Efficacy of herbicidal weed management practices on weed dynamics in direct seeded upland rice of Himachal Pradesh

Abstract

A field experiment was conducted during kharif 2021 at the Research Farm of Department of Agronomy, College of Agriculture, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur, to study the effectiveness of a new post-emergence broad-spectrum herbicide GOD H008 (Bispyribac sodium 5% SC+ Pyrithiobac sodium 12.5% SG) to control mixed weed flora in direct-seeded upland rice (Oryza sativa L). The experiment was laid out in Randomized Block Design with three replications and seven weed control treatments. The treatments consisted of three doses of GOD H008 (Bispyribac sodium 5% SC+ Pyrithiobac sodium 12.5% SG) viz. 375ml/ha, 500ml/ha and 625ml/ha, bispyribac sodium 250ml/ha, pyrithiobac sodium 625ml/ha, hand weeding (weed free) and untreated check respectively. The predominant weed flora present in the experimental field was Ageratum conyzoides, Cyperus rotundus, Commelina benghalensis, Echinochloa colona, Digitaria sanguinalis and Synedrella nodiflora. Application of new herbicide combination product GOD H008 (Bispyribac sodium 5% SC+ Pyrithiobac sodium 12.5% SG) 500ml/ha being statistically at par with GOD H008 (Bispyribac sodium 5% SC+ Pyrithiobac sodium 12.5% SG) 625ml/ha and bispyribac sodium 250ml/ha resulted in significantly lower total weed count, total weed dry weight and highest weed control efficiency as compared to other weed control treatments. Significantly highest grain and straw yield were recorded with the application of GOD H008 (Bispyribac sodium 5% SC+ Pyrithiobac sodium 12.5% SG) 500ml/ha at harvest and this treatment was closely followed by GOD H008 (Bispyribac sodium 5% SC+ Pyrithiobac sodium 12.5% SG), 625 ml/ha.