Epsilon Archive for Student Projects

Abstract

Appropriate nutrient availability supports plant growth and enhances both yield and fruit quality in horticulture. In particular, managing potassium (K) levels can influence tomato growth and fruit quality. This study evaluated the effects of potassium enrichment on tomato growth, yield, and fruit quality under greenhouse conditions. Tomato plants were grown in a completely randomized design with three potassium treatments: 100% standard K level (control), enrichment level using 150% K, and enrichment level using 200% K, with seven biological replicates per treatment. Data were analyzed using one-way ANOVA followed by Tukey's HSD test (p ≤ 0.05) to compare the treatment means. Increasing potassium concentration affected several yield and fruit quality parameters. Fruit yield decreased from 406.64 g plant⁻¹ to 374.70 g plant⁻¹, while the number of clusters decreased from 10.6 clusters plant⁻¹ under 100% K to 7.3 clusters plant⁻¹ under 200% K, respectively. Chlorophyll content measured after harvest increased with potassium enrichment, from 30.48 under 100% K to 40.70 under 200% K. Titratable acidity varied among treatments, with the lowest under 200% K (0.363) and the highest value under 150% K (0.503). Consequently, the total soluble solids to titratable acidity ratio was highest under 200% K (16.71), compared with 13.36 and 12.37 under 100%K and 150% K, respectively. Potassium treatments did not significantly affect plant height, biomass production, fruit number, fruit pH, total soluble solids and chlorophyll content before harvest. Although the total soluble solids to titratable acidity ratio increased under 200% potassium, this change was mainly associated with reduced titratable acidity rather than increase in total soluble solids. These findings indicate that increasing potassium concentration above the 100% potassium levels used in this study did not improve plant growth performance or fruit yield and altered fruit quality through changes in acidity rather than increased sweetness under the tested greenhouse conditions.