Midlands: Latest advice for this and next season’s crops

Current situation

Levels of Brown rust in some wheats are bringing back memories of Alchemy in the 2007 season. There are some horrendous infections in crops even after early treatments, and I think it is assumed what works for yellow rust will also work for brown rust.

Tebuconazole, for example, isn’t as efficacious on brown rust as it is on yellow rust, especially at some of the lower doses we tend to use at T0. There’s also probably not been enough use of strobilurin fungicides, particularly pyraclostrobin.

The worst affected variety is Crusoe, obviously, plus Dawsum, Champion and one or two others.

Yellow rust is continuing to run, and the mid-May weather of low teens temperature and moist air, is perfect for the disease. That said, it is generally more under control than brown rust in this region.

And of course, there is also plenty of Septoria in crops, especially in those drilled before the mid-October deluge begun. They are quite grubby with disease breaking out on leaf three. You can definitely already pick out the top five Septoria-resistant varieties in variety screens, with one or two of the candidates also looking noticeably cleaner.

That meant growers are realising they will need to spend more at T2, which are just starting to go on as this is written. Fortunately, there are some good additional options this year, whether from us in Vimoy (isoflucypram), in Univoq if you are prepared to use it or Syngenta’s new Miravis Plus (pydiflumetofen), although you may need to take out a mortgage to buy the latter.

Ben’s agronomy tips for June and July

1. What was sprayed earlier in the programme will potentially impact on T3 choice

Fungicide programmes to date could be a factor in what ear sprays could be used. I doubt many will have used their two allowed doses of strobilurin fungicide so far, so that mode of action is part of the discussion.

Likewise, anyone who used Univoq (fenpicoxamid + prothioconazole) will still have at least one application of an SDHI-containing fungicide available to use. How many growers will move to stronger chemistry at T3 I’m not sure – it will depend on what crops look like at the time.

Where brown rust is continuing to break through or Septoria still a serious threat, might be the situations where upgrading from good old tebuconazole + Proline (prothioconazole) or Proline plus strobilurin is worth the extra investment.

There are options if you want to upgrade – products like Elatus Era (benzovindiflupyr + prothioconazole) has dropped in price and is good against rusts and want some Fusarium cover, you can buy reasonable rates for mediocre money.

Aviator (bixafen + prothioconazole) offers a stronger option against Fusarium with a higher prothioconazole loading, but will be a bit weaker on brown rust. If you haven’t used Vimoy, in terms of excellent rust and Septoria control and prolonging greening effects, it could fit, albeit at a more expensive price.

You could even look at Revystar (mefentrifluconazole + fluxapyroxad) that’s going to have some Septoria activity and it’s pretty good on brown rust as well.

The danger with the more expensive choices is that you choose rates to fit a price, and when that starts happening you lose all the benefits. You have to see it as a premium investment.

Which brings me to point two…

2. It’s possible to use robust rates at a decent price

With generic versions of actives such as prothioconazole and azoxystrobin relatively cheap, if you’re going down that route and many will be, make sure you use the decent doses for controlling diseases.

Why cut corners and use 0.5 L/ha of tebuconazole when 0.75-0.8 L/ha will give you more persistent brown rust control and better Fusarium cover for just an extra £2-3/ha. The same applies to azoxystrobin. You need three-quarter rates of azoxystrobin to give you the greening and decent yield improvements, so why not do it, if it is not costing you stupid money?

3. Start planning for next season

Demonstration days and event season will be with us in June and it’s a good time to talk to breeders, manufacturers, NIAB and others about next season.

Given what’s happened with the weather this season, it doesn’t take much thought to suggest that growers might be considering drilling wheat earlier this autumn. Hopefully, it won’t be late September, but it might be early October rather than mid-October.

That puts weed control in a whole new ballpark because you’ll have an extra two to three weeks of cover needed from your residuals. The programme will be starting earlier in warmer soils and maybe lower soil moisture levels, so it is worth thinking about whether what you have done traditionally will work that scenario. There’s plenty of people who will have an opinion so get out and chat.

4. Look for oilseed rape varieties with vigour

I’m actually surprised how well some of the oilseed rape has turned out given through the autumn and early spring some crops wouldn’t still be with us at this point. It’s patchy in places but there is some reasonable stuff around. Flowering was the longest I can remember, which caused its own set of problems.

But with better crops than expected, you might be willing to give it another punt next season. A lot will depend on yields and prices, of course, but if you are growing again, then from what I’ve seen this year and in previous ones then vigour to get away from cabbage stem flea beetles in the autumn and pigeons in the spring is a key characteristic to look for.

Those varieties that are known for their vigour have certainly looked better all through the season, although whether that will translate into yield, who knows?

The other two traits I would want in a variety are strong light leaf spot and pod shatter resistances.

5. Could our Magic Traps help decide when to drill oilseed rape?

Bayer has been developing something called a Magic Trap for use in oilseed rape. It’s a little solar powered yellow box – about 30cm by 30cm – with a water trap, and a camera. The idea is to put it into a field either before drilling oilseed rape or after and it will help you monitor cabbage stem flea beetle and other pests attracted to the yellow. Pictures are taken every six hours and, in theory, should help identify cabbage stem flea beetle.

The potential is there for it to be an early warning system for when cabbage stem flea beetle migration has begun and allow you to delay drilling if massive numbers are being caught, for example.

Acknowledgements

Vimoy contains isoflucypram. Miravis Plus contains pydiflumetofen. Univoq contains fenpicoxamid + prothioconazole. Proline contains prothioconazole. Elatus Era contains benzovidiflupyr + prothioconazole. Aviator contains bixafen + prothioconazole. Revystar contains mefentrifluconazole + fluxapyroxad. Vimoy, Univoq, Proline, Elatus Era, Aviator and Revystar 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