Effect of nitrogen and potassium fertilisation on melon plant productivity

The objective of this investigation was to evaluate the effect of different doses of nitrogen and potassium on the productive characteristics of melon plants. The experiment was carried out in San Roque, which is 24km from the city of Concepción, Paraguay, longitude -57.236192 and latitude 23.320015. The study design consisted of subdivided 4x4 plots with three repetitions. The dose used in the main plot was of N (0, 50, 100, 150 kg ha-1) and in the sub-plot, K (0, 95, 190, 285 kg ha-1). A light harrow was carried out to prepare the soil, seedlings were produced in 1500 cm3 pots of 60-micron thickness and the transplant was carried out when the seedlings had between 4 and 6 true leaves at 30 days after planting. Urea with 45% N was used as the source of nitrogen and potassium chloride 60% was used as the source of potassium. Fertilisation was carried out on two occasions: at 15 and 30 days after transplanting, in September 2017. The spacing used was of 1.5 m x 1.5 m, giving a total of 4356 pl ha-1. Harvesting began 90 days after planting and was carried out three times as the fruits reached commercial ripeness. The determinations that were measured were average fruit weight, total soluble solids, polar diameter, equatorial diameter, fruit weight per plant. An analysis of variance was carried out on the data for each one of the variables using Fisher’s exact test. Where significant differences were found, regression analysis was carried out and the significance of equations was verified using the F-test. The values obtained for average fruit weight, total soluble solids and polar diameter of fruits were positively influenced by doses of nitrogen and potassium. The dose combination that produced the best values for equatorial diameter and fruit weight per plant was 50 kg ha-1 of nitrogen and 95 kg ha-1 of potassium.