Quantitative and Qualitative Characteristics of Tomato (Solanum lycopersicum L.) Fruit under Hydroponic Conditions

Most growers do not pay attention to the issue of proper nutrition, including the proper ratio of elements in the nutrient solution and changing the concentration of each element and their ratio at different stages growth. Lack of available information in this regard, in the present study, it has been decided to evaluate the effect of different ratios of nitrogen and potassium on the quantitative and qualitative characteristics of tomato fruit under hydroponic conditions. The balance of nutrients in the culture medium is one of the factors affecting the yield and quality of crops and horticulture. The present study was conducted to investigate the effects of different ratios of nitrogen and potassium on the quantitative and qualitative characteristics of Hirad tomato fruit in hydroponic conditions.

Treatments include concentrations of nitrogen and potassium in the vegetative and reproductive period including 1) nitrogen and potassium at concentrations of 130 and 250 ppm in the vegetative stage and 160 and 350 ppm in the reproductive stage; 2) nitrogen and potassium at concentrations of 140 and 260 ppm in the vegetative stage and 170 and 360 ppm in the reproductive stage, respectively; 3) nitrogen and potassium at concentrations of 150 and 270 ppm in the vegetative stage and 180 and 370 ppm in the reproductive stage, respectively; and 4) nitrogen and potassium were at concentrations of 160 and 280 ppm in the vegetative stage and 190 and 380 ppm in the reproductive stage, respectively.

The results showed that the nutrition of tomato plant with different ratios of nitrogen and potassium affects different characteristics of the plant such as quantitative and qualitative indicators. The highest stem diameter value was obtained in the vegetative and reproductive stages in treatment 3. Treatment 2 showed the highest yield of single plant, total acid and fruit lycopene, and in treatment 4, the highest amount of fruit chlorophyll and soluble solids was observed.

Also, the highest ascorbic acid content was obtained in treatment 1.In general, in order to achieve maximum yield and improve the quality of tomato fruit, it is recommended to use more potassium and less nitrogen.