Diagnosing abiotic leaf spots in cereals
Scattered leaf spots that have an abiotic cause such as droplet freeze damage, spray solvents or topdressed fertiliser burn.
What to look for
- Plants with white lesions with a rim that may initially be pale then go brown that re uniformly distributed or concentrated in frost-prone areas.
- White lesions that are often drop-shaped or span the width of the leaf causing the leaf to kink, or leaf tips to shrivel.
- As the plant grows, lesion position on successive leaves varies reflecting a single occurrence.
- Some leaf sheaths and associated stems areas may be shrivelled or discoloured.
- Some leaves that were emerged at the freeze event can have numerous small interveinal spots.
- Later emerging leaves are unaffected.
What else could it be
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|Similar leaf spots||Symptoms progress as the plant grows|
Where did it come from?
- A common cause is frozen water droplets
- Differing lesion shape is caused by individual droplets on leaf surface, under a leaf bend, or in the leaf axil.
- Freeze damage in the axil can damage the enclosing leaf sheath, stem and up to 3 leaves at various stages of emergence.
- As the leaves develop further lesions are found further up later developing leaves.
Where to go for expert help
+61 (0)8 9368 3431
Page last updated: Tuesday, 27 September 2016 - 3:06pm