In Field Focus Issue 25

ISSUE 25 SUMMER/AUTUMN 2026

MANAGING THE RISK OF RUST As combines roll into rapidly ripening crops, there’s one disease on everyone’s mind that is likely to influence major decisions ahead of next season.

With growers and agronomists being on high alert for yellow rust outbreaks due to Yr15 resistance concerns, southern agronomist, Pip Baptist, says this season has only further demonstrated the importance of well-timed fungicides and using premium chemistry to provide superior control.

However, if one of these factors slipped at any point during the season, yellow rust was ready to pounce.

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IN THIS ISSUE

UNDERSOWING MAIZE ALTERNATIVES EFFICACY OF ETHOFUMESATE AUTUMN GRASSLAND RENOVATIONS

SOUTH WEST With disease challenges from this year fresh in his mind, South West agronomist George Cornwall is using this information to assess variety choices and urges caution for growers sowing varieties that were very susceptible to yellow rust outbreaks.

“We’ve seen yellow rust in every variety this year, which has required greater attention than usual, alongside chasing Septoria.

The importance of robust fungicide programmes from T0 builds resilience in the crop from early growth stages, providing a cleaner base later in the year. Without these early building blocks, the outbreaks could’ve been significantly worse.”

A yellow rust outbreak clearly evident in this wheat crop.

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SOUTH “If timings slipped by just a week this year, a rust infestation turned a field glowing yellow in a matter of days,” says Pip. “I grow a lot of group 1 wheats that are prone to rust, so control at every spray application is vital. If the gaps between timings increase even slightly, the disease can take hold quickly and requires additional cost to bring it under control.

“Using premium chemistry, such as Vimoy (isoflucypram) and Cello (prothioconazole, tebuconazole and spiroxamine), to control yellow rust has paid dividends, due to a much faster knockdown and longevity than cheaper options. This approach meant no T1.5 spray to keep rust at bay, which will certainly be my advice next year.”

Some growers are returning to oilseed rape again with renewed hope that flea beetle infestations don’t reach the peaks that forced them to stop growing the crop.

This year’s crops have looked well all year and are podding superbly. Pip says it currently looks like the best break crop option, but insects are a law unto themselves, so growers aren’t out of the woods just yet, she advises.

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Looking ahead to next year, George says the later season nutrition applications showed that being reactive to the weather and conditions is essential.

“Some growers opted for foliar instead of granular nutrition at third pass to make sure nutrients were readily available to the crops during the dry period. With cost of production being impacted by various external pressures, we need to ensure that all applications are targeted to improve crop response. Crops are looking well and there’s some positivity as harvest begins.”

BYDV has appeared in most cereal crops to varying degrees, and George says it highlights the importance of insecticide timings and cultural controls ahead of autumn drilling.

Dry conditions in the south have kept Septoria contained in the bottom of the plant. However, the dry weather has impacted crop height, meaning straw will be in short supply leading to growers baling for a greater return, which is likely to leave a potential potash shortfall if this isn’t replaced.

“Soil testing following harvest will identify offtake deficiencies and guide nutrient inputs for the following crops. Potash and phosphate are expensive, and there’s resistance to spend on these, but they’re both vital for successful crop establishment.

For later nutrition passes next season I plan to use soil data backed by leaf foliar analysis and be responsive to crop requirements.”

George says early applications of plant growth regulators forced plants to develop extensive root structures for moisture and nutrient scavenging in the dry spring.

He says that leaving these applications to a later timing only provides stem strengthening and not additional root mass.

The spring maize drilling campaign was successful leading to good establishment, despite a few late frosts checking some areas. He says a pre-emergence application of pendimethalin, and Wing P (212.5 g/l dimethenamid-P and 250 g/l pendimethalin) has kept weeds small and allowed the maize to grow without competition. A well-timed post emergence at 4-6 leaves is essential to continue the control.

Using premium chemistry has been a key reason why yellow rust outbreaks were manageable for Pip Baptist

“In comparison to fields that didn’t receive a pre-emergence application, or where the sprayer missed an area, the difference is obvious and helps justify why the chemistry is important and applied before emergence.”

Evaluating different maize establishment methods is becoming popular and George says a crop of strip-tilled maize, drilled into land following a sheep-grazed cover crop, has been slow to germinate in some of the high traffic and heavier clay soil areas.

“The strip-till worked well, and retained the moisture in the dry period, but the poor germination in compacted areas shows the importance of timeliness when removing sheep from the cover crop.”

Oilseed rape looks excellent for the second year in a row, and some growers, who fell out of love with the crop when flea beetle was at its height, could be tempted back in this autumn.

“It remains the best break crop out there in the right growing season. I’ve seen very few aborted pods lower down the main stem, which should lead to more seeds and better yield. Gross margin is still attractive, and good oil premiums provide temptation for growers to return to it next year.”

Gary says autumn cereal drilling date will depend on blackgrass pressure and he advises that delayed establishment to ensure complete weed control is as good as a sprayer pass later in the season. Post harvest, he is planning to evaluate yield maps against soil test results using the FieldSense platform to guide decisions on nutrition and variable seed rates.

“It’s been very handy to spot where issues arose this season and change how we treat certain areas going forward. For growers with variable rate drills, altering the rate as the soil type and texture changes does lead to noticeable differences during tiller counts in the spring,” adds Gary.

Despite some challenges through the season, George says crops are looking well and there’s optimism ahead of harvest

SCOTLAND Spring malting barley markets have made growers economical with nutrition and crop protection spend this season, with an increased adoption of biostimulant and foliar nutrition products to improve nutrient use efficiency and protect margins, says Scottish agronomist, Eilish Johnston.

“Adapting to the season with alternative nitrogen sources, such as Sunburst, Pro+ N-Viron and Encera, are popular in winter cropping, feed barley and high-nitrogen malting barley crops. Where Pro+ Libphos has been incorporated into pre-emergence spray programmes, it’s helped crops access and utilise phosphate more effectively.”

Some growers have opted for a single spray plan on malting barley where two were previously used. Eilish says this choice has made product selection, disease monitoring and spray timings crucial, with Revytur (25 g/l mefentrifluconazole and 600g/l sulphur) offering multiple benefits at T2 from a single application.

Looking ahead, crop rotations hinge on suitable break crops, with the clubrootresistant oilseed rape varieties increasing in area. Likewise, legumes such as peas and beans provide farmers with home-grown protein sources while fixing atmospheric nitrogen for following crops.

The north of Scotland is a strong grassland area, and farmers are investing in reseeding tired leys with new mixtures that include clover to increase sward diversity and forage quality.

NORTH Spread the pressure of yellow rust next season by growing less susceptible varieties rather than relying solely on varieties that have been badly affected this year, says agronomist Gary Webster.

“Big yielding varieties, with RL ratings of 9 for yellow rust, have shown high rust pressure during the season. I’ve sprayed against yellow rust at every application timing, which is unheard of, and any missed areas have shown why I’ve been so belt and braces. I plan to sow more varieties than usual in the autumn to spread the risk.

“Maintaining tight application timings has been essential. I’ve had some customers that didn’t spray for rust at T0, or missed timings, and we’ve been chasing our tail since. There’s been more caution around additional passes or extra spend, but it’s the crops that have received good chemistry at the right time that will return on the investment.”

Gary Webster says spreading the risk of yellow rust by growing multiple varieties is one option he is considering this autumn

Eilish Johnston says accurate timings and alternative nutrition sources have delivered the best return on investment this season for malting barley

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Left: Under-sowing maize protects soils, enhances weed control and produces a valuable secondary crop for over-winter grazing. Right: Italian ryegrass has been the dominant companion crop species due to its ability to grow away quickly after maize has been harvested

EVALUATING ALTERNATIVE SPECIES FOR UNDER-SOWING MAIZE Hayley Wellings outlines the latest thoughts, findings and recommendations for under-sowing maize with a range of different species.

The benefits of under-sowing maize with a companion crop are well documented and its practice has become even more commonplace since the introduction of the Sustainable Farming Incentive.

Italian ryegrass has been the dominant companion crop species due to its ability to grow away quickly once maize has been harvested and its tolerance to typical maize herbicide programmes. However, recent cases of Italian ryegrass developing resistance to some herbicide active ingredients means there’s a clear case for growers to switch to alternative species.

Trials work carried out by ProCam in 2025 on a farm in Herefordshire sought to identify which species are most appropriate for use as a maize companion crop, and which are capable of surviving maize herbicides without restricting the programme’s ability to control weeds effectively.

The herbicides selected for testing in the trial were chosen based on their ability to provide good control of a wide spectrum of weeds. They included, among others, the residual herbicides Most Micro (pendimethalin), Wing-P (pendimethalin + dimethenamid-P), and Camix (mesotrione + S-metolachlor). A range of post-emergence products were also tested.

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Meanwhile, the companion crop species tested were chosen based on their suitability for grazing in the winter/early spring and for their vigorous growth habit and anticipated ability to cope with being planted in between rows of maize. Their ability to protect soils and reduce nutrient losses by providing adequate ground cover was also a key consideration.

PROVEN OUTCOMES As expected, Italian ryegrass performed well in terms of herbicide tolerance and ground cover following maize harvest.

AberRoot (festulolium) and forage rye performed similarly well, with both showing minimal herbicide symptoms and, despite producing significantly less ground cover while the maize was growing, both went on to produce a satisfactory crop after the maize was harvested.

Results from the use of clovers were more varied depending on the species being tested, with some (crimson and white clover) being more tolerant of being established following a pre-emergence herbicide than others (such as berseem and balansa clover).

The trial also showed that there was not an obvious correlation between species vigour and herbicide tolerance. For example, although crimson clover fared better in terms of herbicide tolerance, it didn’t provide the level of ground cover that would be expected from a species that is regularly used in cover crop mixtures due to its vigorous growth habit.

In contrast to the legumes tested, a mixture of chicory and plantain exceeded all expectations — although both species showed some early susceptibility to herbicide-induced stress, they subsequently grew away from these symptoms as the season progressed. The rapid growth of both species meant that five days after the maize had been harvested, the chicory/ plantain mixture had produced a level of ground cover which exceeded that achieved by Italian ryegrass.

As the trial took place during an unseasonably dry summer, it is possible that this mixture performed well, relative to others, due its deep rooting ability which provided better drought tolerance.

CONCLUSIONS From these initial findings, it appears that a chicory and plantain mixture could provide a suitable replacement for Italian ryegrass where the residual herbicide pendimethalin (+/-dimethenamid-P) has been used at the pre-emergence timing. Equally, alternative grasses such as AberRoot (festulolium) or forage rye could be used to good effect.

Grasses also offer the increased flexibility of enabling post-emergence broad leaf weed herbicides to be deployed.

It should be noted that the trial, and indeed the results outlined in this article, do not guarantee crop or companion safety. The use of herbicides alongside companion species must always be done whilst following the pesticide label and manufacturer guidelines.

WHY UNDER-SOWING MAIZE MAKES SENSE •R educes the risk of soil erosion and prevents nutrient leaching • I mproves soil structure making it easier to travel during maize harvest • Increasing

soil organic matter & biological activity • Enhances soil fertility for the following crop • Improves moisture infiltration & retention • Enhances weed & volunteer suppression • Provides a habitat for beneficial insects • Produces a valuable secondary crop for grazing • Eligible for a sustainable farming/ cover crop payment

CHOOSE GRASSLAND MIXTURES WISELY THIS AUTUMN Autumn is the ideal time to carry out reseeds to damaged or unproductive swards, but the focus must be on sowing quality mixtures, as well as achieving good yields.

Hayley Wellings, technical manager – noncombinable and forage seed for ProCam, says selecting grass and forage mixtures that are tailored to the system and fodder requirements, will ensure quality leys continue to produce year after year.

“Growing high-yielding crops that are low in quality won’t improve returns from forage, as a ruminant can only eat so much per day.

We need to ensure that each mouthful is as energy dense as possible to maximise meat or milk production, which means selecting the appropriate species and varieties in our mixtures that will contribute to yield and quality.”

Data from ProCam’s Dartington trial site in Devon, during 2025, showed that diverse mixtures withstood the extremely dry season better.

The top yielding mixture was Hybrid 3x3, which delivered 10.55t/ha on first cut, with an energy value of over 11ME, while yield registered 5.27t/ha at second cut. Hybrid 3x3 Pro Nitro yielded slightly lower at 9.66t/ha, but this mix includes clover to provide higher protein and improved sward diversity, as well as fixing atmospheric nitrogen for this and future crops.

Hayley Wellings explains that Italian ryegrass resistance to some herbicides means there’s a clear case for alternative cover crop species

Hayley explains: “When constructing a mixture, we decide which subspecies to group together depending on the end use.

For example, Hybrid 3x3 mixture is a 50/50 mix between hybrids and perennials, with the hybrid varieties included for high yields and the perennials improving the feed quality of the mixture.

“As last year proved, not relying on one species can be beneficial in extreme

weather conditions. The inclusion of red clover in Hybrid 3x3 Pro Nitro, for example, offers enhanced drought tolerance, which results in higher yielding later cuts compared to where clover is removed. This is because the red clover is a good nutrient and moisture scavenger due to the deeper tap root.”

Hayley also pointed to Eco-Pasture, which registered a first cut yield of 10.41t/ha and 10.7ME, and provided some of the highest yielding late-season cuts of all mixtures.

This mixture contains intermediate and late perennial ryegrasses, alongside herbs such as plantain, chicory, yarrow and sheep’s parsley, with red clover, white clover and birdsfoot trefoil, to deliver a diverse and productive ley with environmental and soil health benefits.

Postseason renovations in the autumn remain popular, and farmers should be looking to sow mixtures into well-prepared seedbeds before soil and air temperatures cool, which is especially important for certain species.

“Herbs and legumes require warmer soils than grasses, and seeds shouldn’t be planted too deep. Some farmers sowed leys in late August last year achieving rapid establishment into the warm soils and helped by the following rain.

“ProCam’s extensive trial data, that stretches back several decades, has been essential in developing the company’s Field Options range of grass mixtures.

We can confidently say that these mixtures are tried and tested in UK conditions and we have the data to prove it,” adds Hayley.

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ASSESSING THE PRE-EM PERFORMANCE OF ETHOFUMESATE As part of its commitment to providing growers with the very best crop protection advice, ProCam has been testing a range of options for the control of difficult grassweeds in cereals.

In addition to assessing the efficacy of ethofumesate at the pre-emergence timing in blackgrass stacks, trials have also been ongoing to assess its effectiveness versus brome. In both scenarios, preliminary observations suggest Xerton (417g/L ethofumesate) provides a useful addition to programmes and, in the case of blackgrass, could be a potential alternative to flufenacet.

The long-term availability of flufenacet is uncertain in the UK after the European Commission agreed a non-renewal in the EU and Northern Ireland in March 2025.

This decision was based on flufenacet’s classification as an endocrine disruptor and the risk of groundwater contamination from its metabolite, trifluoroacetic acid (TFA). It is anticipated that the UK authorities will follow suit in due course, with growers and agronomists already investigating new ways of controlling difficult grassweeds without this key autumn residual herbicide. ProCam has taken these investigations one step further, with initial trail results suggesting that including Xerton at the pre-emergence timing provides a useful uplift in soft brome control.

THE VIEW FROM THE NORTH “Prior to 2025, Xerton’s use in winter wheat was restricted to post-emergence applications only,” explains ProCam agronomist, Nigel Scott. “However, a label extension last year means it can now be used at the pre-emergence timing so we’ve been trialling it to find out exactly how its earlier inclusion can help against difficult grassweeds. In particular, we’ve been testing its efficacy against soft brome, which is getting more problematic.”

Xerton can provide a useful addition to wheat herbicide programmes in place of flufenacet, against both blackgrass (left) and brome (right)

ProCam’s trial is still ongoing, with preliminary observations suggesting that even though established blackgrass herbicides such as cinmethylin and/or flufenacet form an important element of brome control, additional molecules and modes of action (such as ethofumesate) are also required. The trial’s results are expected later in the summer, but Nigel has also tested Xerton on farm.

of action from working,” Nigel adds.

“I’ve used Xerton in conjunction with 2.0l/ha of Tower (chlorotoluron, diflufenican and pendimethalin) to good effect against brome which can be difficult to control at the best of times, so it certainly stands out as a useful addition to the crop protection armoury.”

“Ethofumesate isn’t a new active ingredient as it has been used in root crops and vegetables for a number of years,” Nigel explains. “But its use in cereals is still relatively recent, especially at the pre-emergence timing, so we’re still learning where and when it can and cannot be used.”

Xerton performs well as a pre-emergence residual treatment because it targets weeds via shoot uptake as they push through the soil surface. “This mitigates the potential for uptake to be reduced after weeds have developed a waxy cuticle which can prevent other modes

Nigel Scott, ProCam agronomist in the North, is trialling Xerton for brome control

USE WITH CARE Despite its promising performance, Xerton isn’t without its restrictions as the total amount of active allowed during a three-year period is limited to 1000g. “That could make it tricky to include in rotations where beet crops are grown,” Nigel explains. “And, because its label extension only applies to wheat, it isn’t a direct replacement for flufenacet in barley or other cereals. But, where it can be incorporated into herbicide programmes, Xerton provides a potent, cost-effective and useful top-up, and offers a notable improvement where bromes are concerned.”

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A SOUTHERN PERSPECTIVE Paul Gruber has also been trialling the inclusion of Xerton in herbicide programmes – in his case to assess its potential as a replacement for flufenacet against blackgrass and to improve the performance of stacks against brome.

“Where I’ve used Xerton as a tank mix partner with more robust pre-emergence actives such as cinmethylin, it has certainly packed a significant punch,” Paul explains.

“In fact, I’d go so far as to say that a pre-em treatment of Xerton and Agardia (cinmethylin and picolinafen) performs on a par with Avadex when targeting blackgrass, and at a much lower cost point.”

Paul also confirms Xerton’s superior efficacy versus brome compared to flufenacet but cautions that timing is essential to avoid crop effects.

“Peri-emergence application must be avoided,” he advises, “as should its use if seed has been drilled to a shallow depth.

“Xerton isn’t a direct replacement for flufenacet as it is ineffective against ryegrass,” Paul continues, “but it is certainly a promising addition to the herbicide stack in other scenarios, and I’ve seen good results when it has been used later in the autumn to top-up pre-emergence treatments.”

Paul Gruber, ProCam agronomist in the South has been trialling Xerton to see if it’s a possible flufenacet replacement for the future

VARIABLE RATE SEEDING MADE SIMPLE WITH FIELDSENSE

Varying the seed rate creates a uniform, evenly established and consistently populated crop across the entire field area.

With rising input costs and lacklustre crop prices putting profit margins under intense pressure, the need to improve cropping efficiency and yield has never been higher.

ProCam agronomist Harry James explains how ProCam’s FieldSense system – in particular its variable rate seed mapping feature – can help growers to maximise the performance potential of each and every field.

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Precision farming technologies, including the use of variable rate seeding, can help to reduce wastage and ensure the value of every input is maximised. However, in addition to the necessary hardware (GPS guidance equipment, automatic steering kit and implement control console) the creation of variable rate maps usually requires a significant amount of time and managerial resource.

However, with FieldSense, growers not only get data driven results, they also get the help and support of their dedicated agronomist who will take the complexity, stress and time requirement away from growers by managing and operating the FieldSense platform on their behalf. All this brings greater accuracy to the farm’s agronomic decisions, resulting in optimal plant density, uniform crop growth, higher yields and a better return on input costs.

HOW VARIABLE RATE SEEDING HELPS Contrary to one frequent misconception, variable rate seeding is not intended to reduce the amount of seed needed to sow a field. Rather, it’s primary aim is optimise crop output, quality and consistency by placing more seed in areas where it is needed, and less where it is not. As a result, the total amount of seed required may remain unchanged.

Varying the seed rate according to the field’s changing conditions creates a uniform, evenly established and consistently populated crop across the entire field area.

This is achieved by increasing the seeding rate in parts of the field where soil compaction, waterlogging, nutrient losses caused by leaching, or bird and pest damage usually cause crops to be a little thinner.

Conversely, in areas where crops typically establish more densely, the seeding rate might be reduced to promote tillering, optimise canopy cover and prevent lodging, and to minimise competition for sunlight and nutrients between plants.

Variable rate seeding can also be used as a weed control strategy, with a higher seeding rate helping to reduce competition in parts of the field with a heavy weed burden.

THE BENEFITS OF VARIABLE RATE SEEDING Creating an evenly established, consistently uniform crop provides a range of benefits: •H igher yield potential • I mproved weed control •R educed seed wastage •B etter disease & pest control •E nhanced grain quality •E asier field management & a faster harvest

HOW FIELDSENSE HELPS FieldSense creates variable rate seeding maps by dividing each field into a grid pattern based on historic and current satellite imagery. The field’s previous performance is also taken into consideration, as is boots-on-the-ground knowledge of the field’s peculiarities or variations in conditions, which may need to be considered when creating the bespoke variable rate seeding plan.

The involvement of the ProCam agronomist in this process makes using FieldSense easy, straightforward and less time consuming from the grower’s perspective, and ensures seed is drilled in the right place and at wthe right rate to produce a better performing crop.

FieldSense creates variable rate seeding maps by dividing each field into a grid pattern based on historic and current satellite imagery

PERFORMANCE SEEDS In addition to drilling in the right place and at the right rate, it is also important to choose the right variety to suit the field’s conditions and the farm’s needs.

To ensure you select the correct variety for your specific needs and circumstances, ProCam’s new Arable Guide provides a summary of our selected “focus” varieties from all the main arable species including OSR, wheat, barley, oats, hybrid rye and winter beans.

All the varieties in the guide have been chosen based on their agronomic traits and how they can be utilised to produce the most successful outcomes. This has been achieved by using experience from our own trial network, data from seed breeders and from the AHDB Recommended List, and most importantly, experience from our own agronomists to ensure we can offer a robust choice for all farm situations.

Scan to download the arable seeds guide

FOR MORE INFO PROCAM.CO.UK OR CALL 01954 712150

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