Sowing new pasture? Weed out weeds and reap the benefit

Sowing new pasture? Weed out weeds and reap the benefit

24 February 2020

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Renewing run-out pasture is always a vital job in autumn, but this year, with many farms affected by dry weather during summer, getting your new grass and clover seed off to a flying start is more important than ever.

There are two reasons your grass and clover seed need the best start they can get.

First, healthy, fast seedling establishment means new pasture will be ready for its first grazing sooner.

Second, good establishment will help get your farm back to its full growth potential by spring, when you really need that dry matter (DM) yield to feed cows well and support early lactation.

Many weeds often get a head start in paddocks renewed after a dry summer, because they can germinate earlier and grow faster, with less soil moisture, than ryegrass and clover.

Even in ideal sowing conditions, weeds can suppress the yield and quality of new pasture from day one, because they steal sunlight, space, water and nutrients from emerging ryegrass and clover seedlings.

Fortunately, several post-emergence herbicides are now available to kill weeds at different stages of pasture establishment – all you have to do is decide which suits your needs and your timing best.

Spraying early, about six weeks after sowing and before the first full grazing, is widely recommended as the best option. If this does not work for you, however, other herbicides are suitable for spraying after the first grazing.

Spray before the first full grazing: This has several benefits. Weeds are small, more vulnerable to herbicides and cheaper to remove. Tribal® Gold is the premium treatment at this timing, and it’s perfect where farmers want a broader weed spectrum and/or need to control hard to kill weeds like chickweed, shepherds purse and buttercup. Thistrol® Plus has a narrower weed spectrum and is also very effective before the first full grazing. Valdo® 800WG can be added if required to extend the range of weeds controlled. Always use Bonza® spraying oil with Tribal Gold. Spray when approximately 70 percent of the ground is covered and when clovers have two identifiable trifoliate leaves.

Spray after the first full grazing: Different chemistry is required to kill broadleaf weeds at this stage of pasture establishment, and it’s important not to confuse the first full grazing with the light nip off recommended at about six weeks after sowing. Baton® 800WSG is the preferred herbicide for this timing. It is formulated to kill larger, more advanced weeds and it has a very broad spectrum. It is more clover-friendly than other 2,4-D formulations but young clover leaves must be properly grazed before application, to minimise the risk of clover damage. For weeds that don’t respond to phenoxy herbicide, like perennial buttercup and chickweed, Valdo 800WG can be mixed with Baton 800WSG to extend the spectrum of weeds controlled.

No matter when you spray, it really pays to be vigilant about checking all newly sown pasture for weeds from the time of sowing.

Your local Farm Source TSR can help identify different weeds and recommend the best way to control them.

®Bonza, Tribal Gold, Valdo 800WG are registered trademarks of Nufarm Limited.

®Baton 800WSG and Thistrol Plus are registered trademarks of Nufarm Australia Limited.

Article supplied by Nufarm Ltd