Growth and yield of direct-seeded rice (Oryza sativa) as influenced by seeding technique and seed rate under irrigated conditions

Abstract

A field experiment was conducted during rainy season (kharif) 2002 and 2003 at Ludhiana, to find out the suitable seeding technique and optimum seed rate for realizing high yield of direct-seeded rice (Oryza sativa). The dry-matter accumulation in direct-seeded rice under compaction and puddled condition was 1 15.7-1 39.1 q/ ha in 2002 (drought year) and 178.5-197.5 qlha in 2003 (normal year) compared with 104.1 q/ha under trans- planting 25 days after sowing (DAS). The seed rate of 50 kg/ha produced the maximum dry-matter accumulation. The maximum leaf-area index was (4.37-4.97 in 2002 and 5.24-6.06 in 2003) recorded under direct seeding. The maximum grain yield (57.8 q/ha and 179.3 qlha during first and second years respectively) was recorded under transplanting at 25 DAS (on the day of sowing) which was found on a par with direct seeding done after puddling and compaction at seed rate 50 and 75 kglha. It was mainly due to significantly more effective tillers/m2 (201 and 218 in 2002 and 276.2 and 283.3 in 2003) compared with 25 kg/ha seed rate (166 in 2002 and 267.6 in 2003). The water productivity (kg grain/m3 of irrigation water applied) in direct-seeded rice in 2002 was 0.35 and in 2003 was 0.76 compared with that of transplanted rice being 0.31 and 0.57 kg grain/m3 of irrigation water, clearly indicating better water-use efficiency under direct seeding.