Influence of N levels (30, 60 and 120 kg/ha) on photosynthesis and productivity was studied in 4 early rice varieties, Ratna, Pallavi, Swarnaprabha and Pusa 33 during wet season. The increase in these traits was mostly apparent up to 60 N. Swarnaprabha consistently showed high plant photosynthesis and grain yield at 60 N, Higher leaf area expansion along with high nitrogen content in leaf (NLA) at flowering as in Swarnaprabha is considered to be an useful index for assessing N response in rice varieties during wet season.
