WithTheGrain: Coordinated approach taken to beat grass weed problem

Author: | Date: 16 Apr 2018

LRZ RCSN member Tim McClelland says barley grass has been identified as a “major problem” on his farm.

Barley grass and, to a lesser extent, brome grass present such a problem to Tim McClelland’s farming operation that preventing seed set is now part of a concerted effort.

The mixed-farming enterprise of 6500 hectares in Birchip, Victoria has a significant problem with barley grass and Tim says management decisions are a “tough balance”.

He runs 4500 Merino and Merino/Coopworth-cross breeding ewes for fine wool and prime lamb production. The cropping operation comprises wheat, barley, canola, field peas, oats, vetch, lentils and field pea hay.

“We run quite a significant livestock enterprise as well as our cropping, which means we’re constantly trying to bridge the gap between providing pasture feed for our livestock in the spring but also providing adequate weed control for our crops,” he says.

“When spring dries out and feed gets a bit tight there’s a tough decision to make in terms of whether you keep the grass pastures for feed or whether you spray it out to stop weed seed set.”

Tim says barley grass has been identified as a “major problem” within the farm. It is often difficult to control in cereals and is a great host for root diseases in the pasture phase, particularly take-all.

To help manage the problem and drive down the brome and barley grass seedbank, Tim uses a number of different tactics including multi-year breaks, different chemistries and pasture and fodder rotations.

“On our problem paddocks we would often have canola after a legume. We sometimes also sow canola following a vetch-oats pasture mix which has been sprayed with haloxyfop or quizalofop-p-ethyl,” Tim says

“We desiccate our break crops using paraquat mixed with Sharpen® (saflufenacil) for lentils and glyphosate for canola.

“The field pea hay option gives us another non-chemical method for controlling seed set.”

The use of Clearfield® cereal varieties has also been an effective measure in helping to control brome grass, Tim says.

Tim has found Sakura® (pyroxasulfone) as a pre-emergent herbicide gives excellent barley grass control.

“Even though it’s not designed to be a Mallee herbicide we decided to spend the extra money to get on top of the problem and it’s working for us,” he says.

“In the past we’ve often spray topped our pastures with Gramoxone® (paraquat) to control barley grass seed set and that’s been our approach since forever but we just weren’t getting adequate control.

“What we’ve started to do now is use Verdict™ (haloxyfop) or Targa® (quizalofop-p-ethyl) to control the grasses in the pastures which leaves the broadleaf plants (vetch, medic or canola) for our livestock, leaving feed while we get on top of the barley and brome grasses.

“Our rotation through cereals, pulses and brassicas allows us to mix our herbicide groups to reduce the time to resistance.”

Tim says pastures were traditionally a mix of oats and medic or oats and vetch. Now they have also added straight vetch or vetch and canola pastures into the mix to allow for the control of grasses.  Usually these non-cereal pastures are reserved for feeding young lambs in the spring.

Through this integrated approach the McClellands hope to get on top the problem. Tim says the new Brome RIM software - developed by the CSIRO and the Australian Herbicide Resistance Initiative (AHRI) with support from the GRDC, as well as the Barley Grass RIM software currently under development - was a resource he planned to investigate to research further management options.

“When our lambs were grazing pastures in spring they were getting barley grass seeds in their eyes and we were having to treat about 100 of them every year for blindness,” he says.

“Now we have at least one method of brome and barley grass control in each phase of the rotation which is helping us get on top of it.

“The hay option is particularly effective for us and helps fill a feed gap when we need it and I have also looked into making silage as well. However, that is an extra labour cost both with the making of the silage and feeding it out, so it’s not as easy as hay, which we will continue to use for now.”

GRDC research codes: CSP00186, UCS00020

More information

Tim McClelland, 0408 136 947, tim@modelagronomics.com.au

Related story: Multi-year strategies key in brome and barley grass control

Carefully developed, multi-year management strategies of at least three seasons
are a critical factor in growers gaining the upper hand against barley grass and
brome grass.

GRDC Project code: CSP00186, UCS00020