The Effects of Temperature and Potassium Fertilizer on the Growth, Yield, and Biochemical Parameters of Ipomoea batatas var. Antin-1

The impact of temperature and potassium fertilizers on the growth, yield, and basic biochemical characteristics of sweet potato, Ipomoea batatas var. Antin- 1, was investigated in lowland and highland terrains. In this study we aimed to determine the different traits of the sweet potato, based on its morphology, physiology, and biochemical composition, following treatments with a potassium fertilizer at different temperatures. The study was undertaken using a nested factorial design. The first factor was temperature at each of the two sites: T1 (lowland) and T2 (highland). The second factor was potassium fertilizer (K 2 O) nested within the temperature factor and consisting of four levels of K: K0 (0 kg/ha), K1 (50 kg/ha), K2 (100 kg/ha), and K3 (150 kg/ha). Each potassium treatment was replicated three times at each location. Plant vegetative growth in the lowland region, with a daily average temperature of 26.8 °C, tended to be more bushy, with several different morphological properties: The main stem was longer (160.7 cm) and spreading, the stem diameter was greater, and the petioles were significantly longer in the lowland plants compared with the highland plants; however, no differences were observed in the leaf characteristics. The differential temperature (depending on altitude) resulted in significant differences in relative growth rates (RGR) and net assimilation rates (NAR); the values for RGR-1 and NAR-1 in the lowlands were higher than those in the highlands. The tuber weight, yield index, anthocyanin accumulation, and glucose content were significantly higher in the highland crops than in the lowland plants, which grew under relatively higher temperatures. Potassium applications caused significant differences in the anthocyanin content (mg/100 g fresh weight), anthocyanin production (kg/ha), and glucose production (kg/ha) at different locations.