Central Rice Research Institute, Cuttack-753006
The effect of varying light intensities viz. normal light (400 cal cm−2d−1), 75% (S1). 50% (S2) and 25% (S3) of normal light (NL) on yield and growth attributes in rice was studied in two rice cultures, IR 8 (shade sensitive) and Vijaya (shade adapted). The grain yield, in general, was reduced by 47%, 57% and 74% in S1 S2 and S3 respectively mostly due to impairment in dry matter production, HI, panicle number and grains/panicle. Exposure to low light from primordial initiation to harvest was more detrimental to yield than from establishment (15 DAP) to harvest or from flowering to harvest. The adverse influence of reduced light on yield was lower in Vijaya than in IR 8. The chlorophyll content was high in Vijaya even under low light suggesting the positive association of this trait with adaptability of rice cultivars to subdued light conditions of the kharif (wet) season.
