Influence of redroot pigweed (Amaranthus retroflexus) density and biomass on peanut (Arachis hypogaea) yield

Abstract

Studies were conducted in 2004 and 2005 to evaluate the effect of redroot pigweed on peanut. Redroot pigweed aboveground dry weight was 44, 42, 40, 38, 35 and 30 g plant^-1 at density of 0.2, 0.5, 0.8, 1.2, 2.3, or 4.7 plants m^-1 of crop row. Peanut yield decreased as weed density increased. Yield reduction under redroot pigweed interference was 4.1 and 63.9% at 0.2 and 4.7 plants m^-1 crop row, respectively. The results suggest that redroot pigweed is a strong competitor with peanut and should be controlled to prevent high peanut yield loss.

Key words: Competition, Amaranthus retroflexus, density, interference, peanut, biomass.