عنوان مقاله [English]
Introduction: Environmental stresses such as high and low light intensity are important limiting factors in the growth and development of plants. . In the natural environment, all plants are shaded to some degree by surrounding plants or themselves during their lifecycle. Salicylic acid, as one growth regulator, can increases plants resistance to high light intensity and shading. Tomato is one of the most important consumable vegetables in the world. Also, it is one of the most valuable sources of supply of minerals and vitamins in the human diet and plays an important role in human health. The objective of this experiment, was to evaluate the application of salicylic acid on some morphological and yield and its effect on reducing tomato damage in low and high light intensity conditions, which the plant growth is possible under shading conditions and excess light.
Materia and Method: In order to evaluate the effect of different shading levels (0, 25 and 50% shading) and salicylic acid (0 and 2 mM) on growth, yield and quality of tomato (Solanum lycopersicum L.), an experiment was carried out as split plot based on randomized complete block design with three replications in two cultivars Super beta and Super 6108 at research field of Moghan Pars Abad located to Ardabil province, in 2015. In this experiment stem length, internode length, leaf number, leaf area, stem and leaf dry and fresh weight, chlorophyll content, stomatal conductance and yield were measured.
Results and Discussion: The results showed that the total length of the plant, leaf number, leaf area and fresh and dry weight of leaf and stem decreased significantly with increasing shading intensity, especially in Salicylic acid control treatment. While the internode length and stomatal conductance increased with increasing shading intensity. The leaf chlorophyll content in cv. Super Beta in full sun light conditions and treated with salicylic acid was 20% higher than tomatoes with shading 50% ant treated with salicylic. The highest yield (3383 g plant) was obtained in plants exposed to full light and treated with salicylic acid, but the lowest yield (1563 g plant) was achieved in plants grown at 50% shading and without salicylic acid treatment.
Conclusion: In general, it is concluded that tomatoes grown in no shading treatment had better growth and yield. Salicylic acid application could improve the morphological properties and yield of tomato in shading conditions.
Key words: Stress modulation, Vegetative traits, Light intensity, Tomato