MANGANESE -
A MICRONUTRIENT

Manganese (Mn) is primarily supplied to plants by root interception. Manganese is often deficient in neutral to slightly alkaline soils. Low temperatures and moisture stress reduce manganese uptake. Manganese may cause problems in the soil if present in excessive quantities as well as being deficient. When manganese levels are high, plants show typical symptoms of iron chlorosis. When manganese is low, plants show a breakdown of the interveinal chlorophyll and have a yellowish-brown leaf color.
Manganese seems to be absorbed by plants as the Mn++ cation.
Applications of phosphorus (P) fertilizer will increase manganese availability and plant uptake. This is opposite the zinc relationship in the soil where high levels of phosphorus interferes with zinc uptake and metabolism.
Manganese deficiency is best treated by using a foliar spray. Sprays usually contain 1 to 5 pounds of manganese sulfate per 100 gallons of water. Row crops can be treated with 50-100 pounds per acre of manganese sulfate.
Manganese sufficiency levels in the leaf range from 10-50 ppm in mature leaves. Tissue levels may reach 200 ppm or higher with 700 ppm in cotton. Manganese is not known to interfere with the plant metabolism or uptake of any other essential elements.