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Primiera is an easy to use, selective post-emergence herbicide for weed control in maize. Primiera is effective against a wide range of broadleaf weeds and may also provide some control or suppression of several grass weeds.

  • Outstanding broadleaf weed control including atrazine resistant fathen.
  • Soil and foliar activity.
  • Excellent crop safety and potential yield gains.
  • A flexible period for application.


Active Ingredient: 480g/L Mesotrione


Formulation: Suspension concentrate


How does it work?

Primiera is absorbed through the leaves, shoots, and roots of weeds and then translocated throughout the plant. It inhibits an enzyme responsible for carotenoid biosynthesis which leads to bleaching and then death of the plant.



When used post-emergence Primiera is most effective when applied to weeds up to the 8 leaf stage, typically 5 – 10 cm tall. To increase the spectrum of weed activity Primiera is best used in combination with 1 – 1.5L/ha of Flowable Atrazine 500 or 0.4 – 0.7kg/ha Nu-Trazine™ 900DF.
For optimal post emergence weed control, particularly against grass weeds such as summer grass, Primiera must be used in tank mixture with Bonza® at 0.5 – 1.0L/100L water.

Use Rates Weeds controlled

Bathhurst bur, black nightshade, chickweed, dandelion, fathen, (includes triazine resistant fathen), fennel, fishtail oxalis, galinsoga, hairy nightshade, mallow, redroot, seedling docks, spurrey, staggerweed, twin cress, willow weed, wireweed.

Primiera is only partially effective against grass weeds.

Use 100 – 300 litres of water/ha and ensure good coverage of the foliage.



Providing the spray has dried on the foliage, light rain after spraying will not affect the results. Otherwise rain within three hours of treatment may reduce effectiveness.



Primiera can also be used in tank mix combinations with either 300 – 600 ml/ha Kamba® 500, or 80 – 110g/ha Latro WG if required. (Do NOT use Bonza if tank mixing Primiera with Kamba 500).