Manganese Deficency in Crops
A variety of crops with Manganese deficiencies and also some with Manganese toxicity
Interveinal chlorosis starting at leaf edges in younger leaves. Internal discolouration of seed ("Marsh Spot").
Discrete black/brown spots along veins or over the whole surface of younger leaves in particular. These symptoms, together with general rather interveinal yellowing allow distinction from magnesium deficiency
Mottling of leaves, seen to best effect when viewed against the light. In sever cases, whole leaves become yellow ('Speckled Yellows'). Margins curl inwards, giving characteristic triangular leaf outline with upright growth habit.