2017 Tips and Tactics: Reducing Herbicide Damage

Tips and Tactics Reducing Herbicide Damage Cover image

Key Points

  • Managing weeds in summer fallows conserves soil water for subsequent
    crops and reduces the weed seedbank for subsequent seasons.
  • Drift from the application of herbicides (and from Group I phenoxy herbicides
    in particular) has caused significant damage to crops in recent years.
  • Improved spraying practices are needed along with better understanding
    of and response to weather and other environmental conditions.
  • During summer across the northern grains region, there are only a limited
    number of hours when conditions are conducive for spraying with low
    drift risk.
  • 2,4-D amine formulations have relatively low volatility, meaning they are
    effectively non-volatile when used in accordance with label requirements. As
    such, the large majority of damage is likely to arise from spraying during local
    surface temperature inversion conditions and from incorrect boom setups.
  • In some cases symptoms and damage may be from roots taking up residual
    2,4-D in the soil from previous applications.
  • While cotton is less sensitive to some other Group I herbicides when
    compared to 2,4-D, simply switching to these alternate Group I herbicides
    is unlikely to significantly mitigate risk. Attention must be given to the
    weather and other application factors involved.
  • Alternate herbicide options exist for key weed species (such as fleabane)
    where 2,4-D is currently being used. These include a range of pre- and
    post-emergent herbicides.

Link to this content using: https://grdc.com.au/TT-ReducingHerbicideDamage

Region North