Tuber yield and quality of potato crop in response to nitrogen fertilization management

Abstract

The optimization of nitrogen (N) fertilization with the N supply during the period of greatest demand by plants is a strategy to maximize the yield and quality of potato tubers (Solanum tuberosum L.). Thus, the objective of this study was to evaluate the tuber yield and physical-chemical and nutritional quality of tubers of the potato cultivars Agata and Markies submitted to different forms of traditional N management combined with the application of N rates in the phase of tuber bulking. Two experiments will be conducted, one with the cultivar Agata and the other with the Markies, during two consecutive years, in the winter growing season. The experimental design used in both experiments will be in randomized blocks, with a 4 x 4 factorial scheme with four replications. The forms of traditional N management will be: M1 = 160 kg ha-1 N at the planting; M2 = 80 kg ha-1 N at planting; M3 = 40 kg ha-1 N at planting and 120 kg ha-1 of N at hilling (20-25 days after planting - DAP); M4 = 80 kg ha-1 N at planting and 80 kg ha-1 N at hilling, combined with the N rates of 0, 20, 40, and 80 kg ha-1 applied in the phase of tuber bulking (between 50 and 55 DAP). In the two experiments, the agronomic traits of the potato crop, the use efficiency of N taken up for the biomass production and tubers yield, the fertilizer N recovery efficiency and the physical-chemical and nutritional characteristics of tubers will be evaluated. The obtained data will be submitted to analysis of variance separately by experiment. The means of traditional N management will be compared by the LSD test (pd0.05), while the N rates applied in the tuber bulking phase will be submitted to regression analysis (pd0.05). (AU)