East Anglia: Helpful agronomy advice for June and July

Current situation

For once this season, the weather is just about behaving itself, with some sun and rain. That does mean we have more disease in wheat crops with a lot of yellow and brown rust bubbling around, as well as Septoria.

Crusoe, in particular, has a lot of brown rust, and equally the varieties that are prone to yellow rust.

But generally crops are looking in healthy and those crops that looked a bit naff in February are recovering.

Flag leaf sprays have or are being applied, except the very late January drilled crops, which have only just had their T1 sprays.

What’s left of the oilseed rape has come through flowering and evened up , except for the ragged headlands, while sugar beet that was hit hard with hail when first emerging has either recovered or been redrilled, and just starting herbicide programmes.

Rachel’s agronomy tips for June and July

1. Focus on brown rust for T3 sprays

With the early infections of brown rust this season, and many varieties on the Recommended List having some susceptibility, it’s likely that it will remain a threat through June, particularly as weather becomes more favourable to it.

Brown rust can cycle incredibly quickly and move onto the ear that hasn’t been protected, and, depending on what was sprayed at T2, fungicide persistence could also be running out – some of the new flag leaf fungicides are not the strongest against rusts, with the exception of Vimoy (isoflucypram).

You will also need to be mindful of the traditional ear disease threats, such as Fusarium and Microdochium.

If you haven’t used two SDHI fungicides in the programme yet, something like Aviator (bixafen + prothioconazole) could be useful. It has that brown rust and Septoria control, and with a high enough dose of 0.75 L/ha you’ll also cover a lot of the ear diseases as well.

But I would imagine a lot of growers will go down the prothioconazole, tebuconazole, strobilurin fungicide route because they are good at giving eradicant control of rusts and not too difficult to source.

2. Check carefully for glyphosate timing when spraying off oilseed rape

Glyphosate is an excellent tool for evening up ripening of oilseed rape crops to help with harvest efficiency but needs carefully timing to avoid reducing yield or quality.

When checking, choose a representative part of the field, and pick at least 20 pods to see whether the seeds are changing colour to brown. You’re looking for at least two-thirds of seeds to have changed colour in at least 75% of the pods for the timing not to be too early. Once the timing has been reached try to spray within four days of assessment and remember after spraying you need to leave a harvest interval of 14 days.

If you’re home-saving seed, or the crop is a seed crop, glyphosate shouldn’t be used.

Spraying earlier in the day usually helps the crop take up the glyphosate more effectively. Use at least 1080g a.s/ha of Roundup for desiccation and annual weeds, and up to 1440 g a.s/ha where you also have perennial weeds.

3. Consider these traits in oilseed rape varieties

There are two ways growers are tending to look at oilseed rape – either as a low input, low output type crop using home-saved seed and not many inputs so it if fails the costs are relatively low, or to invest in high quality seed and programmes to look after it.

There’s no right or wrong approach although I think the latter has been more successful this season.

If you’re are looking to invest in new seed and varieties for the coming season, the key trait to look for in a variety is vigorous establishment, especially if you’re planning to drill in the more traditional drilling windows. It’s probably a little less critical if you’re drilling super-early in August or even before.

More growers are ending up either by design or through weather drilling later in August and into September after the first migration window for cabbage stem flea beetles has passed, and that’s definitely where vigorous establishment to get the crop past the pest pressures and with a good canopy before the winter.

If you’re planning to drill earlier, then other traits such as good disease resistance to light leaf spot and Phoma increase in importance, as the crop will be exposed to these threats for longer.

Among the Bayer Dekalb varieties DK Exstar is just one that could suit either slot. All the DK varieties also come with pod shatter resistance and are part of our establishment scheme that gives sone financial support in the event of crop failure.

4. Use a Magic Trap to help understand flea beetle risk

Bayer has developed the Magic Trap to help growers understand flea beetle risk – it’s a yellow water trap with a high-definition camera that will send assessments of the numbers of cabbage stem flea beetles caught directly to your phone.

We piloted it last year and I see two potential uses initially. It can help to understand cabbage stem flea beetle pressure before the crop is drilled or after drilling.

Before drilling that information could be used to help gauge whether peak migration has passed and therefore help better time drilling, or after drilling it could be used to understand whether there is a risk.

If there were better treatments available for controlling flea beetle that info could be used to understand whether thresholds has been reached and help time sprays, even down to understanding what time of day beetles are most active.

In future, we hope to expand its use to other pests where that aspect might be of more value than currently.

A trap costs £150 from the Bayer e-store plus a subscription to Magic Scout app. You can put multiple traps onto an account to create a network.

5. Visit our Bayer Field Day at Long Sutton

Our annual Field Day at Long Sutton is being held on 4 July this year, and we’d welcome the chance to show you around our various plots and demonstrations.

Highlights include all the Recommended List wheat varieties and candidates – both treated and untreated, which given the disease pressure currently should make interesting viewing at the event.

We also have various fungicide trials focusing on Septoria, yellow and brown rust control featuring the new ones on the market, plus the team will be available to talk grassweed management, pest control and digital solutions.

Acknowledgements

Vimoy contains isoflucypram. Aviator contains bixafen + prothioconazole. Roundup contains glyphosate. Vimoy, Aviator and Roundup are registered trademarks of Bayer. All other brand names used are Trademarks of other manufacturers in which proprietary rights may exist.

Use plant protection products safely. Always read the label and product information before use. Pay attention to the risk indications and follow the safety precautions on the label. For further information, including contact details, visit www.cropscience.bayer.co.uk or call 0808 1969522