Response of Amaranthus cruentus cv Mexicano to nitrogen fertilization under irrigation in the temperate, semiarid climate of North Patagonia, Argentina

This article explores the response of three genotypes of Amaranthus to different sowing date and to different doses of nitrogen (N) fertilization. The experimental design was a randomized complete block design with three replicates for cultivars, planting date and fertilization per treatment. Mexicano sown in early December had the best yield (5285 kg ha(-1)) with highly significant differences (p < 0.001) respect to Dorado and Antorcha. To assess the N fertilization Mexicano cultivar was sown at the end of spring (1 December). Morphophysiological variables increased as the N fertilization dose was raised. Higher doses of N fertilizer resulted in greater economic yields this was mainly due to the increase in grain number rather than that of a 1000 grain weight. The results of this investigation suggest that sowing Amaranthus cruentus cv Mexicano on 1 December with 150 kg N ha(-1) favors its general development and allows to obtain high economic and biological yields with an appropriate protein content.