Even though zinc is a micronutrient, its role in plant development is nothing to take lightly.
Zinc deficiency is especially common in corn and soybeans. Alfalfa, cotton, sorghum, sugarbeets and wheat have mild sensitivities to zinc shortages.
“Plants require zinc in varying levels for healthy development. Zinc is also tied to human health because it’s translocated into the grain,” says Kyle Freeman, senior product development manager at The Mosaic Co.
Zinc deficiency in plants can limit yield and decrease water and nutrient utilization. While human zinc deficiencies are most prevalent in developing countries, soil deficiencies exist globally and impact nearly 50% of cultivated soils.
How It Behaves. In plants, zinc is essential for regulating growth hormones, activating enzymes for protein synthesis, aiding in starch, chlorophyll and seed formation, and assisting in healthy root development. Plant intake occurs through the roots.
Visual indication of zinc deficiency varies by species, but often appears early in the season in the youngest leaves. Common symptoms include banding or discoloration of the leaves, stunted growth due to shortened internodes, small leaves or poor flowering and fruiting.
Classic symptoms of zinc deficiency in corn appear as a white-to-yellowish band of tissue on both sides of the leaf midrib, beginning at the base of the leaf and extending to the tip. During the growing season, the band may turn brown or bronze, but the outer leaf edges remain green. Most soil has some zinc, but it’s often unavailable and bound to iron or manganese oxides.