Planning the right spring weed control programme

Planning the right spring weed control programme

1 October 2016

With longer days and warmer temperatures, daily spring pasture growth rates can hit their peak this month.

However, many broadleaf weeds will also thrive just as much – if not more – at this time of the year. So it’s a good idea to take stock of exactly what kind of dry matter you’re actually growing. Is it high quality, cost-effective ryegrass and clover? Or is it ragwort, California thistle, penny royal or buttercup?

With the right herbicide programme, you can minimise the latter and maximise the former, which bodes well for your milk solids (MS) production band your bottom line.

There are two common scenarios when it comes to broadleaf weeds in established pastures, and each requires a different approach for weed control:

  1. Large, mature and/or multi-crown weeds which are difficult to kill and have escaped regular pasture sprays. Ragwort and thistle are typical offenders here. Spot spraying is recommended in this situation, because the chemicals required to kill the big, tough weeds often damage clover, so care is required. Conquest® by Nufarm is extremely effective for this type of weed control. It’s fast-acting and grass friendly, so won’t leave brown patches in your pasture. It is also very cost-effective and kills awkward weeds other herbicides struggle to control, such as alligator weed, horehound, inkweed, cape weed, goats rue, fennel and hemlock, docks and sorrel. Sprayed weeds rapidly show signs of herbicide application and full brownout can occur within weeks, so you see results fast. Conquest has short-term residual soil activity which suppresses weeds that try to germinate around the treated area. Plus you can use it for brushweed control as well.
  2. Young spring-germinating seedling weeds which are still relatively small, and have only just emerged this season. Common examples include pennyroyal, water pepper, willow weed, buttercup, fleabane, hedge mustard and daisy. For these weeds, the whole pasture is usually sprayed using chemicals that are kinder to clover. Nufarm’s Thistrol® Plus, Valdo® 800WG, Baton® and Bonza® are widely used for this purpose, because they are specifically designed to kill broadleaf weeds while the plants are still small. However, correct spray timing is essential for best results, as is accurate weed identification so you apply the right products for the job. Paddocks should be grazed before spraying to expose target weeds and reduce clover leaf area to minimise clover damage. Let the paddock freshen for two to three days, and try to spray as soon as possible thereafter, weather permitting. Wait until the grazing withhold period is finished before grazing, to allow herbicides to move through the weed plants.

Your local Fonterra Farm Source TSR can help you decide on the right weed spray programme for your farm this spring.

®Bonza and Valdo are registered trademarks of Nufarm Limited. Thistrol, Baton and Conquest are registered trademarks of Nufarm Australia Limited.

Article supplied by Nufarm NZ