Residual effect of pre-sowing weed management on the purple nutsedge (Cyperus rotundus) and succeeding maize germination and yield

A study was carried out to evaluate different pre-sowing weed management methods on Cyperus rotundus and on succeeding maize germination and yield at Chinnankuppam village in Dharmapuri district, Tamil Nadu. Pre-emergence, early post-emergence and post-emergence herbicides viz metribuzin, halosulfuron methyl, glyphosate and 2, 4-D were applied at different doses to select an optimum dose suitable for the management of purple nutsedge (C rotundus) as a pre-sowing weed management method. Pre-sowing weed management treatments did not influence the per cent germination of succeeding maize. Among the pre-sowing weed management treatments early postemergence application of halosulfuron methyl at 50 g/ha followed by post-emergence application of glyphosate at 1.00 g/ha resulted in reduced density and dry weight (2.2 and 4.1/m², 0.37 and 0.70 g/m²) followed by early postemergence application of halosulfuron methyl at 75 g/ha (3.5 and 5.7/m², 0.60 and 0.97 g/m²) at 15 and 30 DAS respectively. Simultaneously both the treatments increased the weed control efficiency of C rotundus (69.16 and 58.33%) and (50.00 and 42.26%) at 15 and 30 DAS respectively. Among the treatments pre-sowing application of early post-emergence halosulfuron methyl at 50 g/ha followed by post-emergence application of glyphosate at 1.00 kg/ha recorded the higher grain (9, 387 kg/ha)and stover (9, 500 kg/ha) yield of succeeding maize.