Dormancy, Oxyfluorfen, Pre-sowing application, Stale seedbed, Weedy rice, Wick applicator
Weedy rice (Oryza sativa f. spontanea) is the complex of morphotypes of Oryza species, evolved largely by natural hybridization between wild and cultivated rice. With diverse biotypes, weedy rice has already infested large rice growing areas across the globe. It has also become a threat in major rice tracts of eastern and southern India. The weed has distributed in the commercial rice fields especially in areas where farmers have switched to direct-seeding due to labour shortage and high cost. Weedy rice has competitive advantage over cultivated rice as it grows taller and faster, tillers profusely and competes with cultivated rice for nutrients, light and space. It flowers much earlier than cultivated rice and produces grain that shatter easily thus enhancing the weed seed bank. Survey conducted has revealed the presence of weedy rice variants with respect to morphological characters like number of tillers per plant, height of plant, length of ligule, panicle characters, colour of grains, and length and colour of awns. Management of weedy rice infestation is complex mainly because of its morphological similarities to cultivated rice and lack of herbicides for selective control of weedy rice in cropped fields. Management options found effective for the control of weedy rice in direct seeded puddled rice include pre sowing surface application of oxyfluorfen 0.3 kg/ha, three DBS in thin film of water and selective drying of weedy rice panicles by direct contact application of glufosinate-ammonium or glyphosate or paraquat 15- 20% concentration at 60-65 DAS using specially designed wick applicator. Stale seedbed technique with dry and wet ploughing followed by the application of a broad spectrum herbicide and flooding proved to be effective in exhausting soil seed bank. Integrated management strategies are to be adopted for effective control of weedy rice.