Deficiência de macronutrientes em Cariniana estrellensis (Raddi) Kintze

摘要

Knowledge of the mineral nutrition e?ects on plant physiology of native species is an important aid in order to obtain the intended success when they are used in reforestation or recovery of areas with deteriorated soils. This study investigated the macronutrient defciency e?ects in? Cariniana estrellensis (Raddi) Kintze, known in Brazil as “jequitibá-branco”, in carbon dioxide assimilation and transpiration rates and biomass production of this species, which is widely used in reforestations in Brazil. The experiment was carried on a greenhouse, in a randomized block design with seven treatments with three replicates, using the technique of diagnosis by subtraction of macronutrients, with a control treatment in which the Cariniana estrellensis was grown in nutrient solution with all macro and micronutrients. In di?erent organs of “jequitibá-branco” the nutrient contents by chemical analysis were? determined; using portable infrared gas analyzer (Infrared Gas Analyzer - IRGA, Li-cor Model 6400) carbon dioxide assimilation and transpiration? rates were determined in leaves of three distinct parts of plants, and at the end of the experiment was obtained the dry biomass weight. The defciency of nutrients, in general, limited the carbon dioxide assimilation and transpiration rates and therefore the production of dry biomass of “jequitibá-branco” young plants was lesser than the control treatment. The results of this study suggest that the reforestation or rehabilitation of degraded areas using the Cariniana estrellensis will certainly be severely a?ected if the nutritional supplementation is not performed when the soil is defcient in any macronutrient. ?