Rapid grass growth and multiple silage cuts, taken to make up last winter’s forage shortfall, meant many weedy fields missed out on a herbicide spray in spring, says weed biology specialist, Dr Nicola Perry from Corteva Agriscience.
“Autumn is a great time to clear grass fields of weeds.” said Dr Perry.
“The same rules apply as when spraying in spring. The weeds need to be actively growing with fresh green growth. This is important so that the weeds take in as much herbicide as possible through their leaves, so they can translocate it down to the roots for a thorough kill. Most weeds in grazing fields need cutting down and fresh regrowth sprayed two to three weeks later. “Doxstar Pro (fluroxypyr and triclopyr) controls a wide range of grassland weeds including broadleaved and curled docks, chickweed and dandelion. It has excellent grass safety and is rainfast in two hours.
“Forefront T (aminopyralid and triclopyr) is another option and kills a wider spectrum weeds than Doxstar Pro, including ragwort, thistles and buttercup. It can be used where cattle and sheep graze. It can be used on silage ground after the final cut of the year – as long as the resulting silage is consumed on the farm.
“If creeping or spear thistles are the main problem, topping will be required followed by an application of Thistlex (clopyralid and triclopyr) at 1 litre/ha, two to three weeks later.”