NUTRITIONAL ASPECTS OF SEEDS AND PLANTULE OF GUAPURUVU DEVELOPED IN TWO SUBSTRATES

Abstract

The study had as objective to characterize the nutritional status plantules of guapuruvu (Schizolobium parahyba (Vellozo) Blake), as well evaluate the relations between the chemical composition of the containing seed reserves, macronutrients and micronutrients, to its distribution in the plantule stage when developed on to substrates. The experiment was conducted in 2004, in UFPR (Curitiba – PR) greenhouse under an entirely randomized design being the two substrates, fine sand and soil from A horizon of an Inceptisol. The soil was collected from the region of the seed source. After a period of seven weeks the plantules were collected and separated into above ground, cotyledons and root parts. To obtain a reference pattern of total seed reserves, considering that these are the main nutritional source utilized during germination and plantules stage, a chemical analysis of the cotyledons was performed. These values were compared to the sum of the compartments obtained from the experiment in the greenhouse. In both cases the sample tissues were dried, grinded and analysed for N, P, K, Ca, Mg, Fe, Mn, Cu and Zn. The results indicated that the plantules developed on the Inceptisol substrate presented higher biomass on roots and above ground components. The nutrient contents of guapuruvu plantules growing on sand substrate presented the following decreasing order: N>K>P>Ca>Mg>Fe>Cu>Mn>Zn, while in the soil the content order was N>K>Ca>P>Mg>Fe>Mn>Cu>Zn. In relation to the seed reserves of guapuruvu, the content of N showed to be of highest expression.