Low disease levels at the start of the 2021 season converted to much higher levels by the end of the season, although there were still plenty of situations where lower input approaches to crops could be justified. Learning the lessons from the 2021 trial season and picking out the lessons for 2022 will be core to the information presented at FAS / AHDB / SRUC January agronomy workshops.
This season, winter crops were drilled in good conditions and are generally looking well – and often looking pretty forward. Oilseed rape is already at welly-boot height at the SRUC’s Boghall site, with traces of light leaf spot present after incubation. Winter wheats and barley are similarly well established and, fairly predictably, in early drilled wheats there is yellow rust in some fields already.
Already thoughts turn to how we will manage this in spring fungicide programmes in 2022 and to analysing the messages from the trials programme last year. It was the second very dry Spring in a row so disease development was obviously affected. Trial results show there was certainly scope to reduce inputs at the early T0 and T1 timings, particularly where yellow rust was not an issue. Fungicide trial results show that the erosion of SDHI efficacy against Septoria has continued but it is important to say that this isn’t dramatic and that good efficacy was seen where the SDHIs were used in mixture products – which is always the case in practice. The newer azole – mefentrifluconazole (as in Revystar XE) continued to do well in wheat trials as did the prothioconazole + SDHI loaded product like Ascra Xpro. Univoq (prothioconazole mixed with the new active class of fungicide fenpicoxamid) had its first season in commercial use and its performance in trials was good, particularly where intervals were stretched. The knowledge base around folpet continues to grow in both wheat and barley, but there were some cost-effective benefits to including it in some programmes.
In barley we have the launch of Acsra Xpro (already approved in wheat) so that adds a more SDHI loaded product to the comparator Silta Xpro. Revystar XE also did well and we have a few experimental products coming through that may help us out in the ramularia context, although likely a few seasons away as barley always seems to be regarded as secondary to the wheat market when it comes to getting new actives launched. Ramularia remains challenging to manage in the meantime. In 2021 it came in late in trials and commercial fields but reassuringly prothioconazole has maintained the same degree of efficacy as the year before so, although poorer than it was, it hasn’t declined further and remains a useful support in at risk ramularia fields. Revystar XE brings some improvement but we desperately need new actives in this sphere going forward.
The link between plant nutritional status and plant health remains a very key area, particularly for a disease like ramularia strongly linked to crop stress. All aspects of soil health remain very integral but with fertiliser prices as high as they now are, new ways of optimising fertiliser products and rates are front and central in mind.
Fiona Burnett, SRUC
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