ZINC AND COPPER EFFECT ON THE NUTRITIONAL STATUS OF CASTOR BEAN BRS 188 PARAGUACU

Despite the mineral fertilization is an important factor for increasing castor beans yield, few researches has been made on this issue, mainly on the use de zinc and copper. In order to evaluate the effects of these elements on the nutritional status of castor bean plant two experiments were carried out in a greenhouse. The substrate for the pot plants was a 5 mm-sieved surface soil (Neossolo Quartzarenico). The experimental design was a completely randomized with three replications. The treatments of first composed of five levels of Zn (0; 2; 4; 6 and 8 mg dm(-3)) and second experiment were composed of five levels of Cu (0; 1; 2; 3; and 4 mg dm(-3)) which were applied at the time of planting. One plant of castor bean, cultivar BRS 188 - Paraguacu, was grown per pot after thinning and was irrigated whenever necessary. At 90, 110, and 130 days after planting were collected the 4 th. leaves of each plant; at the end of the experimental period, all the leaves and stems were collected separately and in any plant material were determined the levels of zinc and copper. The Zn levels used affect the Zn level found in the leaves and stem, and this level is considered adequate. Cu treatments affect the Cu level found in the 4 th. leaves collected at 90 and 130 DAP, however, the Cu level in all periods and all parts of plants is low.