Cercospora leaf spot caused by Cercospora beticola is one of the most economically important disease of sugar beet plants. Effect of di-basic potassium phosphate (K₂HPO₄), ascorbic acid and potassium bicarbonates (KHCO₃) against Cercospora leaf spot disease of sugar beet plants under field conditions was evaluated. In laboratory trial, results indicate that ascorbic acid at concentration of 2 and 3 g/l had no inhibitory effect on the tested fungus while, complete reduction in the linear growth was obtained with KHCO₃ at 20 g/l. In field trials, results indicated that the most effective treatments were K₂HPO₄ at concentration 100 mM and KHCO₃ at 20 g/l which reduced Cercospora leaf spot severity more than 70.0 and 76.7%, respectively. Treated sugar beet plants with 50.0 mM K₂HPO₄, 3g/l ascorbic acid, 10 g/l KHCO₃ and Fungicides (Ridomil-Plus at 2g/l) resulted in reducing Cercospora leaf spot severity more than 50.0%. All treatments significantly increased sugar beet yield. The highest increase was obtained with 100 mM K₂HPO₄ and 20 g/l KHCO₃ which increased sugar beet yield more than 15.2 and 17.4% and the total soluble solids (TSS) of sugar beet roots by 18.7 and 20.0%, respectively. Chitinase activity was stimulated by all treatments. Highest increase was obtained with K₂HPO₄ at concentration of 100 mM KHCO₃ at 10 and 20 g/l and ascorbic acid at 3 g/l which increased the chitinase activity more than 113.0%. It could be suggested that some chemical inducers may be used for controlling Cercospora leaf spot disease of sugar beet plants under field conditions.