~ 519 ~ International Journal of Chemical Studies 2021; 9(2): 519-522 P-ISSN: 2349–8528 E-ISSN: 2321–4902 www.chemijournal.com IJCS 2021; 9(2): 519-522 © 2021 IJCS Received: 22-12-2020 Accepted: 04-02-2021 Pradeep Kumar Kanaujiya Ph.D. scholar Agronomy, Acharya Narendra Dev University of Agriculture & Technology, (Kumarganj) Ayodhya UP, India RP Singh Assitant Prof. Deptt. of Agronomy, Acharya Narendra Dev University of Agriculture & Technology (Kumarganj) Ayodhya UP, India Pankaj Kumar Ph.D. scholar Agronomy, Chandra Shekhar Azad University of Agriculture &Technology Kanpur UP, India Naveen Kumar Maurya Ph.D. scholar Agronomy, Chandra Shekhar Azad University of Agriculture &Technology Kanpur UP, India Pramod Kumar Ph.D. scholar Agronomy, Chandra Shekhar Azad University of Agriculture &Technology Kanpur UP, India Ankit Kumar Ph.D. scholar Agronomy, Acharya Narendra Dev University of Agriculture & Technology, (Kumarganj) Ayodhya UP, India Mahendra Pratap Singh Ph.D. scholar Agronomy, Acharya Narendra Dev University of Agriculture & Technology, (Kumarganj) Ayodhya UP, India Corresponding Author: Pradeep Kumar Kanaujiya Ph.D. scholar Agronomy, Acharya Narendra Dev University of Agriculture & Technology, (Kumarganj) Ayodhya UP, India Efficacy of various herbicide combinations on yield, its attributes and economics of transplanted rice in Indo Gangetic plain zone ( Oryza sativa L . ) Pradeep Kumar Kanaujiya, RP Singh, Pankaj Kumar, Naveen Kumar Maurya, Pramod Kumar, Ankit Kumar and Mahendra Pratap Singh DOI: https://doi.org/10.22271/chemi.2021.v9.i2h.11872 Abstract A field experiment was conducted at Agronomy Research Farm, A.N.D. University of Agriculture & Technology, Kumarganj, Faizabad during the Kharif season of 2017-18. The experiment was conducted with Randomized Block Design and replicated three times and comprised with twelve treatments. The herbicides were used individually as well as in combinations viz. Butachlor, Pretilachlor, Bispyribac-Na and Almix. Total weed population and its dry weight, weed index were lowest with Pretilachlor @ 750 g a.i. ha -1 (PE) fb Bispyribac-Na @ 25 g a.i. ha -1 (POE). However, highest weed control efficiency was recorded with Pretilachlor @ 750 g a.i. ha -1 (PE) fb Bispyribac-Na @ 25 g a.i. ha -1 (POE). The growth parameters and yields increased significantly with Pretilachlor @ 750 g a.i. ha -1 (PE) fb Bispyribac-Na @ 25 g a.i. ha -1 (POE) over rest of the treatments. Yield and yield attributes like number of effective shoots m -2 , length of panicle (cm), number of grain panicle -1 , test weight (g), Grain yield q ha -1 ), and harvest index were significantly higher with Pretilachlor @ 750 g a.i. ha -1 (PE) fb Bispyribac-Na @ 25 g a.i. ha -1 (POE). Weed free upto 60 th DAT gave the maximum gross returns (Rs. 94452 ha -1 ), however, Net returns (60729.00 Rs. ha -1 ) and maximum B:C ratio (1.84) recorded with Pretilachlor @ 750 g a.i. ha -1 (PE) fb Bispyribac-Na @ 25 g a.i. ha -1 (POE). Keywords: Pre and Post-Emergence, Herbicides, Profitability, Transplanted, Test Weight, Harvest Index, Rice, Economics Introduction Rice (Oryza sativa L.) is a most important cereal crop, grown under aquatic condition and mostly under submergence or variable ponding conditions. It belongs to family Poaceae (Gramineae). It is a most important staple food of about more than 60% of total world population. Rice is cultivated world-wide over an area of about 160.68 million ha with an annual production of about 650.19 million tonnes and productivity 4.15 tonnes per hectare. About 90% of all rice grown in the world is produced and consumed in the Asian region. It accounts 43% of total food grain production and 55% of cereal production in the country. It is a high caloric food, which contain 75% starch, 6-7% protein, 2-2.5% fat, 0.8% cellulose and 5- 9% ash. In India, rice is grown over an area of about 42.77 million ha which produces 110.40 million tonnes with an average productivity of 2490 kg/ha. In U.P., it is grown in an area of about 25.86 million ha with production of 13.83 million tonnes and productivity of 2358 kg/ha. (Anonymous, 2017-18) [1] . In 21st century there will be need of about 250 million tonnes of food grains to feed the rapidly increasing population. To meet the demand of increasing population and maintain self- sufficiency the present production level needs to be increase up to 14 million tonnes by 2025 which can be achieved only by increasing the rice production by over 2 million tonnes per year in coming decade (Subbaih, 2006) [7] . This has to be done against the backdrop of declining natural resources base such as land, water, labor and other input without adversely affecting the quality of environment. The herbicidal treatments Almix 20 WP @ 4 g ha -1 applied 15 DAT as post emergence effectively control all categories of weeds resulted minimum biomass production of weeds (4.45 gm -2 ) minimum weed index (1.37) and higher weed control efficiency (90.44%) which