Who says over-use of strobilurin fungicides can contribute to the development of diseases becoming resistant to strobilurin chemistry?
The Fungicide Resistance Action Committee of CropLife International. And just who are they? Well, they’re a global organization whose membership comes from all the major crop protection chemical companies in the world. FRAC is a committee of the global organization who’s purpose is to “Provide fungicide resistance management guidelines” for the purpose of “prolonging the effectiveness of AT RISK fungicides”.According to FRAC, one of the major AT RISK groups of fungicides is the strobilurin-class of chemistry.Oh, and by the way, the companies who sell strobi-fungicides are involved with FRAC and they’re the ones who’ve both identified the chemistry as being at HIGH RISK for the development of resistance AND they’re the ones who develop the resistance management guidelines that everyone’s encouraged to follow.
And here’s a summary of the guidelines that FRAC recommends be followed in order to reduce the likelihood of fungal resistance to strobilurin-class chemistries. Note that the first “guideline” isn’t really a recommendation, but instead, it contains the word MUST. So in other words, in order to reduce the potential for disease resistance to strobi-fungicides, this class of chemistry should NEVER be applied as a stand-alone chemistry.Now, let me ask you, what’s the NUMBER 1-applied foliar corn fungicide in the USA? Pyraclostrobin. Alone. By-itself. In direct contravention to the 1st rule for preventing the development of disease resistance to strobi-fungicides.And the guidelines go on to say that strobi’s should be ALTERNATED with other fungicide classes, even if the strobilurin that’s being applied is mixed with a fungicide from another class of chemistry that’s NOT in the same risk-category and mode-of-action as the strobilurins.And finally, it recommends that the TOTAL number of strobi applications be LIMITED. And that’s really important, because, did you know, that, because the way Gray Leaf Spot and other corn diseases can be transported by wind, water, and machines, it’s possible for resistance to occur, even in fields that have never before been treated with a strobi-fungicide? In other words, everyone in the community needs to adhere to the FRAC guidelines in order to reduce the likelihood of fungal resistance to strobilurin fungicides. And if you don’t think that’s important, take a trip to Europe and talk to farmers who’ve experienced almost complete failures of strobi-fungicides in some areas. Or to some of the soybean farmers in Tennessee that can no longer control frogeye with any of the strobi-class fungicides.So what’s a good NON-CROSS RESISTANT fungicide that can be used as an alternative to strobilurin-class chemistry?
Well, there’s LOT’S of data, from multiple sources that shows that PROPICONAZOLE is a very effective, NON-CROSS RESISTANT foliar fungicide when it comes to controlling the disease that most farmers spray for. In fact, it shows that there’s no statistical difference whatsoever between the disease control that’s obtained from propiconazole versus what’s possible from strobilurin-based fungicides.
And the level of disease control that’s obtained from propiconazole is similar to what’s possible from a strobi, without regard to individual hybrids, OR
Without regard to location. This is publicly available data from Iowa State University, but the range of locations includes evaluations that include Nebraska, Illinois, Wisconsin, and Indiana, in addition to Iowa. The take-home message is that Propiconazole delivers disease control that’s comparable to what’s possible with strobilurin-based fungicides, but with less risk of diseases becoming resistant to propiconazole.
And similar disease control means similar yields. And that pattern holds true in both relatively “low-yielding” situations, (And it’s not that 150 bushel/acre corn is really low-yielding, but it does seem to be at the lower end of the range where many farmers are willing to invest in fungicide protection on a regular basis.) and in,
Really high-yield situations as well. Please note that this information is from the University of Nebraska, and that propiconazole, and the strobi’s in combination with a triazole, applied at VT, all delivered about a 10 bushel advantage compared to the untreated. So once again, it’s being demonstrated that similar disease control results in similar yields.
So at this point in the presentation, I think it’s safer to say that Propiconazole defends against Gray Leaf Spot almost as effectively as the leading strobilurin-based fungicides, with considerably less risk of disease resistance.Which brings me to the point of talking about what fungicides are really good at, and what they’re maybe not so good at.
Here’s a picture that represents how Gray Leaf Spot generally shows up in a field. As seen in the picture, where the red indicates HIGH PRESSURE, Gray Leaf Spot tends to be concentrated to a much higher degree in some areas of the field than others. Well, if you compared the average yield loss in those areas, to the yield lost to Gray Leaf Spot in the areas with moderate or low pressure, it’s not uncommon to experience losses that can range up to 30 bushels an acre, IN THE WORST SPOTS, versus what’s going on in areas where the disease pressure is very light. And fungicides, particularly strobi-fungicides, can do a great job of preventing that loss IF they’re applied in time. Because that’s what fungicides do; they PROTECT yield from being lost to disease. But farmers very seldom experience anything remotely close to yield differences of 30 bushels an acre when comparing treated AREAS to untreated areas, and that’s because there’s not enough disease pressure in the other parts of the field to cause a 30 bushel loss in yield, even if nothing’s done to protect the yield. In many fields, there can be areas with substantial disease, while in the same field, there may be areas with no detectable disease whatsoever. That makes it hard to deliver big yield increases across an entire field, and it really makes it hard to realize CONSISTENT yield gains in situations where a fungicide is applied PROPHYLACTICALLY, or as a preventive action that’s made when you don’t even know if there’s much pressure anywhere in the field. Because while fungicides do a great job of protecting yield from disease-induced losses, they don’t do much at all to PROMOTE yields in those places where disease pressure is low or non-existent. And that’s where ProAct comes into play.
As I mentioned earlier, Harpin Alpha Beta doesn’t work directly on any disease organisms. Instead, it ACTIVATES A NATURAL DEFENSE MECHANISM IN PLANTS. While it’s not exactly the same, think of the immune system that humans have. Just like your body has an internal defense mechanism (a fever is simply your body’s way of trying to kill off something that doesn’t belong there), so do plants, and harpin alpha-beta turns on the defense mechanism in plants. When that happens, the plant grows more vigorously, and in a very high percentage of cases, it produces a higher yield as a result. Now please note, that’s not just me saying that. That’s what’s posted on the US EPA website, and you can see it for yourself by visiting the website, and an easy way to get there is to “Google” harpin αβ. (normally when you do that, the EPA website appears near the top of the list.)
Looking at the data across 2 years, across 15 locations, where each treatment was replicated 8 times at each location, we learned that not only did the combination of ProAct and strobi fungicide deliver higher average yields than were achieved when the strobi’s were used alone, but the combination of ProAct PLUS a strobi increased the consistency of performance so that almost 100% of the time, the combination produced a higher yield than the untreated check.We were really starting to get jazzed up about the potential to use ProAct in combination with strobi fungicides, but then we remembered the very first slide that you saw in the presentation:
Strobies do a great job of protecting corn from disease-induced yield loss, but the more they’re used, the more likely they are to stop working. So what else might we do?
Turns out that farmers had similar experiences. When the combination of ProAct & Propiconazole was compared to Headline Amp in farmer tests that were overseen by the Iowa Soybean Association’s On-Farm Network, across 8 locations, the average yield achieved in fields treated with ProAct & Propiconazole was every bit as good as the yield achieved in the fields treated with Headline Amp. So now we’ve got a pretty strong body of evidence to support the claim that it’s possible to get similar disease control and similar yields as what you’d expect from a strobilurin product, but without contributing even a smidgeon toward the potential for the development of disease resistance to strobilurin fungicides.
So now we’re able to draw some conclusions.
So now we’re able to draw some conclusions.
And make a recommendation.
Save the Strobies Presentation
With sufficient disease, strobilurin-treated corn generally suffers lessyield-loss than Untreated.But over-use contributes to disease resistance.* TM* http://www.frac.info/frac/publication/anhang/FRAC_Mono1_2007_100dpi.pdf (After clicking on this link, please scroll down to the 5th bullet point on page 5)
Specialist Technical Group of CropLife InternationalPURPOSE: Provide fungicide resistance managementguidelines to prolong effectiveness of "at risk" fungicides.Qol Inhibitor Working Group is a sub-committee of FRAC• Responsible for global fungicide resistance strategies for all Qo Inhibitor (QoI)Strobiluron-class fungicides.QoI fungicides include: azoxystrobin, pyraclostrobin, trifloxystrobin• All 3 in same cross-resistance group & should be managed accordingly.Participating Committee Companies: BASF, Bayer, DuPont, SyngentaALL strobilurin fungicides considered HIGH RISK for fungal resistance* http://www.frac.info/frac/publication/anhang/FRAC-Code-List2011-final.pdf (After clicking on this link, please scroll down to Page 4 and review FRAC Code 11 compounds)
General guidelines for use of Strobilurin fungicides:• Block (wide area) applications of Strobi’s must onlybe made in mixture with a non-cross-resistant fungicide.• Alternate strobi applications, whether solo or in mixture, in single or block treatments, with applications of effective fungicides from other cross-resistance groups.• Limit the total number of strobi applications within a total disease management program, whether applied solo or in mixture with other fungicides.http://www.frac.info/frac/publication/anhang/FRAC_Mono1_2007_100dpi.pdf (After clicking on this link, please scroll down to Page 42 for strobilurin-specific information)
Propiconazole is aneffective, non-cross resistant Foliar Fungicide for Control of Corn Disease Independent Contract Research – Small-block replicated trials: NOT sponsored by PHC Means followed by same letter are not different.
Propiconazole delivers Similar Disease Control Across HybridsIowa State University: 2008 Mean disease rating (% of diseased leaf tissue) By hybrid&treatment, cross-trial summary. http://masters.agron.iastate.edu/DB/CC/StefflCCProject.pdf
Similar Disease Control Mean disease rating (%) Propiconazole also delivers Similar Disease Control Across LOCATIONS TMIowa State University: 2008 Mean disease rating (% of diseased leaf tissue) By location&treatment, cross-trial summary. http://masters.agron.iastate.edu/DB/CC/StefflCCProject.pdf
Similar Disease Control Means Comparable Yields Relatively Low-yielding Scenario 6.6 bu 5.8 bu increase increase 8 Midwest locations (2007) -- Independent RCB Contract Research
Similar Disease Control Means Comparable Yields Relatively High-yielding ScenarioUniversity of Nebraska: http://elkhorn.unl.edu/webvideoj/UserFiles/Image/PDF/Plantsc09-Jackson.pdf
TM Propiconazoledefends against Gray Leaf Spot almost as effectively as astrobilurin, but with less risk of TM disease-resistance.
High PressureProtect Moderate Pressure Low Pressure PROMOTE Disease pressure varies throughout the field.
Fungicides PROTECT yield. ProAct PROMOTES yield. ® Because it’s a pure “Plant Health” strengthener.
® ProAct = Harpin αβ Protein• Registered with U. S. Environmental Protection Agency (EPA) as: N-Hibit HX-209, ProAct, and Employ• 2nd generation of harpin-derived product• Combination of active domains from 4 different native harpin proteins: HrpN, HrpW, HrpZ, and PopA
Harpinαβprotein US-EPA Fact SheetMode of Action: Harpin αβ does not act directly on disease organisms, nor doesit permanently alter the DNA of treated plants. Instead, Harpin αβ activates anatural defense mechanism in plants, referred to as systemic acquiredresistance (SAR). Harpin αβ and the Harpin protein registered in the year 2000are structurally and functionally similar.Harpin αβ protects against certain bacterial, viral, and fungal diseases; soil-borne pathogens; and harmful nematodes and insects. Harpin αβ protein alsoenhances plant growth and vigor, and increases the yieldfor a variety of crops,including vegetables, trees, and ornamentals.Regulatory Information: The first pesticide product ProAct® (EPA Reg # 69834-5) containing Harpin αβ protein as an active ingredient was registered onFebruary 9, 2005. http://www.epa.gov/pesticides/biopesticides/ingredients/factsheets/factsheet_006506.htm
Schematic of Plant Response toHarpin Protein ProductsHarpin is a pure “Plant Health” Product. ALL it does is IMPROVE Plant Health.
ProAct ®, Used alone, Increases Yields in Field Corn Average Corn Yield (bu/A) by Year 200 ProAct at 0.5 oz/A +7 bu +7 bu CONTROL 190 Primarily +7 bu 180 NCGA +8 bu Demos +8 bu 170 +6 bu 160 6 11 57 17 7 98 150 2003 2004 2005 2006 2007 AVERAGE # on bar = number of data points; includes replicated and commercial field trials
“ProAct + Strobi’s” increased Corn yields more than Strobi’s alone. PHC-contracted Independent Small-block Research:200915 220 Gray Leaf Spot and Common Rust Corn Yield (bu/A) Severity on Ear Leaf (%) A10 210 A B B 5 C BC 200 0 190 Water Control Fungicide + NIS ProAct 0.5 oz/A + Water Control Fungicide + NIS ProAct 0.5 oz/A + Fungicide + NIS Fungicide + NIS 8 replicates per site; treatments applied at VT; summary of all 7 trial locations (IA, IL-3, MN, and NE-2)
ProAct + Strobi increased the # of wins versus untreated controls more than Strobi’s alone PHC-contracted Independent Small-block Research: 2009and2010 Average Yield as % of Control Success Rate (% Wins)110% UTC = 175 bu 100% 105.7% 90% 103.8% 80%105% 10 bushel 96% increase 78% 6.7 bushel versus 70% increase untreated versus 60% untreated100% 50% Strobi @ 6 oz ProAct 0.5 oz + STROB. 6 oz Strobi @ 6 oz ProAct 0.5 oz + STROB. 6 oz8 reps per location; 15 locations; treated at VT; strobilurins applied with NIS 0.25% (v/v).
With sufficient disease, strobilurin- treated corn generallysuffers less yield-loss than Untreated.But over-use contributes to disease resistance.* TM* http://www.frac.info/frac/publication/anhang/FRAC_Mono1_2007_100dpi.pdf (After clicking on this link, please scroll down to the 5th bullet point on page 5)
Can “ProAct ® + Propiconazole” be substituted for strobilurinfungicides, as an aid in the battle to reduce the likelihood of diseaseresistance to strobi-class chemistry? (Without giving up any yield in the process?)
ProAct ® + Propiconazole increased Corn YIELDS and SUCCESS RATES as much or more than Strobi’s alone PHC-contracted Independent Small-block Research: 2011 CORN YIELD: (n=9 locations, sites with light to high disease levels) Bu Diff. Success Rate Treatments Yield (bu/A)* from UTC (% wins)Untreated Control (Sprayed with Water) 169.99 a - N/APropiconazole @ 4 oz + NIS (@ 2 weeks before VT) 171.34 a 1.35 56%Propiconazole @ 4 oz + ProAct @ .5 oz + NIS (@ 2 weeks before VT) 168.14 a -1.85 11%Propiconazole @ 4 oz + NIS (@ VT) 173.92 a 3.93 56%ProAct @ 0.5 oz + NIS (@ VT) 175.01 a 5.02 78%Propiconazole @ 4 oz + ProAct @ 0.5 oz + NIS (@ VT) 178.88 a 8.89 89%ProAct @ 0.5 oz + NIS (@ V5) fb Propiconazole @4 oz + ProAct @ .5 oz + 179.86 a 9.87 89%NIS (@ VT)Headline® @ 6 oz + NIS (@ VT) 178.10 a 8.11 67%Headline AMP @ 10.6 oz + NIS (@ VT) 177.59 a 7.60 89%Quilt® @ 7 oz + NIS (@ VT) 176.86 a 6.87 89%Quadris® @ 6 oz + NIS at V5 fb Quilt @ 7 oz + NIS (@ VT) 172.45 a 2.46 44% 8 reps per location. VT=tasseling. *Mean separation not attempted if Treatment x Location interaction term significant. When letters are presented, means followed by the same letter are not statistically different (Protected LSD, P = 0.1); Values calculated with ARM ST. Each registered trademark shown on this page is the property of its owner
Comparable corn yields without resistance pressure on strobilurin-class fungicides ProAct with Trial ID County Untreated Headline®AMP PropiconazoleST2011303A Webster 209.1 211.4 215.0ST2011362A Kossuth 198.5 202.6 209.4ST2011369A Humboldt 194.4 198.0 193.6ST2011363A Kossuth 185.3 185.1 192.6ST2011368A Boone 191.2 193.9 189.9ST2011357A Story 184.6 186.6 184.3ST2011359A Polk 176.2 173.3 173.4ST2011356A Polk 162.5 172.2 169.7Average 187.7 190.4 191.0 ISA-OFN-Managed, Famer-recorded average yields in bu/ac: 2011 Each treatment replicated at least 3 times via field-strips at each location. Each registered trademark shown on this page is the property of its owner
• ProAct-treated corn usually yields more than untreated whether disease is present or not.• ProAct alone is NOT as effective as strobies or propiconazole at protecting corn from disease-induced yield losses.• Tank-mixingProActwithpropiconazole increases likelihood of higher yields following application.
The use of ProAct & Propiconazole,used in lieu of an application of astrobilurin fungicide canbe an effectivetool in the battle against the developmentof resistance to strobilurin class chemistry.
RECOMMENDATIONS If scouting reveals widespread Gray Leaf Spot infection, apply astrobiluron + triazole combination fungicide product.If Gray Leaf Spot pressure is light-to- moderate and unevenly distributed across area to be treated, apply atank-mix of ProAct + propiconazole.
TM www.savethestrobies.comProAct® logo, Plant Health Care, Inc.® logo Save the Strobies™ and Strobie characters are trademarks of Plant Health Care, Inc., Pittsburgh, PA. All other trademarks are the property of their respective owner.
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