Influence of plant biostimulant and spacing on production and postharvest conservation of watermelons cv. Quetzali

The aim of this study was to evaluate the influence of pre-harvest application of plant biostimulant Crop Set® and different plant spacings on the production attributes and postharvest quality of watermelon ‘Quetzali’. The experiment was set up in a completely randomized split-plot (3 × 2 × 4) design, corresponding to three plant spacings (0.40, 0.45 and 0.50 m), application of the plant biostimulant (with and without) and four storage periods at 10°C and RH 90% (0, 14, 21 and 28 days). Fruits were assessed after harvest in terms of average mass of fruits, number of fruits per plant and yield, and throughout the storage periods for flesh firmness, soluble solids content (SSC), titratable acidity (TA), SSC/TA ratio, pH and total soluble sugars (TSS). The average mass of fruit (4.02 kg) was higher in the larger spacing without application of biostimulant. The pre-harvest application of plant biostimulant negatively influenced SSC of fruits, depending on the plant spacing and storage periods. For TA and TSS content, the effect of this product varies with plant spacing and storage days. The lower plant spacing provided higher TSS to the fruits.