Abstract

Results revealed that Trianthema portulacastrum a broad leaved weed was the dominant in irrigated field. Hand weeding twice (W3) followed by thiobencarb at 1.0 kg ha'' plus one hand weeding (W2) had an effective control of weeds and increased the yield attributes and grain yield of soybean. Fertilizer levels and spacings did not influence the yield. The high net return was obtained under the treatment combination of hand weeding twice adopting a spacing of 30 x 10 cm and a fertilizer dose of 20:80:40 kg N.P.K ha". This was followed by application of thiobencarb at 1.0 kg ha as pre-emergence herbicide plus one hand weeding under the same spacing and fertilizer levels.

Keywords: Soybean, Weed Control, Fertilizer, Population Levels