Non-herbicidal Weed and Organic Nutrient Management in Maize under Rainfed Maize-Sesamum Cropping Sequence

Abstract

During 2013 and 2014, a field experiment was performed in the Instructional-Cum-Research Farm, Assam Agricultural University, Jorhat to study the effect of weed and nutrient management in maize on weeds and maize, sesamum yield. The field experiment was conducted in split plot design (SPD) and the treatments comprised of fertility management (F0 - control, F1 - 2.5 t/ha enriched compost and F2 - 5.0 t/ha enriched compost) as the main factor and weed management (W0-no weeding, W1- hand hoeing and earthing up 20 and 50 days after sowing,W2-in situ cowpea mulching upto 50 days after sowing and W3- in situ blackgram mulching upto 50 days after sowing) as the sub factor in maize and its residual effects tested in subsequent sesamum crop. It was found that W1 resulted in the least weed NPK content (%) at 60 days after sowing (DAS). In case of NPK uptake (kg/ha), W1 resulted in the least at 60 DAS and harvest. It was also noticed that W2 caused the least weed NPK content (%) at harvest during both the years. Organic nutrition had no effect on the above mentioned parameters. The residual effect of weed management and organic nutrition in the subsequent sesamum crop was nil in terms of weed suppression. It was found that W1, F2 and W1F2 resulted in significantly the best LAI of maize for both the years. Treatments W1 (3014.59 kg/ha and 2849.24 kg/ha in 2013 and 2014, respectively), F2 (2322.33 kg/ha and 2178.29 kg/ha during 2013 and 2014, respectively) and W1F2 (4723.81 kg/ha and 4507.24 kg/ha during 2013 and 2014, respectively) too resulted in significantly the highest grain yield of maize. No residual effect of weed management was found while organic nutrition had residual effect in sesamum crop. The best LAI in sesamum was due to fertility management, F2 during both the years while F1 and F2 both at par resulted in the least number of days needed for 50% flowering in sesamum. In sesamum, significant interaction effect was found only during 2014 for LAI, days to 50% flowering and yield. In terms of seed yield of sesamum, F2 (589.08 kg/ha) and F1 (556.28 kg/ha) being at par were better than F0 in 2013 while in 2014, F2 (402.78 kg/ha) was the best treatment. More benefit: cost ratio (2.56 and 2.16 during 2013 and 2014, respectively) of the maize-sesamum cropping sequence was due to F1W1.