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Chris Cooksley
Patrick Stephenson
Sean Sparling
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26/01
26/01
27/01
Contact: Natalie
Reed
Tel: 01608 637805
Date: 10/02/2016
Approx words:503
Don’t get caught out; pull forward post-em applications
Consider pulling forward black-grass herbicide programmes in preparation for
uncertain weather later in February, two independent agronomists are warning
farmers.
Met Office predictions show two possible weather scenarios for the UK in late
February and protracted grass-weed growth will only add to the pressure. Growers
will need to take advantage of any windows of opportunity.
“If conditions remain the same, with reasonable day temperatures and the right
weather, I’d crack on,” says Sean Sparling. “The current slow growth however,
means that application variables will have much more of an impact on the final result,
but close attention to detail will ensure a good application.
“A dry black-grass leaf and at least three hours of dry conditions following application
will secure rainfastness. Nozzles and water volumes are important factors too.
Getting good coverage is absolutely critical.”
Meanwhile, further north, Patrick Stephenson says conditions aren’t yet suitable for
travel. “We wouldn’t normally consider post-em herbicide applications now but if
current conditions prevail then we think we might be on in only a fortnight.
“If temperatures remain high, above 8oC, then pulling applications forward is a good
idea. Weeds will be growing, getting bigger by the day and by March or April we’ll be
dealing with a different animal altogether.”
Mr Sparling agrees. “Bigger grass-weeds produce more amino acids – the antidote
to ALS inhibitors. If the weather warms up then black-grass will get going and any
comprising variables will have an even greater impact.”
Meanwhile, if the cold snap materialises then it’s best to wait until soil temperatures
rise again. “Plant metabolism doesn’t stop but the plants do slow down a great deal below 3-4oC soil temperatures growth is minimal.
“New products such as GF2070 (pyroxsulam, cloquintocet and flupyrsulfuron), like
Broadway Sunrise (pyroxsulam, cloquintocet and pendimethalin), prefer warmer
conditions and more active growth. I’m more comfortable with going on with Atlantis
WG in colder conditions.”
Mr Stephenson wouldn’t apply any post-em herbicides below 4oC either. “The
problem is that we’ve a lot of black-grass out there. I don’t want to have to wait but if
it turns really cold I’ll have to.
“Taking out bigger plants now will give the crop a chance to become more robust
and it will then be able to deal with any second flush itself, crowding out any
germinating weed seeds.”
Mr Stephenson and Mr Sparling agree that active growth is more important than
temperature. “It has become evident as we’ve gained experience with sulfonylureabased products that efficacy is more closely related to active growth of target weeds
rather than temperature. Weather has an influence through impacting growth,"
explains Mr Sparling.
-ends26th January 2012
For further information:
Chris Cooksley
Bayer CropScience
+44 (0) 1223 226615
chris.cooksley@bayer.com
Issued by:
Natalie Reed
Whisper.pr
+44 (0)1608 637805
natalie.reed@whisper.pr