GROWTH OF MAHOGANY SEEDLINGS (Swietenia macrophylla King) IN RESPONSE TO VEGETABLE EXTRACTS

Abstract

Mahogany (Swietenia macrophylla King) requires nutrients for the plants to present good quality during their growth in a nursery. The objective of the present study was to evaluate the response to foliar extracts of Ricinus communis L., Solanum torvum Sw. and fruits of Solanum mammosum L. in mahogany seedlings. The hypothesis was that these extracts improve the quality of the seedlings. The experimental design was completely randomized, with four treatments: 1) R. communis L., 2) S. torvum Sw., 3) S. mammosum L., and T4) control without vegetable extracts, and four replications of 45 experimental units. The variables evaluated were morphological (rates of growth in height and stem diameter, and length and number of roots) and of quality (dry weight, robustness index and Dickson quality index). The data were analyzed through one-way ANOVA and the means were compared with the Tukey test (p≤0.05). The treatments were applied to the seedlings at 15 d of emergence and the extracts were applied to the foliar surfaces every 15 d, with a dose of 60 mL 20 L^-1 of each extract. The units were measured every 15 d, during 60 d. The application of the extracts produced growth rates and dry weights 38% higher with respect to the controls. The extract of R. communis obtained the highest rates and the best Dickson quality index (0.28). Therefore, the extract of this species was the best alternative for improving growth and quality of the mahogany seedlings in the nursery.