The effect of different nitrogen levels on the growth and development on grain amaranth( amaranthus cruentus l)

Abstract

Vegetable Amaranth (A. cruentus) is a promising C4 crop for semi- arid regions due to its nutritive value, medicinal property and ornamental for beautifying gardens . It is widely grown in the tropics and is one of the most important leafy vegetables in the lowlands of Africa, South America and Asia. Little knowledge is known on its Nitrogen requirement, that is why this experiment was conducted to fill in that gap. A field study was conducted in Nyanga which is a high rainfall area receiving over 1000 mm/ annum. The vegetable was sown in the cropping season of 2014/15 to determine the effect of different nitrogen fertilizer levels on (0, 50, 100, 150kg/ha and 200 kg/ha on the growth and yield parameters which were, days to 50 % flowering, dry weight (kg/ha), seed yield (kg/ha) and fresh leaf weight (kg/ha). There was significant difference (p<0.05) on the effects of N fertilizer levels on fresh leaf yield of vegetable Amaranthus cruentus with the highest yield obtained at 150 and 200 kg/ha N. Mean yield of 33562 kg/ha and 58359 kg/ha and the least 12060kg/ha obtained at 0 kg/ha. There was significant difference (p<0.05) on the effects of N fertilizer levels on dry weight. The highest dry weight of 32573 kg/ha and 45102 kg/ ha was achieved between 150 and 200 kg/ha N respectively and the least dry weight of 12621 kg/ ha was obtained at 50 kg/ ha N. The highest seed yield of 2300 kg/ha and 3500 kg/ ha N was also attained at 150 and 200 kg/ ha N respectively. The least seed yield being obtained at 0 kg/ha with seed yield of 292 kg/ha. There was no significant difference on days to 50% flowering due to different rates on N. From this study it can be concluded that Amaranthus cruentus performed well at 200 kg/ha N as it gave the highest yield in terms of fresh leaf weight. Thus farmers can use 200 kg/ha N to maximise yield.