Two field experiments were carried out in Borborema, São Paulo State, Brazil, from October to December 2001 and from February to April 2002, to evaluate the quality of watermelon fruits, hybrid Tide, as a result of potassium sources and doses. The experimental design was a randomized complete blocks, in a 3 x 4 factorial scheme with three replications. The treatments consisted of the three potassium sources (chloride, nitrate and sulphate) and four potassium doses (50; 100; 200 and 300 kg ha-1 of K2O). Total soluble solids (TSS), total titratable acidity (TTA) and TSS/TTA ratios were evaluated. Soluble solids were influenced by the growing season with higher values from February to April. Total titratable acidity increased and TSS/TTA ratio decreased when increasing the potassium doses.
Citrullus lanatus; plant nutrition; fertilizers; potassium