Crop Guide: Citrus Plant Nutrition
Copper deficiency is more likely to occur in new plantings on previously uncropped soils, which are usually deficient or totally lacking in copper. Figure 25: Copper (Cu) deficiency in citrus twigs. Figure 26: Cu deficiency showing gum pocket at node. Figure 27: Copper (Cu) deficiency necroticcorky areas on the fruit surface . Boron (B)