Effect of integrated application of herbicides and straw mulch on productivity and profitability of rainfed upland rice (Oryza sativa)

Abstract

A field study was carried out during rainy (kharif) season of 2019 at Agricultural Research Station, Faculty of Agricultural Sciences, Siksha ‘O’ Anusandhan, Bhubaneswar, Binjhagiri, Chhatabar, Odisha, to evaluate the effect of herbicide and varying rates of straw mulching on weed growth, productivity and profitability of direct-seeded rice (Oryza sativa L.). Twelve treatments were replicated thrice in a randomized complete-block design. The predominant weeds in the experimental area were: annual blue grass (Poa annua L.), large crab grass [Digitaria sanguinalis (L.) Scop.], jungle rice [Echinochloa colona (L.) Link.], rice flat sedge (Cyperus iria L.), perennial water primrose (Ludwigia perennis L.), chocolate weed (Melochia corchorifolia L.), and alligator weed [Alternanthera philoxeroides (Mart.) Griseb.]. Application of oxadiargyl followed by (fb) rice straw mulch at 6 t/ha and oxadiargyl fb hand-weeding registered lower weed density (25.0/m² ), biomass (13.4 g/m² ), and higher values of growth parameters (plant height, 65.1cm; tiller density, 236/m² ; dry-matter accumulation, 318.2 g/m² ) of rice. The maximum grain yield of 3.05 t/ha was recorded under the weed-free treatment, followed by oxadiargyl fb rice straw mulch at 6 t/ha (2.99 t/ha) and oxadiargyl fb hand-weeding (2.90 t/ha). Application of oxadiargyl fb rice straw mulch at 6 t/ha resulted in a higher net returns of `17,530/ha and benefit : cost ratio of 0.52.