Effect of Poultry Manure Rate and NPK 15:15:15 on the Perfomance and Nutritional Content of Sweet Potato (Ipomoea batatas l.)

Abstract

1. A field experiment was carried out to determine the effect of different rate of poultry manure and NPK 15:15:15 on vine length, number of leaves, plant height, number and weight of harvested tubers with the Proximate contents of sweet potato. The experiment was laid out in a Randomized Complete Block Design (RCBD) with five treatments replicated three times. The treatments were 0 kg/ha of poultry manure (PM) (no treatment), 15 kg N/ha PM, 30 kg N/ ha PM, 45 kg N/ha PM and NPK 15:15:15. Poultry manure rates were applied to the soil two weeks before planting while NPK 15:15:15 was applied two weeks after planting. The result showed that, application of Poultry manure at 45 and 30 kg N /ha had a positive response significantly on vine length than other treatments. Nitrogen sources also favoured production of leaves and number of tubers but 45 kg N/ha of PM produced tubers with more weight comparable to 30kg N/ha than other rates and sources. Treatment with NPK 15:15:15 gave high value of ash content, crude protein, crude fat and crude fibre which also increases with increase in the rate of Poultry manure application. However, increase in Nitrogen rate or source decreased carbohydrate and moisture content of the crop. Application of poultry manure at the rate of 30 kg N /ha is therefore recommended for best growth, yield and dry matter content of sweet potato since it also increased its quality in terms of crude protein. NPK 15:15:15 can be used to obtain good quality in sweet potato in the absence of poultry manure.