Grain amaranths are a group of pseudo-cereal species known for drought and heat stress tolerance, high nutritional quality and potential as forage and feed for animals or as a milled or popped seed for baking and industrial processes for human food. Like most row crops, the grain amaranths have a high requirement for soil nitrogen (N) and other types of fertility to grow to their full potential. The goal of this study was to test three levels of urea fertilization (0, 115 and 230 kg/ha N) and four grain amaranth genotypes, two from species A. cruentus and the USDA and two from species A. hypochondriacus and SSE, for yield components, including seed weight, proportion seed per panicle, plant height, panicle length, panicle width and panicle weight. The genotype USDA107 was observed to grow taller and had longer but thinner panicles compared to USDA127 as well as SSE42 and SSE30 with each of these genotypes being shorter but with wider panicles. These contrasts were stable across fertilization levels. An increase in the yield potential of seed weight and proportion seed per panicle was seen at high dose compared to mid-dose or control, unfertilized treatments. Correlations were positive and highly significant for all traits except panicle length and proportion seed or panicle length and width which were negatively correlated. We expect these novel results to spur further study of grain amaranths in the southeastern United States.
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