INTERACTIVE EFFECTS OF VARIETY AND POTASSIUM NUTRITION ON GROWTH, YIELD, AND FRUIT QUALITY OF TOMATO (Solanum lycopersicum L.)

Abstract

The study evaluated the effect of variety and potassium fertilizer rates on the growth, yield, and quality attributes of tomato during the 2017 and 2018 wet seasons under field conditions. The experiment was arranged in a 3 x 4 factorial randomized complete block design involving three tomato varieties (Rio Grande, Roma VF, and Tima) and four potassium fertilizer rates (0, 50, 100, and 150 kg K ha⁻¹). Data were collected on vegetative growth, yield, and fruit quality parameters and using standard agronomic protocols. Results revealed significant varietal variation in plant height, number of leaves, and yield traits, with Roma VF and Tima generally outperforming Rio Grande. Potassium fertilization positively influenced growth and yield, with the highest values recorded at 100-150 kg K ha⁻¹. Quality parameters such as ascorbic acid, titratable acidity, and total soluble solids (TSS) improved with increasing K rates, and a significant interaction between variety and potassium rate was observed for TSS in 2018, where ‘Roma VF’ recorded the highest value (3.03%) at 150 kg K ha⁻¹. Fruit phenolic and flavonoid contents were also enhanced at higher potassium rates. Overall, ‘Roma VF’ combined with 100-150 kg K ha⁻¹ produced superior growth, yield, and quality outcomes, underscoring the importance of genotype-specific potassium management for sustainable tomato production.