Chemical Weed Control in Faba Bean (Vici faba L.) in Dongola Locality, Northern State, Sudan

Abstract

Weeds constitute a major biotic constraint that limits production of faba bean (Vicia faba L.) in Northern Sudan. This experiment was conducted for two consecutive winter seasons of 2009/2010 and 2010/2011 at Dongola Research Station Farm, Dongola Locality, Northern State, Sudan to evaluate the effects of two used pre-emergence herbicides in Sudan, namely, imazethapyr (Pursuit) and oxyfluorfen (Goal) and their tank mixtures on yield of faba bean and weed control. Combined analysis of both winter seasons revealed that imazethapyr (Pursuit) at three rates of application gave poor control of grasses and broad-leaved weeds, while oxyfluorfen (Goal) at three rates gave moderate control of grasses and moderate to very good control of broad-leaved weeds. Also combined analysis referred that Pursuit at two rates low (0.050 kg.a.i./ha) and medium (0.075 kg.a.i./ha) in tank mixture with Goal at all rates (0.24, 0.44 and 0.64 kg. a.i./ha) gave effective control of grasses and broad-leaved weeds. The tank mixtures of herbicides insured persistent and effective weed control in this crop. The best control of both grassy and broad-leaved weeds was achieved with the tank mixture of Pursuit at 0.075 kg a.i./ha. with Goal at three rates (0.24, 0.44 and 0.64 kg a.i/ha.) which gave excellent weed control. Combined analysis of both winter seasons confirmed that all herbicides treatments significantly reduced weed biomass compared to weedy check treatment. The highest weed biomass reduction was achieved by herbicides tank mixtures. Combined analysis of both winter seasons indicated that unrestricted weed growth significantly reduced faba bean seed yield by 49.88% compared to full season weed free treatment. Combined analysis of both winter seasons showed that all herbicides treatments at their different rates and continuous hand weeding gave significant increase (26.33%-99.52%) in faba bean seed yield compared to unweeded control. Within all herbicides treatments the tank mixture of Pursuit at 0.075 kg a.i./ha with Goal at 0.44 and 0.64 kg a.i./ha were the best treatments which controlled annual weeds very effectively and gave significant increase in seed yield which was comparable to that obtained by weed-free full season treatment. Combined analysis of both winter seasons referred that the use of herbicides at their different rates and their tank mixtures gave significantly increased in yield and yield components. Plant height was significantly reduced by 41.84 % under full season weedy infestation. The same trend was observed for number of leaves/plant.