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.
Dioscorea cayennensis; organic fertilization; productivity of tubers
