Consistent control of grass weeds including herbicide-resistant types across different seasons, is offering benefits for entire cropping systems and is continuing to raise the profile and justify grower investment in a specialist pulse crop herbicide.
Ultro contains a new herbicide mode of action (Group 23) and is being targeted for use in pulse crops, where it is consistently achieving higher levels of grass weed control than many industry standards.
The pre-emergent herbicide can be used in faba beans, lentils, field peas, chickpeas, lupins, vetch and broad beans across Australia, as well as in winter fallow.
Glyphosate and clethodim-resistant grass weeds are posing problems for various southern Australian growers, however Ultro is now taking the pressure off some traditional herbicide options and is helping to clean-up paddocks for future crops.
Putting a focus on the whole farming system benefit from each year’s weed control is becoming more recognised. Using Ultro within the pulse phase of crop rotations is benefiting following cereal crops and, thereby, enhancing its cost-effectiveness.
The early weed control with Ultro allows improved crop competition against weeds, while excellent root pruning on the later remaining grasses assists the effectiveness of post-emergent selective herbicides.
South Australian market development manager with ADAMA Australia Andrè Sabeeney, says Ultro has been used in high value lentil crops and has generally provided reduced competition against weeds, as well as in some faba bean and field pea crops.
He considers it the ideal pre-emergent herbicide for use in pulse crops.
“What’s been impressive is that Ultro has delivered some of the most consistent results in control despite the extremes we have experienced in seasons over the last couple of years,” Andrè says.
“It has just been so much more consistent than the alternatives used in these cropping systems and that has been a real benefit.”
Ultro’s high water solubility compared with other herbicides allowed it to perform extremely well in the dry conditions last season and it offers good persistence, which takes some pressure off and enables better efficacy from post-emergent clethodim treatments.
“The mix of a good, robust pre-emergent such as Ultro, followed by an effective post-emergent grass weed herbicide, helps reduce seedset and delay the development of herbicide resistance,” Andrè says
“Ultro controls most annual grass weeds, it’s not broken down by sunlight, it moves off stubble well and it offers good length of control provided the appropriate rate is applied according to soil type, with higher rates used on heavier paddocks.”
At Kadina in SA, AW Vater & Co agronomist Zack Zweck says various growers had used Ultro in combination with Reflex pre-emergent herbicide and achieved good success.
“It has controlled early ryegrass and brome grass, allowing for delayed in-crop grass sprays. It has also helped the in-crop grass sprays work better,” Zack says.
At Wycheproof in Victoria, Elders agronomist Roy Daykin says Ultro applications with simazine and Spraytop had performed well in numerous instances.
“Feedback from growers in recent seasons has been very positive, with good control of ryegrass, including ryegrass with suspected resistance to glyphosate. It has taken a great deal of pressure off Group 1 post-emergent chemistry,” Roy says.
“The solubility of carbetamide (the active ingredient in Ultro) compared with propyzamide seems to fit our dryland programs better.”
Agronomist with Nutrien at Clare in SA’s Mid North Daniel Kuhndt,, says various growers in the region 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 has mainly been used to target ryegrass in more premium crops like lentils, but also in faba beans, particularly where large ryegrass populations are present,” Daniel says.
“It’s a premium product, but it’s up there with the best.
“Crop safety with Ultro 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.”
Andrè says to aid herbicide resistance management, ADAMA Australia recommends limiting the use of Ultro to once every four years.
He says in tight cropping rotations, careful consideration would need to be given to herbicide choice, however in more common rotations featuring pulses, canola and cereals, an application every four years would be easy to achieve and would allow rotation of all herbicide options in the different phases.
