Study the Effects of Salicylic Acid and γ-Aminobutyric Acid on Some Physiological Characteristics of Seedling and Yield of Lycopersicum esculentum cv. Seyran

Introduction Recently, the market demand for high quality tomato fruit is increasing. This product is one of the most important vegetables produced all over the world, and in the last few decades, there has always been a growing trend for its production and consumption. Today, seedling production is considered as a specialized and profitable industry all over the world, which also has a good development speed in our country. The production of healthy and strong seedlings is a prerequisite for proper plant growth and economic production, and nutrition plays an important role in this. Today, the use of natural and organic compounds in various sectors of production and agriculture is increasing. One of these organic compounds, is γ-aminobutyric acid. Biofertilizers are used in order to reduce the consumption of chemical fertilizers and thus reduce the negative environmental effects and increase the yield of plants in agricultural systems. Salicylic acid is a natural phenolic compound and one of the endogenous plant regulators that exists in most plants and is an important component in the signaling pathway. Salicylic acid is effective in regulating the process of plant growth and development, germination, flowering, opening and closing of stomata, respiration, absorption and transfer of ions, photosynthesis, maintaining membrane integrity and plant growth rate. The objective of this study was to examine the influence of varying concentrations of γ-aminobutyric acid and salicylic acid compounds on the physiological attributes, photosynthetic components, and quality traits of Lycopersicum esculentum cv. Seyran seedlings. The aim was to identify the most effective concentration of these hormonal and pseudo-hormonal compounds under the specific conditions of this research. Materials and Methods This experiment was conducted in 2017 in the research greenhouse of Shahid Bahonar University of Kerman as a factorial in a completely randomized design with three replications. Lycopersicum esculentum cv. Seyran seeds were planted and after the seedlings reached the stage of three to four leaves and were well established, the first foliar spraying was done with complete NPK fertilizer containing other micronutrients. After 75 % of the seedlings reached the five leaf stage, foliar spraying of the treatments with γ-aminobutyric acid with concentrations of 0, 5 and 10 mg/l and half an hour later with salicylic acid with concentrations of 0, 0.5 and 1.5 mM was performed. A