Effects of herbicide and timing of removal on interference between barley and weeds

Abstract

Field experiments were done during the rainy season of 1984�85 and 1985�86 at Harma, Qatar. A weed survey of barley fields was conducted with the primary purpose of identifying the weed vegetation present. The effects of time of hand-weeding and of application of the herbicide metoxuron on the yield and yield components of barley were studied. Removing weeds at 15,30,45 and 60 days after sowing gave yields similar to that of the clean-weeded check. Neither a critical period nor a threshold density below which no yield loss occurred were observed. Metoxuron (1,2 and 3 kg ha?1) gave good to excellent broad-leaved and grass-weed control. The use of this herbicide at the rate of 1 kg ha?1 showed considerable promise.