Long-acting herbicide smooths switch to almonds in Riverland

Whilst transitioning from grapes to almonds in South Australia’s Riverland region, the Henwood family have had an eye on the world’s largest industry in California and particularly its early use of a long acting, pre-emergent weed herbicide.

When the herbicide arrived in Australia, the family jumped at the opportunity to test it, and with Mark Henwood also being Branch Manager of a local agribusiness, they had a front row seat to its performance in the local conditions and weed spectrum.

“I’m pretty lucky in my role as both a reseller and being on the farm. I get to bring home some of these great products, trial them and get hands-on with them, helping to develop trust in the products that we’re selling, so it’s a lucky situation to be in,” Mark said.

The Henwoods are making the slow change from grapes to almonds, which they have strong confidence in and already have produced encouraging results. They currently have 14ha redeveloped to almonds and 60ha still under grape production at their property near Berri. They aim to transition 8ha each year to almonds over the coming years.

Mark helps out on the family farm while working with Riverland Ag Supplies at Berri, a branch of the Swan Hill Chemicals business.

He said the family was excited to see the alternative mode of action, Alion^® pre-emergent grass and broadleaf weed herbicide from Bayer arrive in Australia, and its effectiveness against weeds on the property had been “brilliant”.

Containing the active ingredient, indaziflam, Alion is a Group 29 (formerly Group O) broad-spectrum herbicide providing pre-emergent weed control for up to 10 months, offering growers potential to save on applications and, importantly, additional time to focus on other management activities.

“We’ve seen a lot of fleabane, Rhodes grass and marshmallow that have been our main weed culprits, and there’s been a drastic drop in those the last 12 months since using Alion,” Mark said.

Previously, the Henwood’s weed control program involved rotating between glyphosate, glufosinate and paraquat/diquat herbicide applications.

“We would usually have to come in and spray four to five times a year. Since using Alion with glufosinate and glyphosate, we’ve only gone through twice in the last 12 months, so it’s drastically reduced diesel and time, which has been awesome,” Mark said.

He said the biggest challenge for growers was keeping almond orchards clean prior to harvest.

“Once you start seeing nuts fall off trees, you can’t get in and that’s where Alion has been good for us.”

“The most appealing side with Alion is the timeframe it gives you – if used correctly – between applications. It gives you that time to attend to other things around the property.”

The Henwoods timed their first Alion application before some potential rainbands last November and the second spray was not until July this year.

“Up until July, the property was clean, so it was just about getting in before any more weeds might start popping up. But at that stage, Alion was still working pretty well,” Mark said.

“Two days after the application in November, we got 8 millimetres of rain and then another 5mm the following week. The weeds that were there were taken out with the knockdown (herbicide) and then the property stayed clean for a good six to eight months.

“We didn’t spray some of the headlands and you could see the difference between there and under the trees. It was a huge difference and we were extremely happy.”

He said after a further Alion application before nutfall and potentially next June-July, they would then look to use it only in the period before nutfall and would monitor its effectiveness and the property’s weed management to help prevent herbicide resistance.

In the wider Riverland region, Mark said larger enterprises and family farms had since adopted Alion and achieved great weed control results.

“I definitely think we will also see more uptake moving forward. There has been some scepticism with pre-emergent herbicides in the past, but Alion has certainly proven itself just by what we have achieved here and the results we are getting.”

“People are starting to believe in it and are jumping on-board,” he said.