The Science Behind Micronutrients

Plants need light, heat, water, air, and essential nutrients. These are divided into major elements, secondary elements, and trace elements (micronutrients) for growth.

Micronutrient Deficiency Symptoms in Plants

Micronutrient deficiencies in plants can cause various symptoms, including yellowing leaves, stunted growth, and leaf curling. These issues are often linked to soil pH and specific soil types, affecting the plant's ability to absorb essential nutrients.

Element Symptoms of Deficiency Common Soil Types
Iron Yellowing between the veins or ribs of younger leaves. Eventual loss of color and turgidity to the entire plant. Iron is sequestered in neutral to alkaline soils, and in acidic soils where excessive amounts of soluble phosphates are present. Precipitation of iron phosphate is more likely to occur in sandy rather than clay soils.
Manganese Loss of color to the leaf between veins. The resulting color may be yellow to almost white. Small gray specks appear on young leaves first, then eventually the entire plant. Manganese deficiency is associated with neutral to alkaline soils.
Copper Young leaves are permanently wilted, and the growth of the entire plant is retarded. Often, there is die-back in citrus, with bumpy and split fruit. Copper deficiency is often associated with soils high in organic matter.
Zinc Leaves are mottled to uniformly yellow in color. Zinc deficiency is most often associated with sandy, alkaline soils.
Molybdenum A distinctive mottling occurs in older leaves, with veins remaining light in color. As the deficiency is prolonged, puffing of the chlorotic areas occurs. Leaves curl inward and begin to die along tips and margins. Molybdenum deficiency is often associated with soils high in organic matter.
Boron Plant stems become brittle. Leaves will often curl inward and produce a burnt appearance. Growth is stunted or gnarled. Boron deficiency can occur in either strongly acidic or alkaline soils.

After "Hunger Signs In Crops", Howard B. Sprague, ed