Two field experiments were conducted at Al-Noran Farm, Al-Abtal Village-East of Suez Canal, Ismailia Governorate (latitude of 30⁰ 18 N and longitude of 32⁰ 30 E) in 2013/2014 and 2014/2015 seasons to evaluate the performance of three sugar beet varieties and their response to different levels of humic acid and potassium fertilizer on growth, yield and quality of sugar beet crop (Beta vulgaris var. saccharifera, L.) under sandy soils conditions irrigated by center pivot system. The  present work included twenty seven treatments, which were the combinations of three mono-germ sugar beet varieties: (1. Natoura, 2. Henrike and 3. Polat varieties), three levels of humic acid  (without humic acid; 10 liter and 15 liter of humic acid/400 liter water/fed, furthermore three levels of potassien-P compound (30% K₂O and 8% P₂O₅/l as foliar application): without potassien ; one liter and 2 liters /400 liter water/fed. Humic acid treatments were added twice after full emergence and 10 days later after the initial spray. Potassien levels were sprayed twice at 6-8 and at 8-10 leaf stage later. The treatments were arranged in strip split plots design with three replications in the two seasons. Results indicated that varieties significantly differed among them where, Polat variety show the superiority over the other two tested varieties and recorded the highest values of root diameter, fresh and top weights/plant, top yield/fed in both seasons as well as root and leaves dry weights% in 2^nd season, while insignificant differences were found between Polat and Henrike varieties in root diameter and top fresh weight/plant in the 1^st season, root fresh weight/plant and LAI in the 2^nd season. There were no significant differences among varieties in their impact on gross and corrected sugar yields/fed in both seasons. Soil application of 15 l humic acid treatment led to significant increase in most of traits where, it achieved thickest and heaviest tops and roots/plant and higher values of root and top dry weights%, leaf area index, root and top dry weights/plant, root, top and sugar yields/fed in both seasons as well as gross sugar% and corrected sugar% in 2^nd season only, as compared to 10 liter humic acid/fed. While, there were no significant differences among the two rates in their impact on gross and corrected sugar yields/fed in both seasons. Foliar application of 2 l potassien/fed increased LAI, root diameter, root and top fresh weights/plant, root and top dry weights%, gross sugar%, corrected sugar%, quality index, root and sugar yields/fed in both seasons as well as reduced Na and alpha amino-N contents in comparison to the check treatment. The interaction between tested sugar beet varieties and humic acid levels showed that significant increase in root dry weight% in both seasons, root fresh weight/plant in the first season and quality index in 2^nd season when Polat variety planted in soil treated with 15 liter humic acid/fed. While, sowing Polat variety in soil was treated with 10 liter humic acid/fed recorded the highest significant value in top fresh weight/plant in the 1^st season only. The interaction effect between tested sugar beet varieties and potassien levels indicated that Polat variety sprayed with 2 liter potassien/fed was more distinguished as compared to the other two varieties. The interaction effect between humic acid and potassien levels revealed that the highest significant values in root fresh weight/plant, root dry weight% in both seasons, top fresh and dry weights/plant in the 1^st season, as well as root and gross sugar yields/fed in 2^nd season were between soil application of 15 liter humic acid along foliar application of 2 liter potassien/fed in both seasons. it could be concluded that sowing polat variety fertilized with combination of humic acid at rate of 15 liters/fed as a soil applicaion along with sprayed 2 l/potassein/fed to get  the maxiumum of root and sugar yields/fed |in sandy soils under center pivot irrigation system.