Productivity of direct-seeded rice (Oryza sativa) under varying seed rates, weed control and irrigation levels

Abstract

A field experiment was conducted at Punjab Agricultural University, Ludhiana during 2000-05 to establish the agrotechnology, viz seed rate, weed control, irrigation schedule for direct-seeded rice (Oryza sativa L.). The experiment was conducted with 14 treatments; 3 seed rates (50, 100 and 150 kg/ha), 2 weed control methods (chemical and integrated), 2 imgation schedules (irrigation at 2 and 3 days after receding of applied water) and 2 transplanting treatments, viz transplanting of 25 days old nursery on the day of direct sowing and transplanting 25 days after direct sowing. The result revealed that direct-seeded rice with 50 kg seed/ha gave 6.82 tonnes/ha yield which was 0.25 tonnes/ha more than the transplanted crop sown 25 days after direct sowing having the same age as in direct-seeded crop. Seed rate of 50 kg/ha produced significantly more yield than 100 and 150 kg/ha. Integrated weed control and irrigation at 2 days' interval gave significantly more grain yield than those of chemical weed control and 3 days' irrigation interval treatments. The maximum yield (7.59 tonnes/ha) was under transplanting of 25-days-old seedlings on the day of direct sowing. But the direct-seeded rice did not require labour, water and management for nursery raising. Moreover, the water productivity of direct-seeded rice was more than that of crop transplanted on the day of direct sowing had an advantage of 25 days and it was less by 0.025 kg grains/m3. The integrated weed control appeared essential for raising direct-seeded rice. Direct-seeded rice matured 12 days earlier than the transplanted crop.