Root pruning and Osmocote® provides better Jatoba seedlings

Abstract

The species Hymenaea courbaril L. (Jatoba) is widely used in the timber industry. However, its population was reduced due to high exploitation rate, being at risk of extinction. Therefore, production of seedlings of this species should be improved to meet the demand of reforestation programs. Given the above, this study evaluates the effect of Osmocote^® rates and root pruning on the growth of Jatoba seedlings transplanted into plastic bags. A randomized complete block design was used in a 5 x 3 factorial scheme, corresponding to five rates of Osmocote^® fertilizer (0.0; 2.0; 4.0; 6.0; and 8.0 g L^-1) and three root pruning intensities (0%; 25%; and 50%). At 105 days after transplantation, the following were evaluated: plant height, stem diameter, number of leaves, shoot dry weight, root dry weight, total dry weight, height/stem diameter ratio, and Dickson quality index. Rates below 4.0 g L^-1 or above 6.0 g L^-1 decreased seedling quality. The most prominent variables in this study were plant height, total dry weight, and number of leaves of H. courbaril seedlings. Osmocote^® rates between 4.4 and 6.6 g L^-1 combined with 25% root pruning provided the best results for the growth of transplanted Jatoba seedlings.