Weed control in wheat (Triticum aestivum) under rice (Oryza sativa)-wheat system of north Bihar.
A field trial was undertaken at Madhopur on a sandy loam soil during the winter seasons of 1987-88 and 1988-89 to investigate the effects of sowing time (normal or late sowing) and the post-emergence application of 2 isoproturon group herbicides (Arelon and Tolken at 0.5 or 1.0 kg ai/ha) or hand-weeding on weed control and a wheat cv. UP 262 crop. The dominant weed species present were Chenopodium album, Anagallis arvensis, Melilotus alba, M. indica, Fumaria parviflora, Vicia sativa, Convolvulus arvensis, Cyperus rotundus and Cynodon dactylon. Timely sowing of wheat resulted in an increase in effective tillers/m2, while the application of 0.5 kg/ha Arelon or Tolken resulted in the highest yield and additional net returns compared with the application of 1.0 kg ai/ha.