Overwatch® Herbicide - Elders Rural Services

Overwatch® Herbicide

Overwatch® Herbicide from Agricultural Sciences Company FMC is a pre-emergent herbicide option for the control of Annual ryegrass and control and suppression of a wide range of other grass and broadleaf weeds in Wheat, Barley and Canola.

Classified as a Group Q mode of action, Overwatch® provides Australian growers with a unique tool in the fight against herbicide resistant weeds. As part of an integrated weed management program, Overwatch® herbicide will assist in slowing down the development of further herbicide resistance.

“What we see with Overwatch® is that it’s up there to being equivalent in efficacy to our current standard, which is exciting in the sense that we can combat some of the group K resistance which we have with ryegrass,” said Lyndon May, Elders Technical Services Manager South Australia.

“Having a new Group Q chemistry gives growers a lot of confidence that they can actually have a multi-product approach, especially to their ryegrass control across all their rotation within their cropping program,” adds Bill Moore, Elders Technical Services Manager Western Australia.

Alongside controlling Annual ryegrass, Overwatch® also controls weeds including Silvergrass, Bifora, Sowthistle, Hogweed and Lesser loosestrife.

“The other element that is interesting about the herbicide, apart from the change in chemistry away from group k is the broadleaf control,” explains May. “Bifora is one of those broadleaf weeds that we have challenges with and Overwatch® has proven its strength and flexibility across Wheat, Barley and Canola.

The new choice of chemistry provides the long-term ability to control ryegrass whilst also picking up the broadleaf weeds,” says Moore. Because Overwatch® is registered in three key winter crops, it provides greater options for crop rotations.

With a large number of weeds registered for suppression on the label, including Barley grass, Bedstraw, Brome grass, Capeweed, Phalaris, Prickly lettuce, Wild oat and Wild radish, Overwatch® has an excellent fit in many paddocks.


“Overwatch® provides good early season control and allows flexibility in rotations in all three key winter crops,” explains Moore. “What’s exciting about the new chemistry coming to market is that we can start offering a lot more value to those particular crops and start showing growers that the crop can become a really important part of the rotation, without compromising their weed control, and steer away from some of the other chemistry that they’ve been relying on for a really long time.”

“Ultimately it’s the value proposition of how we manage the older chemistry,” explains May. “There will be strategic seasons where it’s more conducive to use one or the other, or when dealing with high numbers in particular paddocks, Overwatch® provides great flexibility to work through that.”

Demonstration sites across the country have been used by FMC in recent years to show agronomists and growers through Overwatch® trial plots and demonstrate the unique herbicides robust performance across a wide range of locations and conditions.

“From the trials observed Overwatch® appears as a safe product, we know it doesn’t affect soil metabolism or cell division,” says May.

Residual herbicides have been challenged with dry conditions in recent years so the introduction of Overwatch® means growers can have more flexibility with regard to following crop safety. Many trials have been conducted by FMC to demonstrate the ability of the crops to metabolise the herbicide and continue to grow.

The unique mode of action of Overwatch® certainly had growers and agronomists taking note at trials, as the plants germinate and come out of the ground, they turn a striking magenta colour before they desiccate.

“The bleaching component of Overwatch® can be seen as a positive to many growers, it indicates the product is actually getting into the plant and that you have enough solubility in the system,” explains May. “As we often sow dry and not sure how much moisture we need for the herbicide to be activated, with Overwatch® we have a tracker with the bleaching that gives you the idea of how much soil moisture is in there.”

“The work we’ve done in our own trials at our sites in Victoria and South Australia, we noticed the bleaching early on but there was no crop impact, no difference in biomass. Supporting yield data that FMC have collected over time has proven that.”

We’re definitely in an exciting space and the new chemistries coming to market have all got slightly different niches and features that will give you a reason to use it. I can see on one individual farm that they could use all the various chemistry in any one year,” explains May.
Good supplies of Overwatch® Herbicide are expected to be available for the 2021 winter cropping season with the product being manufactured in Australia, at FMC’s Wyong plant, on the New South Wales Central Coast.

Article written by FMC for the Autumn edition of Seasons Magazine.

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