Concentrations of 14 Elements in Tissues of Blight-affected and Healthy ‘Valencia’ Orange Trees1,2

Abstract

Abstract Concentrations of N, P, K, Ca, Mg, Na, Fe, Mn, Zn, Cu, Cl, Mo, and Al varied between blight-affected and healthy trees in one or more of the following ‘Valencia’ orange tree ( Citrus sinensis (L.) Osb.) tissues: leaves, twigs, branches, trunks, trunk bark, large roots and feeder roots. Blight had no effect on B concentration; watersoluble phenolics were higher in the trunk wood of blight-affected trees, but not in the wood of branches and roots. Differences in cation exchange capacity, pH and 10 available nutrients in the soil were too small to be significant. The water content of the trunk, branch, and root wood did not vary significantly. The most consistent changes with blight were: higher N levels in the bark and the wood of the trunk; lower K levels in the leaves, coupled with higher K in the wood of the branches and the trunk; higher Na in the leaves and the trunk wood, higher Zn in the leaves and trunk wood; higher Cl concentrations in the leaves and the branch wood together with lower concentrations in the feeder roots.