Accumulation of nutrients and agronomic performance of grafted seedless watermelon

ABSTRACT Chemical fertilizing is one of the main inputs that increase watermelon production costs. Watermelon grafting with compatible rootstocks and a vigorous root system may increase the efficiency of nutrients absorption. This study aimed at determining the accumulation of dry matter and nutrients, as well as the agronomic performance of grafted watermelon. The triploid 'Precious Petite' watermelon was used as graft and the Line BGCIA941 (Citrullus lanatus var. citroides) as rootstock. The experimental design consisted of randomized blocks, in a split-plot, with six replicates. The 'Precious Petite' grafted onto Line BGCIA941, ungrafted 'Precious Petite' and ungrafted Line BGCIA941 were evaluated in the plot, while the subplot corresponded to the sampling time (0, 10, 20, 30, 40, 50, 60 and 70 days after transplanting). 'Precious Petite' grafted onto Line BGCIA 941 accumulated more macro and micronutrients than the ungrafted plants, increasing fruit yield, flesh firmness and rind thickness, but it did not affect the soluble solids contents. The decreasing order for nutrient accumulation in the grafted plants was N > K > Ca > Mg > P > S > Fe > Mn > Zn > B > Cu, whereas for ungrafted 'Precious Petite' it corresponded to N > K > Ca > Mg > P > S > Mn > Fe > B > Zn > Cu.