The first ever dedicated growth regulator product for winter oilseed rape has just been launched on the Irish market.

The product, called Caryx, has been introduced by BASF as an anti-lodging agent with an associated impact on root growth.

While we have practiced growth regulation in winter oilseed rape for years, this was done using the side effects of triazole fungicides.


The level of effect produced depended on the product used and the rate at which it was applied.

These products certainly did have a growth regulation effect, but it was not on the label.

In general, the effects were not big enough or consistent enough over time to warrant a label recommendation for plant growth regulation.

This has now changed. Caryx has a label guarantee of growth regulation.

BASF states that “it works for you when you want it to”, but this is a qualified statement.

The product

Firstly, it is a mix of two actives with growth regulation capability - metconazole (30g/l) and mepiquat chloride (210g/l).

This is a combination of perhaps the strongest azole active in metconazole (Caramba or Juventus) and mepiquat chloride, one of the actives in Terpal and Canopy.

It is only for use on winter oilseed rape, with two timings of application.

On forward crops, it can be applied in the autumn from the three-leaf stage out to the end of autumn growth (GS13-19).

In springtime, it can be applied from the start of stem extension to the yellow bud stage (GS31-59).

It can be applied as an autumn or spring treatment, or both. But it cannot be used as a split treatment in either autumn or spring.

The maximum individual dose rate is 1.4l/ha at either timing.

As the combination of these two actives, Caryx claims to shorten the crop and manipulate its canopy structure, thus reducing the risk of crop lodging.

It should only be applied within the timing windows when conditions are broadly suitable for growth.