Abstract

                                Two field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, India in the wet (September 2001 to January 2002) and dry seasons (February to June 2002) aimed at understanding the effect of different crop management practices on rice yield. Four crop management practices were investigated with two levels: crop establishment (transplanting of 23 d old seedlings vs. 14 d old seedlings in wet season and direct sowing in dry season), Irrigation (conventional flooded irrigation vs. water saving irrigation), weeding methods (manual vs. mechanical weeding) and nutrient management (recommended amount of fertilizers without vs. with green manure). There was no grain yield advantage for planting 14 days old seedlings compared to 23 days old conventional seedlings, though produced higher tillers and spikelets, but because of increased sterility and reduced grain weight in wet season. In dry season, direct wet seeding to 20x20cm spacing was better than transplanting due to higher number of filled grains per unit area, in spite of higher sterility and reduced grain weight. Modified method of planting either younger seedlings/direct sowing is an alternate to the conventional method of planting irrespective of the season or variety. Its superiority lies only when it combines with appropriate irrigation and weed management practices. The water saving irrigation is suitable for the wet season but not for the dry season since it affects the spikelet formation.

Key words : Rice, younger seedlings, direct sowing, mechanical weeding