A master’s thesis in the College of Agriculture examines the effect of foliar application of α-tocopherol and salicylic acid on the growth and yield of three tomato hybrids under protected cultivation conditions.

The College of Agriculture at the University of Diyala discussed a master’s thesis entitled “The Effect of Foliar Application of α-Tocopherol and Salicylic Acid on the Growth and Yield of Three Tomato Hybrids under Protected Cultivation Conditions.”

The study, submitted by the student Jamal Al-Din Dari Hamid, aimed to investigate the influence of α-tocopherol (vitamin E) and salicylic acid in mitigating the effects of low temperatures during the early growth stages and high temperatures during the flowering and fruit-setting stages. It further sought to enhance certain vegetative and productive traits of tomato plants cultivated under greenhouse conditions, as well as to identify the hybrids most suited to the climatic conditions of Diyala Governorate—those distinguished by superior qualitative and quantitative characteristics.

The study reached several conclusions, the most significant of which are as follows:

• The foliar application of a combined treatment of α-tocopherol and salicylic acid proved superior to all other treatments, whether applied jointly or individually, in improving the growth and yield of tomato plants under protected cultivation conditions.
• The hybrid H3 outperformed the others in most of the studied traits, indicating its strong genetic potential and high efficiency in responding to agricultural treatments and environmental conditions.
• The use of α-tocopherol and salicylic acid reduced the impact of extreme environmental conditions during the growing season. This was evidenced by the increased concentration of proline in plants treated with this combination, demonstrating the efficacy of these compounds in enhancing tolerance to environmental stresses during tomato growth.

The study recommends the following:

• Adoption of foliar application of α-tocopherol and salicylic acid at a concentration of 100 mg L⁻¹.
• Encouragement of cultivating the Sandy hybrid (H3) due to its superior performance in most studied characteristics.
• Conducting further studies to examine the effects of α-tocopherol and salicylic acid at other concentrations and on additional tomato hybrids commonly cultivated and preferred in local markets.

The thesis contributes to the achievement of the Sustainable Development Goals (SDGs).