Published on 21/07/2022
For one company, the response was simple, if expensive: actively discourage off-label use of the product in forage crops, sacrifice short to medium term sales, and spend the next five years getting a new registration approved so it can be used on-label.
The company is Corteva Agriscience; the product is Gallant Ultra and the new label claim is for grass weed control in kale, late maturing rape and fodder beet.
It took 462 business days to reach that point, but as of last spring, Gallant Ultra is back, with some key caveats.
Corteva Agriscience national sales manager Richard Brenton-Rule says growers have given the thumbs up to the return of what was a widely-used herbicide in some forage crops.
“We were able to secure that new label claim in time to have a full season with it back in the market during 2021/22, and it’s gone really well.”
The most important change for end users to know is that kale and late maturing rape are the only forage brassicas covered by the new registration. That means no use on swedes, leafy or bulb summer turnips, or early rape. The main reason for this is the reason Gallant Ultra’s active ingredient (haloxyfop) does such a good job killing grass weeds in the first place– it’s highly residual.
Richard says the other change farmers and growers have dealt with well is the withholding periods associated with the new claim.
Rule number one – crops treated with Gallant Ultra cannot be fed to dairy cows in milk.
Rule number two – dry dairy stock (dry cows) can be fed on crops treated with Gallant Ultra, however they must be held on untreated feed for 14 days prior to being milked again.
Rule number three – for meat animals, the grazing withhold is 12 weeks for forage brassicas (kale and late maturing rape) and 14 weeks for fodder beet. This must be followed by 14 days on un-treated feed prior to slaughter.
“We did a lot of work with our channel partners to make sure they and their clients proceeded cautiously until they were confident every-one understood the details of the new label, and how the withholding periods need to be managed within the grazing cycle of the farm. Gallant in this new context is different to what it was before; it’s not simply a case of flicking a switch back on.”
That said, there is plenty of good news around the new claim, and it has been warmly welcomed by merchants and advisors whose farmers have been struggling particularly with storksbill in their crops.
“Storksbill control has been a real battle for some,” Richard says. “Storksbill is now listed on the label and it was the herbicide’s efficacy on storksbill that helped drive its off-label use before it was withdrawn. We knew it was very good on storksbill, but not having it registered in those crops was very limiting. Now that it’s labelled, farmers have got access to an effective control option.”
Although Gallant Ultra cannot be used on summer brassicas, kale and beet for wintering dry cows are significant crops, and the withholding period for these aligns well with best practice advice to transition cows off crop and back onto grass well before calving.
Richard says the lengthy research and trial programme required to deliver the necessary data package in support of the new claim also prompted another important change.
“We have been able to establish a lower use rate of 125mL per ha for control of seedling perennial ryegrass in those specific labelled crops. If the crop is direct drilled into old pasture, our advice is to use 250 mL per ha, which is the maximum permitted in any situation. But if not, the lower rate will suffice.”
Bringing Gallant Ultra back to the market also helps minimise the risk of grassweed resistance developing as farmers are not relying solely on one mode of action to provide control in these crops.
All in all, it’s been a complex task making sure Gallant Ultra is approved for specified forage crops, but the company is pleased it acted the way it did.
“We made a conscience call in the name of good stewardship, as a leader in this market. It cost us in the interim. We lost sales, and had to invest in the regulatory package. But it was the right thing to do.”
For more detail contact your local retailer or agronomy rep.