Reflection of different applications of potassium and iron fertilization on tomato yield and fruit quality in soilless medium

Potassium and iron are the main elements that are of great importance in soilless medium in terms of tomato yield and fruit quality. For this reason, the effects of these elements on yield and fruit quality parameters were investigated. Three different combinations of potassium (150, 300 and 450 mg l(-1)) and iron (1,2 and 3 mg l(-1)) ratios were evaluated. The experiment was conducted according to completely randomized factorial design with 4 replicates. The interaction between potassium and iron applications was significant in yield, total soluble solids, fruit firmness and a*-value. Moreover, titratable acidity, total soluble solids content and pH of fruit juice showed increase by ascending K applications. There were no effects of K and Fe applications on ascorbic acid, fruit diameter, L* and b* values. These results indicated interactive effects between potassium and iron applications on fruit quality and yield are more complex structure. Therefore, detailed investigations are required in different growing medium, ecological condition and on tomato variety.