Mix it up: optimising spring herbicide applications

Mix it up: optimising spring herbicide applications

12 September 2018

Most spring- sown paddocks are chosen for crop or new grass because the soil is damaged and/or the paddocks contain too many weeds and not enough high- quality grazing.

So it’s vital as many weeds as possible are eliminated before new seed goes in the ground.

This applies to every situation regardless of whether you’re going from winter feed to crop or new grass; grass to grass; crop or winter feed to spring crop, or grass to winter feed.

High performance WeedMaster TS540 plus Pulse is a proven foundation of any pre-plant spray programme.

Although WeedMaster TS540 controls grass weeds and a wide range of broadleaf weeds, several common broadleaf weeds including clovers, yarrow, dock and buttercup require their own specialised herbicide strategy.

As a result, it’s becoming common to mix WeedMaster TS540 with companion herbicides where necessary.

Cynthia Christie, Nufarm technical specialist, says mixing options include Archer, Charter 750WDG, Sero 750WG, Nail EC, Kamba 500 and Relay Super S.

While each has different uses they are all powerful partners for WeedMaster TS540.

Cynthia has some important practical tips for getting the best out of these products this spring.

"The most common questions we’re asked relate to control of specific weeds and plantback and grazing withholding periods."

She recommends asking the following questions:

  1. What crop or pasture species do you intend to plant in the paddock(s) selected for spring sowing, and when? Common examples include ryegrass/clover, fodder beet, forage brassicas and spring sown cereals. This can influence your choice of companion herbicides.

  2. What are you spraying out? Is it old grass or are you preparing to spring sow seed into a paddock which has already been cropped and grazed?

  3. What existing broadleaf weeds are present in those paddocks? Different weed species can require different herbicides for best results.

  4. What plantback periods apply to your intended crop or pasture? The increasing popularity of fodder beet as a spring-sown forage crop means plantback periods are more important than before. Some herbicides remain active in the soil for months or years and fodder beet is very sensitive to certain herbicide residues. Chicory and plantain can also be affected by companion herbicide residues months after application. Nail is the only companion herbicide in this range with a nil plantback for all crops, including fodder beet, chicory and plantain.

  5. What grazing withholding period (WHP) applies to your companion herbicides? For example, you can graze, cultivate or drill three days after treatment with WeedMaster TS540 for perennial weeds but Charter has a seven-day grazing WHP while Kamba has two weeks and Archer, Sero and Nail have none.

To help farmers get the best out of their spring spray-out, Nufarm has developed an informative chart, matching companion herbicides with their relevant weeds and showing application rates, grazing WHP, rainfast periods and plantback periods for subsequent crops.

For more information, talk to your local Farm Source team.

Article supplied by Nufarm