Effect of foliar application time of salicylic acid on some of the morphology properties and pigments of tomato (Lycopersicum esculentum) fruit

Tomato plays an important role in providing vitamins and minerals in human nutrition, it has a great potential in exports. As well as it is an important vegetable due to its variety of vitamins, carotene, useful acids, sugar and minerals play an important role in human health. Regarding the fact that tomato is one of the most significant products and its consumption is rising up day after day, performing the extensive investigations is highly important in order to increase the production per unit and enhancing the quality of the fruits characteristics such as, stiffness, high preservation and increasing the pigment which affect the improvement the color and the pomace. In order to test salicylic acid on tomatoes (Supra cultivar) in Deland area in Golestan Province an experiment has been carried out based on random block design through the four replications and four treatments. A solution containing salicylic acid with 10^-4 M concentration was sprayed at different times (That is from cultivating to harvesting the products, from cultivating to the flowering, from flowering period up to the fruiting. and water solution as a control) with 15 days interval. Measuring factors in this experiment included morphological characteristics such as the number of the first cluster of leaves, plant height and number of flowers, yield components characteristics including fruit number and biochemical traits like chlorophyll a, b, total chlorophyll, carotenoids, leaves anthocyanin, fruit anthocyanin, pH and titratable acidity, respectively. Utilizing of salicylic acid from the beginning up to the end of cultivation period significantly increased the number of fruits and reasonably reduces the height of the tomato plant. Leaf area of the plants was measured by leaf area device. Determining the amount of anthocyanin took place according to the method of Vangr (1979). Arnon method (1995) was used for the measurement of chlorophyll a, b and total chlorophyll and carotenoids in tomato leaves. Application of salicylic acid from seedlings transplanting to harvest significantly increased leaf area of the plant. Application of salicylic acid from seedling transplanting until harvest time to the first cluster to increase the number of leaves, number of flowers per cluster and the number of fruit per cluster, as well as reduced plant height of tomato, significantly. According to the survey results, utilizing of typically 10^-4 M salicylic acid, as the foliar application from beginning up to the end of cultivation, causes higher total chlorophyll pigments in the plant and the overall rate of photosynthesis.