Symptoms of manganese (Mn) toxicity appear first on the oldest leaf of a plant and progress to the younger leaves.

Symptoms can vary from variety to variety and include chlorosis with little necrosis, chlorosis progressing to necrosis, and in some cases reddening combined with necrosis and chlorosis. These symptoms begins to appear on the oldest leaf tips and progress along the leaf with the leaf margins being more affected. In some varieties, a brown blotch appears on the leaf, while in others a "grey fleck" of necrotic tissue appears over the entire leaf, usually accompanied by leaf tip chlorosis and/or necrosis.