Effect of tillage practices and herbicides on weed dynamics and yield of wheat (Triticum aestivum) under transplanted rice (Oryza sativa)-wheat system in Vertisols

A field experiment was conducted during the winter season of 2000–2001 and 2001–2002 at Jabalpur, to study the influence of tillage and herbicides on weed dynamics and yield of wheat (Triticum aestivum L. emend. Fiori & Paol.) under rice (Oryza sativa L.)-wheat system in Vertisols. The zero-till planting reduced the infestation of Phalaris minor Retz. and Chenopodium album L. but increased the problem of wild oat (Avena sterillis ssp. ludoviciana). Grain yield of wheat was similar in all the tillage systems. Unchecked weed competition reduced the grain yield by 23.4% and 22.3% compared to metribuzin and isoproturon, respectively. Application of isoproturon 1.0 kg/ha at 25 days after sowing (DAS) and metribuzin 0.30 kg/ha at 35 DAS significantly reduced the population of P. minor and C. album during both the years and resulted in significantly higher grain yield than weedy check but it failed to control wild oat. The highest mean net returns (Rs 6,571/ha) were obtained from zero tillage and application of isoproturon 1.0 kg/ha. Seeds of P. minor and C. album were higher in deep tillage and A. ludoviciana and Medicago hispida in zero tillage and they were mostly distributed in upper 1 cm soil depth. Deep tillage retained higher soil moisture than zero tillage.