Adas sees good chance of blackgrass control

Blackgrass germination rates this season are high enough for growers to get good control of this troublesome weed as it emerges in the coming months.

Crop scientists group Adas says blackgrass seed dormancy rates are “moderate” this season, giving growers the opportunity to control this weed with cultivations and herbicides.

A low-dormancy rate and so high-germination rate offers the best chance for growers to control the weed, while when dormancy is high and germination low, weed control is more difficult.

See also: Cover crops can help defeat blackgrass

Adas weed specialist Sarah Cook says blackgrass is not coming up as quickly as last year, but there should still be a good chance of control, especially if drilling is delayed and blackgrass is allowed to germinate and is then killed off.

“There should be ample opportunities for stale seed-beds and spraying off emerged plants prior to drilling, particularly where drilling is delayed,” Dr Cook says.

“There should be ample opportunities for stale seed-beds and spraying off emerged plants prior to drilling, particularly where drilling is delayed.”
Sarah Cook, Adas weed specialist

She advises delaying drilling where blackgrass is bad to allow time for control, and if it is really serious then growers should move to spring cropping to give maximum time to control the weed.

Dr Cook adds that a little patience may be required this season waiting for blackgrass to germinate due to the moderate dormancy this season.

The past two years have given contrasting conditions with 2013 showing low dormancy and therefore good opportunities for control, while 2012 was a year of high dormancy and more difficult control.

Blackgrass dormancy is linked to temperatures in late June and early July with hot weather giving seed of very low dormancy and high germination while cool temperatures give seed of high dormancy and low germination.

The survey this season was based on 68 samples collected by Adas, growers and agronomists, and the testing was funded by agrichemicals group BASF.

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