Strong investment in radish control saves paddock for 2017 season
Western Australian wheatbelt grower Mark Sutton was a little amazed last year that a crop largely written-off with wild radish could go on to yield higher than the farm average and allow the paddock to continue in the rotation. Mark and his wife, Helen, operate the 10,000 ha ‘Dyard Farms’ property plus leased land near Mollerin in the eastern wheatbelt, cropping 8,000 ha to wheat, canola, lupins and triticale, as well as running about 500 Merino ewes.
Soils range from red loams through to Mallee and Wodjil country, and cropping rotations can include two years of cereals followed by canola or lupins, or two years of cereals before a pasture phase.
Their 200 ha “problem paddock’’ last year had received the standard post-emergent herbicide spray of Jaguar® at 800 mL/ha with LVE MCPA at 400 mL/ha four to ve weeks after sowing.
Mark said Group I herbicides were becoming less effective against wild radish and the population was heavy in this paddock, which was sown to Calingiri noodle wheat.
“The radish was showing signs of regrowth and there was also another germination,’’ Mark said. “Traditionally, we would have gone to a Group I mop-up, but ‘Daz’ (local Landmark Agronomist Darren Marquis) knew that wouldn’t work.’’
Darren advised Mark to apply the Group H post-emergent herbicide, Velocity®, which was sprayed prior to stem elongation at 1 L/ha via a tug-along Sonic sprayer set up with 02 nozzles. The water rate was also increased significantly to ensure excellent spray coverage.
Velocity is based on the novel active ingredient, pyrasulfotole, and also includes bromoxynil and Bayer’s crop safener, mefenpyr-diethyl. The pyrasulfotole interrupts several biological processes crucial to weed growth, while the bromoxynil, which acts primarily as a contact foliar herbicide with virtually no soil residual activity, further disrupts the photosynthetic process, resulting in a unique action against weeds.
“Within days, the radish had shriveled up just nicely,’’ said Mark, who had previously been impressed by Velocity in a local trial in barley.
“The paddock ended up clean – it was spot-on. It worked out at about $30/ha. It’s a bit pricey, but the most expensive chemical is the one that doesn’t work. Velocity got the job done, the paddock was clean and we have got wheat in the rotation again for this season.
If we didn’t use it, the paddock wouldn’t be going into wheat. It yielded 2.1 t/ha, making the noodle grade and with good protein, and overall our paddocks yielded 1.9 t/ha.”
“The radish would have cut this yield in half, we would have chucked it out and there would have been so much seedbank in the paddock for us to control. Velocity is a good tool in the toolbox and we will certainly look to use it for some other problem paddocks.’’
Darren said some growers would have hesitated at the investment and used Ester 800 or Tigrex®, but he said they were also “running out of puff’’.
“In the last five to 10 years, Jaguar and LVE MCPA has been the staple, but we are hitting the wall at three to four leaf with harder-to-kill radish on acid country,’’ he said.
“For larger radish, we are snookered. Group I, C and F (herbicides) are coming under increasing pressure, so we are slowly introducing Group H, with Velocity, into the equation. Precept® herbicide is the best option for oat crops.’’