In order to study the effects of chemical control to defeat weeds in sugar beet farms in Sanandaj, this experiment was done in a randomized complete block design with three replications. 24 compositions of herbicides were done as treatments. The investigation on seven different herbicide, Chloredazone, Trisulfuronmethyl, Phenmedipham, Desmedipham, PDA, Clopyralid, Metamitron, in 24 different compositions showed that herbicide decreased the performance and percentage of the sugar beet in yield root up to 85% and 53% respectively. Spraying Metamitron, PDA and mixture of Desmedipham with Trisulfuron-methyl (2 liter Desmedipham and 30 gram Trisulfuron-methyl), mixture of Clopyralid and Desmedipham (0.5 Liter Clopyralid and 5 liter Desmedipham) and the mixture of PDA and Trisulfuron-methyl (4 liter and 30g) after two weeks, controlled Chenopodium album thoroughly. Spraying Metamitron and mixture of Phenmedipham and Metamitron (3 liter Phenmediphamand 2 kg Metamitron), mixture of Desmedipham and Trisulfuron-methyl (2 liter Desmedipham and 30g Trisulfuron- methyl) and mixture of Chloredazone and Trisulfuron-methyl (5 kg Chloredazone and 30g Trisulfuron-methyl) controlled Amaranthusretroflexus after one month completely. Herbicides such as Metamitron and PDA and mixture of Clopyralid and Desmedipham (0.5 liter Clopyralid and 5 liter Desmedipham) and mixture of Desmedipham and Trisulfuron-methyl (2 liter Desmedipham and 30g Trisulfuron-methyl) increased the performance of root yield up to 73.66, 70.73, 67.23 and 60.33 t/ha respectively.
