Variations in the Growth of Amaranthus cruentus L. as Affected by Different Concentrations of Organic Manures

Abstract

Amaranthus cruentus is an important crop for subsistence farmers and a nutritious green vegetable in South Western Nigeria. The maximum growth and organic production of this vegetable to supply protein and minerals for people is necessary to enhance food security. Pot experiments were conducted in the experimental garden of the Department of Plant Science and Biotechnology, Ekiti State University Ado Ekiti, Nigeria to investigate the effects of organic manures on the growth of A. cruentus. The experiments were laid down in Completely Randomised Design (CRD). The treatments were Poultry manure (PM), Cowdung (CD) and Goat manure (GM) applied at 50g, 100g, 150g and 200g concentrations per 8kg of soil with four replicates. Application of organic manures irrespective of the quantity applied seemed to have no significant effect on the plant height of Amaranthus cruentus. However, the highest mean number of leaves per plant was recorded in soil treated with 100g of GM (69.38), followed by 50g of GM (62.75) which was similar to that of 200g of PM (62.50).  Soil with 50g Poultry manure produced the widest leaf area (66.45cm2) followed by 50g of GM (58.29cm2). Meanwhile, 200g of PM treated plants has the highest stem girth (1.08cm) and 0.64 Relative Growth Rate (RGR) respectively.  Goat manure treated plants at 50g concentration produced the highest dry root and shoot weights with 2.46g and 6.03g respectively. Statistical analysis (P≤ 0.05) showed that significant differences were observed in all the parameters studied compared to the control except the plant heights. The three organic manures improved the growth of A. cruentus but Poultry manure outperformed the other manures in terms of leaf area, stem girth and RGR, while GM treated plants outperformed other manures in producing the highest number of leaves. With the current advocacy for the consumption of food produced organically, it is recommended that the organic manures under study should be used for the cultivation of A. cruentus most especially by the resource poor farmers as it is cheaper, environmentally friendly and might be safer for consumption than vegetables produced through the application of synthetic fertilizers.