بررسي اثرات مصرف علفكش و تراكم بوته روي جمعيت علف هاي هرز و عملكرد باقلا

Evaluation of the effects of herbicide application and plant density on weed population and yield of broad bean (ViciafabaL.)

This study was conducted to evaluate the effects of herbicide application and plant density on weeds population in broad bean crop which cause significant yield loss , at the Safi Abad Agricultural Research Center, Dezful, lran from 1999 to 2001. The experimental design was a randomized complete block design with stripe plot arrangement of treatments and three replications. Row spacing was as vertical factor consisting of 45, 55 and 65 cm, plant spacing within row was as horizontal factor consisting of 10, 20 and 30 cm. Herbicide treatments were as sub-plots consisting preemergence application of Chlorthal Dimethyl at 7.5 and 9 kg ailha, post emergence application of Bentazon at 0.75 and 1 kg ai/ha plus Haloxyfop Ethoxy Ethyl at 0.25 kg ai/ha, weed free and weedy Control. Chenopodium morale L. , Malva sylvestris L. and Sinapis arvensis L. and total number of weeds were controlled and dry weight of weeds were reduced by all herbicide treatments in 1999. Beta maritima L. , Malva sylvestris L. and total number of weeds were controlled and dry weight of weeds were also reduced by all herbicide treatments in 2000. In comparison to the weedy Control, application of Chlorthal Dimethyl at 7.5 and 9 kg ailha, Bentazon at 0.75 and 1 kg ai/ha plus Haloxyfop Ethoxy Ethyl at 0.25 kg ailha and weed free Control increased broad bean seed yield by 192, 156, 453, 457 and 480% in 2000 and by 28, 34, 24, 47 and 48% in 2001, respectively. Row spacings of 45 and 65 cm with 3065 and 2292 kg/ha had the highest and lowest level of broad bean yield respectively. In zoag plant spacing within row of 10 and 30 cm with 2631 and 1989 kg/ha had also the highest and lowest yield, respectively. However, in 2001, plant spacing within row of 20 and 30 cm with 3781 and 2466 t/ha had the highest and lowest yield, respectively. Post-emergence application of Bentazon at 0.75 or 1 kg ai/ha plus Haloxyfop Ethoxy Ethyl at 0.25 kg ai/ha or pre-emergence application of Chlorthal Dimethyl at 7.5 or 9 kg ai/ha or two hand weedings at 5 and 11 weeks after planting , row spacing of 45 cm and plant spacings within row of 10 or 20 cm are recommended for effective weed control and grain yield increase in broad bean fields under safiabad, Dezful conditions.