Author(s): S. KORAV, V. RAM AND L.I.P. RAY

Abstract: A field experiment was carried out during kharif and rabi seasons of 2016-17 at the experimental farm of the College of Post Graduate Studies (CAU, Imphal), Umiam, Meghalaya, India. The experiment was conducted in a randomized block design, replicated thrice with twelve treatments viz., weeds until 15, 30, 45, 60, 75 days after emergence (DAE), weedy check and weed free until 15, 30, 45, 60, 75, weed free check. Critical period for crop-weed competition under 5 and 10 per cent relative yield loss were determined through Logistic and Gompertz equations. The results showed that weed dry matter tended to decrease with increasing weeds free condition up to harvest. It was observed that the lowest weed dry matterassociated with weed free check. While, weedy check resulted in the highest weed dynamics. The highest values of yield and yield attributes were higher with weed free check, and lowest with weedy check. The critical period for weed competition under 5 per cent YIELD LOSS at kharif was 16 to 66 and rabi was 15 to 63 DAE. The estimated critical period for groundnut at 10 per cent YIELD LOSS were 22 to 62 and 21 to 61 DAE in kharif and rabis easons, respectively. The accumulated heat units of kharif and rabi seasons followed linear and quadratic trend might be the reasons for variations in the competitive period of seasons. The present study was concluded that early groundnut stage up to 15-16 DAE is more sensitive for crop weed competition to cause significant yield loss. And early stages rabi groundnut was more susceptible for competition than kharif as compare to later stage.

DOI: 10.22271/09746315.2020.v16.i1.1296

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