Successful post-emergence weed control solutions

Successful post-emergence weed control solutions

22 October 2019

Pre-emergence weed control in maize is the foundation for a successful, high-yielding crop. However, post-emergence herbicides may also be required in a range of situations. When that is the case, one tank mix combination is helping growers get the best out of their maize grain and silage.

Nufarm technical specialist Paul Addison says growers who have switched to Latro® WG, Primiera® and Bonza® are ‘more than happy’ with their results. “It’s an outstanding mix that works very well. It gives growers control of one of the widest weed spectrums of any combination for broadleaf and grass weeds in the market, particularly on long-term maize ground where tough perennial weeds can be a challenge,” he says.

Paul says the mix has become popular because Primiera complements Latro WG so well.

“Latro WG is fundamentally a grass weed herbicide with some activity on broadleaf weeds; Primiera is essentially a broadleaf herbicide with some activity against grass weeds. Together, they give the best level of weed control we’ve seen in maize, including problem weeds like black nightshade, fathen and yellow bristle grass.” The Latro WG, Primiera and Bonza mix also has the advantage of providing a wider application window than the traditional post-emergence herbicide mix of Latro WG and Kamba 500. This gives more flexibility and convenience with spray timing without the resultant risk to crop safety, Paul says. A further benefit is that both Latro WG and Primiera perform best when applied with Bonza spraying oil, while Bonza should not be used with Kamba 500 due to an increased risk of crop damage.

Bonza is a parrafinic oil adjuvant and is a critical part of the mix because it greatly enhances the performance of the other two components. All plants have a natural, waxy cuticle on the surface of their leaves and stems to protect the tissue inside. This cuticle acts as a barrier which can slow or block the plant’s absorption of any chemicals applied, thus reducing their efficacy and helping the plant survive.

Bonza has been formulated to help the active ingredients in Latro WG and Primiera spread over the weed leaf surface, penetrate the waxy cuticle, and get inside the plant to do their job. Grass weeds controlled by Latro WG include couch, ryegrass, kikuyu, Mercer grass and annual grass weeds such as barnyard grass, bristle grasses, smooth witchgrass and summer grass.

Broadleaf weeds controlled by Primiera include chickweed, spurry, mallow, clover, willow weed, wire weed and seedling docks. Primiera also has activity against atrazine-resistant fathen. Application timing is important and Paul advises growers to make sure they spray before maize plants reach 50 centimetres (cm) in height to avoid crop injury.

Paul also recommends trying to avoid spraying into the whorls of the maize plant if possible. Latro WG, Primiera and Bonza should not be applied to sweetcorn or popcorn.

To learn more about successful post emergence weed control in your maize grain or silage crops this season, contact your local Farm Source TSR today.

Article supplied by Nufarm Limited

®Latro, Primiera and Bonza are registered trademarks of Nufarm Australia Limited.