A new tool to combat the growing challenges of weed resistance has been welcomed by agronomist Ian Koch, at J & D Southwood, on the Yorke Peninsula of South Australia.
Mr Koch said most of the farmers in the region were continuous croppers and have a high degree of herbicide resistance through their paddocks.
“The northern Yorke Peninsula is particularly noted for its ryegrass resistance to trifluralin ,” he said. “Most guys have got Group A resistance and there's a reasonable amount of Group M and Group B resistance. Glyphosate (Group M) resistance is coming off the fence lines and moving into the paddocks.”
“There was long history of Glean and Logran in the 80s and now we use a lot of imi's because of the weed spectrum. Most guys are aware of it and are looking at changing products around to keep all the tools in the shed for longer. We've only got the pre-emergent products that do a good job. The post-emergent products are really struggling.”
Last season Mr Koch visited a number of trials to view FMC’s new Overwatch® Herbicide, a Group Q pre-emergent herbicide registered for use in Wheat, Barley and Canola to control Annual ryegrass and a wide range of other weed species.
“This was the third year we've been aware of it and had a look at trials,” Mr Koch said. “Overwatch® Herbicide is another tool to extend the life of current products. It gives us the opportunity to be selective about where we want to use it, we don't just have to go and put it over everything like we have done previously.”
Looking at how Overwatch® Herbicide will fit into his program, Mr Koch said, “Bifora is a huge problem for us on the Peninsula and the fact that it smokes Bifora really well is just a bonus that we weren’t expecting. We're happy to have great Annual ryegrass control but the Bifora is a real win for us because it is an ongoing problem."
He said Overwatch® Herbicide provided a chance to look at the farmer’s rotation and also mix with other herbicides to target the specific weed spectrum to get the best result. “I can see Overwatch® Herbicide being used by itself in certain circumstances but also can see a tank mix with some of the other products that are coming out or are in existence.”
Mr Koch visited the Overwatch® Herbicide demonstration site in Roseworthy last season and was impressed by some of the tank mixes. “In Barley, the Overwatch® Herbicide and metribuzin plot was exceptionally clean for not a huge increase in cost. That's something I would be recommending to a few guys on the coastal country that grow Barley. We could use Overwatch® Herbicide in that situation as it has a much better resistance strategy for Brome grass.”
He said the Overwatch® Herbicide and Callisto® herbicide mix was also one that stood out. “I gave a nine and a half out of ten for the Broadleaf and nine and a half out of ten for the Annual ryegrass control. It has done a fantastic job and I hadn't previously considered it as a serious option.”
“With that sort of weed control, I really have to sit down and have a good look at it and do the sums.”
The ability of Overwatch® Herbicide to be available across the three major Winter crops also adds flexibility in times of crop failure or change. “We can grow Wheat, Barley or Canola, so if you had a bad snail or slug problem or something went wrong at least you could put something back on it,” Mr Koch said.
He said it was important to ensure new chemistry is utilised well, which also allows the lifespan of existing options to be increased. This includes mixing and rotating herbicides, and always using the full label rate of Overwatch(R) Herbicide.
“Everybody knows that in the chemical market it is getting harder to produce new products. We should try to keep our existing products and also look at mix options. That is going to be better for everybody."
Ian Koch, of J & D Southwood, sees a great fit for Overwatch® Herbicide in a range of crops and as a tank mix to help control a wider weed spectrum.