Manganese deficiencies usually show up in the younger leaves first. The affected areas appear as light green or yellow patches in areas between leaf veins. The veins themselves and bands of tissue on either side remain green. Severe deficiencies will persist in mature leaves. Other symptoms include stunted growth.
Manganese is soluble and quick acting. It is most effective when applied as a foliar spray in spring or summer when new growth is being made.
Manganese deficiencies are most common in alkaline soil, so it is recommended you test the soil pH and apply correcting agents if needed.