Haan), is a disease in upland rice that markedly reduces yield. The disease is exacerbated by nutritional imbalance in the soil (Shukla 2002). Low phosphorus (P) and potassium (K) content contributes to infection (Chattopadhyay and Chakrabarty 1965). Also, the disease has higher incidence in dry soil than in wet soil and is therefore more severe in rainfed fields than in irrigated/flooded ones (Kulkarni et al 1979). In the rainfed upland, nutrient availability depends not only on the potential nutrient amount but also on rainfall pattern during crop growth.