Growth analysis, protein and yield of vegetable <i>Amaranth</i> under varying nitrogen fertilizer levels and contrasting season

Abstract

Plant growth indices, protein and yield of Amaranthus were evaluated during dry and wet cropping seasons, under the influence of varying levels of nitrogen fertilizers (0, 45, 90 and 180 kg N/ha). The experiment was designed and analyzed as factorial in randomized complete block designed with three replications. The results showed significant variation in growth indices and protein (PRO) response in seasons and levels of nitrogen fertilizer. All the traits (growth indices and protein) were higher in magnitude during dry season at all levels of nitrogen fertilizer except leaf area ratio (LAR) at control (0 kgN/ha) and 45kgN/ha. Net assimilation rate (NAR) during dry and wet season was; 67.12% and 64.22% at 45kgN/ha; 85.54% and 67.77% at 90kg N/ha; and 92.36% and 83.40% at 180kgN/ha respectively. Leaf area index (LAI), relative growth rate (RGR) and percent protein (PRO) increase as the amount of nitrogen fertilizer increases irrespective of the season. Correlation analysis revealed, high, positive and significant association between yield and growth indices, and PRO as from 45kgN/ha.

Keywords: Amaranthus, growth indices, nitrogen fertilizer, rainfed, irrigated


Nigerian Journal of Horticultural Science Vol. 9 2005: 29-34