Abstract

In upland direct seeded jhum rice, weed infestation is a serious problem, which results in drastically reduced the crop yield. Average yield of rice crop in North-Eastern Hilly region including the Nagaland is very low due to non-availability of adequate and suitable crop production technology. Among them, the principal factor associated with low yield in jhum rice is severe weed competition. Jhum farmers of this region traditionally apply common salt (NaCl) in upland rice as a post-emergence to manage broad leaf weeds. Keeping the above facts in view, an efforts have been made to study the validation of indigenous technical knowledge for weed management in upland jhum rice to evolve a feasible weed management practices for tribal community of the region. Therefore, a replicated field experiment with rice cv. Bhalum-3 was conducted during kharif seasons of 2013 and 2014 at farmers’ field in Medziphema village of Dimapur district in Nagaland. The following 12 treatments of common salt (2–20% or 20–200 kg/ha) including control and weed free check were imposed in completely randomized block design and replicated thrice. The common salt was applied as foliar spray through flat fan nozzle using water as a carrier @ 500–600 l/ha at 20 and 40 DAS to the rice. Results revealed that altogether 17 weed species were identified in upland jhum rice, among them the broad-leaved weeds viz. Borreria hispida, Urena lobota, Eupotorium odoratum and Biden pilosa noted the prominent weed flora. Application of increasing levels of common salt i.e. 2 to 20% NaCl increased weed control efficiency (WCE%) but highest values were recorded with application of 20% common salt at 20 DAS as compared to salt applied at 40 DAS. Among the levels of common salt, application of 10% NaCl gave significantly higher grain yield (2315.6 kg/ha) as compared to their preceding levels except weed free check (2517.7 kg/ha).