Expert organization in plant nutrition
Expert organization in plant nutrition
Aquaculture Pests Diseases Flowers Products Deficiencies Subject


There is a close relationship between manganese compounds in soil and soil pH. Due to the solubility of manganese compounds in acid soils, manganese availability is quite high.

In contrast, manganese availability is low in high pH soils. The amount of Mn + 2 ion dissolved by a unit increase of pH decreases 100 times. Therefore, manganese deficiency is common in plants grown in soils with high pH.

The frequency and severity of manganese deficiency also depends on seasonal conditions. Deficiency is generally severe in cold and rainy seasons. Under these conditions, the metabolic activity of the root decreases and manganese intake decreases.

Vegetables most sensitive to manganese deficiency include beans, onions, peas, cucumbers, tomatoes; leek is the least sensitive vegetable and other vegetables are moderately sensitive.

Oat, pea, sugar beet, potato, cotton, peanut, apple, cherry and citrus fruits are particularly sensitive to manganese deficiency in field crops and fruits.

Symptoms of manganese deficiency in fruit trees can easily be mistaken for iron deficiency. Leaf analysis is an important tool for accurate diagnosis. If less than 25 - 30 ppm Mn is found, manganese deficiency is likely. Mn less than 20 ppm indicates a definite deficiency. Stone fruits require more manganese than peach, apricot and plum trees.