Diagnosing glyphosate damage in narrow-leafed lupins

Glyphosate is a systemic knockdown herbicide that is used extensively for brown fallow, summer weed or pre-seeding weed control, or selective weed control in glyphosate resistant crops.

 

First sign is new growth yellowing
Plants then wilt and slowly die
Root growth is severely affected, young plants develop a mushy hypocotyl

What to look for

    Paddock

  • Limp discoloured plants that may slowly die.
  • Direct spray damage is uniformly distributed but varies with spray coverage on overlaps or boom turns.
  • Spray drift damage is worse near the source.

    Plant

  • The first sign is pale new growth.
  • Plants then wilt and die.
  • Dying seedlings develop a mushy hypocotyl.

What else could it be

Condition Similarities Differences
Diagnosing group B herbicide damage in narrow-leafed lupins Yellowing of new leaves Plants do not wilt and they take much longer to die back.
Diagnosing sulphur deficiency in narrow-leafed lupins Pale small new leaves Plants do not wilt and die.
Diagnosing iron deficiency in narrow-leafed lupins Pale small new leaves. Plants do not wilt and die.
Diagnosing zinc deficiency in narrow-leafed lupins Stunted plants with pale new leaves. Plants do not wilt and die.

Management strategies

  • No treatment - plants then wilt and die.
Page last updated: Thursday, 5 February 2015 - 9:53am