Improving Tolerance of Cabbage Plants to High Temperature Stress by Using Some Treatments.

This study was carried out during the two summer seasons of 2021 and 2022 at Shabrawish Village, Aga, Dakahila Governorate, on cabbage cv. Balady to improve tolerance of cabbage plants to high temperature stress by using some treatments as following (potassium nitrate at rate of 1%, magnesium sulfate 0.5%, calcium chelates 0.5 %, proline 150 ppm, salicylic acid 100 ppm, mannitol 500 ppm, alpha- tocopherol 150 ppm in addition to control) tap water). All treatments exhibited significant influence on growth, yield and quality of cabbage, the obtained results indicated that the vigorous cabbage plants, i.e. plant height, number of outer and inner leaves as well as fresh and dry weight percent per plant additionally to yield and its components were recorded with plants which received foliar sprayed at 0.5 % of magnesium sulfate, in both seasons, the highest percentage of N and K were recorded with  1% of potassium  nitrate  moreover, P was increased  in response to  foliar spraying salicylic acid at 100 ppm in both seasons meanwhile, alpha- tocopherol gave the highest values of chlorophyll a, b content and total chlorophylls, total soluble solid and  ascorbic acid in head leaves in both seasons compared with the other treatments.
The results indicated that foliar applied magnesium sulphate at a rate of 0.5% was the most effective treatments for enhancing the growth and yield of cabbage plants, also, potassium nitrate and alpha tocopherol treatments showed the most significant in mineral nutrients and quality of cabbage plants grown under high temperature stress conditions.