Zinc Deficiencies
Deficiencies appear as chlorosis in the inter-veinal areas of new leaves producing a banding appearance as seen in figure 18. This may be accompany reduction of leaf size and a shortening between internodes. Leaf margins are often distorted or wrinkled. Branch terminals of fruit will die back in severe cases. Also gets locked out due to high pH. Zn, Fe, and Mn deficiencies often occur together, and are usually from a high pH. Don't overdo the micro-nutrients- lower the pH if that's the problem so the nutrients become available. Foliar feed if the plant looks real bad. Use chelated zinc. Zinc deficiency produces "little leaf" in many species, especially woody ones; the younger leaves are distinctly smaller than normal. Zinc defeciency may also produce "rosetting"; the stem fails to elongate behind the growing tip, so that the terminal leaves become tightly bunched.
Figure 17.
Zinc Toxicity
Excess Zinc is extremely toxic and will cause rapid death. Excess zinc interferes with iron causing chlorosis from iron deficiency. Excess will cause sensitive plants to become chlorotic.