Autumn Canopy Management
Forward oilseed rape crops require both autumn and spring PGRs to regulate growth and protect against lodging. Nitrogen management and a spring PGR alone are not enough on some crops.
Likelihood of forward crops this autumn?
Crops drilled early to get a head-start against cabbage stem flea beetle have also had excellent growing conditions and are already racing away in early September. Those sown at low seed rates will have space around them but any populations of 35-40 plants/sqm or more will grow tall quickly, with weak lower stems, making them prone to lodging in the spring. For these crops which reach 4-6 leaves in September or by mid-October, north_east Caryx ® is recommended.
Caryx® recommendation:
- Timing: 4-6 leaves of the crop in September or October. Don’t delay - plants larger than 4-6 leaves will be too big to benefit properly. Also, growth starts to slow down by late October and PGR activity will be much less.
- Rate: 0.7l/ha on 4-6 leaf crop. If high plant population or fertile soil, 1.0l/ha may be required.
Why use Caryx®?
Caryx® used in the autumn regulates top growth and increases rooting. In addition to reducing lodging risk, it helps the crop withstand hard frosts, saturated soils and pigeons.
| Autumn Caryx® Effect | Benefits |
|---|---|
| Short stem base | Reduced lodging risk No ‘exposed’ stem vulnerable to direct Phoma infection Growing point protected from frosts, pigeons |
| Large root collar diameter | Resists damage from cold, wet soils Provides reserves for early spring vigour |
| Increase in rooting - both in autumn & persists through spring (ADAS field trials) | Improved anchorage - reduced lodging risk More able to cope with poor soil conditions Better nutrient and water uptake in spring |
Profitability
On crops with a high lodging risk, an autumn and spring Caryx® sequence will be more cost effective than a single high rate in the spring.
| Dose | Yield | MOIC £/ha |
|---|---|---|
| Spring ONLY 1.4 l/ha | + 0.5 t/ha | £122 |
| Autumn fb Spring 0.7l/ha fb 0.7l/ha | + 0.86 t/ha | £230 |
N = 5 BASF biological dossier trials with lodging. Yield untreated = 3.3 t/ha. OSR price £300/t
Disease control – spray thresholds
- Phoma control – May not be present when Caryx® is applied and since big plants are more tolerant of Phoma, the 30% dose of metconazole in 0.7l/ha will give some protectant activity. If 10% of plants are infected, consider adding a 20% dose of difenoconazole or prothioconazole.
- Light leaf spot control – The main infection period for light leaf spot is from November onwards. Since this is later than the Caryx® timing, a separate spray will be required.
Caryx® is a registered trademark of BASF. Caryx® contains metconazole + mepiquat-chloride. Use plant protection products safely. Always read the label and product information before use.
For further product information including warning phrases and symbols refer to north_east www.agricentre.basf.co.uk .
For further information, please do not hesitate to contact your local north_east BASF Agronomy Manager or the BASF Technical Services Hotline: 0845 602 2553.
