North: Agronomy tips for June and July

Current situation

Well, what can I say, it’s been pretty dire out on farm because of the weather. However, to keep positive things are starting to look better as there are some good-looking crops that have survived the winter and spring onslaught.

The weather through this month has put a bit of a spring in our step and allowed growers to make some much-needed progress.

Spring cereals drilling has now all but finished for this season, but the potato growers are hard at it, where the ground is good. As suggested last month by my colleague Tom Sowerby, Wold land has been easier to travel, but the Vale of York is now looking smashing with tractor tyres rolling.

Adam’s agronomy tips for June and July

1. Fusarium will be the focus for T3 sprays

A lot of our winter wheat crops within the region missed the important T0 spray, which has then led to the bumping up of T1 sprays due to the weather increasing disease threats. T2 sprays have also needed to be robust – product choice was key to hit specific targets such as rusts and Septoria.

From an ear spray (T3) perspective, one of the key diseases which in my opinion could be quite prevalent, is the FEB (Fusarium Ear Blight) spectrum.

While mycotoxins are rightly central when we think about Fusarium, don’t forget there are also yield penalties from it causing shrivelled grain, reducing quality, and thus affecting final yields circa 10%.

Humid and showery weather around the flowering time favours this disease, and it is important to hit that spray timing at the right time. Early to mid-flowering is the ideal to hit Fusarium species, which is GS63-65, when the first anthers are visible from the florets. However, saying this, sometimes the weather which favour this disease hamper application timings.

Variation in crop potential also makes T3 product choice difficult. In my opinion you have two choices - Folicur t(ebuconazole) or my preferred choice Proline (prothioconazole) as this gives you a more flexibility with application timing.

2. Watch out for new resistant blight strains

The potato teams across the Yorkshire regions have been going hell for leather recently, in the good dry spell. With the better weather and higher temperatures recently, we’re likely to see quicker emergence of crops due to potato seed having broken its dormancy and later planting.

Blight has always been at the forefront of my mind since managing potato crops back in the day. Potato blight is an ever-evolving beast that has to be tamed.

The decreased sensitivity of aggressive blight strain EU_37_A2 to fluazinam and now the spread of the more aggressive blight strain EU_36_A2 has brought resistance management more into focus for growers and agronomists alike.

What is worrying is the recent finding of the fungicide resistant blight strains EU_43_A1 and EU_46_A1 in Europe. They are yet to be found in the UK, but I guess it will be a matter of time. These blight strains have shown resistance to CAA fungicides such as mandipropamid, and OSBPI fungicides - oxathiapiprolin.

Advice is strongly suggesting using both mixtures of different modes of action and alternating blight products to minimise both resistance development and impacts on efficacy in our programmes. The continued availability of mancozeb this season is helpful in both cases.

But it does mean we have to focus more on our blight programmes, and from a Bayer point of view where Infinito fits into that scenario.

Due to the season, I am expecting to see rapid growth. Tubers become at risk following this phase once tuber initiation begins, so thinking about zoospore activity from this time is important. Infinito is one of the best products available to protect from zoospores infecting tubers.

Another option for tuber blight is the quinone inside inhibitor (QiI) mode of action products, such as Ranman Top (cyazofamid). But you do not want to become solely reliant on these and there is the added complication of not exceeding 50% of your program with QiI.

With both resistant strains and tuber blight in mind, Infinito has a good fit from mid-season onwards, where it’s anti-sporulant activity is extremely useful, and also towards the end of the season when tuber blight activity is more critical.

You can use up to four applications of Infinito in a season, so I’d suggest reserving a couple for the end of the season for tuber blight and fitting in the other applications into your alternation strategies from mid-season.

3. Timing crucial for oilseed rape desiccation

The big topic, unfortunately, is do you have an oilseed rape crop to kill off? But assuming your oilseed rape has made it through to harvest timing is crucial when planning desiccation.

Going on too early can impact quantity and quality of yields, as well as increasing the risk of red seeds, leading to crop rejections.

To judge when to apply Roundup (glyphosate), pick around 20 pods from the middle of the main raceme of a representative part of the field. Around two-thirds of the seeds should be brown. The crop is generally ready for harvest 14-21 days later, but bear in mind that, glyphosate is less effective in severely lodged crops.

The glyphosate rate needs to be robust when desiccating, and I suggest a rate around 1440 g a.s./ha especially if you have perennial weeds to control.

Think also about adding a product to prevent pod shatter if your variety doesn’t have pod shatter resistance in built.

4. Start assessing varieties for next year’s oilseed rape crops

Obviously, we are still a little time off OSR establishment, but start thinking about variety choice. Field days and events are a good opportunity to discuss with breeders, including us, what is available.

I’m a firm believer in establishing oilseed rape early to minimise the damage from cabbage stem flea beetle attacks by getting the crop past the vulnerable stage as quickly as possibe.

However, the flip side is you have a large crop by winter and then be reliant on growth regulators, and potentially higher risk from diseases such as light leaf spot and Phoma.

Look for varieties with good early vigour, suitable for early drilling and decent disease resistance. Pod shatter resistance is another useful trait for the end of the season.

Our DK Exstar fits into the early drilling options. It’s a reliable variety with vigorous establishment, without over rapid development in autumn, and fits a wide drilling window. It also has a good early restart to growth in the spring, and so is useful if pigeons have caused a headache over the winter.

If you grow Clearfield varieties, DK Imprint or DK Imove are possible options. The Clearfield system is most useful where broad-leaf weed control is important, particularly of brassica weeds such as targeting hedge mustard, runch, or charlock.

You may also choose a DK CL variety if you are susceptible to volunteer OSR which can affect erucic acid of your crops.

Thinking ahead to establishment, while planning with our weather is difficult and unpredictable, think about moisture retention, as this is key to good establishment in my eyes. I would, if practically possible, stay away from plough-based establishment, and go for the direct drill approach in order to retain moisture in the ground to allow for the best possible establishment and rooting of the crop.

If you cultivate heavily, the loss of moisture is huge, and so has a direct effect on establishment, and considering the situation last year, crops may suffer at early establishment phase.

Acknowledgements

Folicur contains tebuconazole. Proline contains prothioconazole. Infinito contains propamocarb + fluopicolide. Ranman Top contains cyazofamid. Roundup contains glyphosate. Folicur, Proline, Infinito 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