Arable By T2, many crops still appeared disease-free on the upper leaves, but as it warmed up, latent infection developed which saw many crops carrying significant septoria pressure – especially where it continued to rain. This meant that disease management became much more of a curative situation rather than preventative. The waning resistance in some varieties (notably those with Cougar in their parentage) was mentioned, which will need careful management moving forward, and Mr Bailey also posed the question: “With the loss of CTL, how many programmes included a multi-site?” This will have led to a lot of pressure on single site chemistry, particularly in T2.
Staying ahead of the game
Disease control:
Getting the balance right In mid-January, Adama held an online press briefing to discuss its latest news and data relating to disease control. Rachel Hicks reports. Opening the briefing, Adama’s fungicides technical specialist Andy Bailey (right) gave a short market update. Of course, the dreaded Covid was mentioned, with Mr Bailey saying it continues to roll on – just as we think we’re coming out of it, it hits again. The face-to-face contact is being missed, with events still being affected and screentime just isn’t the same. He explained that last autumn was pretty horrific in terms of supply logistics – with problems getting product into port, then from the port into HGVs, from HGVs into warehouses and so on – due to Covid-19, driver shortages and other HGV industry issues. However, he also pointed out that Adama is resilient, and has planned in advance as much as possible in order to ensure that spray programmes in spring 2022 won’t be negatively impacted. The marketplace was an extremely aggressive, dynamic place last autumn, with the Q4 Chinese
production cessation ahead of the Winter Olympics 2022 in order to control air pollution, along with the usual decrease due to energy consumption policy leading to customers acting in more unusual ways. Meanwhile, pricing is evolving by the day from Q1 into Q2 for 2022. Crops went into the ground in significant volumes in the autumn, with the winter wheat crop looking to be around 1.8 million ha in 2022, compared to 1.3 million ha planted in autumn 2021; and winter barley at 0.42 million ha compared to 0.3 million ha in the previous season. In terms of 2021 disease management experiences in winter wheat, Mr Bailey said that many growers cut back fungicide inputs at T0 and T1 based on cool, dry conditions in early spring – even on some earlier drilled crops. While it turned wet in May, it remained cool, which slowed crop growth and extended the gap between T1 and T2.
“Beyond the use of resistant varieties and delaying drilling to reduce disease pressure, the over-arching key to effective disease control in cereals is to stay ahead of infections,” explained Mr Bailey. “This is best achieved by applying a diverse range of fungicide modes of action, with a multi-site such as Arizona (500g/litre folpet) included at the appropriate timing(s) to add an extra layer of disease control, protect single site actives from resistance and boost the crop’s yield potential by maintaining green leaf area for longer.” When it comes to disease control, the importance is getting the balance right. Mr Bailey explained there are three primary elements that all need to be considered in order to make the best decision: • Efficacy • Resistance management • Return on investment. New field trials carried out by Adama between 2018 and 2021 have shown that the inclusion of the multi-site fungicide folpet in spring spray programmes contributes to yield improvements of up to 0.6t/ha in winter-sown wheat and barley. The trials indicated that the inclusion of Arizona, alongside single site fungicides, enables wheat and barley crops to stay ahead of key diseases including septoria and rhynchosporium (as well as providing valuable protection against ramularia – although this is not currently indicated on the label so is anecdotal only at this stage) and ensures each successive leaf stays greener for longer.
Sustainable disease control “Sustainable disease control is about achieving the right balance in terms of fungicide efficacy, resistance management and return on investment,” Mr Bailey continued. “Across a total of 29 wheat trials, a single application of Arizona at T1 more than paid for itself by giving an average yield uplift of 0.26t/ha. When applied at two spray timings this yield response increased to as much as 0.6t/ha when used alongside older single site fungicides and by a more modest but still respectable 0.2–0.25t/ha when used at two spray timings in conjunction with newer single site actives such as Revysol and Inatreq.” A two-spray inclusion strategy also gave the best results in barley, where the yield response ranged from 0.3–0.6t/ha. “Arizona can deliver a significant yield improvement and represents a viable return on investment,” added Mr Bailey, who explained that T1 is the key timing for the inclusion of folpet in wheat programmes. “In high-risk wheat situations – for example where a susceptible variety which was drilled early and is growing in wet conditions in an area with a high disease loading – folpet can also be applied at T0 and/or T2 as the season dictates. “In winter and spring sown crops of barley, T2 (GS39/49) is the key timing for including Arizona, with a two-spray approach at T1 and T2 giving the best results.” The inclusion of folpet in spring fungicide programmes is also endorsed by FRAG-UK (Fungicide Resistance Action Group) which it describes as a “valuable tool to manage resistance by preventing development to many pathogens [...] which can protect and prolong the lifespan of medium to high resistance risk fungicides like SDHIs [...] and which provides added levels and spectrum of disease control”. FG
18 www.farmersguide.co.uk February 2022
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