Tackle grassland weeds now

13 Aug 2019

Controlling grassland weeds during the next few weeks, particularly this season’s dock infestation, could result in more milk from grass at turn out next spring, cut concentrate bills, and achieve a return on investment of 12:1. So says Nufarm’s Brent Gibbon.

Herbicide application during August and September is often way down producers ‘to do’ list, but these are the ideal months for grassland weed control in established swards.

Actively growing

All weeds will be actively growing in the warm moist soil, providing an opportunity for the herbicide to be actively taken up and translocated down to the roots.

Timing is crucial and perennial weeds are, once again, at the leafy rosette stage following second or third cut – the optimum stage for take up of herbicides, such as Thrust (2,4-D + dicamba).

Cutting interval

“Late-summer application also means that there are likely to be no issues re cutting interval, and we anticipate there will, if necessary, be alternative grazing available on most units,” says Mr Gibbon.

He adds that for multi-cut and rotational grazers, now is the first seasonal opportunity.

Weed competition

“Thinking ahead and introducing a weed control programme now will allow producers to minimise the chances of weed competition in early spring.

“For every 1% increase in weed ground cover, grass growth will decrease by 1%. So controlling common weeds in a grazing sward with a 20% dock infestation could improve spring yields from 7t DM/ha to 8.5t DM/ha.”

Improved grazing

This extra grass could be fed to replace more expensive bought-in feeds, providing a 5:1 return on investment (ROI). Improved grazing availability and subsequent stocking rates to take more milk from grass will deliver a 12:1 ROI.