Watermelon yield and fruit quality under different graft patterns and NPK doses

Abstract

Abstract. The watermelon graft on pumpkin rootstocks protects the plant from pathogens from the soil and it could increase the yield. The purpose of this work was to evaluate the effects of rootstocks and NPK (N, P₂O₅, K₂O) doses on yield and fruit quality of the Royal Charleston watermelon hybrid. The experiment was carried out in the municipality of Santa Elena, Ecuador, between October 2014 and February 2015 on Inceptisol soil with sandy loam texture. It was evaluated three rootstocks (Shintoza, RS-841 and Ercole interspecific hybrids of Cucurbita maxima x Cucurbita moschata), three doses of nitrogen (100, 150, 200 kg ha^-1), three of phosphorus (60, 80, 100 kg ha^-1) and three of potassium (150, 200, 250 kg ha^-1) in an orthogonal design L9 (3)⁴, arranged in a completely random block design with three replicates. The variables evaluated were: stem diameter, number of fruits per plant, fruit weight, agricultural yield (t ha^-1); total soluble solids expressed as ^oBrix, flesh firmness and peel thickness. In addition, it was the “regular analysis”, which includes elaboration of the response table, selection of the optimal combination and prediction of the maximum response. The Royal Charleston watermelon hybrid grafted on the pumpkin pattern RS-841, by the approach method and the application of a mineral fertilization of 150, 100 and 150 kg ha^-1 of NPK produced the highest quantity of fruits and the yield was significantly higher than other analyzed variables.