Characterization of the effects of macronutrient deficiencies in mangabeira seedlings

Knowledge of the mineral nutrition requirements of mangabeira (Hancornia speciosa Gomes) is relatively scarce and rudimentary because there is a lack of consistent data concerning its nutritional demands at different developmental stages. The aim of this research was to characterize the visual symptoms of macronutrient deficiencies and to evaluate the effects of these deficiencies on the growth, the production of dry matter, and the leaf content of mangabeira. To achieve this goal, a greenhouse experiment was conducted at the Goiano Federal Institute (Instituto Federal Goiano) in Rio Verde - GO, from January to June 2011 in which mangabeira plants were arranged in a random block design and grown in nutrient solutions. This experiment was replicated four times. The plants were treated with either a complete nutrient solution or a nutrient solution from which the individual macronutrient of interest (nitrogen (N), phosphorous (P), potassium (K), magnesium (Mg), calcium (Ca), or sulfur (S) had been omitted. The omission of a macronutrient from the nutrient solution resulted in morphological alterations that were characteristic symptoms of the particular nutritional deficiency and caused decreases in growth and dry matter mass production. The accumulation of macronutrients displayed the following order in mangabeira leaves: N>K>Ca>P>S>Mg