Effect of different potassium fertilizers on yield and quality of tomato (Solanum lycopersicum L.) under drought stress conditions

The experiment was carried out in open field conditions in Ciğir village, located in the Idil district of Sirnak province, during 2020 tomato growing season. The aim of the study was to investigate the effect of different potassium (potassium chloride, potassium sulfate and potassium nitrate) fertilizers on yield and quality characteristics of tomato plants (Fereng genotype and Kamenta F1 variety) grown under drought stress. The fertilizers were foliar applied at a dose of 1%. Irrigation treatments of the experiment were full irrigation (control, 100%), 66% of the full irrigation, and 33% of the full irrigation. Leaf temperature, relative water content of leaf, chlorophyll content, fresh and dry weight of green parts, membranes injury index, soluble solid content (SSC) in tomato juice, pH of tomato juice and total yield were determined. The results indicated that drought stress had a significant adverse impacts on yield and quality of both Fereng genotype and Kamenta F1 variety. The application of potassium nitrate and potassium sulfate caused an increase in the chlorophyll and water soluble solid content. Potassium chloride application resulted in a reduction in membrane damage. The effects of potassium sulfate fertilizer on yield was significantly higher than the other two potassium fertilizers.