04 March 2024

GLYPHOSATE and clethodim-resistant grass weeds are posing a problem for southern Australian grain growers, however a new mode of action pulse crop herbicide is taking the pressure off traditional options and helping to clean-up paddocks for future crops.

The pre-emergent herbicide, Ultro^®, is being targeted for premium pulse crops in high weed pressure paddocks and is achieving higher levels of grass weed control, however it also offers wider benefits for entire cropping systems.

Increased early weed control also reduces root disease build-up for following seasons and allows improved crop competition against weeds, while excellent root pruning provided by the herbicide on the later remaining grasses assists the effectiveness of post-emergent selective herbicides.

Ultro-treated grass weeds can also remain greener for longer and in particularly high weed pressure paddocks requiring crop-topping, this allows these applications to be delayed, reducing the risk of crop damage from the operation and concern over grain maximum residue limits.

Featuring a new herbicide mode of action (Group 23), Ultro can be used in faba beans, lentils, field peas, chickpeas, lupins, vetch and broad beans across Australia, as well as in winter fallow.

Alistair Crawford, Market Development Manager with ADAMA Australia in Victoria and Tasmania, said Ultro was used last season especially in high value lentil crops, which also generally provide reduced competition against weeds, as well as in some faba bean and field pea crops.

“It was used in problem weed paddocks mainly against ryegrass, and where there is some increasing resistance to glyphosate and clethodim, but it was also very effective against brome grass, which is more prominent in northern areas,” Alistair said.

“Ultro affects the whole plant and prunes roots, so it reduces weed numbers and can improve post-emergent grass weed control. This can reduce seedset for next year, which can help delay the development of herbicide resistance.”

At Clare in South Australia’s Mid North, Nutrien Agronomist Daniel Kuhndt said various growers tackling high weed pressures, including herbicide-resistant annual ryegrass, were now growing back-to-back break crops and the new mode of action chemistry in Ultro had become attractive for the pulse phase of programs.

“It is mainly targeting ryegrass and is used in more premium crops like lentils, but also in faba beans, particularly where large ryegrass populations are present,” Daniel said.

“With options like this and others now available, it’s a matter of working out and mixing up the chemistry across your program and not doubling-up.”

He said after an average start to the season before good moisture availability, Ultro, including in tank mixes, performed exceptionally well and resulted in higher levels of control.

“It’s a premium product, but it’s up there with the best. It was in the top two products that were used last year and it blew stuff out of the park. There were huge numbers of grasses and they were just scarce (where Ultro was applied).”

“Crop safety with this herbicide is also really high, whereas you can get some crop effects with other options. Plantback flexibility and an application rate range gives ‘agros’ and growers greater flexibility, which is important.”

Ashlyn Ridgway, Agronomist with Nutrien Ag Solutions at Pingelly in Western Australia, said various growers used Ultro with paraquat, metribuzin and simizane for their lupins last year and achieved a great weed control result.

Ashlyn Ridgway, Agronomist with Nutrien Ag Solutions at Pingelly in Western Australia, shows the excellent root pruning of later germinating ryegrass provided by the pre-emergent application of Ultro herbicide in lupins.

Good herbicide activity was observed on late germinating ryegrass roots up to three months after the knockdown treatment with Ultro.

“The residual activity was great. It certainly took the pressure off the ‘post-em’ grass spray and growers will be using more in future years,” Ashlyn said.

On the Yorke Peninsula in SA, Daniel Hillebrand, Agronomist with Nutrien Ag Solutions at Kadina, said Ultro had been one of the better performers against ryegrass with multiple resistance to herbicides, as well as brome grass, which featured more strongly in sandy belts, and barley grass, which once again had been rearing its head.

Daniel Kuhndt, Agronomist with Nutrien Ag Solutions at Clare in South Australia, says the pulse herbicide, Ultro, was in the top two products used in the area last year and it “blew stuff out of the park. There were huge numbers of grasses and they were just scarce (where Ultro was applied),” he says.

“It is used particularly in lentils and although pre-emergent conditions were not ideal at the back end of seeding, Ultro doesn’t need a whole lot of follow-up rainfall to activate. We had a lot of marginal rainfall last year and Ultro showed the upper hand over alternatives,” Daniel said.

“It showed that if you need to step things up against higher grass pressure, it is the more consistent product and it doesn’t need as much rainfall as propyzamide.

 “More herbicide mode of action tools in the toolbox is also good and if we were going through plans and looking at a paddock with high grass pressure and a history of brome, we would sway to Ultro over propyzamide.”

He said the herbicide was highly effective across all soil types and with good crop safety, and it definitely advanced the control provided by in-crop herbicides later.

“Grass control in pulse crops is definitely better when there is a ‘pre-em’ under its feet, as we have seen in the past when growers opted for two in-crop sprays against populations that already had some resistance to fop and dim herbicides and had not already been affected by a ‘pre-em’ application.”

Receive double points on purchases of Ultro and Tenet from ADAMA*. And get one step closer to joining ADAMA and Nutrien Rewards for an Unforgettable Study Tour to the USA. Find out more about the Study Tour here**

*DISCLAIMER:

The ADAMA Ultro^® and Tenet Double Points promotion is valid nationally to Nutrien Rewards Members. To be eligible for the double points offer, the Nutrien Rewards member must purchase ADAMA Ultro and Tenet from any Nutrien Ag Solutions store that is part of the Nutrien Rewards Program between 1 March and 30 April 2024 (inclusive) using their Nutrien Account. Points will be applied to the Member’s Nutrien Rewards account the following month. Please see Nutrien Rewards Terms and Conditions for more details.

**Terms and conditions for the ADAMA USA study tour can be found here.

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