Article taken from Crop Production Magazine
Praxim (metobromuron) was a welcome introduction to the potato herbicide armoury last season, especially as some of the old stalwarts are under close scrutiny by ORD. After a full seasons experience in 2015, has it lived up to expectations?
As far as agronomist Stuart Maltby's concerned, the answer is a 'yes'. ""Praxim can be used pre-emergence right up to cracking of the ridges and I'm comfortable using it late on when potatoes are very near emerging. I haven't seen any adverse crop effects so it appears to live up to the claims of good crop safety on all soil types."" Stuart Maltby has his own potato demo site near Holbeach where he's able to run a number of 'experiments' both on and off-label, though the latter requires crop destruct. ""I looked at Praxim on the demo site last year and investigated a number of different tank mixes and rates," he explains. So what were his key findings? ""There's a very definite drop off in performance when used at 2 I/ha rather than 3 I/ha. When used at 2.5 I/ha there's still a slight drop off in comparison to the 3 I/ha rate. At the full rate of Praxim (4 I/ha) there was no noticeable difference to using 3 I/ha," he explains. ""The conclusion I've come to, is that you need to be using Praxim at 3 I/ha and definitely not below 2.5 I/ha, and then only with a partner product, such as Defy (prosulfocarb) or Sencorex (metribuzin), There's an impression that Praxim is highly priced and for that reason some growers aren't using rates that are robust enough. At the 3 I/ha rate, I'm seeing broad-spectrum weed control and good longevity on weeds like bindweed and willow weed (pale persicaria). ""There've been issues in a few following wheat crops where clomazone (Gamit 36CS) and metribuzin were applied the previous spring to the potato crop. I'm not seeing any visible effects in wheat this year following potatoes where Praxim was used in 2015," he notes. Although there aren't any buffer zone restrictions for Praxim, Stuart Maltby reminds growers to be mindful of the buffer zone requirements of any partner products. Agrovista agronomist Luke Hardy advises growers in Shrops and was keen to try Praxim last year, particularly because of the likelihood that linuron may soon disappear and leave a yearning gap for a light land herbicide replacement.
“I have a lot of light land in my area, so there’s potential for problems with crop damage if using metribuzin. I’ve used Praxim at 2 I/ha in tank mix with Defy on light land where fumitory is the main problem. On the heavier land I’ve either used metribuzin as a partner product or a three way mix of Praxim plus clomazone,” he explains.
According to Luke Hardy, Praxim looks to be so much more than just a linuron replacememnt. “its expensive compared with linuron but also offers flexiability and a broader spectrum of weed control, with activity of metribuzin which makes them ideal tank mix partners,” he says.
Although Praxim appears expensive in comparison to other pre-ems, he believes it’s money well spent.
“Last season, no post-em follow up treatments with Titus (rimsufuron) were needed where we used Praxim”