BASF Agricultural Solutions UK


Plant Growth Regulator

A flexible and impressive plant growth regulator for autumn and spring use in winter oilseed rape.

The first oilseed rape product to justify its label approval on the strength of its growth regulation capabilities alone. In autumn, Caryx should be used on early established or forward crops, regulating top growth to withstand a hard winter and reduce lodging risk. It increases rooting to make the crop more resilient to cold and wet winter conditions and pigeon grazing. Once spring arrives, crop growth will be more uniform, helping to optimize timing for spring inputs.

In spring it is economic to treat crops with a GAI>0.8 (or >50% ground cover), measured before the start of stem extension in February. Caryx should be applied to these crops once there is active growth – anytime between stem extension and yellow bud.

OSR treated with Caryx® in the spring works in three ways to help minimise risks and maximise OSR yields – we call this ‘The Caryx Effect’: all three Caryx® effects will be needed in spring 2020: a triple lock-in for yield

  • Reduces Lodging
    Why the need in 2020? Plants may be able to tolerate feeding by CSFB larvae but feeding in the main stem increases lodging risk. Reducing lodging risk will protect seed yield and qualily.
  • Increases light penetration
    Why the need in 2020? Canopies of well-established crops are likely to be too thick. Increasing light penetration to the lower canopy will increase seed set, maximising seed number for optimum yields.
  • Increases rooting
    Why the need in 2020? A wet autumn and winter has resulted in plants with poor rooting, even the leafy crops. Improved rooting at depth will help maintain seed fill later in the season, especially if summer conditions are dry.


  • Increases the light into the canopy and reduces any leaning or lodging. ADAS trials work shows yield increases up to 0.4t/ha through a reduction in lodging and increases in seeds/sqm. Around a third of the crop area lodges each year (ADAS survey).
  • Improves rooting at depth can add 0.2t/ha yield benefit in a dry summer. A recent ADAS survey showed that the average rooting of OSR crops at depth is inadequate, which means yields can suffer in a dry May.
  • Two complementary actives ensure that the product works effectively in typically variable spring weather conditions and which allows for flexible timing from stem extension through to yellow bud.
  • Tested against the GAI tool to ensure a financial return in crops with a GAI > 0.8, measured just before stem extension

Product Profile

Active ingredient(s)30 g/l metconazole and 210 g/l mepiquat-chloride
FormulationWater based
Pack size5 litres in outers of four
CropsWinter oilseed rape
Maximum individual dose1.4 litres per hectare
Maximum number of treatmentsTwo
Latest time of applicationUp to and including crop growth stage 59 (Yellow bud)
Water volume200-400 litres per hectare*
Aquatic buffer zoneLERAP B
Other specific restrictionsThis product must not be applied via hand

Which crops will benefit from Caryx® in the spring?

In crops that grow away relatively normally at stem extension, Caryx® will reduce lodging risk. It will also encourage secondary branching to compensate where the terminal raceme or primary branch is weakened by larval damage.

Measure the GAI just prior to stem extension, not much earlier, using the BASF website tool or GAI app for iPhone. If the GAI is >0.8, then it is cost-effective to use Caryx® later in the spring, adding 0.2t/ha and up to 0.4t/ha where lodging occurs.

  • Earmark potential crops for Caryx® (those where GAI >0.8 or 50% ground cover)
  • Wait for stem extension to check plant development

Where crop development is under question, application of Caryx® at yellow bud allows more time to assess. Yellow bud timing will have the strongest effect on secondary branching and is likely to be of particular benefit to these crops.

Find out YOUR GAI

Find out YOUR GAI

Our OSR GAI Online tool is a trusted partner when working out your Green Area Index.

If the GAI is >0.8, then it is cost-effective to use Caryx® later in the spring, adding 0.2t/ha and up to 0.4t/ha where lodging occurs.

Find out more
What's YOUR cost of lodging?

What's YOUR cost of lodging?

Have a go on our OSR cost of lodging calculator to estimate the impact of lodging in your oilseed rape!

Do the maths


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 Technical Services Hotline +44 845 602 2553

Technical Services Hotline +44 845 602 2553

Technical Services Hotline



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