bayer cropscience cropfocus2015(west) growers
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Bayer CropScience Cropfocus2015(west) growersTRANSCRIPT
BayerField Days:The results
Profit from good diseasecontrol in 2015
the cultural solution
Time-lapse photos showvalue of protection
Timing matters
Septoria
www.bayercropscience.co.uk
Spring 2015
West Edition
2
Crop Focus
Learning thelessons onfungicidesPages 4-7
L
MAYFungicid
Se
e
Page 16
Timing mattersPages 18-20
Barley in focus
2015
Aviator235Xpro contains prothioconazole + bixafen. SiltraXpro contains prothioconazole + bixafen. Proline275 contains prothioconazole. Fandango contains prothioconazole + fluoxastrobin.Folicur contains tebuconazole. Mesurol contains methiocarb. All are registered trademarks of Bayer.
Adexar contains epoxiconazole + fluxapyroxad. Imtrex contains fluxapyroxad. Ignite contains epoxiconazole. Comet200 contains pyraclostrobin. Opus contains epoxiconazole.Brutus contains epoxiconazole + metconazole. Filan contains boscalid. Elk contains dimethenamid-p + metazachlor + quinmerac. Tracker contains epoxiconazole and boscalid.All are registered trademarks of BASF.
Bontima contains epoxiconazole + isopyrazam. Seguris contains isopyrazam + epoxiconazole. Zulu contains isopyrazam. Bravo contains chlorothalonil. Amistar Opti contains azoxystrobin + chlorothalonil.Plenum contains pymetrozine. SAN 703 contains cyproconazole + chlorothalonil. All are registered trademarks of Syngenta.Hyvido is a registered trademark of Syngenta.
Vertisan contains penthiopyrad and is a registered trademark of DuPont.
Falcon contains propaquizafop and is a registered trademark of Adama.
Astrokerb contains propyzamide + aminopyralid and is a registered trademark of Dow AgroSciences.
Rubric contains epoxiconazole and is a registered trademark of Cheminova.
2014: A year to learnPages 4-7
SDHI fungicides at T1?Pages 8-9
Septoria: The cultural solutionPages 10-11
Bayer Field Days: The resultsPages 12-13
Predicting a Fusarium seasonPages 14-15
Good timing is all you needPages 16
Time-lapse photography puts timing in focusPages 17
Finding the right combination in barleyPages 18-20
Red alert: Light leaf spot coming to a field near youPages 21
Beating flea beetles to profit from OSRPage 22-23
Contents
3
Spring 2015
Bayer CropScience Ltd.230 Cambridge Science ParkMilton RoadCambridgeCB4 0WB
Bayer Assist: 0845 6092266or 01223 226644www.bayercropscience.co.uk
©Copyright Bayer CropScience 2015.
Mike AbramPR and CommunicationsManager
Andrew FlindDevelopment ManagerCombinable Fungicides
Will CharltonProduct ManagerCombinable Fungicides
Tim ShortProduct ManagerCombinable Fungicides
The survey, which is conducted across300 commercial crops in July, providesa snapshot of what has taken place andgives a very useful overall picture ondisease incidence, explains Dr JudithTurner, plant pathologist at FERA.
“The 2014 results confirm what manypeople suspected with Septoria,”she says.“All areas were affected by the disease,with no regional variation being seen.That’s very unusual.
“Septoria was found in 100% of crops,making it the worst year since 1970, whenthe survey started.”
To put this into context, a low disease yearwould result in just 50% of crops beinginfected, she points out.“That shows whatgrowers were up against and whatfungicides had to do.”
A comparison with 2012, which wasanother bad Septoria year, shows that thedisease pressure wasn’t as high then.“Disease was very evident in wheat cropsin 2012, but it was due to the lack ofspraying opportunities caused by theincessant rain, not because of unduly highdisease pressure.”
The 2014 results show that Septoria levelswere at 5.9% on the flag leaf and 11.5%on leaf two, she notes.
The importance of the forecast“Septoria is largely weather driven,”explains Dr Turner.“That means one badyear won’t necessarily be followed byanother – a cold, frosty winter followed bya dry spring will have a huge effect onreducing the threat. Last year, of course,we had a very mild winter.”
Indeed, analysis done at FERA for BayerCropScience has shown that there’s norelationship between Septoria levels insuccessive years, she stresses.“That’s verydifferent to diseases such as light leaf spot,which has a very significant relationshipfrom one bad year to the next.”
This means that growers should not worryabout 2015, based on what happened in2014.“The weather will driveany epidemic,”notesDr Turner.
Crop Focus
Septoria was found in
100% of crops, making it
the worst year since 1970,
when the survey started
A lessonLearned?High disease pressure brought fungicide programme effectiveness andtiming into sharp focus in 2014, not least because growers faced the highestSeptoria levels since the DEFRA winter wheat disease survey began. It makes the2014 growing season one to remember for more than just the easy harvest.
4
Bill Clark, commercial technical director atNIABTAG, recalls that it was a two diseaseyear for many growers, with both yellowrust and Septoria causing difficulties.
“Even in areas which don’t usually getthem, both diseases were severe,”he says.
He believes that yellow rust will continueto be an issue for growers, given that thereare at least four different types of theWarrior race and a high number ofsusceptible varieties being grown.
“Don’t forget that some resistant varietiesare susceptible at the seedling stage, whichhelps to build up inoculum levels throughthe autumn and winter if it’s mild.”
But Septoriawas the more difficult tocontrol this year, he says, for a number ofreasons – both simple and complicated.“Unfortunately, people are still gettingtheir growth stages wrong and spraying atGS31 rather than GS32.All too often, thiscauses them to leave too long a gapbetweenT1 andT2, allowing the disease toget onto leaf two and three.”
The use of chlorothalonil at bothT0 andT1is beneficial to protect against Septoria , hecontinues.“If it was missed, Septoriacontrol was more difficult.And wheredisease pressure was high, straighttriazoles, even with chlorothalonil, weren’tgood enough.”
Eradicant controlIn addition,T2 sprays were very important,points out Mr Clark.“It was only theSDHI/triazole mixtures which gave goodenough eradicant control of Septoria. Highrates of triazoles aren’t enough in highpressure situations.”
So the best fungicide programmes in 2014were those that had early intervention onyellow rust, the inclusion of chlorothalonilfor Septoria and used robust rates of SDHImixtures at the flag leaf stage, hesummarises.
“By early action on yellow rust, I meanseed treatments or an autumn/preT0
spray,”he stresses.“And by robust rates ofSDHIs, I mean three quarter doses ofproducts such as Aviator.”
The average spend on fungicides in 2014was high, he accepts, but the return oninvestment was even greater.“Yieldresponses of over 4t/ha were not unusual,especially where both diseases werepresent.”
Even today’s grain prices mean thatgrowers will get a good return on theirinvestment, he notes.“It’s not what peoplewant to hear, but the optimum fungiciderequirement of a wheat crop is only slightlyaffected by the wheat price.
“Wheat at £200/t and at nearer £100/tshould only have a slightly alteredprogramme. Perhaps spending £15-20/haless.”
Product differences weren’t obvious at T2,providing the timing was right, he says.“The two market leading SDHI/triazoleformulations,Aviator andAdexar, bothperformed very well (see chart below) andin line with our expectations.The key withboth of them is to keep rates high underhigh disease pressure.”
Whichever product growers opted to use,they should have used at least threequarters rates.“You can’t afford to get itwrong at theT2 timing – if this spray ispoor your yield is lost.”
Looking forward to the 2015 season,MrClark believes yellow rust is here to stay.“The more aggressiveWarrior races now
dominate the UK population so we canexpect the disease to be around next year.
“Furthermore, the UK wheat area is stilldominated by rust-susceptible varieties.”
This means that if there’s another mildwinter, early intervention will again beimportant.“If you haven’t used a seedtreatment, you will need to take action atT0.”
Mr Clark adds that loss of efficacy in thetriazoles against Septoria should continueto be a consideration in disease controlprogrammes.“The SDHIs will be veryimportant, especially at T2. But if we have awet spring, then they may also be neededat T1.That’s a decision that can be takennearer the time.”
Accurate growth stage recognition isessential, particularly when leaf three isbeing targeted, he advises.“It’s so easy toget it wrong, which then makes the wholeprogramme difficult.”
His final word is on cost.“Remember thatthe wheat price shouldn’t dictate yourfungicide programme.Trim it back a bit, byall means, but don’t make drasticchanges.”
The average spend on
fungicides in 2014 was
high, but the return on
investment was even
greater. Yield responses of
over 4t/ha were not unusual
5
Spring 2015
• Huge return on investment fromfungicides in 2014
• Wheat price has little impact onoptimum programme costs
• Disease well controlled wheretimings good
• Protectant programmes need tobe used
• Concentrate on identifying finalleaf 3 emerging correctly
Key Messages
Continued...
Yie
ldt/
ha
Untreated Aviator235Xpro 1.0 L/ha Aviator235
Xpro 1.25 L/ha
10.5
11.0
10.0
9.5
8.0Adexar 1.25 L/ha
9.1
10.7 10.7
9.0
8.5
10.8 10.8
Adexar 1.5 L/ha
Source: Mean of 15 trials: (AICC, ADAS, SRUC, NIABTAG, BCS) (Leaves 1 & 2)
Santiago: Untreated
Yield comparison between Aviator and Adexar
6
Crop Focus
Andrew FlindDevelopmentManagerCombinableFungicides
Average yieldincrease 0.7 t/ha
High Septoria pressure(60-100% untreated)
Average yieldincrease 0.5 t/ha
Medium Septoria pressure(20-60% untreated)
Average yieldincrease 0.3 t/ha
Low Septoria pressure(<20% untreated)
Wheat: Aviator T2 yield uplifts over strob+azole +/- CTLare dependent on disease levels (7 year dataset)
2.5
Source: 85 independent and BCS trials over 7 years: 2008-14.Aviator235
Xpro 1.0 L/ha vs. Ignite 1.125 L/ha OpusRubric 0.75-1.0 L/ha + Comet 0.3 - 0.4 L/ha +/- Bravo 1.0 L/ha
2
1.5
1
0.5
0
-0.5
Yie
ldb
enef
ito
fA
viat
or23
5 Xp
rovs
azo
le+
/-st
rob
Andrew Flind of Bayer CropScience says it was no surprise that Septoriawas bad in 2014. “We had a warm, wet winter and there had been plenty of earlydrilling of susceptible varieties. Crops were under pressure right from the start, sothat fungicides had a lot of work do.”
However, very good trials results showsthat the chemistry stood up well to thechallenge, with no performance issuesbeing identified, he adds.“The very highdisease pressure meant that there wassome disease evident on upper leaf layersin commercial crops.This was exacerbatedwhere growers were under pressure to geton and spray, and went a little too early.”
In some cases, that caused them to misstheT1 target, leaf three.“Where there arevery large areas to spray, it can take up to10 days to get round. Poorly timedT1s werea feature of 2014 and that’s whereproblems can arise.”
A well-timed standardT0,T1,T2 andT3programme was sufficient in 2014, eventhough some growers added in aT1.5spray, he continues.
“The impact of theT0 spray was very clearin 2014.Any delays after that causedproblems with disease control, as re-infection was constant.”
Mr Flind stresses that results are alwaysbetter from protectant sprays.“The spraywindow has narrowed because of thereducing curative ability of triazoles. In a
year like 2014, if you’re too late or too earlywith spray timings, the task becomesmore difficult.”
Getting theT1 spray timing right meansapplying it as soon as leaf three has fullyemerged, he advises.“TheT0 needs to bethree weeks before that.”
Aviator was mostly used at T2 in 2014, hereports.“There was some applied at T1, butthe flag leaf timing is where you’ll get themost benefit in terms of protecting yieldpotential and that seems to have beenrecognised.”
As Septoria pressure rises, so do the yieldbenefits, says Mr Flind.That could easily beseen in last year’s trials. Over the past sixyears, the average yield response fromAviator over azole + strobilurin +/- CTLwas 0.4t/ha. Last year it was 0.75t/ha.Where Septoria infection levels reached60% or over in untreated plots the yieldresponse was 1.3t/ha last season.
Even if disease pressure is lower,Aviatorstill pays as, alongside its excellent Septoriaand rust control, it also drives yield throughimproving overall crop health.“At flag leafthese include better nitrogen utilisation,
increased chlorophyll levels for moreefficient photosynthesis during grain fill,and better water use efficiency to helpreduce drought stress in dry seasons,”saysMr Flind.
While the yield benefits in lower diseaseyears are less, at an average of 0.3t/ha overthe traditional strob + azole +/- CTLapproach, which is still a £36/ha benefit at£120/t for a £5/ha investment, saysMr Flind.
“It’s time to move on from thetriazole/strobilurin/chlorothalonil mixesnow.There’s clear evidence of the value ofthe SDHIs at this timing.”
Against other SDHI fungicides at T2,Aviator andAdexar have clearly separatedfrom other competitors, such as SegurisandVertisan.
In 2014, across 15 independent and Bayertrials, the yields from 1.0 L/ha Aviator and1.25 L/ha Adexar were equivalent, and atthe higher rates of 1.25 L/ha Aviator and1.5 L/ha Adexar.“But with Aviator a littlecheaper thanAdexar, it gives a greaterreturn on investment for the grower.”
The BayerV iew
Spring 2015
7
Last year’s extremely high Septoriapressure demonstrated the value of arepeat SDHI application at T1 andT2 at JBSands Ltd, Brewood.
Some 900ha of wheat is grown across1600ha of owned, rented and contractfarmed land, with the focus on feedvarieties that include Grafton, Diego,Leeds, and Dickens, plus a small area ofCubanita. Oakley was grown in 2014, buthas been dropped due to its yellow rustsusceptibility.
Wheat with the highest yield potential(around 40% of the area) received 1.0 L/haof Aviator at T1 on 18 April last year andagain at T2 in mid-May, after a T0 of SAN703 at the beginning of April.
The remainder received aT1 mix of0.6 L/haVertisan + 0.6 L/ha Bravo +0.6 L/ha Opus, followed by 1.0 L/ha ofAviator at T2. Everything also received 0.5L/ha of Proline at the end of May.
“We had a fairly steady growing seasonlast year, but there was high Septoriapressure, which is where Aviator did agood job,”Mr Sands says.“We had somegood yields, with an average across firstand second wheats of 10t/ha (4t/acre),which is above the 3.5t/acre we’d normallyexpect.The best land did nearly 11t/ha(4.4t/acre).”
Mr Sands acknowledges two Aviatorapplications can work out slightly moreexpensive than the penthiopyrad mix, butsays it is a lot easier and quicker to put a
single product in the sprayer and go,rather than mixing several differentproducts.
He believes it is crucial to treat cropspreventatively as soon as they reach theoptimum growth stage otherwise diseasegets established and risks chasing diseasecontrol through the rest of the season.
Accurate agronomy advice is key tooptimising timings and Mr Sands says herelies on information provided by AICCagronomist Bryce Rham.
Spray intervals were kept tight to reducethe risk of letting disease in, he adds.“Wehave two self-propelled sprayers whichgive us the ability to cover a lot of groundin a day and get sprays on at the optimumtiming. If conditions are right we can do800-1,000 acres in a day.”
Mr Sands says this season’s fungicideprogramme is likely to be similar to last,although he may opt for penthiopyrad +chlorothalonil + epoxiconazole mix at T1,with Aviator at T2 and Proline at T3.“A lotdepends on how products are priced andhow disease pressure looks nearer thetime.”
With almost 1,000ha of wheat to manage, Staffordshire farmer Peter Sands is a firmbeliever in using robust chemistry and a preventative approach to disease control
GrowerV iew Peter SandsJB Sands Ltd,Staffordshire
WheatHighyieldpotential
Loweryieldpotential
SAN703
SAN703
Aviator235Xpro
Vertisan+Bravo+Opus
Aviator235Xpro
Aviator235Xpro
1.0L/ha
1.0L/ha
Proline275
Proline275
0.5L/ha
0.5L/ha
1.0L/ha
0.6L/ha+0.6L/ha+0.6L/ha
Rate Rate RateT0 T1 T2 T3 Rate0.75L/ha
0.75L/ha
We had a fairly steady
growing season last year,
but there was high Septoria
pressure which is where
Aviator did a good job
The
Fungicide Programmes
8
Crop Focus
In most situations, a well-timedT1 spraybased on Proline + chlorothalonil timed toprotect the fully emerged leaf three willgive all the protection that a winter wheatcrop needs at that stage of the growingseason, where a T0 has been applied, saysAndrew Flind of Bayer CropScience.
“What we’ve seen over the past few years,in trials, is that there’s little difference indisease control if an SDHI/triazole productis used instead of Proline at T1, where a T0has been applied,”he says.
“Providing the right rate is applied and thetiming to hit leaf three is correct, a Proline+ chlorothalonil mix will give excellentresults.”
For the best outcome, he recommends thatcereal growers use a minimum of threequarters rate at T1.“That means Proline at0.55 L/ha and chlorothalonil at 1.0 L/ha,following an effective T0.The message thatrates need to be kept up remains the samethis year, ahead of the new season.”
In addition, accurate spray timing isessential with this approach, he stresses.“There is a case for an SDHI in more
curative situations, such as where spraytimings have been delayed and/or there’shigh disease pressure, or where T0 hasbeen missed,”he acknowledges.
No need for two SDHIsBayer trials conducted in 2014 comparingT1 sprays showed 84% control of Septoriafrom a well-timed Proline + chlorothalonilspray.That went up very slightly, to 86.5%with Aviator, but remained at 84% when aVertisan + Proline mix was used.
“The SDHIs were no better in theseprotectant situations,”he says.“Even in ahigh pressure year, it’s still possible to getvery good results from Proline +chlorothalonil. So providing everything isgoing according to plan, there’s no need touse two SDHIs in a winter wheat diseasecontrol programme.”
Yield responses from theT1 spray were upto 2t/ha this year, continues Mr Flind.“There is an argument for using an SDHIat T1 for insurance, but that tends to bewhere growers struggle to get round all oftheir crops with the sprayer in a tighttimescale.
“But there’s also a counter argument thatkeeping the best chemistry for the timingthat protects the leaf layers driving yield isa good way of reducing the risk ofresistance developing, so safeguarding thechemistry for longer.”
The role of chlorothalonil at T1 has beenanother focus of Bayer trials, so that thecompany can gain a better understandingof the situations in which antagonismbetween active ingredients andchlorothalonil can occur.
“There’s always been an issue withchlorothalonil and triazoles in a curativesituation, which everyone in the industryhas been aware of for a while,”explainsMr Flind.“So it was important to look athow chlorothalonil might affect theperformance of Aviator, by using threedifferent rates and investigating bothprotectant and curative situations.”
Key points to bear in mind
Why CTL may have a place at T1 but not T2
First sporesarrive
Latent infections(no symptoms)
First sporesarrive
Leaf 3
Leaf 1
At GS39, CTL:
Leaf 2
Leaf 3
T1 T2
With a T1, well timedat L3 emerged, CTLwill have a usefuleffect on this yieldproducing leaf
• The ear and top 3 leaves contribute 98% to total yield and are the key focus
• CTL is purely protectant and needs applying before spores land on the leaf
May have auseful effecton L1
But no effect onlatent infectionin L2 and L3and may alsointerfere withcurative activityof partnerproducts
SDHIT1 sprays don’t have to contain an SDHI fungicide to give the best performance on Septoria,Bayer CropScience trials have shown, even in a season where disease pressure was high.
Is it reallynecessary to
switch tofungicides at T1?
9
Spring 2015
Use CTL as a protectantFollowing ADAS work, it was establishedthat there is a small disease control andyield benefit from adding 0.75-1.0 L/ha ofchlorothalonil to 1.0 L/ha of Aviator,providing it is being used in a protectantsituation, he says.
“Chlorothalonil has a useful effect inprotecting a leaf three once it has just fullyemerged, which contributes significantly toyield,”explains Mr Flind.
These findings confirm that where growersare keen to follow their T0 spray withAviator at the T1 timing, it is fine to includechlorothalonil, says Mr Flind.“But it isimportant that a T0 spray was used to helpmake sure the T1 is being applied in aprotectant situation.”
However, where there’s been a delay andthere is a need for curative control on leafthree, or disease pressure is very high, herecommends leaving chlorothalonil out ofthe tank, as it can compromise diseasecontrol.“That’s especially important if rustis already present in the crop.”
The best returns from using Aviator comefrom aT2 application, however, stressesTim Nicholson, Bayer CropScience’scommercial technical manager for theSouthWest.“The flag leaf and leaf twocontribute most to yield and are thereforethe most important leaves to protect withthe best chemistry. It is also the timingwhere you get most improved crop healthbenefits from applying Aviator.”
And with wheat prices under pressure thisyear, it also makes sense to use the mostcost-effective programmes, he says.“Byapplying Proline + CTL followed byAviator, rather than a new SDHI at T1 andT2, you can potentially trim up to £15/hafrom programme costs and still achieve thebest possible yields, as was shown in ourdemonstration trials last season.
“Across 200ha of wheat on a farm, thatsaving is the equivalent of the cost of a 27tlorry load of wheat.”
Bayer won’t be supporting the use ofchlorothalonil at T2 with Aviator, addsMr Flind.“While there should be noinfection on the flag leaf when theT2 isbeing applied, leaf two often has latentdisease infection already present, and withthat leaf contributing around 25% toyields, it is not a good idea to potentiallycompromise disease control on that leaf.”
“Our trials have confirmed disease controlcan be adversely affected by adding CTL toAviator at T2, due to the curative situationon leaf two so it’s better to stackchlorothalonil early in the programme andget its protectant benefits then.”
Aviator +/- CTLWhen does antagonism occur?
Yield benefit/loss vs Aviator (1.0 L/ha)
A key advantage for Proline at T1 is itsall-round strength on the key diseasesat that timing, says BayerCropScience’s Tim Nicholson.“Byusing Proline at 0.55 L/ha, you notonly get effective Septoria control, butit also widens the spectrum to includeeyespots and Fusarium foot rots,yellow rust and some mildewactivity.”
Proline is also useful for beginning aFusarium inoculum managementprogramme ahead of the main controltiming of T3. Research carried out byHarper Adams University College andFERA over a number of years hasshown the benefit of usingprothioconazole at T1 in reducingFusarium build-up, and ultimatelylevels of mycotoxins in grain.
The active also has useful activityagainst mildew, which could meannot needing to apply a specialistmildewicide unless there is activemildew in the crop, and is strongagainst yellow rust, when applied as aprotectant, in particular.“If there isactive yellow rust at application, itmakes sense to add a strobilurin tohelp knock down the yellow rustquickly.”
Disease control (%) Benefit/negative vs Aviator alone 1.0 L/ha
6
0
2
4
-2
-4
-8
-10
-6
Aviator235Xpro
Aviator235Xpro
Protective
Curative
Yield (t/ha) Benefit/negative vs Aviator alone 1.0 L/ha
0.40
0.20
0.30
0.10
0.00
-0.20
-0.30
-0.10
1.0 L/ha + CTL0.75-1.0 L/ha
Aviator235Xpro
Protective
Curative
Dis
ease
cont
rol(
%)d
iffer
ence
Yie
ldt/
had
iffer
ence
1.0 L/ha + CTL0.75-1.0 L/ha
1.0 L/ha + CTL0.75-1.0 L/ha
Aviator235Xpro
1.0 L/ha + CTL0.75-1.0 L/ha
By applying Proline + CTL
followed by Aviator, rather
than a new SDHI at T1 and
T2, you can potentially trim
up to £15/ha from
programme costs and still
achieve the best possible
yields
• Proline + CTL as good as SDHI atT1 in protectant situations
• Proline + CTL cheaper, as effectiveand helps protect SDHI chemistry
• Switch to SDHI at T1 in high diseasepressure / curative situations
• Add CTL to Aviator at T1 only whenusing in protectant situations
• Don’t add CTL to Aviator at T1 incurative situations or when activerust present
Key Messages
Prothioconazolebrings more than justSeptoria control at T1
Source data: ADAS 2014
controlsare not just for black-grass
Cultural controls are becoming an accepted part of black-grass control, buthow many growers consider their value when it comes to combating disease?
Cultural
However, the difficult season also highlightedthe value of cultural controls, such as moreresistant varieties and delayed drilling, tosafeguard yields and reduce the pressure onfungicides to maintain their efficacy.
Had these techniques been widely adoptedcommercially, howmuch better might thingshave been?
Clare Bend,Agrii’s Head of StrategicCommunications, can provide some clues.The R&D team at Agrii compared theperformance of four varieties drilled at twodifferent drilling dates at the firm’s AgriiFocussite inWiltshire last season. Each of thevarieties at the two drilling dates were treatedwith one of three different fungicideprogrammes or left untreated.
As with most of the country, the site wassubjected to intense disease pressure,particularly from Septoria tritici, and theimpact of delaying drilling in thesecircumstances was graphically illustrated,with the untreated plots from the laterdrilling date yielding 2t/ha more than theuntreated early drilled.“The importance ofvariety choice was further highlighted by thelater drilled untreated Crusoe yielding only0.3t/ha less than the fully treated early drilledKWS Santiago,”Mrs Bend points out.
Only where both good genetic diseaseresistance and a full fungicide programme
were used was it possible to maintain yieldsacross the two drilling dates, she says.“Itshows that the combination of genetics andchemistry were able to cope in what was anextreme season.
“However, where the genetic diseaseresistance package was weaker, for examplein KWS Santiago, the early drilled plots stillsuffered a yield penalty of nearly 2t/ha evenwhen the best fungicide programmes wereapplied as the disease could not be effectivelymanaged.
Bayer CropScience trials at Callow inHerefordshire backed those results, saysGareth Bubb, a commercial technicalmanager for the firm. In the variety trial,varieties rated a seven for Septoria resistanceyielded 16.09t/ha compared with 15.13t/hafor those with a Septoria rating of four.
KWS Santiago and Solstice were also sownat two different drilling dates, just 10 daysapart on the 20 and 30 September.“Those 10days made a massive difference. KWSSantiago gave an extra 1t/ha of treated yieldwhen drilled at the later date, while Solsticegave almost 2t/ha more.
Septoria ratings are based on Octobersowings, and this trial reinforced theobservation that for each week you drillbefore October a variety’s rating falls by0.5 t/ha.”
Harvest 2014 clearly illustratesthe value of fungicides inprotecting yields. Despiteintense disease pressure
during the season in manyareas, commercial crops
performed exceptionally well,producing a record UK
average of 8.6t/ha according tothe NFU harvest survey
released in early October.
10
Crop Focus
11
Spring 2015
Integrated approachAmore integrated approach using bothgenetics and chemistry is needed to combatdisease, Septoria tritici in particular, says wellknown wheat breeder Bill Angus, of AngusWheat Consultants Ltd.
“Key fungicides are under a huge amount ofpressure because we are growing so manysusceptible varieties and drilling earlier.Unless we start thinking about raisingstandards on the Recommended List we facea losing battle.”
Septoria tritici is the key battleground, headds.“Yellow rust is very visible and a veryemotive disease, but we have good seedtreatments and foliar fungicides that allow usto control lower-rated varieties, unless thegenetic resistance breaks down completely,which is often predictable.
“Septoria tends to lurk low in the crop early inthe season, so is easily overlooked. Once itgains a foothold, you are stuck in a highinput/high risk regime for the season.We didget big yields this year, but at what cost?Thiscan only get worse as azole efficacy comesunder more pressure.”
A lack of genetic diversity is not helping, saysMrAngus. Over the past 30 years there hasbeen little incentive to change, due to thesuccess of azoles and other chemistry, he adds.“Some breeders have been operating a spray-it-and-weigh-it philosophy for too long.”
Change is in the air, he believes.“We need toproduce high yielding, highly resistantvarieties. Long term we need to broaden thegenetic base, for example introducing
resistance from wild relatives of wheat, tointroduce robust, polygenic resistance.
“The best way is to put promising material inthe ground and assess it, but this is veryexpensive. New technologies such as genechipping will allow breeders to assess millionsof combinations in the lab and grow only themost promising.”
Breeding programmesIn the shorter term, some breeders areachieving significant success by tapping intobreeding programmes beyond the UK.Skyfall, Relay and particularly Cougar, allfrom the RAGT stable, are showing goodresistance to Septoria tritici as well as the rusts,as are Revelation and Crusoe from Limagrain.
“But there are still only a handful available,”says MrAngus.“We should perhaps belooking more to the Continent to build onthis.”
More thought also needs to be given topositioning varieties within the rotation, assome varieties pre-dispose a following wheat
crop to disease, notably eyespot, he believes.
“Growers need to use genetics strategically.For example, consider the effect of growingvariety A followed by C, or B followed by C. IfA produces 11t/ha and C only 7, they wouldbe better off growing B at 10.5t/ha if C thenyields 9.”
Robigus derivatives should be avoided as thefirst of two successive wheats, whereas thosewith Xi19 in their background tend toperform better in that slot, says MrAngus.“Very few growers check wheat pedigrees, butthey should.
“Variety choice is an incredibly importantdecision, especially with the pressurechemistry is now under. Once the seed isplanted you can’t change it – it pays to get itright first time.”
• Cultural controls are not only forblack-grass
• Using cultural controls to helpprotect fungicides from resistancedevelopment
• Delayed drilling of susceptiblevarieties increased yields
• Varieties with higher Septoriaresistance yielded more thansusceptible varieties regardless ofyield potential in the high Septoriaseason of 2014
• Huge return on investment fromfungicides in 2014
Key Messages
The importance of variety
choice was further
highlighted by the later
drilled untreated Crusoe
yielding only 0.3t/ha less
than the fully treated early
drilled KWS Santiago
12
Crop Focus
Extremely high disease pressure,particularly from Septoria tritici and to alesser extent yellow and brown rust, madefor a testing environment for both varietiesand fungicides at the Bayer Field Dayssites around the country.
And the results highlighted that acombination of both varietal resistanceand effective fungicides were more thancapable of producing wheat crops withvery high yields, even when tested to thelimit.
At each site the performance of 30 wheatvarieties was tested, both untreated andafter treatment by each of three four-sprayprogrammes that reflected commercialpractice.
Assessing the results by RecommendedList ratings for Septoria tritici highlightedthe important role genetic resistanceplayed last season.Wheats rated a four forSeptoria on the new HGCARecommended List produced an averageuntreated yield of 8.46t/ha. For those witha rating of 5, that increased to 9.09t/ha,and then to 9.83t/ha for varieties with asix. Cougar, the only variety with a sevenon the RL, yielded an incredible 11.29t/hauntreated across the four sites.
These figures show the value of varietalresistance to Septoria in untreated crops,and the inherent benefit growers can getfrom choosing varieties with better diseaseresistance. But it was also interesting thatthe same pattern also emerged when
analysing the results of the treatedvarieties.
Again, those rated a 4 – Gallant and KWSSantiago – yielded the least on averageacross the four sites, at 13.82t/ha, whilethe fives averaged 13.92t/ha.Varieties witha six achieved 14.29t/ha while Cougar, theseven, yielded 14.57t/ha.
Those results showed that to some extent,at least, varietal resistance was a driver inthe performance of varieties last season,says Gareth Bubb, a commercial technicalmanager for Bayer CropScience.“Whatwas interesting is that some of the higheryielding varieties, which had lower diseaseratings could not live up to theirRecommended List yield rating under this
disease pressure, even when treated with awell-timed four-spray programme,whereas inherently lower yieldingvarieties with more resistance, such asCougar out-yielded them.”
But the results also highlighted the valueof fungicides.The average yield responseacross all varieties and all treatments was4.66t/ha over the untreated.At a wheatprice of £127/t that equates to an extra£492 /ha in margin over the cost of thefungicide programme.
The standard Bayer programme of Proline+ Bravo at T1 followed by Aviator at T2,started and finished by a standard Folicur+ chlorothalonil at T0 and three-quarterdose prothioconazole at T3, achieved thebest yield responses, producing just under0.4t/ha more than the same programmewith Adexar substituted for the Aviator.
The results were consistent across sites,says Mr Bubb.“Of the 30 varieties in thetrials, the Aviator programmes producedthe highest yield in 27.And with Aviatoralso being less expensive than Adexar, thisprogramme also produced the best returnon investment for growers.”
Adding a second SDHI at T1 did notproduce any additional yield indicatingthat where programmes are well-timed, asthese were, and intervals betweentreatments kept to no more than threeweeks, then the extra expense of a secondSDHI was not required.
The average yield
response across all
varieties and all treatments
was 4.66t/ha over the
untreated. At a wheat price
of £127/t that equates to
an extra £492 /ha in margin
over the cost of the
fungicide programme.
BayerFieldDays
Spring 2015
At the Callow site in Herefordshire,varieties that performed well includedKWS Lili, KWSTrinity and Crusoe, whileCordiale, Solstice and KWS Santiago wererelatively poorer.The stand out variety wasCougar, says Mr Bubb.“Its Septoriaresistance stood out a mile.”
Across the site the average response tofungicides was over 7t/ha – giving a hugereturn on investment of nearly £800/haafter fungicide costs. Even Cougar whichgave the lowest yield response tofungicides of only 3.4t/ha still gave a returnon investment of over 300% using acurrent grain price of £127/t.
At the HintonWaldrist site in Oxfordshire,KWS Santiago came out on top in the
treated plots, with KWS Kielder andEvolution also performing well.
This was because the disease pressure waslower than at Callow, as shown by anaverage yield response to fungicides of justunder 3t/ha, says Ben Giles, who overseesthe site for Bayer.“It sits in a little bit of arain shadow, and while Septoriapressure was still quite high, the levelof disease was much more easilycontrolled than at Callow.
“That was highlighted by the relativeperformance of the more diseasesusceptible feed wheat varieties, such asKWS Santiago and KWS Kielder, beingmuch better than all our other sites.”
Wheat Crops
Oilseed RapeCrops
Oilseed rape
Thorney Dyke, Peterborough26 March (pm) & 27 March (am)
Wickenby, Lincoln30 March (pm) & 31 March (am)
Hinton Waldrist, Oxford9 April (pm) & 10 April (am)
Callow, Herefordshire14 April (pm) & 15 April (am)
Cawood, Yorkshire16 April (pm) & 17 April (am)
Coupar Angus, Perth21 April (pm) & 22 April (am)
Wheat
Chishill, Cambridgeshire and RAGTHinxton site - 16 June
Cawood, Yorkshire - 18 June
Hinton Waldrist, Oxford- 22 June (pm), 23 June (am)
Callow, Herefordshire - 25 June
Petersfield, Hampshire - 30 June
Long Sutton, Lincs - 2 July
Coupar Angus, Perth - 9 July
All open days are registered by BASIS & NRoSOIf you would like to visit one of our field days please visit our #BayerFieldDays webpageat www.bayercropscience.co.uk/bayerfielddays, contact Bayer Assist on0845 6092266 or 01223 226644 or look out for an invite in your inbox or post in themonths before the event.
West Field Days: Results
13
KWS Santiago
7.0115.19
Callow untreated yield
Callow treated yield
t/ha
t/ha
RL Septoria resistance rating 4
Untreated grain yield* 80
Treated grain yield** 105
Revelation
9.6915.67
Callow untreated yield
Callow treated yield
t/ha
t/ha
RL Septoria resistance rating 6
Untreated grain yield* 92
Treated grain yield** 100
JB Diego
8.2115.85
Callow untreated yield
Callow treated yield
t/ha
t/ha
RL Septoria resistance rating 5
Untreated grain yield* 87
Treated grain yield** 103
Cougar
12.6916.08
Callow untreated yield
Callow treated yield
t/ha
t/ha
RL Septoria resistance rating 7
Untreated grain yield* 96
Treated grain yield** 101
Fungicide treatments: T0 – 31 March: Folicur (0.4 L/ha) + Bravo (1.0 L/ha)T1 – 24 April: Proline275 (0.55 L/ha) + Bravo (1.0 L/ha) or Aviator235Xpro (1.0 L/ha)T2 – 19 May: Aviator235Xpro (1.0 L/ha) or Adexar (1.25 L/ha)T3 – 11 June: Proline275 (0.55 L/ha
Bayer
14
Crop Focus
Predicting a
seasonDr Phil Jennings of FERA has
pieced together live monitoringdata and weather records withisolate and mycotoxin analysis for thepast seven years and compared themwith what actually happened eachseason to help understand the riskfactors which lead to the colonisation
and infection of FEB pathogensand the production ofmycotoxins.
The starting point is the autumnwhere warm dry conditions allowFusariums andMicrodochiums toestablish in the crop debris and stembase respectively, providing a sourceof inoculum for the season ahead.
That initial risk can be reduceddepending on the winter, says Dr Jennings.“A particularly wet winter reduces the riskfromMicrodochiums and Fusariumgraminearum as these species don't like lotsof standing water.”
Inoculum build-upA good example of this was in 2000 whenautumn flooding continued through thewinter leading to hardly anyMicrodochiumbeing found in summer 2001.A similarsituation occurred in winter 2013 followinghigh levels in 2012 and inoculum wasagain reduced, he says.
A warm dry April and May allowsinoculum to build and then in late springit’s all about moisture, especially when itcomes to the maturation of F. graminearumperithecia.“If May is totally dryF. graminearum perithecia cannot matureand ascospores are not released.”
Finally the weather at flowering isimportant, with warm wet weather givingthe best chance for infection.“If all thesefactors are satisfied in one year, we getpretty hefty disease,”says Dr Jennings.
It is the correlation between all thesefactors plus the weather post floweringand around harvest that dictates thespecies favoured and the level ofmycotoxins produced. Comparisons of
recent years illustrate the differences inFEB and mycotoxin levels.
The clearest comparison is 2007 and 2008,says Dr Jennings.The spring conditionswere similar leading to comparable levelsof F. graminearum infection, but themycotoxin levels were very different.
That’s because deoxynivalenol (DON), thetoxin that is produced when the fungusinfects the ear, increases in concentrationas the ear is subjected to repeated wettingand drying during latter grain fill andripening.The more rainfall post infectionfrom GS80 onwards the more DON willaccumulate in the grain resulting in highercontamination levels. And this is whathappened in 2008 with above averagerainfall in July and August compared with2007.
The higher than average August andSeptember rainfall delayed harvest in 2008leading to saprophytic growth of Fusariumculmorum and F. graminearum on the grainresulting in zearalenone (ZON)production and the highest everpercentage of samples exceeding the EUlimit. In contrast harvest 2007 was not wetor delayed and ZON levels were low.
The 2010 and 2011 seasons highlight thatsimilar conditions throughout the growingseason with lower than average rainfall inJune resulted in similar low ear infectionand low toxin production in both years.
A comparison of the highest mycotoxinyear, 2008, and the highest FEB symptomyear, 2012, might have led to projectedmycotoxins in 2012 being much higherthan 2008, says Dr Jennings. Springconditions favoured development of F.graminearum, while the cool extendedflowering period in 2012 gave multipleinfection opportunities leading to veryhigh FEB infection. But unlike 2008 whereDON and ZON especially was very high,a wet July and August caused exceedancesin DON but the harvest, although it waslate was not delayed and therefore ZONexceedances were not as high as thoseseen in 2008.
Fusarium ear blight(FEB) severity is increasing,but is it possible to predictwhether a season will below or high risk?
Fusarium
15
Spring 2015
60
Untre
ated
20
30
10
40
50
0
52.3
13.3
GS59: nozzle 90º
Fus
ariu
mea
rb
light
infe
ctio
n
GS63: nozzle 90º GS63: nozzle 30º
16.1
5.8 7.0 4.7
16.0
11.0
7.2
26.0
Prol
ine
275 0.
55L/
haTe
buco
nazo
le0.
75L/
haBru
tus
1.5
L/ha
Prol
ine
275 0.
55L/
haTe
buco
nazo
le0.
75L/
haBru
tus
1.5
L/ha
Prol
ine
275 0.
55L/
haTe
buco
nazo
le0.
75L/
haBru
tus
1.5
L/ha
12
Untre
ated
4
6
2
8
10
0
3.3
7.1
GS59: nozzle 90º
Yie
ldd
eliv
ery
t/ha
GS63: nozzle 90º GS63: nozzle 30º
6.3
9.6
7.9
9.1
7.0 7.4
8.5
5.6
Prol
ine
275 0.
55L/
haTe
buco
nazo
le0.
75L/
haBru
tus
1.5
L/ha
Prol
ine
275 0.
55L/
haTe
buco
nazo
le0.
75L/
haBru
tus
1.5
L/ha
Prol
ine
275 0.
55L/
haTe
buco
nazo
le0.
75L/
haBru
tus
1.5
L/ha
Fusarium ear blight infection Yield delivery t/ha
Mean of 2 inoculated trials (FERA and Harper Adams). AVG untreated stats; yield 3.3 t/ha,TGW 33.1 HLW 59.1, Fusarium infection 52.3%. Forward angles were used at one site andbackward angles at the other. No difference was observed between spray angle.
Mean of 2 inoculated trials (FERA and Harper Adams). AVG untreated stats; yield 3.3 t/ha,TGW 33.1 HLW 59.1, Fusarium infection 52.3%. Forward angles were used at one site andbackward angles at the other. No difference was observed between spray angle.
When to controlUnderstanding these seasonal risk factorsis very important especially when relatingto fungicide choice and timing to controlFEB.
AlthoughT3 is the most responsive timingto control FEB, studies at Harper AdamsUniversity identified that whereprothioconazole is used in the programmeat T1 and/or at T2 it delivers a secondarybenefit to foliar disease control with anadditional 20-40% final control of DON ateach timing, says HAU’s Professor SimonEdwards.
T1 andT2 products shouldn't be chosenwith Fusarium control in mind, rather as anadditional benefit if the product choice fitswithin the foliar programme.T3 should bethe main focus.
"And for T3 the optimum time ofapplication is at mid flowering, GS63-65when the flowers are open and the anthersare extended in the main canopy."
The difficulty with achieving this is that theoptimum timing is not static and isweather dependent, explains ProfEdwards. He encourages growers to go onearlier from GS59 onwards if wet weatheris forecast or hold off until GS65 if theforecast is dry. "But this is our worst timeof year to predict rainfall because oflocalised thunderstorms," he adds.
T3 Fusarium control is primarily protectant,with +/- 3 days activity and control isdependent on timing the applicationrelative to an infection event. In a wet yearwhen multiple infection events take placecontrol will be lower than if just oneinfection event occurs. In this instance 80-90% control is achievable depending oninfection pressure, he says.
Inoculated trials carried out by FERA andHAU last season highlighted that theoptimum timing is early to mid-flower,ideally prior to an infection event. Fusariumcontrol, reduction in mycotoxins, yield andgrain quality were all better when Prolineat 0.55 L/ha was applied at GS63 ratherthan the earlier timing (see charts above).
The trials also compared Proline withBrutus and Folicur at each timing, andconfirmed Proline as being the mosteffective product, while a further test ofangling the nozzle forward at 30 degrees atGS63 showed a small advantage overcrops treated with nozzles pointingstraight down.
• Conditions in lead up to spray timingcan be used to help predict risk
• Weather post-flowering and atharvest helps dictate species andmycotoxin levels
• GS63 key timing for application
• Proline (0.55 L/ha) gives best controlof Fusarium, Microdochium andreductions in mycotoxins
Key Messages
Independent agronomist Steve Cookroutinely treats Group 1, 2 and some highHagberg 3 and 4 wheats for FEB to protectpremiums.And that means planning theT3programme well in advance so that productis on farm before the weather forecastaround flowering is known, he says.
“T3 will always be a prothioconazole basebecause it controls the mycotoxin FusariumsandMicrodochium nivale.”Mr Cook plansfor about half rate and then tops up withtebuconazole to deliver a full rate ofFusarium actives. He also uses Amistar Optiwhere he is looking for brown rust andextra Septoria protection.
“Timing is critical as there is very littlekickback, just a day or so.As soon as thefirst anthers are out we are telling farmersto go if there is wet forecast. If it is dry wecan wait a bit and get better protection.”The risks from not getting the spray on arehigh.“Growers that didn’t get the timingright in 2012 might have lost a third of theear which just shrivelled so there is a yieldloss factor and specific weight as well. It’snot just about mycotoxins.”
And losing specific weight means losingpremium, he says.“The extra spendbetween a standard and FusariumT3 costs£10-15/ha yet we are protecting a premiumthat is potentially £20/t @ 9-10t/ha. So it iscost effective.”
That extra fungicide application will givegrowers additional yield worth two or threetimes the value in most years anyway fromlate infections of rust and Septoria andgreen leaf area retention, he adds.
Practical advice
16
Crop Focus
• Traditional timings provide goodcontrol if timed correctly
• Early T1s can cause problems
• Dissect plants to check for final leafthree emerged
• If T1.5 required, don’t use an azolefungicide
Key Messages
Good timingis all you need
MARCH
APRIL
MAY
Fungicide
Effec
tivee
GS39Week
sTimingGTimingGPTZFlagleaf
SeptoriaSDHI GS32
LeafthreeCurative
ControlPr
otec
tant
Eradicant
Wheat fungicide spray timings are coming under scrutiny as the unpredictable climate andincreasingly difficult to control diseases make their presence felt.
Keeping leaves disease free for as long
as possible is vital to protecting yield,
says Dr Jonathan Blake, principal
research scientist at ADAS. So last
season when some growers struggled
to control Septoria on leaf two in
particular, it opened discussions about
whether an extra spray that
specifically targeted that leaf might be
required.
However, control of Septoria, even in highpressure situations, was achieved by manywheat growers thanks to their efforts earlyin the season, Dr Blake says.
“WhereT0s andT1s were correctly timed,the disease was well-controlled. But theT1spray had to be robust.”
Some of the difficulties encountered in thefield were to do with timing, he points out.“Last year, we had an early spring, so cropswere thought to be reaching theT1 timingearlier than usual.”
But those crops needed to be carefullychecked for whether final leaf three wasemerging, as that is the critical timing forT1sprays. Earlier sprays risk spraying beforeleaf three has emerged and then leaving toolong a gap beforeT2, because an earlierspring doesn’t mean the flag leaf willemerge much sooner, explains Dr Blake.
“Through the spring, crops becomeincreasingly dependent on day length ratherthan temperature for reaching growthstages. In‘early’seasons there is naturally alonger gap between leaf three and flag leafemergence, as above average temperaturescause leaf three to emerge early, but thenthe influence of day length slows theemergence of leaf two and the flag. TheT1toT2 gap then gets even longer if T1s areapplied before leaf three emerges. In suchsituations this could be stretched to four tofive weeks.
“Ideally growers should be aiming to have agap of not much more than three weeks tokeep Septoria out.”
Correctly identifying when final leaf three isperhaps the trickiest and most crucialdecision within a fungicide programme,admits Ben Giles, Bayer’s commercialtechnical manager in theWest.
“The best way to get it right is throughcareful dissection of the main stems of atleast three plants in a field. It is fiddly andrequires a steady hand, but it is the only wayto be sure that you are getting theT1 timingcorrect.
“With eradicant activity from azolefungicides declining,making sure sprays areapplied protectantly and that intervals arenot stretched is the key to getting gooddisease control.”
EarlyT0 sprays can sometimes put pressureon going too early with aT1, he adds.“TheT0 spray is an important treatment, as it
helps keep inoculum down and acts as abuffer against anyT1 delays.
“But any sprays applied before the last weekof March should be viewed as an additionaltreatment, rather than aT0.That way theT0application won’t be applied more than fourweeks before theT1.
“The idea is to keep the gap betweenfungicides down to three to four weeks.”
If the gap betweenT1 andT2 is going to bemore than three weeks, then aT1.5 may berequired.This is likely to only be in seasonswhere growth slows down around lateApril, as in 2012, or perhaps whereconditions are ideal for yellow rust to cyclequickly, Dr Blake says.
“If it is deemed necessary, a strobilurin athalf rate would do a good job on rust, anduse chlorothalonil for Septoria. Don’t betempted to increase the number of azolefungicides being used – this is just likely tohasten resistance development.”
17
Spring 2015
The ravaging effect that Septoria triticican have on an unprotected winterwheat crop and the effectiveness of awell-planned robust fungicideprogramme in controlling it aregraphically illustrated in a newvideo from Bayer CropScience.The short film compresses a three-month timespan into just 90seconds, juxtaposing footage ofuntreated and treated plots ofSantiago from first node detectable(GS31) to just before harvest.
It was shot at Bayer’s Callow(Herefordshire) and Oxford FieldDays sites, which were subjected tovery high Septoria pressure lastseason.The result is a fascinatinginsight into the association betweencrop and disease development and spraytiming, says Bayer combinable fungicidesproduct managerWill Charlton.
“The viewer can clearly see how Septoriaclimbs an untreated plant, showing therelationship between rain events, growthstages and new infection, latent periodswhen disease is present but unseen, andhow the disease can explode onto anunprotected flag leaf when conditions areright.
“It also shows how a well-executedfungicide programme can keep Septorialower down in the crop for longer.Theresult is two very contrasting sets of imageson the screen.”
The dramatic footage will be uploaded ontoBayer’s website as a benchmark of Septoria
spread and control. It will be part of a newinteractive area that will also track thecurrent season’s crop growth and diseasedevelopment as it happens, saysMr Charlton.
The site willprovide anupdatedimage of the crop every 10 minutes, soviewers will be able to see a virtually livescenario whenever they log on.“Our trialsmanagers will comment on what they areseeing, and what they expect as a result, aswell as detailing spraying decisions andtimings,”he explains.
“The current footage will also have atime-lapse facility so that the results ofdecisions taken can be reviewed inseconds.
“People really will be able to see fungicideprogrammes in action, and we hope thiswill provide the basis for some usefuldialogue as the season progresses.”Keyupdates will also be relayed viaTwitter to
help broaden the debate, he adds.
The relationship between leaf emergenceand the key spray timings is one keymessage he hopes the newmini-websitewill achieve.“The videos will highlight thekey growth stages and which fungicideswere applied.Any problems with the
programme, such as delays,will be highlighted and theresults will be visible for all tosee.”
The programme will alsoincorporate yellow rust, saysMr Charlton.“Next spring wewill install cameras at ourtrials site at Chishill,Cambridgeshire, which isprone to the disease.
“Yellow rust often creates alot of noise in the press andelsewhere, and this cansometimes lead to the keyT1
andT2 timings being compromised.Weaim to show that sticking to these keytimings will usually control yellow rust, or,where it doesn’t, that an appropriatetreatment should be an addition to theplanned programme.”
Given the high percentage of wheats witha poor Septoria rating in the ground, themild outlook and the amount of inoculumstemming from last season’s outbreak,Mr Charlton believes there will be plenty toobserve in the straightforward treated-versus-untreated plots this coming spring.
“We could well be in for another seriousSeptoria year, some more dramatic footage– and hopefully plenty of discussion.”
Disease Control
Time-lapse cameras are providing a striking insight into disease developmentin wheat and are set to help growers improve their spray planning in the comingseason, thanks to a new initiative from Bayer CropScience.
Hereford: treated
Hereford: untreated
Picture perfect
Checkwww.bayercropscience.co.uk/timelapse frommid-March for live pictures of 2015 crops
Disease pressure in barley was higherin 2014 than for many years, and ithighlighted the need to use aprothioconazole-base to achieve thebest disease control.
Net blotch and mildew caused earlyconcern in winter barley in 2014, says DrFiona Burnett of SRUC, butRhynchosporium was also showing up inplaces, often at severe levels.
“Just as it was with wheat diseases, 2014was a high pressure season,”she recalls.“That means it was also a responsive yearfor fungicides, providing they were appliedat the right time.”
As the season developed, the wetter areasin the west increasingly suffered fromRhynchosporium, while there was more netblotch and brown rust found in crops inthe drier parts of the east, she notes.
“The regional differences seen in diseaselevels were also related to previouscropping,”says Dr Burnett.“Where barleyhad been grown before, there was more ofan issue with Rhynchosporium.”
Although spring barley varieties tend tocarry better mildew resistance, there’salways a risk that the spring crop will pickup any other disease that’s alreadyestablished in the winter crop, shecontinues.
“So any early problems in winter barleytend to transfer onto the newly sown crop.And that’s what happened in 2014.”
The mild, wet winter experienced last yearprovided favourable conditions for diseasedevelopment, with events to datesuggesting that the same scenario will berepeated this year, points out Dr Burnett.
“So far, it’s almost a replay.We’re seeingnet blotch and mildew already, followinganother relatively mild autumn andwinter.”
Without a sustained period of coldtemperatures, there is likely to be highdisease pressure again this year, shepredicts.“Fortunately, growers can use thelessons from last year to help them copewith the disease threat.”
Those lessons included making good useof T0 andT1 sprays, she says.“It wasapparent early on that disease was around,
so the early treatments were essential.There was plenty of warning of what wasto come.”
More T0s were applied to winter barley,followed by robust T1s, she confirms.“Crops had disease, but they also hadpotential. So growers were prepared tospray and to use the stronger fungicideproducts.”
Omitting a T1 spray on spring barleyproved to be a mistake.“It meant that theT2 treatment then had to be eradicant,putting yield at risk.”
The greater choice of chemistry for use onbarley is good news, stresses Dr Burnett.“There are more products to choose fromand most offer good performance againstdisease. So there are plenty of options.”
But within the different chemistry groups,there are some stronger candidates, shesays.“We know that prothioconazole is thestrongest azole on barley, and that is alsoreflected in the performance of co-formulations containing prothioconazole,such as Siltra.
“These continue to perform very well, aswas confirmed by the latest HGCA-fundedfungicide performance trials results.”
barleyFinding the right combination in
Crops had disease, but
they also had potential. So
growers were prepared to
spray and to use the
stronger fungicide product
18
Crop Focus
SDHIs all offered good efficacy in thefungicide performance trials, with Imtrexbeing at the top end of the straight SDHIsfor disease control in 2014, while Zulu wasat the other end.“It still has a place butwould need to be balanced by its partner –as they all should.
“Adexar is available for barley now, but itsepoxiconazole content makes it a lesswell-balanced barley product.”
Strobilurins can also be used and havegiven good results againstRhynchosporium, she notes, whilechlorothalonil has a role in providing amore protectant T1 spray.
“Chlorothalonil can also be used at T2 forRamularia control,”points out Dr Burnett.“If the warnings indicate that there’s ahigh risk of Ramularia, it can be addedinto the mix.There’s less evidence of itsinterference with the efficacy of otherproducts in barley.”
Looking ahead to 2015, she highlightsthat the warning signs are already present.“The disease is there and the conditionsare conducive to its development. So payattention to early sprays, bothT0s andT1s,and see what disease gets transferred tospring barley.”
Again, the T1 spray will be important forspring barley crops.“There’s always atemptation to omit it, but it wouldn’t besensible this year.”
Staffordshire grower Roger Hopleyhas already got his winter barleydisease control programme plannedfor 2015, and will be puttinggreatest emphasis on the T1 spray.With 190 acres of KWSMeridian beinggrown at Half Head Farm nearStafford, Mr Hopley is aiming for agrain yield of 10t/ha together with5t/ha of straw.
“The straw yield is important to us,”hesays.“It adds another £250/ha to ourincome.”
He has chosen to grow KWSMeridianover a hybrid barley for its betterstanding ability and lower seed cost, aswell as its versatility with seed rate.“We do have a brome problem incertain fields, so we can use high seedrates to smother it.
“That wouldn’t be possible with ahybrid barley – the seed cost isprohibitive and the crop wouldn’t giveits best performance.”
The winter barley crop is alreadygrowing very well this year, addsMr Hopley.“It’s been very mild andcrops are thick, so Rhynchosporium andmildew are just starting to show.”
He always takes crop condition,disease risk and yield potential intoaccount before deciding on hisfungicide strategy, followed by theefficacy of the chemical.
“I have to be clear about what I’mtargeting and when I’m going to spray.
After that, I see which products offerthe best value.”
This coming season, he will be using aT0,T1 andT2 spray, with the main hitbeing theT1.
“TheT1 is our big spend.That’s wherewe get the best response, both interms of disease control and yield.”
For this reason, a robust rate of Siltraat 0.6 L/ha will be used at T1, just as itwas last year. It will be preceded by aT0 of spiroxamine + fenpropimorphand followed by aT2 treatment basedon Fandango, so that he sticks to hisbelief that only two triazole treatmentsshould be made to each crop.
“It’s cold when we apply our T0, andplants are still small,”notes Mr Hopley.“But it protects them until we get tothe more important T1 timing.”
Both Rhynchosporium and mildew arelikely to be targets at T1, he adds.“Wewill need some eradicant activity atthis stage, after the mild weather, andSiltrawill provide that, as well asfurther protection.”
That further protection is needed forRamularia, he points out, which comesin later.
Fandango at T2 replaces last year’schoice, Bontima.“There isn’t muchbetween the two, but prothioconazoleis an important component in barleyprogrammes. I need to be happy withthe end result at harvest.”
• Use prothiconazole as foundationfor barley disease control
• Make good use of T0 and T1sprays in programmes
• Use different modes of action tohelp reduce risk of net blotchresistance spreading
• Siltra / Fandango programmestrong against net blotch andRhynchosporium
Key Messages
Roger HopleyGrower Focus
The disease is there and
the conditions are
conducive to its
development. So pay
attention to early sprays,
both T0s and T1s, and see
what disease gets
transferred to spring barley
19
Spring 2015
20
Crop Focus
“The wet, mild conditions that we experienced were just right for net blotch,”says Mr Flind.“Of course, those are the same factors which also suit Rhynchosporium.”
Siltra followed by Fandango programme performed extremely well where net blotch wasthe main threat, says Mr Flind.
1 Hybrid barley netblotch trials
That was shown in twoindependent trials where netblotch in untreated Hyvidowinter barley plots averagedaround 10%. In those trialstwo sprays of Bontima yieldedalmost 1.0t/ha less than twosprays of Fandango, with theSiltra followed by Fandango,giving a further 0.3t/ha (seechart 1).“That equates toaround £75/ha more returnfrom Fandango and over£100/ha more from Siltra overthe Bontima programme, aswell as providing a better netblotch anti-resistance strategy.”
2 Winter barleyRhynchosporium trial
The Siltra / Fandangoprogramme is also strongagainst Rhynchosporium, saysMr Flind.That was illustratedin a trial conducted by OAT,which had high levels ofRhynchosporium infection. Inthat trial two sprays of Siltrayielded the most at 8.79t/ha,but the Siltra followed byFandango plus chlorothaloniltreatment was only 0.1t/haless, and two sprays ofFandango 0.25t/ha behind.
In contrast, a two sprayprogramme containingBontima yielded over 1t/ha lessthan Siltra, which translatesinto an extra £130/ha income.
3 Scottish Agronomywinter barley trial
A second trial in Scotlandcarried out by ScottishAgronomy showed a similar pattern, with two sprays of Siltra giving the highest yield at8.1t/ha with Siltra followed by Fandango at 7.84t/ha.Again the two spray programme ofBontima was lower yielding by over 0.5t/ha, with Adexar also 0.4t/ha behind Siltra.
2014FungicidePerformanceNet blotch was one of the most common diseases found in winterbarley in 2014, although Rhynchosporium was also present.
10
Yie
ldt/
haUntreated Bontima x2
1.6 fb 1.4 L/haFandango x2
1.0 fb 0.75 L/ha
5
7
2
1
6
8
9
4
2
0SiltraXpro fb Fandango
0.6 fb 0.75 L/ha
£53.58*£124.69*
*Margin over fungicide cost (*/ha)
£158.75*
10
Yie
ldt/
ha
5
7
2
1
6
8
9
4
2
0Bontima x2
1.6 fb 1.2 L/ha
£121.30*
*Margin over fungicide cost (*/ha)
Fandango x21.0 fb 0.75 L/ha
£218.17*
SiltraXpro x20.6 fb 0.4 L/ha
£255.31*
SiltraXpro fbFandango + CTL
0.6 fb 0.75 +1.0 L/ha
£240.54*
Untreated
10
Yie
ldt/
ha
5
7
2
1
6
8
9
4
2
0Bontima x2
1.6 fb 1.0 L/ha
£19.15*
Adexar x21.0 fb
0.75 L/ha
£42.81*
*Margin over fungicide cost (*/ha)
Fandango fbFandango
+ CTL1.0 fb 0.75 +
1.0 L/ha
£75.38*
SiltraXpro x20.6 fb
0.4 L/ha
£91.15*
SiltraXpro fbFandango
+ CTL0.6 fb 0.75 +
1.0 L/ha
£57.00*
Untreated
Source: 2 independent trials 2014. 10% net blotch in untreated.Winter barley £114/t. Average fungicide web price September 2014
Source: Oxford Agricultural Trials 2014.Untreated: 42% Rhynchosporium leaf 2; 12% on flag leaf.Winter barley: £114/t. Average fungicide web price September 2014
Source: Scottish Agronomy. Untreated Rhynchosporium 14% leaves 3&4.Winter barley £114/t. Average fungicide web price September 2014
1
2
3
Net blotch spores with less sensitivityto SDHI fungicides were first pickedup in Northern Germany in 2012, andspread to other parts of Europe,including the UK in 2013.“It’s a worrying development as it is thefirst case of SDHI resistance to a diseaseto be found in an arable crop in the UK,”says Andrew Flind, Bayer CropScience’scereals fungicides development manager.
“But equally growers should be reassuredthat so far it has not resulted in anyperformance failures in the field.
“It is a warning, however, to continue toemploy suitable strategies to minimise therisk of resistance developing andspreading in all diseases, not least Septoriain wheat,”he says.
In barley, it is positive that there are arange of other actives that will helpcontrol net blotch when used in aneffective programme, includingprothioconazole and strobilurins, such asfluoxastrobin or trifloxystrobin.
Programmes making use of all threeshould provide very effective control of netblotch and other barley diseases, Mr Flindsuggests.
“But it is important that you don’t leaveany one partner exposed to controlling asingle disease. For example, if you use aweaker azole, such as epoxiconazole,against net blotch, you will leave theSDHI component more exposed topotential strains of the disease that areless sensitive to SDHIs.”
Net blotchresistance
21
Spring 2015
For crops that have survived the pestattacks and are coming out of winter ingood shape, protecting them againstdiseases such as light leaf spot andSclerotinia, as well as making sure croparchitecture is managed to maximiselight penetration, will be important toproducing the highest yields andreturns.Crop Monitor’s preliminary forecast forlight leaf spot shows that disease, inparticular, will need watching, even insouthern England, where the disease isincreasingly a threat. It suggests a high riskof light leaf spot virtually everywhere in theUK due to the high infection levels on podsand stems last season, resulting in carryoverof inoculum on trash.Already symptomsare being seen across UK trials sites.
The risk alert is based on the percentage ofcrops with more than 25% plants infected,but Julie Smith, plant pathologist at ADASRosemaund, warned at the recent AICCconference that the disease might beunderestimated.“We have data to show ifthere is 15% infection when crops reachstem extension, you can expect a yieldreduction of 5%.”
Several factors help light leaf spotproliferate, including varieties chosenprimarily for yield, favourable weather aswell as the proximity to last year’s infectedtrash, her colleague Faye Ritchie says.
“The disease can cycle in the crop every sixweeks in warmer conditions and canremain active in cooler temperatures,so a normal southern winter isn’t going tostop it.”
The constant source of inoculummakescontrol difficult, especially as fungicideswork as protectants, she notes.“Timing iseverything.At high risk sites an autumnspray should have been used and then allcrops should be checked for the diseasefrom January.”
To help assess the threat, leaf samples fromthe suspect plant and surrounding onesshould be incubated in a warm place for upto 48 hours to confirm symptoms.“Pre-stem extension there is no threshold fortreatment so treat as soon as infection isseen. Once stem extension begins, spraywhen 15% of plants are infected.”
The benefit of a well-timed sprayprogramme was highlighted in 2014.Average light leaf spot control across ADASandADAS / HGCA trials hit 90% whencrops were re-treated pre-stem extension inFebruary. In previous years, the figure wascloser to 50-60% when spraying wasdelayed to late stem extension.
The average uplift from a two-sprayprogramme (November / February) inADAS / HGCA trials at Malton, NorthYorkshire, a high risk site, was 0.6t/ha.“That’s by no means atypical,”she says.
Autumn applications of 0.46 L/ha of Prolinehelp set the foundation for successful lightleaf spot control, says Tim Nicholson, a
Bayer CropScience commercial technicalmanager.“If growers haven’t managed tospray for light leaf spot yet, then beprepared to spray as soon as groundconditions allow, as untreated or earlyNovember treated crops are alreadyshowing symptoms.”
A watchful eyeCrops then need to be monitored carefullyfrom around four weeks after treatment,with follow-ups applied if symptomsare seen.
Effective control through to stem extensionwill see the crop out of danger – Prolineapplication at flowering to controlSclerotiniawill top up light leaf spot control.
Sclerotinia is the other main disease oilseedrape growers need to watch out for, andagain a two spray approach is best wheredisease pressure is high or flowering isprolonged.
“Growers can keep costs under controlusing Proline for Sclerotinia control,”saysMr Nicholson.“Not only does it give morepersistent Sclerotinia control than Filan, andoffer light leaf spot control, it is around£15/ha cheaper.”
How much to spend on oilseed rape this springwill be a key decision for growers. Lowercommodity prices has put pressures on budgets,
not least after costs of pest control in the autumn
increased for some growers without neonicotinoid
insecticidal seed treatments to tackle cabbage stem flea beetles and aphids
transmitting turnip yellows virus.
Not only does it give more
control than Filan, and offer
light leaf spot control, it is
around £15/ha cheaper
• High risk of light leaf spot
• Monitor for symptoms ifalready treated
• Treat ASAP if not yet tackled
• Proline cost-effective option forSclerotinia control
Key Messages
22
Crop Focus
OxfordshireColin WoodwardGreat Tew Farms, Chipping Norton
Good-looking oilseed rape crops will getthe attention they deserve this season atGreat Tew Farms, near Chipping Norton,Oxfordshire.Rains immediately after drilling promptedrapid establishment and ideal growingconditions for the 210ha of Harper and DKExtrovert, and crops haven’t looked back,says farm manager ColinWoodward.
“We sowed the rape on 21-24 August into apretty dry seed-bed, not ideal on our heavysoils. But 40mm of rain fell, as forecast, soonafterwards.All the seed was treated withMesurol, and half the area was dressed withchicken litter and the rest with anaerobicdigestate.
“The combination certainly helped with fleabeetle control. Crops grew away very evenly.”No follow-up insecticides were needed.
MrWoodward is already reasonablyconfident of achieving his budgeted outputof £1250/ha, based on the farm’s five-year
average yield of 4.5t/ha and £270/t, includingoil bonuses.“We sold quite a lot early so weshould make that target,”he says.
Not surprisingly variable costs won’t betrimmed – crops would have to be very poorfor that to happen.“We cannot afford to takeour foot off the pedal – yield is the key profitdriver.We are only just about breaking even,so we are pushing hard to achieve 5t/haacross the board.”
Making an impactDespite that, MrWoodward did save afungicide in the early autumn as Phomawasall but absent. He waited until the end ofNovember to apply 0.3 L/ha of Proline toprotect the crop from light leaf spot, now thenumber one OSR disease on the estate and areal threat to the thick crops.The fungicide
was applied withAstrokerb to clear
out blackgrass andproblem broad-leaved weeds.
Herbicide costs are slightly higher. Heavoided a pre-em application as he wasworried about the heavy rain washingchemical down to germinating seed, so heapplied Elk in September, but dry soilscompromised control.
An early spring growth regulator has beenpencilled in at green bud, given the forwardstate of the crop. Proline will be added forSclerotinia control where light leaf spotthreatens.
“It had a significant impact last summer – itwas hard to spot in the thick crops but wehad a lot of small seed. Overall yields slippedto 4.2t/ha,”says MrWoodward.
A follow-up fungicide with a different modeof action will go on at mid flower.Where nolight leaf spot occurs, he’ll apply thefungicides at mid-flower and petal fall,unless it is very dry when a straight strob willbe applied as necessary.
Oilseed rape crops that avoided theworst flea beetle attacks haveestablished well. We speak tothree growers to see how thepest affected spend andhow crops aremeasuring up
The combination certainly
helped with flea beetle
control. Crops grew away
very evenly. No follow-up
insecticides were needed.
flea beeto d
Overcoming
23
CheshireAndrew ShawAston Grange, Runcorn
Good establishment and strong autumnvigour set up oilseed rape crops at S & AShaw’s Aston Grange, Runcorn, Cheshire,and most of the 120ha now looks strong.The only slight concern is about 24ha that hassuffered pigeon damage, says Andrew Shaw, apartner in the family farming business.
“But I’m not too worried – in the past,pigeon-damaged crops have produced someof our best yields.And this year we are trying30cm rows for the first time, double our usualspacing, drilled at 2.8-3.4kg/ha. Plants havedeveloped strong root systems – provided Ican get some nitrogen on the affected areas inmid-February they should recover quickly.”
Two passes with aVaderstadTopDown,shallow then deeper, created fine, moist seed-beds on the farm’s sandy loam and clay loamsoils.“We were dreading flea beetle,”recallsMr Shaw.“But we drilled in good time – halfwent in around the 20 August after barley andthe rest after wheat a few days later.
“We applied three lots of cypermethrin – onewith the pre-em herbicide, another with someFalcon we applied to control volunteers, andthen the last 0.5 L/ha of Proline we applied tokeep Phoma and light leaf spot in check.Wesaw very little sign of flea beetle attack –unlike some crops further south ours gotaway with it well, this year at least.”
All varieties – hybrids Compass andPR46W21 as well as conventional varietyCharger – showed excellent vigour in theconditions. He is also trying some of Bayer’snew oil-rich hybrid Fencer.
“Up until October you couldn’t really see anydifference between them,”he notes.“Sincethen, Fencer has edged away and thedifference is quite striking.Whether that willhelp yield remains to be seen, but pigeonsdon’t seem to be bothering it as much.”
Fields are now being assessed forpropyzamide applications.“We don’t sufferfrom blackgrass – brome is our mainproblem,”says Mr Shaw.“We have to ploughbefore potatoes and we also plough beforewinter barley to help control. It seems to payoff – some fields won’t need any furtherherbicide.”
Folicur at 0.7 L/ha will optimise plantarchitecture at green bud.This will befollowed by Proline at 0.5 L/ha to controlSclerotinia – the aim is to apply oneapplication just before petal fall, though thatwill depend on the weather.
Overall the oilseed rape is pretty much onbudget,Mr Shaw reckons.“We average4.5t/ha and are aiming for 5t/ha, butregardless of how a crop looks or the price,we will to stick to our spending plans.
“Whether a crop is worth £350/t or £200/t,you can’t risk losing yield.”
CambridgeshirePaul DrinkwaterAbbots Ripton Farming Company,Huntingdon
Despite being hit hard by flea beetle,oilseed rape crops are back on track atAbbots Ripton Farming Company nearHuntingdon, Cambridgeshire.The attack happened at the start ofSeptember, recalls crop production managerPaul Drinkwater, who is growing threevarieties on most of his 460ha of OSR.PR46W21, semi-dwarf PX 113 on lighterland and DK Cabernet are the key varietiesand he is growing some Advance as apotential Cabernet replacement.
Fortunately, the early harvest allowed cropsto be drilled in good time; the farm’sheaviest boulder clay soils were direct drilledon 11 August and the lighter land completedtwo weeks later.“That was early for us, butwe knew we had a potential problem withflea beetle.”
The strategy worked.Although the pestinitially stopped crops in their tracks when
the weather warmed up, most were robustenough to recover and grow away and areon track to top the farm’s 4t/ha average.
“We were left with a few windows whereslugs took over but overall I’m notcomplaining – we’ve not lost any crops,”saysMr Drinkwater.
“We did use Mesurol on some seed but theattack came later and I suspect the effectshad worn off. If it’s available next year I’llstick with it to help crop emergence.”
The power of protectionOne unwelcome legacy is a higherinsecticide bill.“We applied twocypermethrin sprays, which had little effect,and went back in late September withPlenum.We’ve spent about £30/ha, fourtimes more than normal.
“We did save a bit on fungicide.We used
difenoconazole with the Plenum as therewas not much Phoma, and intended to addProline to our Astrokerb spray in November.But conditions weren’t right and then theweather closed in.”
Crops are not over-thick, thanks to seedrates of 3kg/ha or less, but plants are huge,says Mr Drinkwater. An early spring Folicurat 0.7 L/ha will damp down growth.However, if the lack of fungicide protectiondoes allow light leaf spot in he’ll switch toProsaro.
Sclerotinia protection usually consists of asingle Proline spray at mid flower.“It’s not abig problem, but it’s protection all the waywith this disease, so if it is wet we’ll go againat petal fall.”
Crops look set to achieve the farm’s 4t/haaverage, which, if sold at the budgeted£250/t plus oil bonuses will leave a smallprofit, says Mr Drinkwater. However, he’d bereluctant to curb inputs even on poor stands.
“You can never tell how a crop will turn out,but treat half a crop like half a crop, andthat’s what you’ll end up with.”
Spring 2015
tleseliver returns
Treat half a crop like half a
crop, and that’s what you’ll
end up with
Northam
ptonshire
Use plant protection products safely. Always read the label and product information before use. Pay attention to the risk indications and follow the safety precautions on the label.For further information, please visit www.bayercropscience.co.uk or call Bayer Assist on 0845 6092266 / 01223 226644. © Bayer CropScience Limited 2015
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