"Impact of Irrigation Scheduling and Weed Management on Water Use Efficiency and Yield of Direct Dry Seeded Rice"

Abstract

Field experiment was conducted at Soil and Water Management Research Institute, Kattuthottam, Thanjavur during kharif season (July - October) of 2017 to assess the water use efficiency and yield of direct seeded rice under different irrigation scheduling and weed management practices. Field experiment was laid out in split plot design which was replicated thrice. The treatments comprised of four different irrigation scheduling viz., AWDI at 10 cm depletion of water below the soil surface, AWDI at 15 cm depletion of water below the soil surface, AWDI at 20 cm depletion of water below the soil surface and irrigation on the day of disappearance of ponded water, in main plots and three weed management practices in sub plots viz., PE pendimethalin 1kg a. i. ha-1 on 3-5 DAS fb EPOE bispyribac sodium @ 25 g a. i. ha-1 (Two to three leaf stages of weeds), EPOE bispyribac sodium @ 25 g a. i. ha-1 (Two to three leaf stages of weeds) fb hand weeding at 35- 45 DAS (S2 ) and weedy check. It was found that AWDI at 10 cm depletion of water below the soil surface recorded higher water use efficiency and comparable yield when related to irrigation on the day of disappearance which was recorded higher yield. On the other hand, AWDI at 20 cm depletion of water below the soil surface reduced total water consumption and recorded lower grain yield. Among weed management, EPOE bispyribac sodium @ 25 g a. i. ha-1 (Two to three leaf stages of weeds) fb hand weeding at 35-45 DAS had recorded higher grain yield which was on par with PE pendimethalin 1kg a. i. ha-1 on 3-5 DAS fb EPOE bispyribac sodium @ 25 g a. i. ha-1 (Two to three leaf stages of weeds). But, due to higher labour cost involved in hand weeding, EPOE bispyribac sodium @ 25 g a. i. ha-1 (Two to three leaf stages of weeds) fb hand weeding at 35-45 DAS recorded higher cost of cultivation. Thus, in water and labour scarce situation AWDI at 10 cm depletion of water below the soil surface with PE pendimethalin 1kg a. i. ha-1 on 3-5 DAS fb EPOE bispyribac sodium @ 25 g a. i. ha-1 (Two to three leaf stages of weeds) was the best option to get higher productivity in rice. .