Three independent samples of at least 3 injury-free watermelon fruits for each cultivar were hand harvested randomly at
four ripening stages indicated as white (60 days after sowing): low fruit size and white flesh; white-pink (66 days after sowing): not yet mature fruit with white-pink flesh; pink (73 days after sowing): large fruit size with pink flesh and green tendril; red-ripe (80–90 days after sowing): mature fruit with red flesh, brown tendril and yellow ground spot (Fig. 1)