ZINCO E COBRE EM PINHÃO MANSO. I. CRESCIMENTO INICIAL DA CULTURA

Abstract

Jatropha curcas crop is raising attention as an alternative crop for oil and biodiesel production. Despite the mineral fertilization is an important factor for increasing Jatropha curcas yield, few research has been made on this issue, mainly on the use de zinc and copper. In order to evaluate the effects of these elements on Jatropha curcas plant growth two experiments were carried out in a greenhouse, in Campina Grande, Paraiba State, Brazil, from July to December 2007. The substrate for the pot plants was a 5 mm-sieved surface soil (Neossolo Quartzarênico). The experimental design was a completely randomized with three replications. The treatments of first and second experiment were composed of five levels of Zn (0; 2; 4; 6 and 8 mg dm-3) and five levels of Cu (0; 1; 2; 3; and 4 mg dm-3) which were applied at the time of planting. One plant of Jatropha curcas was grown per pot after thinning and was irrigated whenever necessary. Data on plant height, number and length of leaves and stem diameter were measured at 40; 60; 80; 100 and 160 days after planting. Under conditions that the experiments were carried out the Zn and Cu levels used did not affect the Jatropha curcas plants growth.