Quality of seedless watermelon fruits as a function of sources and doses of potassium

The experiment was carried out in the Borborema region, State of Sao Paulo, in the period of February the April to 2002, with the objective to evaluate the quality of seedless watermelon fruits (Citrullus lanatus (Thumb.) Matsum. & Nakai) as a function of sources and doses of potassium. The experimental design was a randomized complete block, with three replications, in 3 x 4 factorial scheme, being evaluated sources: potassium chloride, nitrate and sulphate and doses 50, 100, 200 and 300 kg ha(-1) K2O. Total soluble solids (TSS), total titrable acidity (TTA), ratio TSS/TTA and rind thickness were evaluated. Soluble solids increased and ratio TSS/TTA decreased with increment of K dose. Sources and doses of potassium did not affect total titrable acidity. The biggest rind thickness was achieved with 202 and 300 kg ha(-1) K2O of KNO3 and KCl, respectively.