Well-equipped for weed control

Atlantis for blackgrass in wheat; Axial, depending on price, for mixed ryegrass and wild oat populations and in winter barley; Pacifica if brome and blackgrass are a real problem.


For the first time in several seasons growers head into the spring seemingly in a good position against grassweeds.


Part of that is due to growers taking advantage of good conditions in the spring to spray autumn herbicides, says agronomists.


Residual herbicides have worked particularly well.


Indeed on some fields they have been so effective against blackgrass it is unlikely to need any spring treatment, says Bath-based AICC agronomist Stephen Harrison.


“I had around 35% of fields scheduled for spring contact materials, but around 15% of those will not now need treating.”


In all those situations the key has been a pre-emergence spray, followed by a well-timed isoproturon follow-up onto small weeds, he says.


“IPU activity has been helped because it has been a fairly dry winter, so leaching losses have been less.”


Treating those fields with Atlantis in previous years has also been a factor, he suggests.


“It’s helping to get blackgrass levels down.”


In Lincs fellow AICC agronomist Ruth East similarly reports good activity from residual chemistry.


“The low blackgrass dormancy really helped.”


She has only around 25% of her blackgrass area left to treat this spring.


“The farms with serious blackgrass got the pre-emergence on, and then treated with in November with Atlantis.


That has worked well.”


The areas left to be treated tend to have lower pressure blackgrass populations, either because they were later drilled or ploughed.


“On some of these the autumn residual worked well, so we might even be able to leave them.


It is a case of looking at the populations.”


If they do need treating, Atlantis will be the choice, but only when it warms up sufficiently.


“At the moment soil and air temperatures are too low.


It is quite temperature dependent.”


Ideally temperatures need to be above 4C and rising, with no frosts at night, says ProCam agronomist Nick Myers.


“And not just one decent day, but a run of them.


The plant needs to be actively growing.”


He has much more spring spraying to do.


“I’ve probably got 60-70% of fields needing some follow-up treatment.”


Again, he is hoping where autumn residuals have worked well he will be left with very little to mop up.


“More typically they have worked reasonably well, but there are aggravating levels of blackgrass to finish off.”


Very few of his fields have had autumn Atlantis, he admits.


“I haven’t got exclusive grassweed problems – most are some combination of bromes, ryegrass, blackgrass and wild oats.”


The good all-round activity of Atlantis in the spring leaves farmers keen to use it to hit all the targets in one go, he says.


“In hindsight I wonder whether more Atlantis should have been done pre-Christmas.”


Where blackgrass has been controlled, or isn’t present, Mr Myers will look at alternative, more specific, weed killers.


“Axial will be part of the armoury for ryegrasses and wild oats, depending on what it costs.”


Shropshire agronomist Bryce Rham is also keen to use Axial.


“That’s done a busting job, so where I haven’t got annual meadowgrass, but have ryegrass and wild oats, it will be my first choice.


It will do just as good a job as Atlantis.”


Where cleavers are a problem the cost of tank mixing the right dose of Eagle with either Atlantis or Axial will be the deciding factor, he says.


“Atlantis has some activity so I only use 15g/ha of Eagle, whereas I will need more like 25g/ha with Axial.”


Hutchinson’s agronomist James Short says it is competitively priced.


“The recommended service price is 65/litre, plus the adjuvant Adigor.”


That costs around 1.60/ha when spraying at 100 litres/ha.


“I can see it being quite a big product in the future – probably taking some of the Topik/Cheetah market for wild oats.”


The product, despite being an ACCase inhibitor like Topik and Cheetah, has a different resistance profile to the fops, which will help where growers have fop target-site resistance, says Ms East.


“I’ll look to use it on farms with wild oat resistance.”


In some fields wild oat control may have already been taken care of, she hopes.


“An awful lot seem to have come up this autumn, because there were good germinating conditions, so where I haven’t got resistance problems I’ve put some fop on already. I hope I won’t have to come back.”


On ryegrass, Axial should be more reliable than Atlantis, Mr Short says.


“Another advantage is it’s not a sulfonylurea [like Atlantis], and you don’t have to worry about following crops.”


All the agronomists agree Axial will be a bonus in barley.


“It is going to be a very useful addition,” Mr Myers says.


Unlike wheat, where the availability of other products means its use against blackgrass will be limited, the lack of alternatives in barley could see it being a prime choice.


Fields with awned canary grass problems will be another target, says Mr Harrison.


“I’ve got a few farms where that is a problem, one farm in particular is riddled with it.


So far, the best control I’ve seen has been with Atlantis, but on the information I’ve seen Axial should be more cost-effective.”


In contrast, Pacifica’s premium over Atlantis will mean it should only be a niche product, Mr Myers says.


“The ball-park figure is it will cost 20/acre by the time you add in the adjuvant cost.


That’s a 6-7/acre premium over Atlantis.


It’s not a broad-acre treatment, more a specific treatment where brome is an issue in combination with other grassweeds.”


The product, which has a 500g/ha recommendation compared with Atlantis’ 400g/ha, strengthens efficacy against the key grassweeds, particularly brome.


“Brome isn’t actually on the Atlantis label.”


But where brome is the only grassweed target growers will be better off using Attribut or Monitor, Mr Myers says.


“It is the same with ryegrass where Hussar is an option.


They are all lower cost options.”


mike.abram@rbi.co.uk