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Act early on post-emergent grass weed survivors

Broadacre
07.05.2020
Boxer Gold® from Syngenta is registered for the management of early post-emergent grass weeds.
It pays to consider how effective those pre-emergent applications have been and whether a salvage job might be required.

Wheat and barley germination bring a nice sense of achievement and the opportunity to evaluate the effectiveness of those pre-emergent, grass weed management programs.

There could be a number of reasons for an escape, including ineffective incorporation of triallate-trifluralin mixes, or perhaps a lack of soil moisture to activate the chosen product.

BOXER GOLD is a solid choice for those salvage jobs helping manage weed seed set, where a Group K or J hasn’t already been used.

“Pre-emergent programs remain the best way to control weeds, including annual ryegrass,” Syngenta Technical Services Lead James Considine said.

“If growers are faced with a high number of survivors it could be necessary to consider a salvage job to help manage the weed seed bank for years to come.”

The BOXER GOLD label allows for early post-emergent management of annual rye grass, while in the one-to-three leaf stage, where there is adequate soil moisture. Where prosulfocarb or S-metolachlor selective herbicide hasn’t already been used, BOXER GOLD should be applied at a full-rate of 2.5 litres per hectare.

“Post-emergent grass weed control options are limited and can be expensive,” James said.

“BOXER GOLD is a good option to supress those survivors and manage seed set. You may not achieve the 80 to 90 percent control that’s possible in a pre-emergent pattern but suppression in the order of 60 to 70 percent is feasible, provided that BOXER GOLD is applied to moist soil and is incorporated with adequate rainfall while the target weeds are still in the one-to-three leaf stage.”

Where weeds do survive, BOXER GOLD will still supress a majority of weeds, reducing potential seed set and significantly reduce competition for moisture and nutrients.

James said the real difference between control and suppression is most clearly observed where annual rye grass populations are higher.

“Where 80 to 90 percent control is achieved in a population of 100 seeds/m2, this will result in as few as 10 seeds being returned to the weed seed bank - most people will be pleased,” he said.

“But if that same rate of control is applied to 1000 seeds a square metre, this is going to look ugly. It is important to pause and consider what risk any survivors pose for the future.”

For more on how and when to use BOXER GOLD in an early post-emergent pattern, refer to the product label or this tech note.