Scotland: Latest agronomy tips from Bayer

Current situation

A better spell of weather has helped growers drill most of the remaining spring cereal crops. It’s certainly not unheard of to be drilling this late, albeit a little unusual, but these crops can still perform despite drilling this late.

Potato planting is in full swing, with the last likely to be planted in early June.

More rain is forecast before June, which, despite all the rain previously, will probably be good for crops, depending on how much falls.

While there are dodgy looking fields of oilseed rape, the rape that is flowering is looking really good. Even winter wheats have come on, but I don’t get too excited until we find out how they’ve really done at harvest.

Grant’s agronomy tips for June and July

1. Look out for Fusarium in wheat

Most flag leaf sprays, bar the very latest drillings, should have been sprayed in the last 10 days of May, weather depending.

Once ears emerge, the biggest disease issues will be a continuation of Septoria pressure and Fusarium and Microdochium infections. There’s still a long time before harvest after T3 in Scotland, so make sure crops are protected because every grain is going to count this year.

Options for ear / head sprays could depend on what you’ve previously applied. If you went cheap and cheerful at T1 and didn’t apply a SDHI-containing fungicide or used a fenpicoxamid-containing product without a SDHI, then that gives the opportunity to use a SDHI at T3, such as Aviator (bixafen + prothioconazole).

Aviator at 0.75 L/ha will help protect against Fusarium ear blights, while providing a good top up against Septoria and yellow rust.

If Septoria pressure is extremely high, and you haven’t used Vimoy (isoflucypram) or two other SDHIs previously that could also be an option, although cost will likely rule it out for most.

Where two SDHIs have been used or budget is an issue then Proline (prothioconazole) at 0.55 L/ha will make a decent base, to which a strobilurin or tebuconazole could be added.

2. Awns emerging is key spray timing in spring barley

Spring barley will likely romp through growth stages this year, because of the late drilling and hopefully warmer weather.

I’d always try for two fungicide sprays in spring barley but the second timing, awns emerging, is the key one for controlling Ramularia, as well as other foliar diseases, such as Rhynchosporium and net blotch.

Ramularia is a bit hit and miss – it’s not guaranteed to be a problem every year – but it should be in your mind at T2. It’s brought on by stress and wet leaves and there are issues with resistance so using multiple modes of action should be considered.

Check product labels carefully, especially if you’re growing the crop for malting – some newer ones might not be one the Institute of Brewing approved list, and there are also latest timings of application to consider.

Bayer products such as Ascra (bixafen + fluopyram + prothioconazole) and Siltra (bixafen + prothioconazole) have both malting approval and a later cut off.

3. Advice for oilseed rape desiccation

Looking further ahead into July to oilseed rape desiccation timing, and the key, as always, is not to go too early. As difficult as it can be to get into fields to assess when to spray, it remains the best way to judge – just make sure you pick a representative part of the field to sample pods from.

Take a sample of around 20 pods, and check whether around two-thirds of the seeds in 75% of the pods have turned brown or black. That’s usually the indication that crops are on the turn and good to spray off. If you go to early then you risk getting too many red seeds and rejected loads, plus you will have hit yields and oil content.

4. Early vigour high on list of key OSR variety characteristics to look for

Generally speaking you will want an oilseed rape variety in and growing by the end of August, unless the weather forecast is looking exceptionally good.

There are a number of characteristics or traits to look for in oilseed rape varieties to suit early drilling, with early vigour key. I would look to a hybrid variety with good growth to get the crop established early doors.

Obviously, club root is another key trait where it is needed, while also look for light leaf spot and increasingly Phoma resistance ratings. Most varieties, including all the Bayer Dekalb range come with pod shatter resistance, which is definitely a benefit to growers at harvest. Late maturing varieties are best avoided in Scotland.

5. Quick emergence and blight concerns in potatoes

With some potato crops still being planted there will be some herbicide to apply in early June. Remember crops will emerge much more quickly in warmer soils, and that matters for some herbicides, including Emerger (aclonifen) which should be applied at least seven days before emergence.

Emerger should be mixed with another herbicide for best results. Artist (flufenacet + metribuzin) is one possible option, depending on variety. That mix would give excellent broad spectrum control of annual meadowgrass and broadleaf weeds, but there are other options to consider mixing Emerger with.

If using Emerger, remember to follow best practice application guidelines. Agitation, in particular is key, including agitation of the product can before adding to the sprayer.

Once crops have reached rosette stage, first blight sprays will be imminent. Make sure you’re signed up to Fight Against Blight for early warnings of blight in your region, and that all the cultural controls have been done, including spraying off dumps and controlling volunteers in previous crops.

With new CAA- and OSBPI-resistant strains of blight found on the continent last year, sensible programmes will be required. These strains, if, or perhaps when found in the UK will mean products like Revus (mandipropamid) and Zorvec (oxathiapropalin) might be less effective.

Sensible strategies regardless of strain would be to avoid block spraying the same active and keeping intervals to seven days, and using a range of modes of action.

Infinito (propamocarb + fluopicolide) efficacy isn’t affected by the resistant new strains, and could have a place both from mid-season for foliar blight control – it’s a strong anti-sporulant – and at the end of blight programmes for tuber blight control.

Consider using Caligula (prothioconazole + fluopyram) if you have any varieties at risk from early blight. It controls both strains Alternaria alternata and Alternaria solani but it won’t control late blight, so has to be added to a late blight spray.

But given that we know mancozeb won’t be with us past next year, it might be worth trying some Caligula to see how you get on with it.

6. Contact us to look round our Field Days site in Edinburgh

We’re not having a Bayer Fields Days event at our Edinburgh site this summer, but are hosting bespoke tours for groups. If you’re interested in coming to visit and seeing the various variety and fungicide trials plots, please get in touch with either Edward or myself.

Acknowledgements

Aviator contains bixafen + prothioconazole. Vimoy contains isoflucypram. Proline contains prothioconazole. Ascra contains bixafen + fluopyram + prothioconazole. Siltra contains bixafen + prothioconazole. Emerger contains aclonifen. Artist contains flufenacet + metribuzin. Revus contains mandipropamid. Zorvec contains oxathiapropalin. Infinito contains propamocarb + fluopicolide. Caligula contains prothioconazole + fluopyram. Aviator, Vimoy, Proline, Ascra, Siltra, Emerger, Artist, Infinito, and Caligula 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