Effect of Ascorbic Acid and Zinc on the Productivity of Sunflower (Helianthus annuus L.) under Saline Stress Conditions

Saltiness is the most restricting factor for agriculture in arid and semi-arid regions, in addition to zinc is deposited in forms not accessible to plants in calcareous soils. Generally, less availability of nutrients associated salinity is a stumbling block in front of the agricultural expansion. Therefore, during the 2018 and 2019 seasons, two field experiments were conducted at the Desert Research Center, Agriculture Experimental Station at Ras Sudr, South Sinai Governorate, Egypt. The cooperative impact of seed priming by soaking seeds in ascorbic acid at 0, 100, 200, and 300 mg ASC/L and the soil application of zinc at the rates of 0, 3, 6, 12, and 24 kg zinc sulfate/ha on sunflower yields and its attributes were studied. The results reported that plant height, head diameter, number of seeds/head, seed weight/head, seed index, in addition to biological, seed and oil yields and seed oil content responded considerably to ascorbic acid (ASC) in both seasons. In this connection, sunflower seeds soaked in 200 mg ASC/L was the Potency practice compared to other treatments in both years. While zinc application (ZnSO4) significantly affected all the aforementioned traits in both seasons. The findings of this study suggest that soaking sunflower seeds in 200 mg/L ASC alongside with ZnSO4 fertilization at a rate of 12 kg/ha could be used to alleviate the harmful effects of salinity stress and consequently could improve the sunflower yield.