An untreated plot in a trial at Coomalbidgup showing annual ryegrass pressure in wheat, amounting to 121 plants per square metre.
The recent launch of Spruce herbicide, comprising an innovative combination of two highly effective active ingredients, has been welcomed by agronomists across the country this season, offering them a powerful tool in pre-emergent programs with growers.
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Developed by UPL, Spruce has been specially calibrated to maximise weed control efficacy whilst also offering improved crop safety and compatibility.
It provides broad-spectrum control of annual ryegrass, barley grass, phalaris, silver grass and toadrush, including herbicide-resistant weeds, plus suppression of various pre-emergent grasses and broadleaf weeds in wheat (not durum wheat).
More than 50 trials with Spruce since 2020 have highlighted its effectiveness and crop safety, while industry research also has shown its ability to control pyroxasulfone-resistant weeds and reduce wild radish populations resistant to diflufenican.
Spruce’s formulation is characterised by a smaller and more uniform particle size than with the individual active ingredients, improving its stability in suspension and allowing improved coverage, uptake and efficacy, including against small-seeded weeds (surface germinators).
The end result is longer term weed control, reducing the need for follow-up herbicide applications.
Victorian agronomist Stephen O’Connor, based at Shepparton with Advanced Ag, says the length of weed control offered by Spruce is attractive for the region’s growers, some of whom already had applied the herbicide when sowing wheat this season.
Originally from a mixed farm at Yabba North in the area, Stephen was previously a research agronomist and has spent the past seven years with Advanced Ag, which has grown strongly and now has a number of agronomists working across northern Victoria and southern New South Wales. They support growers from Corowa down to Seymour, and from Wangaratta across to Kerang.
Stephen says in the area he works, about 100km radius around Shepparton comprising low through to higher rainfall crop and pasture production, plus irrigated land, Spruce had been incorporated by sowing (IBS) in various wheat crops, including forage wheat for dairy farm silage.
Annual ryegrass, barley grass and some silver grass were the main target weeds, as well as any broadleaf weeds including capeweed, wild radish and fumitory. Some grass weed populations in the area also have shown tolerance of pyroxasulfone and glyphosate herbicides.
“We have used a lot of Group 2 IBS herbicides and have seen higher development of resistance to this chemistry and not optimal results, whereas Spruce, with the inclusion of diflufenican, will now help to combat that resistance in high and low rainfall seasons,” Stephen says.
“We saw Spruce in some of the trial sites, and it was quite good, and we’re looking for higher quality herbicides and like to support companies bringing through R&D products and enhancing the effectiveness of existing products.”
Strong weed control after an application of Spruce pre-emergent herbicide at 500 millilitres per hectare, which reduced annual ryegrass numbers to 11 plants/m 2.
Stephen O’Connor says Spruce from UPL will help growers as a great rotational pre-emergent herbicide for both grass and residual broadleaf weed control, relieving the pressure on post-emergent sprays and pushing out their application timing.
He says depending upon weed pressure levels, the stronger early residual control from Spruce could help delay typical mid-tillering weed sprays until crop growth stage 31.
“Diflufenican is a residual product and with good crop competition as well, it could stretch out the control, allowing growers to spread fertiliser and take care of other paddocks early, and then assist better spray timing with fungicide and more effective broadleaf herbicide than typically used at stage 31.”
Stephen says Spruce will be included with glyphosate and other knockdown herbicides in tank mixes, which will enhance residual broadleaf weed control during early crop development.
“Ultimately, it will help as a great rotational pre-emergent herbicide for both grass and residual broadleaf weed control, relieving the pressure on post-emergent sprays and pushing their timing out,” he says.
