Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore-641 003, India.
Dominant weeds of soybean in different locations of India have been compiled. Trianthema portulacastrom, Flaveria australasica, Amaranthus viridis, Cynodon dactylon, Dactyloctenlum aegyptium, Echinochloa colonum and Cyperus rotundus were the major weed species found in soybean at Coimbatore, Tamil Nadu, India. Soybean yield was adversely affected by the weeds due to their competition for nutrients and moisture during early growth stages. Most of the reports indicate that critical period of crop - weed competition to be upto 45 days after sowing for soybean. Soybean yield reduction ranged from 10 to 86 per cent depending upon weed infestation.
