Redistribution of 10B Absorbed by Leaves and Roots of Cashew Seedlings

Boron (B) is transported mainly in the xylem, but by using isotopic tracers it was possible to verify that B has significant mobility in the phloem of polyols-producing species. Thus, the objective of this study was to evaluate the mobility of ¹⁰B applied to cashew plants. The experiment was conducted from 05/10 to 07/10/2010 in a greenhouse of University of São Paulo State-UNESP, Ilha Solteira Campus, State of São Paulo, Brazil. 0.5 mg of B L^?1 of soil was used in the substrate. A solution of 255 mg of B L^?1 was used in recently mature and fully developed leaves. The total content of B and and percentage of boron in the plant derived from fertilizer (Bppf%) were evaluated in the old and new leaves stemming at 30 and 60 days after the application of ¹⁰B. As evidenced, B applied to leaves had restricted mobility in cashew tree. However, B applied in the substrate was absorbed and translocated to young leaves.