The Brazilian mahogany has high timber value but its commercial cultivation is rendered impossible by the attack of Hypsipyla grandella shoot-borer. The aim of this study was to evaluate the effect of doses of calcium and boron on mahogany growth variables and on the resistance to the attack of its shoot-borer, H. grandella. The design was a 4² factorial randomized blocks with four doses of calcium (0, 100, 200 and 400 mg L-1), four doses of boron (0, 0.5, 2 and 4 mg L-1) and three replications with three plants per replication. It was evaluated: height; diameter; air dry mass and root dry mass; relation air:root; infestation rate and length of the gallery promoted by the shoot-borer. The results were analyzed by Tukey test at 5% and subjected to correlation analysis and regression. There was no statistical interaction between the nutrients and no significance for height and stem diameter. The mass of roots and aerial parts showed the highest results in the deletion of elements and showing the lower ratios of air: root parts in the doses of 100 mg L-1 due to calcium and 0.5 mg L-1due to boron. The 100 mg Ca L-1 dose yielded the lowest rate of infestation of H. grandella. As for the resistance to the development of the mahogany gallery, both calcium and boron were significant, and the smaller lengths observed at doses of 100 mg L-1 Ca and 0.5 mg L-1B, respectively. These nutrients influence the resistance of mahogany to the shoot-borer and show the need for studies in field conditions.
Swietenia macrophylla; Mahogany shoot-borer; Mineral nutrition of mahogany
