Forecastsfor continued mild weather into November should focus growers minds oncontrolling black-grass this autumn, rather than relying on pre-em chemistry tohold control over until spring.
BayerCropScience says the successful conclusion of the winter wheat drillingcampaign, coupled with good establishment conditions, has favoured emergence ofgrass weeds such as black-grass and that theres now a golden opportunity to reducethis years black-grass populations significantly.
Controllingblack-grass has always been difficult, says herbicides development managerGordon Anderson-Taylor in the companys latest Technical Update, but 2014trials conducted by independent contractors and distributors showed that autumnis the time to be thinking about post-emergence herbicide applications.
Weatherforecasts into November predict that were unlikely to see any significant coldweather for two to three weeks, which means emerged black-grass will continueto grow and tiller.
Hopingto tackle large, well tillered black-grass plants with applications of AtlantisWG (mesosulfuron + iodosulfuron) in spring is tantamount to preparing yourselffor a failed weed control programme, he warns. If you experienced poorcontrol of black-grass last season, dont automatically assume youve gotresistance to mesosulfuron its more likely that the plant was just too bigfor the dose within Atlantis WG.
Resultsfrom ten UK trials during 2013-2014 showed that there was a 29% fall inefficacy between Atlantis WG applications made at GS11-13 and those made atGS23-25. This drop-off in control is directly related to the increased size ofthe plant, Dr Anderson-Taylor points out.
SinceAtlantis WG was launched in 2003, the beginning of November has always beenseen as its optimal application timing, says Phillippa Overson, combinablecrops campaign manager. This year looks set to be a golden opportunity forgrowers to really get on top of black-grass populations.
Littlerainfall and above average temperatures over the next couple of weeks shouldprovide some good spray windows, she says, particularly for those crops whereblack-grass is already well advanced.
Youmight still need to deal with cleavers and wild-oats in spring, but theresgood chemistry for those. You wont get a second chance to deal a blow toblack-grass, so take it now.