Despite recent dry conditions proving concerning for the harvest potential of crops, growers are being urged to keep calm and carry on. CPM investigates what this could mean for the coming weeks, in particular, disease control.
“Although the weather currently looks settled and dry, most crops have decent potential to carry through.” MATT KEANE
By Janine Adamson
While on the face of it, some growers may feel they’re in a similar position to this time last year, in reality, crops should be able to withstand current dry conditions, believes BASF’s Matt Keane. This is because autumn establishment was favourable, whereas in the previous season, that wasn’t the case, he explains.
“If we compare now with this time last year, crops were already compromised and struggling. Whereas this year, plantings are well-established with strong rooting, receiving early moisture in January and February.
“So although the weather currently looks settled and dry (end of April), most crops have decent potential to carry through.”
Matt points out that conditions are highly variable across the country, with near-drought in some areas but not others. “It’s been an odd spring in that respect. If we take the east coast, after excellent crop establishment in the autumn, it appeared that disease was brewing up well at the beginning of the year.
“But now, with very little rain in that region, disease spread has inevitably slowed. Inoculum is still there, but rather than one primary target, it seems there are low levels of all key wheat diseases. This should have had an impact on T1 choices – hopefully shifting from a septoria-focused tank mix to more of an all-rounder,” he says.
With this in mind, he believes it’s likely that most T1 sprays will have included an active ingredient that targets yellow rust, given the genetic break-down of Yr15 in the majority of available wheat varieties, plus how quickly the disease cycles. He also notes the value of R&D chemistry such as Revystar XE (fluxapyroxad+ mefentrifluconazole) in providing protection against a broad range of foliar diseases, thus offering value.
DESPERATE BUT HOPEFUL
Grower George Atkinson from South Lincolnshire explains that with ground currently dry and cracked open, the situation is looking a little desperate. However, despite the conditions, he agrees that winter crops seem to be holding their own, plus spring crops have established well.
Unlike last year, disease has been evident from the beginning of the season, he notes, meaning a robust fungicide programme has been required. “T0 was tebuconazole, while at T1, we’ve used Revystar XE. Having looked at all of the options, we concluded that it’s reasonably priced for how effective it is. We’ve used it for several years and know it’ll do a good job.”
Then in the West, Matt anticipates that due to receiving more rainfall, it’ll have been business as usual – hitting septoria hard.
Either way, he stresses that at the moment, crop potential remains and therefore must be protected. “Having applied an all-rounder at T1, if the dry conditions continue, then there could be the potential to refocus at T2 onwards. This could involve changing product choice to make critical savings,” says Matt.
“As always, it’s having an awareness that if dry weather conditions do continue, yield may be compromised, so being realistic about product choices will be prudent.”
Matt recognises that growers are under increasing pressure as a result of geopolitical events influencing the price of all inputs. “Everything is going up, bar the price of wheat. It’s increasingly difficult on farm so all aspects of a disease control strategy must be assessed in the view of making potential savings.
“Of course, specialist products targeting specific diseases come at a cost, but other fungicides may be used if disease burden is lower and pressure has changed,” he suggests. “It’s about choosing the appropriate spend and product for a crop’s potential and the disease profile presented.”
While George is looking ahead to harvest, he points out that fuel requirements currently appear a little daunting. “We use up to 18,000 litres of fuel a week during harvest, and our suppliers currently have orders capped to 8000 litres per delivery. We desperately hope fuel prices and supply will have normalised a little by the busy season. Although hoping that prices will return to where they were feels a little optimistic.”
MIXED PRESSURE
Adama’s David Griffiths agrees that rather than one stand-out disease this season, it’s more of a mixed bag. He believes that taking an all-rounder tank mix approach should also be extended to T2s.
“Even though weather conditions have been relatively favourable in recent weeks, there’s still plenty of both diseases [yellow rust and septoria] present in crops. Any spores sitting in the lower canopy could easily be transmitted onto the upper two leaves during heavy rainfall events, so a robust fungicide treatment is a must to keep both leaves as clean and green for as long as possible.”
For David, this means utilising a mixture of active ingredients, including single-site and multi-site modes of action. “The inclusion of an azole and/or an SDHI/Qil fungicide will provide a certain amount of curative activity, but because they only work against one biochemical pathway within their target pathogen, these single-site chemistries are more prone to sensitivity shifts or mutations.
“For that reason, a multi-site fungicide such as folpet should be included to provide greater longevity of protection,” suggests David.
Furthermore, he points to trial data that suggests including Arizona (folpet) at T2 is a cost-effective layer of protection – boosting wheat yields by an average of 0.14t/ha across dry and wet seasons. “With this year’s septoria loading high thanks to the wet winter and spring, Arizona is a no-brainer.
“Equally, trials indicate that it can also improve yields by an average of 0.9t/ha, where yellow rust is the main disease pressure.”
While advice usually stipulates to include folpet at both T1 and T2 timings to get the most from the product, David explains that it has value, even when applied at just T2. “There’s still a clear advantage, especially as it doesn’t interfere with the uptake of partner products, therefore enabling single-site actives to provide curative control of any latent or active septoria infections.”
Independent agronomist, Chris Taylor, hopes that where there is yield potential, growers will continue to invest in the crop to see it through its final months. “Conversely, where growers aren’t likely to get the returns they’d hoped for, they’re cutting their cloth accordingly,” he says.
Chris, who’s based in Monmouthshire, notes that being in the west, rainfall has been high. While usually this would mean a belt-and-braces approach to tackle septoria, there’s a new threat that growers won’t be typically accustomed to controlling – yellow rust.
“The breakdown of the Yr15 gene has been a game-changer in the region. Historically it hasn’t been an issue, but that’s all changed in the past 12 months. Due to usually receiving high rainfall here, most varieties are chosen for their septoria resistance. This means KWS Extase, Champion and Graham are all still prevalent,” he explains.
As resistance management is important to him, Chris says Revystar XE will play a role in fungicide programmes. If the chemistry hasn’t been used at T1, he says it’ll be applied at T2. “It offers diversity which is a good anti-resistance strategy, and seems to be holding up well compared to some of the other older chemistry.”
As for central and southern Scotland, Cloud Farming’s Chris Leslie says so far, the season has been kind. “We’ve had more normal conditions in comparison with the really dry springs of recent years,” he says.
With more than 700ha of cover crops, Chris Leslie and his team have a quarter of their spring cereal crops left to drill at the time of writing, but notes that soil conditions are great with few signs of disease. “While there’s lots of talk about yellow rust, we’re on top of it and with plenty of days under 5°C it won’t be cycling. It’s just nice to be able to get on and get the field work done.”
Chris Leslie’s winter wheat is all Group 1 milling therefore he says his focus is optimising nutrition to maintain tillers and maximise yield potential. “Although, the crops’ growth stage isn’t there yet, T1s are on my mind. We know that septoria inoculation is quite high at this timing so I tend to see if disease is present, if so, I’ll invest to take it out. The latest trials results and, of course, price are the final decision-makers.”
This article was taken from the latest issue of CPM. Read the article in full here.
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