Diagnosing potassium deficiency in barley

Potassium is a major nutrient that is increasingly required as soil reserves become depleted. Potassium deficiency results in poor water use and other nutrients, making crops more susceptible to drought, waterlogging, frost and leaf diseases.

 

Pale plants with bright yellow older leaves amongst areas of better growth.
Less symptoms in swathe rows
Bright yellow colour extends from tip and edges
Deficient plants have more leaf death and leaf disease

What to look for

    Paddock

  • Areas of plants that have leaf tip death and bright yellowing extending down from tip of older leaves.
  • Symptoms are worse in sandier areas or between header/swathe rows.
  • Plants look unusually water-stressed despite adequate environmental conditions.
  • Affected areas may have more leaf disease.

    Plant

  • Stunted plants with short stout stems and pale foliage, but tillering may not be affected.
  • Older leaves affected first with leaf tip death and yellowing that progress down from the leaf tip and edges.
  • There is often a marked contrast in colour between yellow leaf margins and green centre.
  • Yellowing leaf tip and leaf margins often generates a characteristic green 'arrow' shape towards leaf tip.
  • Leaf symptoms can be accompanied by increased leaf disease and physiological leaf spot.
  • Affected plants can appear water stressed, hay off prematurely, and produce shrivelled grain.

Where does it occur?

Soil type
Soil type
  • Sandy soils and deep grey sandy duplex soils tend to be more susceptible to potassium deficiency.
  • High rates of hay or grain removal can result in potassium deficiency.

Management strategies

Top dressing
Top dressing
  • Top-dressing potassium will generally correct the deficiency.
  • Foliar sprays generally can not supply enough potassium to overcome a severe deficiency and can also scorch crops.

How can it be monitored?

Tissue test
Tissue test
Soil test
Soil test
  • Use whole-top plant test to diagnose suspected potassium deficiency.
  • 0-10 centimetres soil test for potassium is reliable in deep sands but may not be for duplex soils that have potassium reserves in the clay.

Further information

Soil Quality - Potassium [1]
Plant nutrition [2]

Links
[1] http://soilquality.org.au/factsheets/potassium
[2] https://www.agric.wa.gov.au/crops/production-postharvest/plant-nutrition

Source URL: https://www.agric.wa.gov.au/mycrop/diagnosing-potassium-deficiency-barley
This print version was generated at 5:05pm on the 6th of October, 2024.
The original document was last revised at Fri, 17/04/2015 - 2:06pm

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Important disclaimer

The Chief Executive Officer of the Department of Primary Industries and Regional Development and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it.