Production of yam in a soil fertilized with different sources and rates of organic matter

The objective of this study was to evaluate the behavior of yam, variety Da Costa, fertilized with different sources and rates of organic matter. The experimental design was a randomized complete blocks distributed in a factorial 2 x 6, corresponding to six rates (0, 6, 12, 18, 24 and 30 t ha(-1)) and two sources of organic matter (cattle and goat manure), with three replications. The length of tubers increased linearly with maximum value of 27.5 cm at a rate of 30 t ha(-1) of goat manure and the bovine manure provided tubers with mean length of 23.64 cm. The diameter was of 9.1 and 9.3 cm in rates of 20 and 21.6 t ha(-1) of goat and bovine manure, respectively. The maximum mean mass of 1.4 kg was obtained with the rate 17.4 t ha(-1) of goat manure and in function of rates of bovine manure the mean value obtained was 1.11 kg. A rate of 20.9 t ha(-1) of goat manure provided the maximum commercial productivity of tubers of 14 t ha(-1), while mean productivity of 10.1 t ha(-1) was obtaines with the use of bovine manure. The goat manure is better than bovine manure and the rate around of 20 t ha(-1) of both the manures promoted the highest values of the evaluated characteristics.