This investigation was carried out at El-Manyal Village, Talkha District, Dakahlia Governorate, during 2012/2013 and 2013/2014 growing seasons to evaluate the role of three times of foliar and soil applications of yeast at 60, 75 and 90 days after sowing (DAS), compared to the control  on productivity and quality of sugar beet "cv. Kawemira". The main results could be summarized as follows: 1- Spraying plants with yeast significantly increased the averages of all studied characters in both seasons compared with the control treatment (without yeast spraying), except root diameter and root juice apparent purity percentage. 2- Delaying spraying beet plants with yeast from 60 to 70 and 90 DAS resulted in gradual significant decreases in root fresh weight/plant, root length as well as root and sugar yields/fad., in both seasons. On the other side, the same treatment resulted in gradual significant increases in total soluble solids and sucrose percentages in both seasons. 3- Soil applications of yeast significantly increased the averages of root fresh weight/plant, root dimensions (length and diameter) as well as root and sugar yields/fad., in both seasons compared with the control (without yeast soil application) as well as total soluble solids percentage and root sucrose contents in the second season. On the other hand, the same treatment significantly decreased root juice apparent purity percentage in the second season. 4- Delaying soil applications of yeast from 60 to 90 DAS significantly decreased root fresh weight/plant, root length and diameter as well as root and sugar yields/fad., in both seasons and the percentages of root sucrose and root juice apparent purity in the second season. However, the same treatment significantly increased total soluble solids in the second season. 5- The interaction between times of foliar and soil applications of yeast had significantl effect on root and sugar yields/fad., in both seasons. Generally, it could be concluded that adding yeast as a foliar and a soil applications for sugar beet plants at the age of 60 days is recommended to maximize its productivity and quality under the environmental conditions of Dakahlia Governorate.