Chemical Management of Grain Discolouration Disease of Rice

Two years pooled data from field experiments on management of grain discolouration disease of rice by chemical molecules revealed that the lowest per cent disease incidence (PDI) (6.11%), the highest disease control (78.9%), the highest yield (59.2 q ha⁻¹) and the highest B-C ratio of 2.10 were recorded in the treatment of tebuconazole + trifloxystrobin 75 WG @ 0.4 g L⁻¹. The chemical was sprayed twice, once at panicle initiation and then at 15 d after first spray. The next in order were propiconazole 25 EC @ 1 mL L⁻¹ and azoxystrobin 23 SC @ 1 mL L⁻¹ (pooled PDI 10.56 and 10.74, 63.4 and 62.8% disease control over check) respectively. The discoloured grains when examined in laboratory revealed the presence of seven fungi viz. Fusarium sp, Alternaria sp, Drechslera sp, Curvularia sp, Diplodia sp,Pyricularia sp. and Aspergillus sp.