Growth, yield, and quality of selected watermelon (Citrullus lanatus L.) varieties as influenced by NPS+UREA fertilizer rates over the seasons at Arba Minch, Gamo Zone, Southern Ethiopia

Abstract

Watermelon (Citrullus lanatus) has been produced in Ethiopia in small land coverage for economic value. The production of watermelon is hindered by diminished quality and yield, primarily due to insufficient agronomic practices, the unavailability of suitable varieties, and inadequate fertilization. The research was conducted at the Research Farm of Arba Minch University, Ethiopia, in the 2023 Belg and Meher seasons to evaluate the effect of watermelon varieties and NPS+UREA fertilizer rates on the watermelon growth, yield, and quality over seasons. The experiment was structured using a randomized complete block design in a factorial configuration with three replications, and the treatments consisted of a combination of three varieties, Polymer, Lahat, and Liyu, with four fertilizer rates: control, 0.05 t/ha, 0.1 t/ha, and 0.15 t/ha NPS+UREA. Growth, yield, quality, and meteorology data were collected, and R software version 4.4.1 was used perform a two-way ANOVA. Results indicated that more leaves, the longest and widest leaf, the longest vine length, and more secondary vines were recorded by the combination effect of the Liyu variety with 0.15 t/ha NPS+UREA at 30 DAS, 45 DAS, and 60 DAS at the Belg and Meher seasons, respectively. In addition to a higher fruit number of 8.3 and the highest fruit length of 28.6 cm. Whereas, the highest fruit width (23.1 cm), highest fruit weight (3 kg), and highest marketable yield (30.4 t/ha) were recorded with the effect of the Liyu variety in the Meher season. Moreover, a total soluble sugar of 8.5° Brix and Vitamin C of 8.5 mg/100 g were recorded with the interaction of the Liyu variety with the 0.15 t/ha NPS+UREA fertilizer rate at Meher and Belg, respectively. Therefore, it was concluded that 0.15 t/ha NPS+UREA/ha and the Liyu variety in the Meher rainy season revealed the highest growth, yield, and good fruit quality. This combination showed better performance than other varieties and NPS+UREA fertilizer rates.

Keywords: Growth, NPS+UREA, Quality, Season, Variety, Watermelon, Yield