Early Summer is the ideal time to spray YBG infestations before they flower and drop seed into existing pastures.
That’s the advice from Nufarm Territory Manager Celese Smit, who says the only thing worse than paddocks that turn yellow with YBG flowers this summer is knowing they will look even worse next season if left unsprayed.
YBG can become a serious production limiting weed, especially when feed is tight over summer.
“One reason for this is it’s a highly-aggressive, annual-seeding weed that spreads rapidly through pasture, it reduces feed quality in late summer and autumn.
"Cows don’t normally willingly eat YBG, leading to low pasture utilisation".
“Grazing avoidance leads to a massive seed set, rapid re-infestation and an opening for other weeds”. Celese says.
Researchers have counted up to 20,000 seeds per square metre in severe YBG infestations, ranging down to 5-10,000 seeds/m2 under light infestations.
A key recommendation for best practice control of known infestations is to stop YBG plants setting seed. This is a critical to prevent YBG from spreading.
Celese says Dockstar® herbicide from Nufarm is registered for this use, and when applied to YBG after it has emerged from the ground, but before seed heads appear, has proven very effective.
“Dockstar has a nil stock withholding period, which is a real bonus when trying to co-ordinated timely YBG spraying with summer grazing rotations,” she adds.
“In saying that, for best results it is recommended pre and post spray timings are observed, but pastures sprayed with Dockstar can still be grazed on a rotation as short as 21 days”.
Previously to Dockstar, the earliest return time for paddocks sprayed for YBG control has been 35 days - seven days required before spraying, plus a 28-day stock withholding period.
Dockstar requires at least seven days between grazing and spraying, plus a gap of 7-10 days after spraying until the next grazing - this maximizes YBG control and minimizes pasture suppression. This is much easier to fit into a summer grazing rotation.
While YBG seed heads are easy to spot, Celese says identifying the weed as a young plant is crucial but difficult. Dockstar does not control YBG once it has set seed, so it’s important to be able to distinguish it from other grasses before it flowers, early identification is key.
“Look for a flattened, hairless leaf sheath; long hairs at the base of rough-edged leaves and reddish-purple colouring at the base of the sheath. If you get the timing wrong this season taking note of the paddock via a farm map or photos this season and using it as reference for next season can be very beneficial,” she advises.
After spraying, Dockstar is likely to cause temporary yellowing and growth suppression of some pasture species, including ryegrass and clover.
For more advice on stopping the spread of YBG on your farm, contact your local Farm Source TSR today.
®Dockstar is a registered trademark of Nufarm Limited.