A new pre-emergent herbicide available for Wheat, Barley and Canola looks an exciting option for Elders agronomist Peter Watt, at Cowra, in the central west of New South Wales.
Mr Watt said the new Overwatch® Herbicide offered an alternative to the chemistry they have been using on the different crops.
“The cropping system was based on trifluralin. We've had it for nearly as long as I've been in this game,” Mr Watt said. “We’ve now moved into the more soluble products and our system has changed. We've gone more to a direct drilling system. We might be looking to retain stubble, so we're looking for other attributes in our soil chemistry to work with our cropping system."
He said pre-emergent chemistries were vitally important with the rate of herbicide resistance and the variability in the seasons.
“If you get a wet year, your post-emergent pass is not guaranteed, or it could be delayed or compromised. The simple fact is the post-ems aren't working. We've got to rely on the pre-em package."
Overwatch® Herbicide was first trialled by Elders Cowra in the dry season of 2018. Overwatch® Herbicide controls susceptible weeds by disrupting photosynthesis, which turns it pink and bleaches the plant before eventual death.
“In Canola and Wheat trials, Overwatch® Herbicide was very visual” Mr Watt said. “What impressed us most is that we rely on a couple of things with weed control, efficacy of the product but then the host crop has got to impart really good competition. You don't want the herbicide knocking the crop too much because it's about competition and efficacy of your product."
“We really did see the efficacy of Overwatch® Herbicide. It was still paying out a long time after some of the other products had given up the ghost."
Overwatch® Herbicide is registered for the control of Annual ryegrass, Bifora, Hog weed/Wireweed, Lesser loosestrife, Silvergrass and Sow thistle. It also provides suppression of Barley grass, Bedstraw, Brome grass, Capeweed, Phalaris, Prickly lettuce, Wild oats and Wild radish.
“You don't have to step too far before you see Annual ryegrass, so it is pretty much endemic here,” Mr Watt said. “What is also endemic is Group A and B resistance and, in some cases, multiple resistance.”
He said there were also challenges with weeds such as Black oats (Wild oats), Barley grass, Silvergrass, Wild radish and others which are all on the Overwatch® Herbicide label.
“For Ryegrass control, Overwatch® Herbicide is up there with some of the other market leaders. We’re seeing mid-eighties up to mid-nineties in weed control."
Mr Watt said the three crops on the label provided flexibility and gave options for growers. “I particularly like Overwatch® Herbicide in the Barley market, but it doesn't lock it in to the Barley market,” he said. “It will find some space in Wheat, and we'll be utilising it in Canola.
To take broadleaves out of Canola has been a tricky situation unless we default to the triazine chemistry or the increasingly unreliable Clearfield chemistry. Overwatch® Herbicide is a lovely complement in that Clearfield space, also in the TT space and in non-herbicide tolerant Canola. In Wheat, and Barley, it gives us a lot of flexibility."
“There's a broad spectrum of weeds in there. I think we'll learn a lot more about this product over the next couple of years as it gets out into the commercial space."
Peter Watt, of Elders Cowra, is excited about the opportunities for Overwatch® Herbicide in Barley, Canola and Wheat.