Effect of cultural and chemical weed management on weed population and economics in drilled paddy (Oryza sativa L.)

An investigation was conducted at College of Agriculture, Nagpur to study the effect of Weed management in drilled paddy (Oryza sativa L.) during kharif season of 2014-2015. The experiment was laid down in Randomized block design having treatments viz., Control (T1), 2 hand weeding at 20 and 40 DAS (T2), Butachlor @ 1500 g a.i. ha-1 at 7 DAS (T3), Pretilachlor @ 750g a.i. ha-1 at 7 DAS(T4), 2, 4 D @ 1000 g a.i. ha-1 at 20 - 25 DAS(T5), Pyrazosulfuron ethyl @ 25 g a.i. ha-1 at 20 - 25 DAS(T6), Butachlor @ 1500 g a.i. ha-1 at 7 DAS + 2, 4 D @ 1000 g a.i.ha-1 at 20 - 25 DAS(T7), Butachlor @ 1500 g a.i. ha-1 at 7 DAS + Pyrazosulfuron ethyl @ 25 g a.i.ha-1 at 20 - 25 DAS(T8), Pretilachlor @ 750 g a.i. ha-1 at 7 DAS + 2, 4 D @ 1000 g a.i. ha-1 at 20 - 25 DAS(T9), Pretilachlor @ 750 g a.i. ha-1 at 7 DAS + Pyrazosulfuron ethyl @ 25 g a.i.ha-1 at 20 - 25 DAS(T10) thereby making Ten treatment combinations replicated three times. Rice variety PKV- Khamang was used as a test crop. Results revealed that two hand weeding at 20 and 40 DAS (T2) caused significant reduction in population of monocot and dicot weeds as compared to control and it was at par with butachlor @ 1500 g a.i. ha-1 at 7 DAS + 2,4-D @ 1000 g a.i. g ha-1 at 20 - 25 DAS (T7), butachlor @ 1500 g a.i. ha-1 at 7 DAS + pyrazosulfuron ethyl @ 25 g a.i. ha-1 at 20 - 25 DAS (T8), pretilachlor @ 750 g a.i. ha-1 at 7 DAS + 2,4-D @ 1000 g a.i. ha-1 at 20 - 25 DAS (T9) and pretilachlor @ 750 g a.i. ha-1 + pyrazosulfuron ethyl @ 25 g a.i. ha-1 at 20 - 25 DAS (T10). Lowest dry matter of weeds and higher weed control efficiency was recorded by treatment two hand weeding at 20 and 40 DAS (T2) and it was at par with T7, T8, T9 and T10. Maximum net return and B:C ratio were obtained by treatments two hand weeding at 20 and 40 DAS and was at par with butachlor @ 1500 g a.i. ha-1 at 7 DAS + 2,4-D @ 1000 g a.i. g ha-1 at 20 - 25 DAS(T7), butachlor @ 1500 g a.i. ha-1 at 7 DAS + pyrazosulfuron ethyl @ 25 g a.i. ha-1 at 20 - 25 DAS (T8), pretilachlor @ 750 g a.i. ha-1 at 7 DAS + 2,4-D @ 1000 g a.i. ha-1 at 20 - 25 DAS (T9) and pretilachlor @ 750 g a.i. ha-1 + pyrazosulfuron ethyl @ 25 g a.i. ha-1 at 20 - 25 DAS (T10).