Chemical Weed control in Sunflower (Helianthus annuus L) in Dongola Locality, Northern State, Sudan

Abstract

A field experiment was conducted at the Demonstration Farm of the Faculty of Agricultural Sciences-University of Dongola- Sherg Elneel Unit, Dongola Locality, Northern State, Sudan, during two consecutive winter seasons of 2012/2013 and 2013/2014 to evaluate and compare the effects of Hadaf and Mister (two formulations of oxyfluorfen) and Stomp used pre-emergence on weed control, tolerant and yield of sunflower in an endeavour to determine the most suitable weed control treatment that secure high yield. The weed flora in the experimental site consisted of grassy and broad-leaves weeds. In both winter seasons broad-leaves weeds were predominant. The mean of both winter seasons indicated that, all herbicides treatments, and the weed free full season treatment significantly increased percentage graminae and percentage broad-leaves weeds control. Among the three herbicides used the best control of both grassy and broad-leaves weeds was achieved by the Stomp at high rate treatment (20.8 kg a.i/fed). The combined analysis of both winter seasons showed that, all herbicides treatments significantly reduced weed biomass (g/m2). The lowest weed biomass (g/m2) was achieved by the high rate of Stomp (20.8 kg a.i/fed). The combined analysis of both winter seasons indicated that, all herbicides treatments and the weed free full season treatment significantly increased growth parameters. Stomp at high rate was the best treatment among the herbicides treatments. The combined analysis of both winter seasons showed that, all herbicides treatments and the weed free full season treatment significantly increased seed yield and its components. The combined analysis of both winter seasons indicated that, unrestricted weed growth significantly reduced sunflower seed yield by 50.1%. The combined analysis of both winter seasons indicated that, among the three herbicides treatments the best seed yield (1218.4 kg/fed) was achieved by Stomp at high rate (20.8 kg a.i/fed).