7/21/11

Nutrient Basics -- Zinc

Zinc plays a roll in the same enzyme functions as manganese and magnesium. More than eighty enzymes contain zinc. Zinc participates in chlorophyll formation and helps prevent chlorophyll destruction. This means zinc deficiencies look similar to nitrogen deficiency with rolled leaf margin. Chlorosis shows up first in young leaves, which are also reduced in size. Zinc deficiency may also produce "rosetting"; the stem fails to elongate behind the growing tip, so that the terminal leaves become tightly bunched. Zinc deficiencies appear as chlorosis in the inter-veinal areas of new leaves Zinc deficiency produces "little leaf" in many species, especially woody ones; the younger leaves are distinctly smaller than normal

Zinc 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. Too much zinc is toxic. Foliar feed if the plant looks real bad. Use chelated zinc.

Zinc toxicity can occur when adding too much zinc and in soils excessively high in phosphates, nitrogen, calcium, or aluminium. 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.

Good Growing,
Dr. E.R. Myers

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