Indigenous leafy vegetables (ILV) form a major part of human nutritional needs by providing the necessary vitamins and minerals needed by the body. However, to achieve better growth of these vegetables, adequate nutrient supply through fertilization is essential. In light of this, an experiment was conducted to evaluate the effects of organic and inorganic fertilization on the growth and yield of Amaranthus accessions belonging to the species: A. Retroflexus and A. Hypochondriacus in both summer and autumn seasons. A factorial experiment comprising of two Amaranthus accessions: A. Retroflexus and A. Hypochondriacus and four fertilization regimes namely: no fertilizer (absolute control), cattle manure, goat manure and NPK fertilization (positive control). The treatment combinations were then arranged as follows: A. Hypochondriacus + control (T1), A. Hypochondriacus + cattle manure (T2), A. Hypochondriacus + goat manure (T3), A. Hypochondriacus + NPK (T4), Retroflexus + control A. (T5), Retroflexus + cattle manure (T6), A. Retroflexus + goat manure (T7), and A. Retroflexus + NPK (T8). The experiment was laid out in a Completely Randomized Design with four replications. Plant height, number of leaves, stem girth. fresh and dry biomass yield were measured. Goat manure treated plants exhibited the maximum increase in the growth of A. Retroflexus and A. Hypochondriacus in summer whilst in autumn the tallest plants and highest number of leaves were observed from T8. The greatest fresh shoot biomass yield (137.27g plant-1) was attained from T7 whilst T1 (50.09 g plant-1) was the lowest. T3 produced the highest dry biomass yield in summer (21.25 g plant-1) and autumn (5.00g plant-1) whilst the lowest was recorded from T5 (10.14 g plant-1) in summer and T1 (1.47g plant-1) in autumn. The results provide evidence that fertilization increased the growth and yield of Amaranthus. Goat manure application produced substantial results in terms of growth and yield parameters and thus serves as a good alternative to small-scale farmers who may not be able to purchase inorganic fertilizer. T3 was the best performer in most of the measured parameters.

Keywords: Amaranthus accessions, biomass yield, fertilization, goat manure, growth.