VEGETATIVE GROWTH OF VEGETABLE AMARANTH AS AFFECTED BY NITROGEN FERTILIZATION

Abstract

Influences of nitrogen (N) rate were evaluated on vegetable amaranth. Amaranthus tricolor, grown at uniform populations over two year. The main objective was to determine an optimum level of N fertilization for successful production in middle Georgia. In 1992 and 1993 accession `RRC 241' was planted in randomized complete block design on June 19 and 23, respectively. Four N rates, equally split were evaluated: 0, 45, 90, and 135 kg ha-1. First of the applications were 18 and 13 days post planting for 1992 and 1993, and again when plants were 5 weeks old. Plants were harvested 48 days after planting with green yield, leaf fresh weight. and stem fresh weight collected in both years and leaf area for 1993. In years 1992 and 1993 green yields were 5.3 and 6.5, 10.7 and 9.0. 13.2 and 12.1, and 13.5 and 14.0 Mg ha-1. respectively for the 0, 45, 90, and 135 rates. In both years vegetative components showed significant regression for all treatments. Vegetative response (R2) for green yield in 1992 and 1993 was quadratic (85%) and linear (73%), leaf fresh weight in both years was cubic (63% and 48%), while stem fresh weight response was linear (29%) and cubic (72%). During 1993 leaf area was linear (58%). Non-significance predominantly occurred between the two higher rates for each year and when combined. indicating that 90 kg N ha-1 should provide optimal production of amaranth for the middle Georgia region.