With good seedbed conditions and fairer weather suggesting a positive drilling period, are there any watch-outs looming for this autumn’s weed control? CPM finds out.
“Really make the most of improved conditions – check nozzles and application techniques – be detailed.” DR WILL SMITH
By Janine Adamson
With drills on the move across the country there’ll undoubtedly be a lot of wood being touched, ladders avoided and four-leaf clovers being sought, in the coming weeks.
At the time of writing (end of September), conditions have permitted wheels to roll, with just enough moisture to penetrate to drilling depth, says Niab agronomist for the eastern region, Gary Rackham. “Growers are motoring on and drilling cereals; crops seem to be going into good conditions.
“I certainly don’t want to jinx it, but in the East on lighter soils we have the capacity to take more rain and still be out drilling a few days later. Hopefully it’ll remain a positive picture,” he comments.
HOLDING FIRM
With the impetus to get going, Frontier’s Paul Fogg counters that until now, he’s been encouraging growers to wait, mainly due to a lack of weed flush. “With the exceptionally early harvest, it’s admittedly hard to sit on your hands.
“But in the North, for those who didn’t wait, we’re seeing grassweeds coming through now in-crop, which of course are much more challenging to control.”
Otherwise, for those more patient, he says they’re entering a decent wheat drilling period. “Where soils have been worked post-harvest they’ve taken any rain well; most places have then seen a flush and applied glyphosate accordingly.
“In terms of herbicides, it’s now building the best chemistry into a programme balanced against the most cost-effective approach. If wheat has been drilled early, growers may want to consider a top-up early post-emergence, paying particular attention to the qualities of the different actives, such as persistency.”
Weed expert, Dr Will Smith, believes growers should be in a ‘genuinely good place’ compared with previous seasons. “Following a solid control year, in most cases, the seed return will be low. However, due to the nature of the weed seed-bank, you can’t afford to be complacent.
“Many will have seen a significant flush already following a couple of decent rainfall events – moisture has soaked in, opened up soils and consequently, weeds have germinated.
“But we’re in this for the season – with a potentially open autumn we may see an elongation of the germination period; the weeds will keep coming,” he cautions. “Of course for high pressure grassweed areas, the hope would be that drilling is delayed.”
According to Will, if the weather continues to permit, paying attention to the finer details can reap rewards. “Really make the most of improved conditions – check nozzles and application techniques – be detailed. Then, evaluate how successful pre-ems have been and whether you might have to go back in with a top-up,” he adds.
As technical lead for Gowan, he also highlights the potential use of Avadex Factor (tri-allate). “For those drilling later in the season, this remains a good pre-em option, and is a robust addition to herbicide programmes, offering diversity.”
PRODUCT SUPPLY
Gary warns of a watch-out looming on the horizon: “While most cereal crops will have a pre-em, there appears to be a supply problem with some chemistry which may complicate programmes. This is especially the case if growers are working hand-to-mouth due to cash flow or time management issues, it means they could miss out on their preferred herbicide options,” he says.
Paul agrees that flufenacet appears limited. “This means having FMC’s Fundatis (bixlozone+ beflubutamid), which was recently launched in GB, is useful, particularly in winter barley where cinmethylin can’t be used,” he raises. “With no post-em options in winter barley, a robust pre-em strategy is essential.”
Another concern for Gary are areas which are coming out of SFI agreements and going back into cereal crop production. “These could be hard to manage this season due to the weed burden which will have been allowed to build. Robust herbicide stacks and careful management will be required in these situations.”
While for Paul, it’s yellow rust that’s high up his agenda. “Let’s not sleepwalk into a yellow rust disaster in spring – we should have it in the back of our minds from the get-go.”
This article was taken from the latest issue of CPM. Read the article in full here.
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