Component analysis for grain yield in hybrid rice under tarai condition

Correlation and path coefficient were computed to assess the association between direct and indirect influences of different characters on yield in hybrid rice. The grain yield exhibited positive association with total number of spikelets m-2, number of filled spikelets m-2, spikelet sterility, thousand grain (test) weight, grain straw ratio except for number of panicles m-2. The number of filled spikelets m-2 was most significantly and positively correlated with grain yield ha-1. The path analysis revealed their highest positive direct effect on biological yield followed by harvest index and crop duration. The contribution of number of filled spikelets m-2, spikelets sterility, thousand grain (test) weight, number of panicle m-2, grain: straw ratio and dry matter production was positive but associated more indirectly to biological yield. Negative direct effect of growing degree days, total number of spikelets m-2, heliothermal units, ripening periods, plant height and days taken to 50% flowering was established.