Effects of different sources of phosphorous on the initial growth of Schizolobium parahyba (Vell.) S. F. Blake

Abstract

Initial growth of Schizolobium parahyba (Leguminosae – Caesalpinoideae) under different sources of phosphorus taken from both chemical and natural fertilizers, as wel as the cost-advantage relation of the used sources were analized. The experiments were carried out in greenhouse, in Santa Teresa, ES, Brazil, from December, 2002 to April, 2003. The phosphorus sources were: Simple Superphosphate (SFS), Triple Superphosphate (SFT), Natural Reative Arad Phosphate (SNA) and Thermophosphate (TEF). Monthly evaluations were made of plants growth based on shoot height, base stem diameter and number of leaves. The earliest evaluations were made when the plants were six month old and were repeated in the following four months, add to that, at the begining and at the end of the experiments, were evalueted the shoot and roots dry weight. The attained results indicated a similar development of the plants in the four sources of phosphorus used, thus, the phosphorus source recommended is the SFT because it was used in the smallest quantity.