Effects of Nitrogen Fertilizer on the Growth of Vegetable Amaranths (Amaranthus cruensis. L) in Mubi, Adamawa State Nigeria

A field experiment was conducted at Food and Agricultural Organization / Tree Crop Programme (FAO/TCP) Teaching and Research Farm, Faculty of Agriculture, Adamawa State University, Mubi, Northern Guinea Savannah zone of Nigeria on sandy loam soil. To study the three levels of row spacing (20, 30, and 40 cm) and five levels of nitrogen (N) fertilizer (0, 30, 60, 90, and 120 kg ha-1) laid out in a Randomized Complete Block Design and replicated three times. Data were collected on growth and yield parameters. Data generated were analyzed using Analysis of Variance (ANOVA). The crop was harvested at 6 weeks after sowing. The result show that stem girth and fresh weight (plant-1) of vegetable amaranth increased significantly (P = 0.05) as row spacing and applied N rate was increased and leaves area index increased as the applied N increased and row spacing decreased. Application of higher dosage of fertilizer at the rate of 120 kg N ha-1 with a broader row spacing of 40 cm produced significantly higher mean fresh plant weight of 127.57g in 2014, 125.78g in 2015 and 126.67g (plant-1) in the combined. The least mean value (19.40g) was obtained in the treatment with narrow row spacing and no application of N fertilizer (0 kg N ha-1 at 20 cm row spacing). Therefore, the optimum N rate and row spacing for the maximum fresh weight(plant-1) of vegetable amaranth (Amaranthus cruentus L.) is 120 kg N ha-1 at 40 cm inter-row spacing and was found as the best combination for the production of vegetable amaranth in the Northern Guinea Savannah zone of Nigeria. j