Seedling formation of "taxi-branco" (Sclerolobium paniculatum Voguel). I. Response to time and phosphorus application

Abstract

An experiment was carried out to evaluate the effect of lime and phosphorus application on Sclerolobium paniculatum Voguel seedling production. The experiment was conducted in a greenhouse with the utilization of subsurface samples of a Red - yellow Latossol as the substratum. Treatments started through the experimental matrix Plan Puebla III, receiving as a corrective mixture, dolomitic lime + commercial CaCO₃, and as P source, pure solutions of the active ingredient. Further fertilization (N, K and S) was applied during the 190-day growing period of the greenhouse experimentation. The regression equations obtained for leaf and branch dry matter production showed a quadratic response to P addition to substrate and also showed there was no response to liming. Ca needs were supplied by the addition of 0.37 meq/100 cm³ through gypsum application to basic S fertilization. Plant absorption of Ca was dependent on P levels in the soil. Critical levels of available P in the soil and in the leaf dry matter basis (26.10 meq/dm³ and 0.12%, respectively) were also determined.