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In this issue... Microbial vision page 42 Digital outlook page 58 Carbon culture starts with soil life Precision platforms refine their offering Irrigation salination page 64 Policy pointers page 36
Opinion
4 Talking Tilth - A word from the editor.
Volume 23 Number 4
6 Smith’s Soapbox - Views and opinions from an Essex peasant…..
Arable Extra March 2021
67 Last Word - A view from the field from CPM’s technical editor.
Technical
8 Disease control - Putting the ‘breaks’ on
It might be tempting to focus most fungicide firepower on T2. But is it wise?
13 Disease delve - Barley needs a boost?
The loss of chemical options may have left barley genetics relatively exposed.
16 Pushing performance - Control the controllable
A lot of thought and attention goes into picking the best fungicide products.
20 Survey – Strategies for success
A look at some of the key issues and challenges highlighted in a recent survey.
23 Real Results Pioneers - A delve in the detail
Editor On-farm trials are allowing a greater level of scrutiny.
Tom Allen-Stevens
Technical editor 26 Spring agronomy - Lodging a war on flea beetle
Lucy de la Pasture The relationship between the beetle and the risk of lodging.
Machinery editor
Charlotte Cunningham 29 Insiders View - A genetic triumph
Writers When sclerotinia strikes, it can be extremely damaging to oilseed rape crops.
Mike Abram Rob Jones 32 Pulse crops - Beans means feed?
Tom Allen-Stevens Lucy de la Pasture There could be exciting prospects on the domestic market for beans.
Charlotte Cunningham Paul Spackman
Design and production 36 NFU Conference - Dynamic vision for a market that rewards
Britain’s leaders present their plans for farming.
Brooks Design
Advertisement co-ordinator 39 Carbon farming - Farming for the future
Peter Walker Some of the key issues and opportunities.
Publisher
Angus McKirdy 42 Climate Change Champions - The might of the microbe
Business development manager Every operation revolves around ensuring a thriving community.
Charlotte Alexander
To claim two crop protection BASIS points, send an email to 45 Grow the future - Tools for the new normal
linda@basis-reg.co.uk, quoting reference CP/100659/2021/g.
It’s important to focus on tailoring applications to in-field variance.
To claim two NRoSO CPD points, please send your name, 48 Nutrient Nurture - Testing times for plant health
NRoSO member number, date of birth and postcode to In-season tissue testing combined with targeted nutrition.
angus@cpm-magazine.co.uk
*the claim ‘best read specialist arable journal’ is based 51 Sustainable gain - Prepared for uncertain times
on independent reader research conducted by Four farmers from across the UK are on a three-year journey.
McCormack Media 2020
54 Agri-intelligence update - Counting carbon makes soil sense
Editorial & advertising sales A new study is shedding light on carbon’s role within soils.
CPM Ltd, 1 Canonbury, Shrewsbury, Shropshire SY3 7AG
Tel: (01743) 369707 E-mail: angus@cpm-magazine.co.uk
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Advertising copy 58 Digital farming - The power of precision
Brooks Design, The level of accuracy offered by precision agronomy platforms is accelerating.
24 Claremont Hill, Shrewsbury, Shropshire SY1 1RD
Tel: (01743) 244403 E-mail: fred@brooksdesign.co.uk
62 Wheat genetics - Hope for the wheats of wonder
CPM Volume 23 No 4. Editorial, advertising and sales offices are at Traits captured from landrace wheats and wild relatives have been identified.
CPM Ltd, 1 Canonbury, Shrewsbury, SY1 9NX England.
Tel: (01743) 369707. CPM is published eleven times a year by
CPM Ltd and is available free of charge to qualifying farmers
and farm managers in the United Kingdom.
Roots
In no way does CPM Ltd endorse, notarise or concur with any of the
advice, recommendations or prescriptions reported in the magazine. 64 Potato agronomy - Brackish water for irrigation
If you are unsure about which recommendations to follow, please consult There may be scope to irrigate potatoes with saline water.
a professional agronomist. Always read the label. Use pesticides safely.
CPM Ltd is not responsible for loss or damage to any unsolicited
material, including photographs.
crop production magazine arable extra march 2021 3
CPM (Print) ISSN 2753-9040 CPM (Online) ISSN 2753-9059
land in stewardship and the terms of new plant breeding evolution of the wildlife in our
ambition is that by 2026, technologies is doubtful. care. A farmer who doesn’t take
we’ll be selling the same One aspect is clear, however good counsel on how these
amount of produce as we –– the pesticide bill will be resources are managed should
do today from a smaller significantly lower and could not be farming in my view,
area. The other even be zero. I should add because there is no possible
ambition is that it’ll be largely replaced by way one person could know
additional opportunities biosolutions, but integrated everything needed to manage
offered under the ELM pest management will have even the smallest farm.
scheme will bring our matured and become the norm Although we’ve always had
Who decides how overall public money income while targeted, precise use will serviced agronomy, the nature
you’ll farm? close to what it is today. be essential, perhaps even of the advice has changed as
Despite all the frustrations mandatory. The notion of farming has evolved. I know
and queries there are over the prophylactic treatments and that will continue as priorities
By 2026 –– just five years away ELM scheme, the ironic thing is precautionary chemical use will change, and if I ever had a
–– farming could look very that it’s probably the element be as socially unacceptable doubt that advice was given on
different to how it does today. that has most certainty. How the as smoking is today. the basis of selling product we
And if you don’t think that’s land will be farmed is more So where does that leave the didn’t need, we would have
likely, cast your mind back open to debate. serviced agronomist? On this changed the source of our
to 2016. For me, the biggest farm, it’s been an essential part advice long ago.
We were in the EU, David difference will be in data and of the fabric for as long as I On this farm, more important
Cameron was Prime Minister, digital farming. Just how that can remember. I’m aware the than how the advice is
Donald Trump was a noisy US will play out by 2026, based advice is paid for by the rewarded is that the person
property tycoon making a on technologies that probably chemical or fertiliser that then who provides it shares and
ridiculous bid to be president haven’t yet appeared on the arrives to be applied, and that understands the values I care
and we shook hands, gathered scene, is almost impossible the more we order, the larger about. And that comes back
at meetings and enjoyed each to predict. But embracing the return for the person who to our role as farmers. More
other’s company. So much has the move to digital and the advises it. important than the plans
changed. information revolution that will We could switch to an we implement or even the
In five years’ time, there’ll bring to farming will represent independent agronomist, who’ll resources we manage are the
be a new government, quite the lasting impacts of COVID, be making decisions unaffected decisions we take.
probably a new US president in my view –– just consider by the seismic changes set to By 2026, farming will look
(the first woman?) and the how many webinars you’ve unsettle input use over the very different, but the people
nightmare year of COVID will attended over the past 12 next five years. But will that it revolves around will be the
be a distant memory. So what months compared with the individual have access to the same. Whether it thrives or dies
about farming? previous 12. same resources and wealth of won’t be down to the changes
Here, the farm will be coming Robotics is another proprietary trials expertise? that happen but the ability of
out of its second Countryside technology that will be making For me, it comes down to those making them to come
Stewardship agreement, its presence felt by 2026, in all whom you trust, and I hope that to the right decision.
although we may already aspects of farming. These will changes little over the next five
have turned that into an ELM be part-driven by the data years, because advice is the
agreement. We took the step for revolution and informed by currency on which farming Tom Allen-Stevens has a
the new agreement that starts sensors connected together thrives or dies. As farmers, 170ha arable farm in Oxon,
this year to significantly step up in the Internet of Things (IoT). we make decisions that have and can’t decide whether
the CS payments to 2.5 times Plant breeding by its very staggeringly far-reaching it’s been a mild end to
their current value, knowing that nature won’t have moved as implications –– on the food we winter or cold start of
by 2026 our BPS payment will fast –– we’ll have hybrid eat, the soil that supports us, spring.
have dropped to a quarter wheats, but even if consumer the air we breathe, the water tom@cpm-magazine.co.uk
of today’s. opinion favours it, whether we drink, the social fabric of @tomallenstevens
We’ve doubled the amount of there’ll be much on farm in our communities and the very
the regulator’s eye. Most arable If it accepts the NFU proposal, non-target species such as
farmers I know recognise this Defra will want to see some raptors. The farming industry
greater volatility in warmer weather rigorous on-farm checks through response was to agree to better
so they only put it on in March. Red Tractor and/or FACTs. This training and stewardship which
After all, it’s in the farmers possible increase in the load would be checked through RT
interest to concentrate when it comes to RT inspections audits if plans for the ban were
fertiliser to where it is cost leads me to a related issue that shelved. This was the outcome.
effective rather than losing has been causing a lot of lively Another role Red Tractor has is
it into the atmosphere or discussion lately among arable giving farmers Renewable energy
down the drain. Nonetheless farmers. I took the chair of the directive (RED) compliance so
The baby and the Defra seem non plussed by this Red Tractor Cereals, Oilseeds wheat can access the supported
self-policing and want much and Sugar Beet Board on biofuel market. Unfortunately, we
bath water tougher measures, their preference 1 January. To say that the now have RED II coming over the
being an outright ban. chair feels a little hot already is horizon which will make the
As I was going round the crops The NFU is working hard to probably an understatement. compliance more demanding
with their first dressing of subvert this proposed ban by Cereals, particularly wheat, which in turn could make Red
nitrogen in early March I was lobbying to bring in mandatory could be described as the difficult Tractor audits more demanding.
conscious this could be the last date restrictions rather than an child in the Red Tractor family in So as British farmers evaluate
time I use urea. Defra has been outright ban. The loss of urea that 90% end up being routinely the role of Red Tractor in light of
warming us up about a potential would cost UK arable farmers co-mixed with imported grain that a changing position in the world
ban for some time now. millions mainly because it’s a has different or little assurance. brought about by Brexit, there is
In the government’s drive for cheaper form of N than ammonium While there are consumer much to think about. Red Tractor
cleaner air, urea with its more nitrate but also because it puts a products like Weetabix that will undoubtedly have to change
volatile tendency to put ammonia bit of needed competition into the proudly bear the Red Tractor logo as the world around it changes
into the atmosphere has caught fertiliser market place. as made from 100% assured but while there is a head of
British wheat, the vast majority of steam in the farming community
cereal products do not because for change, it’s worth checking
of the routine co-mixing which is the baby and what is
with imports. Red Tractor the bathwater.
understandably has rules about
only putting the logo on products The OSR took a significant knock
that are made from 100% assured back from the snow and frost, but
ingredients. As most bakery with rapeseed prices approaching
products are of a composite the gold price let’s hope the margin
nature, they usually fall foul of potential is maintained.
this 100% rule.
But Red Tractor does more
than assure food items as they
appear on the retail shelf. One of
the biggest demands in the Red
Tractor audit, such as checks on
NROSO membership, yearly
sprayer MOTs and Crop
Protection Management plans, are
because of the Voluntary Initiative
(VI). For those who don’t Guy Smith grows 500ha of
remember what happened combinable crops on the north
20-25 years ago, the Blair east Essex coast, namely
Government was in the process St. Osyth Marsh –– officially the
driest spot in the British Isles.
of bringing in a pesticide tax. The
Despite spurious claims from
industry response to avert this others that their farms are
was the VI. actually drier, he points out
Similarly a few years ago that his farm is in the Guinness
Government were under pressure Book of Records, whereas
from the wildlife lobby to restrict others aren’t. End of.
farmer access to rat poison @essexpeasant
because it was turning up in
6 crop production magazine arable extra march 2021
Putting the ‘breaks’ on
Technical
Disease control
It might be tempting to focus has already got out of hand. Instead, before Christmas and it’s been a mild
most fungicide firepower on a good T1 has become increasingly winter. Later drilled crops may be at lower
important for keeping a lid on infection septoria risk, but they can be hit hard by
T2. But with unpredictable earlier, says Harry Fordham, new farming yellow rust because they’re so small.”
weather and disease risks, is technology lead at Syngenta. Paul Gruber, regional technical manager
for agronomy firm ProCam, agrees T1
this shutting the stable door Disease firebreak provides a crucial disease ‘firebreak’. He
after the horse has bolted? “Think of T1 as a disease firebreak. says the aim of an effective T1 when leaf
Although the primary spray target for T1,
CPM finds out. leaf three, only contributes about 8% to
yield –– compared with 23% for leaf two
By Rob Jones and 43% for the flag leaf –– its strategic
and Lucy de la Pasture importance goes well beyond this.
“By keeping leaf three clean with an
effective T1, it’s essentially ‘sanitising’ a
Few of us need reminding how stepping-stone that otherwise facilitates
unpredictable yellow rust has become disease transmission up the plant. It’s
over recent seasons –– including important because the tip of the flag leaf
growers in the west where yellow rust emerges from below leaf three and it
hasn’t historically been that much of a becomes even more so if you haven’t
problem. Septoria tritici also has a history got on top of disease at T0.”
which shows it’s becoming more difficult A big temptation at T1 can be to trim
to control. fungicide inputs if disease levels appear
Seasons such as the washout summer to be low at the time of spraying. But that’s
of 2019, when sudden weather changes a huge gamble, Harry stresses. “The
exposed any weaknesses in earlier impact of future weather on disease
fungicide inputs, have provided some development at that point is still unknown.
harsh lessons. So while the flag leaf Rusts cycle very quickly in favourable At T1 plants are growing more upright so you
remains the biggest yield contributor in conditions,” he notes. want the spray to penetrate down into the crop,
winter wheat, it’s no longer possible to rely “This season there’s been a wide range says Harry Fordham.
on a robust T2 to rectify things if disease of drilling dates, with yellow rust found
8 crop production magazine arable extra march 2021
Cereal diseases
“ If the
wheels come off early
three is emerged is to minimise latent
infection on leaf two above it, so that the
T2 spray can be applied to a clean flag
with yellow rust control,
leaf, to deliver its best results.
you never get the “Get T1 right and there shouldn’t be a
crop back.
” need for a T1.5 spray between T1 and T2,
apart from in exceptional cases,” says
Paul. “But get it wrong, and that’s when
you end up chasing your tail.
Varietal resistance
“If the wheels come off early with yellow
rust control, you never get the crop back.
Early yellow rust prevention has become Paul Gruber believes in keeping crops in a
even more pertinent, given how quickly preventative rather than curative situation
we’ve seen varietal resistance ratings when it comes to disease.
break down.”
Paul says that for septoria, curative prevention is also important at T1. “By
ability may potentially be improved with keeping the lower canopy disease-free for
new fungicide chemistry, but even with longer, there’s less of an infection source
this, he believes keeping crops in a to move upwards. This also gives some
preventative situation is still better than reassurance if there are delays to the T2.
a cure. We talk about maintaining a maximum
“The more we expose new chemistry three-week interval between spray timings,
to established disease, the sooner it will but we don’t always know if the weather
break. The cleaner we keep the crop, not will allow this.”
only the better the yield protection, but Trials at ProCam’s main hub at the
the longer the new chemistry will be Stockbridge Technology Centre in
preserved.” Yorkshire have shown T1 to T2 intervals
Allied to this, he says persistent disease vary widely depending on variety and
▲
Cereal diseases
“If there’s a hot spell between T1 and three won’t have emerged fully, so it won’t
T2, brown rust soon gets going. There be fully protected and there’s an increased
are plenty of varieties relatively tolerant to risk the treatment will run out of steam
septoria but not to brown rust. Solatenol is before T2. Spray too late and you
inherently strong on yellow and brown can miss the boat when it comes to
rusts and is persistent in its control.” maintaining preventative control.
“You can aid spray timeliness by using
Practical considerations drift-reducing nozzles to maximise spray
These are the biological arguments for windows. At T1 plants are growing more
effective T1 disease control, but what upright so you also want the spray to
about the practical considerations? With penetrate down into the crop.”
other inputs such as growth regulators, To these ends, for most situations Harry
herbicides and foliar nutrition also advocates Amistar nozzles for both T1
potentially going in the spray tank, and T2 sprays. As well as being 75%
Paul says good tank mixability of the drift-reduction nozzles, he says their
T1 fungicide is crucial. slightly rearward-facing spray pattern
“Opt for a fungicide that doesn’t move counters the sprayer’s forward motion, so
By achieving effective control at T1, latent
up the leaf rapidly and accumulate in the droplets travel more vertically into the
infection on leaf two will be minimised so that
leaf tip, which is what can cause scorch,” canopy for more even coverage on the
the T2 can be applied to a clean flag leaf.
he suggests. front and back surfaces of upright leaves.
Additionally, with the shape of the plant The coarser droplets they produce also
drilling date. And while brown rust is changing at T1 from its flatter T0 shape, aid canopy penetration, he notes.
▲
considered a later season disease, he and chances of catchy weather, Harry “Although the primary target at T1 is
says pressure can be building between says pay close attention to application, leaf three, a coarser droplet also helps
T1 and T2. For persistence and rust not only to get the maximum spray on the get spray down to leaf four and leaf five,
control he rates the SDHI Solatenol target, but also to achieve timely spraying. which can boost the firebreak effect. In
(benzovindiflupyr) highly at T1. “Spray too early and the base of leaf normal conditions, our guidance is to
▲
More than just disease control?
multisite fungicide still boosted A further disease-free occur in plants,” explains Tudor.
yield by 0.65t/ha, to 10.25t/ha. experiment also showed less water “This work has demonstrated
“At £165/t for wheat, that’s loss from the flag leaf and leaf two non-disease control benefits from
worth an additional £107/ha, so a in plants treated with Solatenol at Solatenol. It indicates that SDHI
significant return on the extra GS31, compared with an untreated chemistry may help plants to
investment. Being a dry year, this control. This was backed up by field conserve water, which could be
yield uplift was unlikely to have results in the low disease year of important in water stress situations.
been due to disease control, but 2020 in a crop under drought “The practical consequence is to
more likely physiological effects –– stress, where there was also less help the grower and agronomist
maybe increased rooting or better flag leaf rolling following a GS39 choose products that can exhibit
tolerance to drought,” he suggests. Solatenol application. non-disease control properties to
The physiological benefits of an “SDHI fungicides are very augment the returns from disease
early-season SDHI fungicide in effective at inhibiting processes control that fungicides offer, should
disease-free situations has also in fungi, but the same pathways disease not develop.”
been researched by Dr Tudor
Even in disease-free conditions, Dawkins at the University of Effect of SDHI on water loss
Tudor Dawkins found that flag leaf Warwick over the past two years.
greenness was boosted following A former agronomist, he’s well
an earlier application of the SDHI aware of the temptation to cut back Leaf 2
Solatenol at GS31. at T1 if disease pressure looks low,
Leaf layer
so was keen to understand what
The argument for investing at T1 fungicides do in addition to
may be convincing. But what disease control and to identify any
Flag leaf
happens if it turns into a low predictable and measurable effects.
disease year? According to Paul, Using a SPAD meter to measure
ProCam trial plots showed that leaf greenness in disease-free 0 5 10 15 20 25 30 35 40
Water loss per hour per cm2 of leaf
even in the low disease year of glasshouse conditions, he found the
2018, when T2 fungicides gave chlorophyll content of flag leaves was Reductions in water loss (mg water/hr/cm2) from flag leaves and leaf 2
only a modest yield increase, boosted by about 5% following an following application of Solatenol at GS 31.
adding SDHI plus strobilurin to earlier application of Solatenol at Source: University of Warwick, 2021
a T1 base treatment of azole plus around the T1 timing (GS31).
10 crop production magazine arable extra march 2021Cereal diseases
Fungicide choice a factor in yellow rust control
Agronomist reports last season about the in disease levels between pyraclostrobin,
difficulties controlling yellow rust was put down to epoxiconazole, tebuconazole and prothioconazole
a combination of late drilling, winter weather and treated plots. But second assessments, one month
changes to the pathogen. But research by Bayer after application, revealed high disease levels in
at the Cawood trial site in Yorkshire suggests that strobilurin treated plots.
fungicide choice might have been a factor. “Strobilurin speed is an asset where the
A single application of various fungicide disease is established as the fungicide acts
treatments were applied to JB Diego and followed quickly against the pathogen. But for a fast-cycling
up with disease assessments approximately one disease like yellow rust it leaves plants exposed to Bayer trials illuminate the differences between
week and one month after application. The trial new infection,” says Rosalind. speed of activity in knocking down yellow rust
confirmed what had long been suspected –– that While strobilurins were at the bottom of and persistence.
there are few ‘all-rounders’ in the yellow rust performance tables when it came to persistency,
fungicide armoury, with most actives ideally suited Elatus Era (prothioconazole+ benzovindiflupyr) tebuconazole, she says.
to protectant or curative situations, but rarely both. came out at the top of the list, offering protection Bayer-formulated Prosaro was also compared
How these curative and protectant fungicide over multiple-cycles, she says. However on with a generic prothioconazole+ tebuconazole
properties differed was quite marked. Strobilurins established disease Rosalind believes a strobilurin formulation. While they both performed well at the
stood out for their curative properties but proved or fast-moving azole is probably the best option. first assessment, the later assessment revealed
to have limited persistency. Some strong In addition to highlighting differences between 5% more yellow rust in the generic plots,
protectants offered little against established actives, the trial also confirmed the importance demonstrating its limited persistency compared
disease, says Bayer’s Rosalind Martin. of formulation. Bayer-formulated Folicur with Prosaro.
It all comes down to fungicide formulation and (tebuconazole) was compared to Toledo “Given the uncertainties and unpredictability of
the speed of active on the pathogen, she says. (tebuconazole) and the first assessment, factors affecting yellow rust, both tebuconazole
“It’s common practice to include a strobilurin in a just one week after application, found the and prothioconazole proved themselves as the
fungicide mixture to boost yellow rust control, but Toledo-treated plots had 5% more yellow rust best all-round actives against the disease,
their movement on and through the leaf means infection compared with the Folicur-treated plots. delivering a good balance of persistency and
they are short-lived on leaf surfaces. Our first This confirmed that SC (suspension concentrate) curativity, particularly when well formulated,”
assessments showed only small differences formulations don’t act as fast as Bayer-formulated she concludes.
Tailoring disease control to risk
Understanding risk based on early cropping automatically calculates which crops are at the
decisions, like variety or drilling date, and highest risk from disease, taking into account all
in-season monitoring of crops are key to using of the factors affecting disease developing in the
Integrated Crop Management (ICM) successfully. crop and allowing the user to tailor a fungicide
Many farmers may already be taking these steps approach accordingly.
without fully realising it, says Dave Howard, “It’s about being better informed to plan a
head of ICM at Hutchinsons. strategy. The job of the model is not to tell us
“ICM doesn’t require a drastic change from that disease is present, but rather to plan for
the norm, in fact many ICM principles have what disease will be more likely to develop in a
already been taken up over the years due to particular variety/field etc. This allows the user
the positive effect they can have on disease to temper that risk as much as possible, not
management. It’s simply a more strategic eliminate it, by tailoring a planned fungicide
approach when planning which crops and approach accordingly.”
varieties to grow, assessing where risks lie and The model takes into account the data
then adapting management and inputs in already entered into Omnia, like variety and Dave Howard explains that a new disease risk
response to changing weather patterns and drilling date, alongside the climatological data forecasting model within Omnia can help justify
disease levels –– or visualizing risk,” he says. provided by the Omnia Climate module. The fungicide applications.
“This can be more complicated than it output is a visual risk map across the farm,
sounds. Over the past two years growers have illustrating which fields pose higher risks and to be planned more effectively.”
juggled with a spectrum of drilling dates and where that risk is coming from, he explains. The risk is recorded though the season to
varieties across their farm, which makes “Users can allocate specific fields and are provide a record for justification purposes which
assessing which crops are at higher risk more presented with a sliding scale to access visual is something that is becoming increasingly
complicated. And that’s without the extremes of representations of crop growth and certain important, he adds.
weather to consider throughout the season.” growth stages. Likely spray days are then The Omnia team are developing a similar
So to make this process much simpler predicted and as the weather patterns model for barley and a lodging risk model for
Hutchinsons has developed a Wheat Disease change, the calculated risk constantly wheat, which are both being trialled this spring
Risk Forecasting model within Omnia. The model evolves, allowing fungicide programmes at Hutchinsons’ Helix farms.
crop production magazine arable extra march 2021 11Cereal diseases
Brown rust can build between T1 and T2 so in “In conditions when drift reduction
susceptible varieties it’s wise to use a fungicide becomes even more important, consider
with both good preventative activity and 90% drift reduction nozzles but use a
persistence. minimum of 200 l/ha of water to
maintain coverage. Nozzle height
should be 50cm above the target, but
use Amistar nozzles at a water volume remember the target is higher than at T0.
▲
of 100 l/ha and 12 km/h forward speed. “Overall, it’s well worth investing in
In an especially thick crop, a higher water getting T1 right. You still need to do a
volume won’t harm, but don’t simply good job at T2, but it may be possible
increase the pressure to achieve this to use a less expensive T2 fungicide
–– the finer droplets produced won’t because of reduced need for curative
penetrate and will be more prone to drift. control.” ■
Biofungicides can take pressure off chemistry
Disease control is all about about 10 weeks and helps protect registration for barley is anticipated
prevention these days and this new and developing plant tissues.” in the future after trials have shown
is where early use of the The difference between a promising reductions in net blotch,
elicitor-based biofungicide, Iodus conventional T0 and an elicitor is rhynchosporium and ramularia.
(laminarin), provides an added ‘same time, different place’ –– the
dimension to septoria control target is leaf four but the Iodus Sticky sulphur
strategies, says Greg Hanna, trials provides systemic protection for the Sulphur is something that’s been
manager at UPL. whole plant, including the leaves used for decades for its fungicidal
“When used at 0.75 l/ha, yet to emerge, explains Greg. activity. It’s now available as
Iodus triggers the self-defence “Traditionally a fungicide applied biofungicide Thiopron, a liquid
mechanisms within the wheat at the T0 timing aims to protect the formulation with enhanced sticking In trials Iodus has reduced the
plant. Normally it takes 48 hours basal leaves that have just capabilities due to its formulation incidence of septoria by a
for these defences to be activated emerged and can contribute up which includes Xanthan gum. It also similar level to both folpet and
after a pathogen has invaded plant to 5% of the crops yield. Iodus has good compatibility with other chlorothalonil, providing another
cells, but Iodus causes them to be provides protection to the basal fungicides. tool for tackling disease,
‘switched on’ in advance of a leaves along with a reduction in Elemental sulphur is effective says Greg Hanna.
fungal attack so the plant is already the inoculum that would spread when formulated as a fungicide due
prepared to fight it.” upward, but also confers benefits to a process known as sublimation, future establishment of spores.”
Laminarin, the active ingredient to the upper canopy that isn’t the transition of a solid substance Thiopron can be used as an
in Iodus, is a natural metabolite present at the time of application. to a gas state without passing alternative multisite at T1 and T2
extracted from a special species of This ‘priming’ of the upper leaf through a liquid phase, explains and in trials provides equivalent
seaweed, Laminaria digitata, found layers against subsequent disease Greg. levels of control to folpet when
in the North Atlantic Ocean. can help reduce the pressure “Atmospheric hydrogen binds used at 2-3 l/ha. On the label
“Laminarin is a protein which on the T1 and T2 fungicide with the sulphur active and forms approval is for powdery mildew but
mimicks a protein found in dead programmes.” Hydrogen Sulphide (H2S) gas in Greg says trials have provided
fungal cells and this tricks the plant In trials Iodus has reduced a surface layer on the leaf. This good efficacy data for septoria in
into thinking that a pathogen has the incidence of septoria by a gas layer is toxic to fungal wheat and for rhynchosporium and
invaded,” explains Greg. similar level to both folpet and pathogens, providing curative ramularia in barley, where it has a
“The plant responds to this chlorothalonil, with an average effects but also toxifying the particularly good fit because of its
elicitor action in three ways. It yield response of 0.3t/ha across surface of the leaf to prevent the disease profile.
increases the thickness and the trials which is comparable with
lignification of cells walls to provide the multisites. Greg emphasises Main contributors to yield
a barrier to invading fungal hyphae. that as an elicitor, the biofungicide
Ear
The plant also produces isn’t actually acting on the
phytoalexins which circulate in pathogen so is a parallel product Flag leaf - Leaf 1
the vascular tissues and bind to multisites, providing another tool Leaf2
to pathogens, inhibiting their for managing disease. Lea 3
development –– producing The reduction in disease burden
Leaf 4
a vaccine-type effect. that Iodus brings to the party is
“As well as phytoalexins, the plant something that Greg believes can Leaf 5
produces pathogenesis-related (PR) play a key role in supporting other 0 10 20 30 40 50
proteins in response to cell-to-cell fungicides as they come under Contribution to yield (%)
signalling as part of the systemic increasing pressure due to the
Iodus switches on the plant’s systemic acquired resistance pathways so
acquired resistance (SAR) evolution of resistant pathogens.
protects leaves yet to emerge.
response. This is maintained for Currently only approved in wheat, a
12 crop production magazine arable extra march 2021“ The breeders
are beginning to look
at the bigger picture
and helping growers
Barley needs produce profitable crops
in a sustainable
way.
”
a boost?
Technical Disease
delve - barley
The loss of chemical options or higher for resistance on the RL. summer of 2018 pushed some of the
That means emphasis is still on fungicides pathogen population back to be more
for barley disease control for control of most diseases, but the cracks sensitive.
may have left barley genetics are showing, not least with a stalwart of “Some of these mutations incur a fitness
barley disease control, chlorothalonil, no penalty, where the fungal isolates are not able
relatively exposed. CPM longer available. to withstand other stresses, and we think in
takes a detailed look at how Without it, control of one key barley that hot dry summer they died off and resulted
disease, ramularia leaf spot, is likely to be in a shift back to more sensitive isolates.”
the key pathogens play out a major challenge as other chemistry only Last season, ramularia was mostly
in current programmes. offers limited control. non-existent as a threat. “With two months
where there was no rain it was too dry. The
By Mike Abram Ramularia fungus grows in the spaces between plant
“For the past 20 years chlorothalonil has cells and needs available moisture to be
been a mainstay of barley disease control present, and if the plant is water stressed
Developing effective genetic resistance programmes,” Neil says. “So growers are there isn’t going to be any for the fungus.”
to key barley diseases may have been looking at what to do in its absence, “So the big question around azoles is
overlooked in favour of yield by plant especially against ramularia.” what will we see in a year with higher
breeders, perhaps in part because of the In terms of fungicide options, the toolbox ramularia pressure?”
strong options for disease control from is rapidly emptying for ramularia control From the AHDB fungicide performance
fungicides such as prothioconazole. options, with resistance evolving to all the curves in 2019, the BASF azole
But as resistance starts to bite and single target-site modes of action. mefentrifluconazole has the most activity,
chemical options diminish, it’s an area that Strobilurins were the first to succumb giving around 75-85% control from a
may well need to be prioritised in future, during 2002, when the G143A mutation half dose, while a half dose of Proline
suggests Dr Neil Havis, crop protection team within the Ramularia collo-cygni population (prothioconazole) was nearer 50%, Neil says.
leader at Scotland’s Rural College (SRUC). conferred complete resistance to the “The other question is what is the value
▲
“For many years, yield has been king,” chemical group.
he says. “It’s a characteristic breeders chase The first warning signs of trouble ahead
more than anything because if you get a for SDHIs was in 2014 when single isolates
variety which yields 2% above the standards with slightly decreased sensitivity were
on the AHDB Recommended List it gets on discovered in France and Germany. But
automatically. it was 2017 when the major shift happened
“The breeders are beginning to look at the with a complete collapse in field
bigger picture and helping growers produce performance from not only SDHIs but
profitable crops in a sustainable way with a also azole fungicides, he says.
sustainable level of inputs, reducing the This was caused by separate mutations,
environmental impact of farming, instead with one affecting azoles and another SDHI
of just chasing yield.” chemistry. While the SDHIs now appear to
As yet that hasn’t resulted in better have completely lost their activity against
resistance traits coming through for three ramularia, the same is not quite true of
Growers are looking for what to do to control
of the four main barley disease threats: azoles, Neil says.
ramularia in the absence of chlorothalonil,
ramularia, rhynchosporium and net blotch. “In 2019 we saw a little bit of residual
says Neil Havis.
Only brown rust has varieties with an eight activity from the azoles. We think the hot
crop production magazine arable extra march 2021 13Disease delve - barley
by stress, with the ultimate stress being producing mutations that impact on the
flowering as that changes the physiology efficacy of fungicides, although currently it
of the crop. is reduced sensitivity rather than outright
“But so far there is very little independent failure.
evidence to show direct benefits for “There have been SDHI mutants recorded
ramularia control. We do know that if you in Europe, although as yet we haven’t seen
can delay senescence you get reduced too many strains in the UK.
symptoms, so there is a question about “Both Imtrex (fluxapyroxad) and Proline
whether biostimulants can influence (prothioconazole) have performed well in the
senescence, and mean ramularia comes AHDB fungicide performance work, while
Rhynchosporium shows itself as large, pale green
in later and for a shorter period.” there is a drop in efficacy from Kayak
watery oval lesions on the leaf blade that turn
(cyprodinil), which could be a problem for
pale brown and develop a darker margin.
Net blotch growers in future who have been using it as
Net blotch, which can easily be mistaken for a cheap option early in the programme.”
of the one remaining multi-site, folpet,
▲
ramularia, is a growing threat, particularly in Insensitivity to strobilurin fungicides is
to the value of the barley programme?
winter barley in some parts of the UK, Neil present, but it is a different mutation, F129L,
“This is a contentious question among
suggests. It’s favoured by wet and warm to the G143A one that causes complete loss
plant pathologists. The product is approved
spring and summers and tends to be seen of control in ramularia and septoria in wheat.
for rhynchosporium control and our work has
more in England than Scotland. Efficacy has declined but, generally, field
shown there is some intrinsic activity against
“There are a number of possible reasons performance is still useful in a programme,
ramularia in controlled conditions, but in the
why it has been increasing –– it’s both he says.
field it is nowhere near the levels of CTL.
trash and seed-borne, and we’ve lost seed Growers using a min-till establishment
“On a good day it will give maybe 30-40%
treatment products, such as Raxil Star technique are potentially more at risk, again
control, but its value in the programme is
(prothioconazole+ tebuconazole+ fluopyram) especially if previous crops had high levels
when it is combined with other chemistry
in spring barley, which is putting more of net blotch infection. “You don’t want to be
from an anti-resistance development point
emphasis on the foliar fungicides.” sowing into a dirty seedbed.”
of view.”
With less effective seed treatments, Thick crops also create a favourable
Currently there are no standout
growers home-saving seed should consider micro-climate for net blotch so higher
spring barley varieties with better
getting seed tested especially if the disease seed rates can be a problem, he adds.
resistance to ramularia, he says. “All
has been seen in the seed crop, he advises. Varietal resistance is again lacking ––
are moderately-susceptible, so that has
Like ramularia it is also adept at there’s nothing above a disease score of six
put more pressure on the chemicals.”
Finding varietal resistance has moved
up breeders’ target lists and Neil has a PhD Brown rust most prevalent barley disease?
student looking for genetic factors that point
Within the AHDB Recommended List winter
towards resistance, but it’s not likely to be a
barley trials brown rust has been the most
short-term solution.
prevalent disease for the past three seasons,
Alleviating stress through nutrition or
says Katie Murray, Syngenta area manager
biostimulants is another research area, he
for Scotland.
adds. “We know the disease is exacerbated
“It’s probably due to the mild winters, and
warm, humid springs. It survives on the green
How to identify ramularia bridge and spreads into crops. In barley you need
to control it earlier than in wheat but we do have
Ramularia is easy to misidentify, Neil says. the chemistry to do so.”
“Follow the five R guide. If it satisfies all Elatus Era (benzovindiflupyr+ prothioconazole)
of the five Rs then you’re probably looking in Syngenta’s portfolio is known as a strong
at ramularia.” choice against rusts, she notes. “If you have
1. Ringed with yellow margin of chlorosis brown rust coming in at T1, it’s an obvious
2. Rectangular shape choice.”
3. Restricted by the leaf veins The product is strong against all the other key
4. Reddish-brown colouration barley diseases, but it’s best position in winter Brown rust has been the most prevalent
5. Right through the leaf barley programmes will depend on which disease disease in winter barley the past three years,
is the main risk, she says. says Katie Murray.
For net blotch, as well as early infections of
brown rust, typically that would be at T1, while In spring barley, in low disease situations
for rhynchosporium it would usually be T2 usually where a single shot of fungicide will suffice, she
in mix with folpet. “The folpet is there to provide recommends Elatus Era plus folpet at GS37-39.
protection against ramularia.” “If it is higher risk for ramularia, we would
Where net blotch and rhynchosporium suggest an alternative SDHI plus azole plus
threaten, there could be a place for Kayak folpet at T1, and following up with Elatus Era
(cyprodinil) at T0, she adds. plus folpet at GS45-49.”
14 crop production magazine arable extra march 2021Disease delve - barley
for winter barley and no scores Fairing came through it was a With net blotch, small, dark brown
for spring barley. nine, it’s now a six, although lesions develop into short brown
“AHDB has switched some of we’ve seen in the field in some stripes or irregular blotches which
the trials that were on yellow rust years that it can perform better consist of a network of brown lines.
into net blotch in an attempt to than a six.
provide more information on “More resistant varieties could potential set early on, you need to
varietal resistance,” notes Neil. allow growers to cut back on control disease early on when the
fungicide inputs in spring barley. grain sets are forming.”
Rhynchosporium If you’ve got clean crops and no Fortunately, there are good
Breeding is also behind the visible disease, on a variety with fungicide options. “There has
curve in providing genetic decent rhyncho resistance there been a gradual decline in the
resistance to the other key barley is a question mark about T1 in efficacy of azole fungicides over
disease, rhynchosporium. spring barley.” the past 20 years, but the bulk of
“There’s nothing in spring That’s not the case in winter activity in Siltra Xpro (bixafen+
barley that is currently above barley, where the disease has prothioconazole) is coming from
a disease score of six. When more time to develop. “With yield the SDHI.”
Strobilurins are effective
Prevalence of winter barley diseases in past against rhyncho with only
four years occasional G143A mutations In those conditions it can take
recorded across Europe, while off, but we have the chemistry
cyprodinil also has some activity. to control it.”
“I’ve not seen any data that SDHIs, strobilurins and azoles
suggests folpet contributes all provide good control, with bar
strongly to rhynchosporium the occasional isolate showing
control, but application at T2 slight insensitivity to SDHIs,
may also help control ramularia,” which has had no impact on
Neil adds. field performance, there are no
resistance concerns, according
Brown rust to the latest Fungicide
Brown rust may be the most Resistance Action Committee
common disease in winter report.
Source: AHDB Recommended List Harvest Data 2017-2020 barley by some measures (see Varietal resistance in winter
Average yield responses to fungicides in panel on p14), but it is probably barley is a bit better than for
spring barley the easiest to control and least other diseases with Jordan rated
worrying in terms of yield loss, an eight, and multiple other
Neil says. varieties rated as sevens, Neil
“It’s another one that likes says. “But there’s nothing above
warm and humid conditions. a five for spring barley.” ■
Yield (t/ha)
Disease delve – barley
Knowing your enemy is the first line reassurance of prothioconazole
of defence against disease –– stay with the persistent green leaf area
a step ahead and you maintain protection of the SDHI Solatenol, its
better control. But it’s an evolving label approval covers net blotch,
picture with cereal diseases –– brown rust and rhynchosporium.
Source: AHDB spring barley RL control varieties varietal susceptibilities shift, Plus, it can be used on malting
pathogens mutate, research moves and feed barley, as well as wheat.
Fungicide yield response in winter barley related
on and our understanding changes. Meanwhile while the multi-site
to conditions
It’s easier to manage a problem if folpet may not yet be fully
you know more about it. So CPM established in barley, it’s
has teamed up with Syngenta to becoming a compelling proposition.
bring growers bang up to date. Trials have shown that adding
In barley, growers are lucky to folpet to an already robust
have several fungicide modes of SDHI/prothioconazole/cyprodinil
action to choose from, to deliver programme cut ramularia infection
a multi-pronged attack on key by an additional 40%.
diseases.
As a popular foundation
in barley, Elatus Era has
Source: AHDB winter barley RL control varieties gained ground. Combining the
crop production magazine arable extra march 2021 15“ The leaf
cuticle is the most
challenging barrier for
the penetration of
pesticides.
”
Control the
controllable
Technical Pushing
performance
A lot of thought and attention Agrii have a well-established rapidly the pesticide breaks down (alkaline
programme for testing adjuvants to sift hydrolysis) and this will reduce overall
goes into picking the best out the wheat from the chaff and Kantor efficacy,” explains Stuart.
fungicide products and rates has proven to be one of these, he says. “Alkaline hydrolysis can be very fast
“We look at the technical story behind when the pH of the water is greater than
to do the job, yet efficacy is adjuvants and put them through their 8 or 9. Some pesticides begin to break
highly dependent on good paces to better understand their down as soon as they are combined with
properties and, most importantly, find alkaline water in the tank and as a result,
delivery to the target. CPM out where is the right place to use them.” the active ingredients start to change
discovers how an adjuvant before the pesticide even leaves the spray
Doing many things tank. For other actives this only becomes
can help achieve this. The list of Kantor’s attributes means an issue if the spray is left in the tank for
it’s not an adjuvant that can be easily a period before spraying.
By Lucy de la Pasture pigeon-holed –– it appears to be capable “Reduced product performance may
of doing many things. Stuart Sutherland, not be obvious. In some cases, the
technical manager at Interagro, explains influence of water on the pesticide
“When you master the things under your that this makes Kantor different to all other
control, the uncontrollable eventually adjuvant products.
becomes irrelevant.” Those may be the “Kantor helps the active ingredient on
words of an American motivational its way from the sprayer tank to its target.
speaker, but they also ring very true Crop protection product efficacy is often
when it comes to considering disease under pressure from tank to tissue –– from
control. factors such as high pH water, compatibility
Many factors that can influence fungicide problems, spray drift, poor spreading and
efficacy are relatively uncontrollable –– the penetration of the leaf and low levels of
weather, the mutations that evolve during the spray retention on leaf tissues. Kantor is
season, the fungicide chemistry available the only adjuvant to offer corrective action
and breakdowns in varietal disease at every step in this delivery process,”
resistance to name a few. he says.
At a time when the sensitivity of septoria The journey starts with the spray water
pathogens to the two main fungicide that delivers the chemistry to its target
groups continues to shift, getting the best and it’s a factor that can influence the
performance out of products has never effectiveness of plant protection products
been more important and is largely under and compatibility in the tank. One SDHIs and azoles have acropetal movement, so
grower and advisor control, says Agrii important influence on the efficacy of will only move from where they land on the leaf
regional technical advisor and some chemistry is the pH of the water. towards the leaf tip, explains David Felce.
Cambridgeshire grower David Felce. “The more alkaline the water, the more
16 crop production magazine arable extra march 2021Pushing performance
reduces its effectiveness only slightly, yet David stresses the importance of spray
enough that tolerant or tough-to-control coverage, especially when it comes to
weeds, insects and diseases aren’t fungicide applications. “Multisites act as a
well controlled.” protectant but don’t move on the leaf ––
David adds that while Kantor isn’t a this means they can only protect the parts
water conditioner as such, it definitely of the leaf that the spray covers.
helps with tank-mix compatibility because
of its slight buffering effect (to pH6). Acropetal movement
“We’ve found that adding Kantor to the “Azoles and SDHIs have acropetal
tank results in better compatibility, movement, so will move from where they
especially in early season when the land towards the end of the leaf. So if the
spray water tends to be cold and when base of the leaf doesn’t receive adequate
tank-mixes can be quite hefty.” coverage the fungicide will not move in a
One of the most important ways Kantor downwards direction and that part of the
influences spray delivery is the effect it leaf will either be completely unprotected
has on droplet size and this is something or have received a sub-lethal dose of Stuart Sutherland explains that by paying
David has looked at closely in Agrii trials. active ingredient.” attention to the water that delivers the active
“Typically a flat fan nozzle will produce a Once the spray has been delivered to ingredient, product performance can be
range of droplet sizes, with a Number its target, Kantor’s other properties help optimised.
Median Diameter (NMD) to Volume Median get the active ingredient to where it needs
Diameter (VMD) ratio of approx. 5:1. to be. It achieves this by retaining the of the spray solution on the leaf surface.
“The addition of Kantor results in a active ingredient on the leaf, spreading When a spray droplet lands on a leaf it
narrower range of droplet sizes, with the spray droplets and helping the may be retained or bounce/run off. Aqueous
fewer very fine or coarse quality drops, active penetrate the waxy cuticle of fungicides have droplets with a high
reducing the NMD:VDM. As a result, the the leaf. Stuart explains how Kantor dynamic surface tension which will frequ
spray is more controllable so there is a achieves these many functions. ently bounce off, leaving the leaf or ear
reduction in drift and improved spray “The surface characteristics of the leaf with poor coverage.
deposition on the target leaf tissues.” influence both the retention and spreading “Kantor reduces the dynamic surface
▲
View from the field
Agrii agronomist Greg Taylor What I believe is that the properties Another useful attribute of Kantor
looks after crops in the North of Kantor that alter the droplet is that it also helps improve
Buckinghamshire, Northamptonshire, spectrum and better reach the lower rainfastness,” he adds.
Oxfordshire and Hertfordshire areas. parts of the canopy don’t make Earlier in the season Greg also
In his view there are three key timings fungicide products better, it believes Kantor is justified when
that suit Kantor –– with certain enables them to do their job conditions are cool. Often this
herbicides, with fungicides in cereals more effectively,” he says. coincides with PGR applications,
and oilseed rape and with PGRs. One of the problems Greg when the adjuvant can also aid
“We’ve seen in Agrii trials that identifies is caused by the structure compatibility and help to safen the
there’s a yield benefit from adding of crop plants and this makes it very multiple tank-mixes that may go on.
Kantor to fungicide applications. challenging to get a fungicide to the Further east, Agrii agronomist
Making products work better is what basal region of leaves and down into Matt Clark is seeing a lot of early
adjuvants do, the question is why? the canopy. “Brown rust can bubble yellow rust in varieties across the Greg Taylor favours adding Kantor
away low down in the crop canopy, board, in spite of the cold spell in to the tank at the later T2 and T3
particularly at the junction where the Feb. Where that would have been timings in cereals and with
leaf sheaf joins the stem. Products surprising a few years ago because sclerotinia sprays in OSR.
like Kantor can help get the most out cold weather would have subdued
of the fungicide programmes we’re infections more, he points out that
using by getting the fungicide to the new strains of yellow rust affect of the azoles that remain when it
where it’s needed.” varieties differently than expected comes to controlling yellow rust and
Greg sees Kantor as a very and are much harder to control. this is where Matt sees Kantor as
versatile adjuvant but favours adding “We’ve now lost morpholine playing a key role.
it to the tank at the later T2 and chemistry, which would have been “Kantor helps get the spray
T3 timings in cereals and with the go-to for a quick knockdown, across the whole of the leaf surface
sclerotinia sprays in OSR because and we’d have added a triazole for a and down to the base of the
Matt Clark is using Kantor with of its ability to help get fungicide into more persistent effect. With a smaller canopy, which is where the
early yellow rust treatments to all the nooks and crannies. range of chemistry now available, we fungicide is needed to knock
help get fungicide to the base “At this stage the crop canopy is have to be careful how we use it,” out yellow rust infection. It’s an
of the canopy. massive in OSR and you need to he says. additional cost that we don’t really
achieve good fungicide coverage. That means getting the most out want but sometimes it’s needed.”
crop production magazine arable extra march 2021 17You can also read
