Time to get pastures back in shape before winter

24 February 2019

If you could do with more high-value grass and fewer weeds come springtime, you’ve probably already considered undersowing paddocks that have come through the past season a little worse for wear.

Fast, cost-effective and efficient, undersowing is a popular way to extend the life of pastures that may be thinning out but are not yet ready for full renewal.

Like full renewal, however, undersowing offers a great opportunity to get rid of common and costly pasture weeds.

Think of this as protecting your investment and giving paddocks the best chance to perform to their potential in the weeks and months ahead.

At this time of year the goal of any pasture repair effort is to restore lost dry matter (DM) production as swiftly as possible, so any damage or deterioration over the past winter, spring and summer does not continue to undermine farm performance in 2019 and 2020.

Nufarm technical specialist Cynthia Christie says where hybrid, Italian or perennial ryegrass seed is used for undersowing, (2,4-D) amine products such as Baton^® 800WSG or Sprinter^® 700DS tank mixed with Valdo^® 800WG can be applied afterwards to control broadleaf weeds such as chickweed and stinking mayweed.

“If clovers are included in the seed mix it is critical to allow the pasture to be fully grazed once before spraying to ensure clover safety.

“However, most undersowing is done with ryegrass seed only and, in such cases, correctly-timed weed control can enhance establishment by removing competition for young ryegrass plants. It also helps prolong the production gains undersowing sets out to achieve in the first place,” says Cynthia.

Recommended rates are Baton 800WSG at two kilograms (kg) per hectare (ha) or Sprinter 700DS at 2.3 litres (L) per ha in tank mix with Valdo at 65 grams (g) per ha.

“This will not be too tough on clover already present and offers broad spectrum control for the weed spectrum likely to be present,” says Cynthia, adding the best timing is after the undersown grasses are grazed for the first time so that weeds are exposed and existing clover plants have less leaf area.

What about established pastures that don’t need undersowing, but still need a clean-up before winter? Thistles, pennyroyal, water pepper, willow weed, buttercup and other weeds will germinate under existing pasture covers in autumn and once paddocks are grazed they will take off. Fortunately, this is a good time to kill them because they’re small and susceptible to herbicides. Options include Baton or Sprinter, Valdo, or Tribal Gold. Conquest is an option where weeds are extremely large or species not well-controlled by phenoxy herbicides. Conquest will severely damage clovers and these may need to be resown in spring.

^®Baton 800WSG is a registered trademark of Nufarm Australia Limited. Sprinter 700DS and Valdo 800WG are registered trademarks of Nufarm Limited.

Article supplied by Nufarm