Integrated weed control of sugar beet in Dezful and Boroujerd

This experiment was conducted in 2002 to 2004 to evaluate the co-efficacy of reduced rates of herbicides and cultivation for weed control in sugar beet at the Safiabad Agricultural Research Center of Dezful and Agricultural Research Station, Boroujerd, I. R. Iran. The experimental design was a randomized complete block with stripe plot arrangement of treatments with three replications. Cultivation was as vertical factor at three levels including: application of shovel and blade cultivator at 6 to 8 leaf stage of sugar beet and repeating it one month later, and uncultivated treatments. Herbicide application was as horizontal factor at eight levels including: application of chloridazon + phenmedipham at 3.2 + 0.78 and 2.4 + 0.63 Kg ai ha-1, phenmedipham + desmedipham + ethofumesate at 0.54 and 0.72 Kg ai ha-1 at 4 to 6 leaf stage of sugar beet, triflusulfuron at 10 and 15 g ai ha-1 at cotyledon leaf stage of sugar beet, weed free and weedy controls. Results showed that in 2002, at Safi Abad and Boroujerd application of chloridazon + phenmedipham at 2.4 + 0.63 and 3.2 + 0.78 Kg ai ha-1 were effective treatments in controlling broadleaf weeds and had also the highest level of sugar beet root yield after the weed free controls. In 2003, at Safiabad, application of phenmedipham + desmedipham + ethofumesate at 0.72 Kg ai ha-1 was the most effective treatment in controlling broadleaf weeds, but in Boroujerd there were not significant difference among herbicide treatments and application of chloridazon + phenmedipham at 2.4 + 0.63 Kg ai ha-1 and triflusulfuron at 10 g ai ha-1 had the highest level of sugar beet root yield after the weed free control at Safiabad and Boroujerd, respectively. Application of shovel and blade cultivator compared to uncultivated plots increased sugar beet root yield by 11 and 27%, respectively. According to this experiment application of chloridazon + phenmedipham at 2.4 + 0.63 and 3.2 + 0.78 Kg ai ha-1, phenmedipham + desmedipham + ethofumesate at 0.72 Kg ai ha-1 at 4 to 6 leaf stage of sugar beet and triflusulfuron at 10 g ai ha-1 at cotyledon leaf stage of sugar beet together with the application of shovel or blade cultivator at 6 to 8 leaf stage of sugar beet repeated at re-emergence of weeds is recommended