Herbicide efficacy in retained stubble systems

Type: Research Paper
Knowledge level: Advanced

This trial was undertaken to assess herbicide efficacy (effectiveness) in different stubble management systems.

What did the research involve?

  • 2016 trial was sown into paddock S3N, a CL Grenade wheat stubble which yielded 2.4 t/ha in 2015, and was grazed before the trial site was selected in February 2016.
  • The trial was sown on 30 May into good moisture conditions with Mace wheat @ 60 kg/ha and DAP (18:20:0:0) @ 60 kg/ha.
  • Stubble treatments
    • standing stubble with burnt windrows (burnt on 31 March) and slashed stubble also with a burnt windrow (slashed on 8 April).
  • The trial area received a knockdown of 1.2 L/ha of Roundup Attack on 29 May.
  • The trial was sown at 3-4 cm depth with an Atom-Jet spread row seeding system with press wheels.

What were the key findings?

  • At seeding: stubble load was 1.48 t/ha of standing stubble and 1.28 t/ha of slashed stubble.
  • The slashed stubble treatment had lower grass weed numbers and the only difference between the blocks was that the standing stubble was closer to the fence line.
  • Plant establishment was the same with either standing stubble or slashed, but there were differences in dry matter and crop yield.
  • No impacts of stubble management on the performance of individual herbicide treatments.

Final comment

Stubble management; standing stubble, burnt windrows, slashed stubbles and stubble removal by whole paddock burning, is unlikely to impact on the performance of pre-emergent herbicides.

Read ArticleSave For Later

Related Resources