Abstract
Knowledge of the mineral nutrition effects 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 deficiency effects 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 different 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 deficiency 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 affected if the nutritional supplementation is not performed when the soil is deficient in any macronutrient.
Keywords:
Cariniana estrellensis; Nutrient deficiency; Carbon assimilation; Transpiration