Diagnosing glyphosate damage in cereals

Glyphosate is a systemic knockdown herbicide that is used for brown fallow, summer weed or pre-seeding weed control, or selective weed control in glyphosate-resistant crops. Symptoms appear within five to seven days of spraying.

Normally plants wilt, twist, become discoloured and then die
Symptom severity from spray drift at plant emergence varies with seeding depth
Glyphosate contamination can cause growing point death and profuse tillering
Emerging seedlings have many spiky stunted tillers

What to look for

    Paddock

  • Areas sprayed after emergence have uniformly pale limp and dying plants.
  • Symptoms on areas affected as plants emerge may vary between rows or soil types from differing times of emergence.
  • Wind drift damage is worst on paddock edges, temperature inversion drift occurs in low lying areas.

    Plant

  • Seedlings that receive a low dose as they emerge, either from spray drift or soil residuals, will die or show the following characteristics:
  • Plants become pale and growth ceases until recovery or death.
  • Leaves look limp and may twist.
  • New shoots are pale and may die.
  • Leaves turn pale yellow or red, often followed by browning.
  • The whole plant dies.
  • Surviving plants are pale with prolific spiky tillers and remain stunted for several weeks. Plants gradually recover but often with reduced yield, and they may lodge due to poor crown root growth.

Where did it come from?

Time of herbicide application
Time of herbicide application
  • The pattern of damage reflects areas exposed to spray drift (edge of paddock).

Management strategies

  • There is no treatment. Plants will either die or recover. As a precaution, spray when the risk of drift is low.

Further information

HerbiGuide [1]
GRDC Incrop-Herbicide-Use [2]
APVMA registered products database [3]

Links
[1] http://www.herbiguide.com.au/
[2] http://www.grdc.com.au/Resources/Factsheets/2012/05/Incrop-Herbicide-Use
[3] http://www.apvma.gov.au/

Source URL: https://www.agric.wa.gov.au/mycrop/diagnosing-glyphosate-damage-cereals
This print version was generated at 12:11pm on the 1st of September, 2024.
The original document was last revised at Wed, 04/02/2015 - 2:37pm

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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.