Ever since time began farmers have been fighting against weeds in their cropping programs.
For brothers Bob and Murray Preston, a move to wider seeding row spacings has allowed for higher application rates of pre-emergent herbicides, and when combined with a new herbicide strategy, has proven to be successful for this farming family.
Situated 80 kilometres east of Geraldton in the south-west corner of the Mullewa Shire, the brothers predominantly grow wheat and lupins, as well as canola and barley on sandplain country.
Cropping wheat and lupins for the last 56 years on the same land and continued use of herbicides from the same or related chemistry groups, has caused weed control challenges, including reduced herbicide efficacy when targeting annual ryegrass and wild radish.
Looking for change the Prestons, over the last two seasons, have widened the row spacings on their John Deere paired-row seeding bars from 17.5 centimetres (7 inches) to 25 cm (10 in) and have added to their toolbox a herbicide applied at the early post-emergent (EPE) crop timing, Mateno Complete.
Targeting mainly annual ryegrass in high weed pressure paddocks, the use of Mateno Complete followed the pre-emergent application of trifluralin, which has typically been applied for grass weed control, along with prosulfocarb.
Farm consultant Grant Thompson from Crop Circle Consulting said the narrow spacings meant lower than optimal rates of pre-emergent herbicides had to be used due to the soil throw and hence grass weeds persisted from time to time. The wider spacings allowed for high label rates to be used and the addition of Mateno Complete complemented the improved weed control strategy.
“Mateno Complete worked in really well with our transition to 10-inch spacings and after so many years of continuous cropping and herbicide use, you are always looking for a new edge to bring into the rotation,” Bob said.
“It’s about looking years ahead and finding that chemical that you want to move forward with.”
Mateno Complete, which can be incorporated by sowing or applied EPE in wheat and barley, contains aclonifen, a herbicide mode of action available last season for the first time to the Australian industry, in a unique, complementary co-formulation with pyroxasulfone and diflufenican herbicides.
“The advantage with Mateno Complete applied EPE is getting 100 per cent coverage over the soil, which means we are not so driven about getting the seeding operation perfect. Before, we were worried about where the pre-emergent chemical was ending up in the seed row, whereas now we can just concentrate on seeding and then the EPE chemical application,” Bob said.
“Applying Mateno Complete EPE over the entire soil surface profile also means we can get back to doing our soil amelioration at seeding the way it needs to be done.”
Up against tough weed populations and the challenge of controlling weeds on some non-wetting sandplain soils, the Prestons have been applying the highest label rate of Mateno Complete EPE in wheat.
“We were fairly happy with it last year despite an extremely challenging start and we knew we had to put it on earlier this year and hope that it rained and it did. It wasn’t a lot, but it was enough to get it washed in,” Bob said.
We applied early mixed in with bromoxynil and Logran to pick up early radish and volunteer legumes.
“Traditionally we have been applying a radish herbicide early anyway, so the fact we can now add it in with Mateno Complete as well, it works together and we seem to be getting a really good job out of that.
“The tank mixing was also quite good. There was no antagonism and very little crop effect over both years. There was a little bit of discolouration in the crop, but nothing compared to some other chemistry. It grows out of the crop effects a lot quicker than some of the other early broadleaf chemistry out there that we have used previously. We were very happy with it.”
He said despite Mateno Complete being put under the pump in high weed pressure areas, they were pleasantly surprised by its control of annual ryegrass that was noticeable at harvest and in the cleanliness of paddocks.
“Mateno Complete is allowing the crop to get that far in front of the ryegrass that we are getting a lot of natural suppression from the crop as well versus our other products.
“The big thing you look at in a continuous cropping rotation is quite simply how many weeds are there at harvest time, because that then leads into the next three to four crops.”
He said the cost benefit of using the product is not just for one season.
“Every time you use the product, you have got to run it forward three to four years to assess the investment.”
Mr Thompson said non-wetting soils were always problematic in providing an even germination of weeds and can result in annual ryegrass germinations over a two-month window.
However, Mateno Complete was achieving a whole new level of grass control on these soils and offered some big advantages.
“Integrated weed management is all about rotation and being able to change things, so whether it’s new chemistry, going EPE and getting 100pc coverage all over the soil, it all adds another benefit.
“Being able to use Mateno Complete as a tank mix partner with other broadleaf weed herbicides and setting up your crop potential is a big advantage. Its longevity in
controlling key grasses will be a big advantage not only in the current season, but in seasons to follow.”
“In typical years, it’s also not a product that has carryover concerns for the crops we are growing, even in light soils that are ameliorated, so it’s got a lot of benefits,” Bob said.
