Adubos orgânicos no desenvolvimento de variedades da palma forrageira.

The cactus forage cultivated in the Brazilian semiarid region is a crop of extreme importance for the local population, being used as alternative sources for feeding the animals in critical periods of drought. However, for this species to reach maximum growth potential are required soils with high fertility levels, wich are not found in this region. The aim of this study was to evaluate the development of three varieties of cactus forage, resistant to carmine cochineal, with different sources of organic fertilization. The experimental design was a randomized complete block design with four replications in the factorial scheme (3x4): three varieties of cactus forage cv. (Orelha de Elefante Mexicana, Baiana and Miúda/Doce) and four fertilization treatments (Manure, Fulvic acid, Humic acid and Control). At 90 and 240 days after planting, plant development evaluations were performed, such as the survival index; plant height; number of shoots per plant; as well as the variables for cladodes (area, area index, mean weight, length, width and thickness) and, finally, the average productivity mean of phytomass. Manure fertilization presented significant results for the cladode area and the cladode area index, mainly in the cv. Orelha de Elefante Mexicana variety in relation to the control and fulvic acid. The increase of cladode area in this variety of forage cactus as a function of the manure application represented 63, 34 and 40% on Fulvic acid, Humic acid and the Control, respectively. The cv. Orelha de Elefante Mexicana variety responded positively to Manure fertilization, obtaining the highest productivity mean phytomass among the others varieties, with 81 t ha-1 at the end of the experiment. Among the sources of organic fertilizers used, only Manure had a significant effect on the forage cactus variety of cv. Orelha de Elefante Mexicana. [ABSTRACT FROM AUTHOR]