Comparative Effect of NPK (15:15:15) and Poultry Manure on the Growth and Yield of White Yam (Dioscorea rotundata Poir.)

Background and Objective: White yam is one of the most cultivated and accepted species of yam in Nigeria and its production is constrained by many challenges such as high cost of production and poor yield due to low soil nutrient amongst others. Hence, a study was carried out to evaluate the comparative effect of NPK (15:15:15) and poultry manure on the growth and yield of white yam. Materials and Methods: The experiment was laid out in a randomized complete block design with three replications. The experiment involved seven treatments: 400 kg haG 1 NPK (15:15:15), 200 kg haG 1 NPK+20 t haG 1 poultry manure (PM), 40 t haG 1 PM, 30 t haG 1 PM, 20 t haG 1 PM, 10 t haG 1 PM and control. NPK fertilizer was applied in about 3 drills made around the plant, while the poultry manure was applied on the mound as mulch at 6 weeks after planting. Results: Results indicated that NPK (15: 15: 15) produced the highest dry matter yield of 20.36 t haG 1 compared to poultry manure treatments which had dry matter yield of 14.93-16.42 t haG 1 , while control had 15.21 t haG 1 . The fresh tuber yield of poultry manure treatments varied from 45.89-57.22 t haG 1 , while NPK fertilizer and control had fresh tuber yield of 48.22 and 48.67 t haG 1 , respectively. Conclusion: Poultry manure at a rate of 40 t haG 1 effectively increased soil fertility and produced the highest tuber weight and yield.