*3.2. Impacts of Foliar Applications of GA3 on Sugar Beet Growth and Yield Parameters*

Data collected in Table 2 reveal that increasing the concentration of GA3 from 0 to 80, 160, and 240 mg/L significantly increased root length, root diameter, root fresh weight/plant, foliage fresh weight/plant, and root yield/ha in the two seasons. However, no significant differences were detected between the concentration of 0 mg/L (control) and 80 mg/L on root length. Additionally, the differences between plants treated with GA3 at 160 mg/L and those treated with 240 mg/L did not reach the significance limit in both seasons for the same trait. In the first season, foliar spraying of GA3 with 240 mg/L recorded an increase in root length by 6.7, 5.3, and 1%, root diameter by 8.8, 4.7, and 1.8%, root fresh weight/plant by 9.4, 5.5, and 2.1%, foliage fresh weight/plant by 34.8, 17.3, and 6.3%, as well as increasing root yield/ha by 10.2, 5.7, and 2.0% compared with the applications of 0, 80, and 160 mg/L, respectively. The same trend was recorded in the second season, where the increase was estimated as 5.7, 4.6, and 1.3% in root length, 9.1, 4.9, and 1.9% in root diameter, 8.1, 4.2, and 2.2% in root fresh weight/plant, 36.9, 16.5, and 9.5% in foliage fresh weight/plant, and 9.2, 4.9, and 2.4% in root yield/ha.

As shown in Table 3, significant effects were found in foliage yield/ha, sucrose, and TSS percentages, as well as sugar yield/ha due to GA3 foliar spraying concentrations. This was clear in both seasons of study, while the differences in purity percentage in both seasons did not reach the level of significance due to the effect of GA3 concentration. Foliar spraying of GA3 at 240 mg/L gave the highest values of foliage yield (42.5 and 40.0 t/ha) in the first and second season, respectively. On the contrary, along with each increase in GA3 concentration, the percentage of sucrose, TSS, and purity had negative impacts. Regarding sugar yield/ha, as the concentration of GA3 increased to 160 mg/L, sugar beet

plants produced more sugar yield by about 5.3 and 4.4%, 2.2 and 1.5%, and 2.1 and 1.0% against concentrations of 0, 80, and 240 mg/L in the first and second season, respectively.

**Table 3.** Means of foliage yield (t/ha), sucrose (%), TSS (%), purity (%), and sugar yield (t/ha) as affected by nitrogen fertilizer levels and GA3 spraying concentrations and its application time in the 2014/2015 (I) and 2015/2016 (II) seasons.


\* and NS indicate significance at 5% level of probability, and not significant, respectively. Means followed by the same letter(s) is/are not significantly differ at 5% level of probability; DAP = Days after planting.
