Manganese toxicity

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Pale green and sunken  patches between veins are early symptoms of Mg toxicity (J. O'Sullivan).  

Brown to black spots in interveinal areas spread and join together (J. O'Sullivan).

Diagnostic summary

  • What you see on plants

- older leaves develop first pale, angular patches and then small dark spots on interveinal tissue.


- veins on the undersurface of the older leaves may turn black.


- severely affected leaves turn yellow and fall off.


- young leaves may develop pale interveinal chlorosis, due to induced iron deficiency.

  • May be more severe in wetter parts of the field or after wet weather.

  • May be more severe in cold weather, and show recovery in warmer weather.

Characteristics and occurrence


Confusion with other symptoms

Diagnostic tests



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