Document Type : Research paper

Authors

• Saeed Alah Tavakoli ¹
• Abdolhossein Abootalebi Jahromi ¹
• Abdolrasoul Zakerin ¹
• Abdolkarim Ejraei ¹
• Hamed Hassanzadeh Khankahdani ²

¹ Islamic Azad University, Jahrom Branch, Jahrom, Fars, Iran

² Agricultural Organization Fars, Shiraz, Fars, Iran

Abstract

Plant growth in hydroponic systems is affected by the nutrient solution concentration. The present study evaluated the effects of nitrogen (N) and potassium (K) on the concentration of some nutrients, chemical fruit qualities, and yield in tomatoes (Solanum lycopersicum, cv. Hirad). The experiment was arranged as a completely randomized design with four treatments (T1: N160 + K350 ppm at the vegetative stage and N130 + K250 ppm at the reproductive stage, T2: N170 + K360 ppm at the vegetative stage and N140 + K260 ppm at the reproductive stage, T3: N180 + K370 ppm at the vegetative stage and N150 + K270 ppm at the reproductive stage and T4: N190 + K380 ppm at the vegetative stage and N160 + K280 ppm at the reproductive stage). Results indicated that higher N and K supplies in the nutrient solution
decreased Ca, Na, Mn, and Zn concentrations in leaf samples. In contrast, the concentration of various elements in fruits was unaffected by the increase in N and K (except for Cu). The second treatment (T2) had the most beneficial effect on the Cu concentration in tomato leaves and fruits. The increase in total soluble solids, chlorophyll, lycopene, and total acids could improve fruit quality in tomato fruits. The best treatment in the present study was N170 + K360 ppm at the vegetative stage and N140 + K260 ppm at the reproductive stage.

Keywords

• Generative growth
• Macro and microelements
• TSS
• Vegetative growth
• Vitamin C