Diagnosing group I herbicide damage in narrow-leafed lupins

Group I herbicides are used for broadleaf summer weed control or selective broadleaf weed control in cereals. Damage can be caused by soil residues, spray contact or vapour drift.

Seedlings rapidly become distorted after spray contact
Upper stems and petioles advanced plants bend rapidly
Spray damage is easily seen
Distorted growing point from dicamba spray
Phenoxy acid Pyridines
Chemical name Example trade name Chemical name Example trade name

2,4-D amine

Amicide Advance®

Clopyralid

Lontrel®

2,4-D ester

Estercide Xtra 680®

Triclopyr

Garlon®

MCPA amine

Agritone 750®

Fluroxypyr

Starane®

MCPA ester

LVE MCPA®

Picloram

Tordon®, Grazon®

MCPB

MCPB®

Benzoic acids

2,4-DB

2,4-DB, Buttress®

Dicamba

Banvel®

 

What to look for

    Paddock

  • Severely distorted plants that gradually die or recover.
  • Direct spray damage is uniformly distributed but varies with spray coverage on overlaps or boom turns.
  • Spray drift damage is usually worse near the source, but ester vapour drift can cause widespread damage that can be apparently random due to swirling wind effects.

    Plant

  • Rarely, herbicide residue damage causes poor emergence.
  • Plants rapidly develop distorted stems and petioles after spray contact.
  • Plants very slowly become pale necrotic then die.
  • Growing points are pale and distorted and may die.
  • Slightly affected plants can gradually recover.

What else could it be

Condition Similarities Differences
Diagnosing frost in narrow-leafed lupins Bent and twisted plants Wilted stems become necrotic and die

Management strategies

  • No treatment - plants can recover or die

Where to go for expert help

Page last updated: Monday, 15 June 2015 - 3:18pm