A field experiment was carried out with the aim of studying the effect of graduated concentrations of cobalt sprayed on plants on some growth characteristics of sweet corn crops under water stress conditions for the two autumn seasons 2018 and 2019. Use of a Randomized Complete Block Design (R.C.B.D.) according to the spilt-plot arrangement with three replications. The main-plots included three levels of water stress, which are irrigation after depleting 30, 50 and 70% of the available water, with symbols W 1 , W 2 and W 3 respectively. While the cobalt solution spraying concentrations represented 0, 4, 8 and 12 mg L -1 and symbolized as CO 0 , CO 1 , CO 2 and CO 3 respectively on the Subplots. The results showed that there were no significant differences between the two irrigation treatments after depleting 30 and 50% of the available water, with regard to the number of days to 50% tasseling, plant height, number of leaves, leaf area, plant dry weight and crop growth rate for both seasons. Whereas, irrigation after depleting 70% of the available water led to a decrease in all the studied characteristics. While the cobalt spray concentrations significantly affected most of the studied traits, except for the number of days to 50% tasseling and number of leaves. The treatment of spraying with a concentration of 12 mg L -1 significantly outperformed the rest of the treatments with the highest average plant height reaching 148.60 and 148.66 cm, leaf area 3547.00 and 3703.00 cm 2 plant -1 , plant dry weight 150.63 and 151.30 g plant -1 and crop growth rate 2.96 and 2.79 g m -2 day -1 compared with the comparison treatment CO 0 (distilled water) respectively, For the two seasons. The interaction between water stress and cobalt treatments was significant in the characteristic of plant height, leaf area and plant dry weight for both seasons. Therefore, we recommend the possibility of irrigation after depleting 50% of the available water without a significant effect on the vegetative growth characteristics, as well as the possibility of treating sweet corn plants with cobalt at a concentration of 12 mg L -1 to improve their ability to withstand water stress conditions.