Weed dynamics and productivity under different tillage and weed-management practices in maize (Zea mays)-wheat (Triticum aestivum) cropping sequence

A field experiment was conducted during 2013–14 and 2014–15 at Sher-e-Kashmir University of Agriculture Science and Technology of Jammu, to study the effect of tillage and weed-management practices on weed dynamics and productivity in maize (Zea mays L.)-wheat (Triticum aestivum (L.) emend. Fiori & Paol.] cropping sequence. Weed density, weed biomass, grain and stover yields of maize were found statistically at par in continuous conventional tillage and rotational conventional tillage in maize and zero tillage in wheat under maize. However, in wheat the density and biomass of grassy weeds were found significantly lowest under continuous zero tillage preceded by zero tillage or conventional tillage in maize. The different tillage treatments had non-significant effect on density and biomass of broad-leaf weeds and yields (grain and straw) of wheat. Amongst the weed-management practices, 2 hand-weedings 15 and 30 days after sowing (DAS) in maize and application of metribuzin (200 g/ha) at 30 DAS in wheat significantly reduced weed density, biomass and recorded significantly higher yields of maize and wheat respectively, over weedy check in both maize and wheat. Among the tillage treatments, adoption of zero tillage in maize and conventional tillage in wheat also proved economically beneficial with the highest benefit: cost ratio and the lowest cost of cultivation in maize-wheat system followed by continuous zero tillage in both the crop. However, in weed management, application of atrazine 1 kg/ha in maize and metribuzin (200 g/ha) in wheat resulted the highest benefit: cost ratio and net returns followed by 2 hand-weedings. At the end of the maize-wheat cropping cycles, both tillage and weed-management practices did not influence on status of bulk density of the soil.