HALO BLIGHT IDENTIFICATION, SOLUTIONS and REsoruces

It’s THAT time of year when hop disease pressure starts to show up. So we wanted to send out a conversation between our President, John Condzella and Dr. Frank Hay of Cornell AgriTech that focuses on Halo Blight solutions. If you'd like Dr. Hay to come visit your farm in the near future to look at any potential Halo Blight issues, or you wish to submit a sample for Halo Blight testing.  Please contact me at adam@hopgrowersofnewyork.org

Halo Blight Under the Microscope

Sending Strength for your Growing Season!

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JOHN:

Hi Frank,

I know you said that fungicides effective on powdery mildew should work for halo blight…

Are there any that are more effective than the others? Any better for curative ? Any recommended for preventative?  

Any information you could share on this would be appreciated. This is the first time that I’m having to deal with it in my yard.

Thanks,

John Condzella

President

Hop Growers of New York

DR. HAY:

Hi John,

Hope all is going well! 

I have cut and pasted (with some amendments) from the Michigan hops information online for Powdery Mildew (see below).  At the moment, we expect fungicides in the FRAC 3, 7 and 11 groups to be effective against both Powdery Mildew and Halo Blight.  Note the Canadians have an emergency permit for a fungicide containing flutriafol (FRAC 3) against halo blight, which would be similar to the fungicide Rhyme.    I’ve highlighted fungicides in bold (below) that should be effective against both diseases.   Be careful to adhere to label information regarding rotation of FRAC 3, 7 and 11’s for resistance management.  These groups are prone to the development of resistance.

Fungicides in other FRAC groups such as Quintec, Vivando, Torino and Gatten are known to be more specific for control of Powdery Mildews.  Therefore, at this stage we assume they may not be effective against Halo Blight.  Tim Miles in Michigan has done some work recently, and depending on the outcome of his trials may be able to suggest some of these for halo blight control in the future.  However, at this stage I think we should just use these for Powdery Mildew.

I have no information on whether protectants such as copper and sulfur are likely to be effective against halo blight.  

As always, check registrations and pre-harvest intervals as these may have been updated or different in different States.

Let me know if you need more information.

Best regards,

Frank.

Frank Hay (Ph.D)

Senior Extension Associate,

Cornell AgriTech,

College of Agriculture and Life Sciences,

Cornell University

HOP POWDERY MILDEW

Managing hop powdery mildew in Michigan in 2020 - Hops (msu.edu)

Emergence to mid-June

Consider a combination of applications of sulfur (FRAC M2), oils, Flint (trifloxystrobin, FRAC 11), Rhyme (flutriafol, FRAC 3), Procure 480 SC (triflumizonle, FRAC 3).  Under high pressure, tank mix with oils and integrate copper (FRAC M1) into your downy mildew programs when possible. Avoid tank mixes of copper and sulfur, as phytotoxicity may occur.

Mid-June to bloom

Consider Rhyme (flutriafol, FRAC 3), Procure 480 SC (triflumizole, FRAC 3), Luna Experience (fluopyram + tebuconazole, FRAC 7 + 3), Vivando (metrafenone, FRAC 50), Gatten (flutianil, FRAC U13) and Torino (cyflufenamid, FRAC U6). Under high pressure, tank mix with oils and integrate copper into your downy mildew programs when possible.

Bloom to preharvest

Use a combination of Quintec (quinoxyfen, FRAC 13, 21-day preharvest interval), Pristine (pyraclostrobin + boscalid, FRAC 11 + 7, 14-day preharvest interval), Luna Sensation (fluopyram + trifloxystrobin, FRAC 7 + 11, 14-day preharvest interval) (dried cones in NY registration), Vivando (metrafenone, FRAC 50, 14-day preharvest interval), Gatten (flutianil, FRAC U13) and Torino (cyflufenamid, FRAC U6, 6 day preharvest interval).  

Many fungicide programs can give adequate disease control on leaves when applied preventively under low disease pressure. On cones, however, differences among fungicides are substantial. Mid-July through early August is an essential disease management period. The fungicide Quintec (quinoxyfen), Luna Sensation (fluopyram + trifloxystrobin), Vivando (metrafenone), Gatten (flutianil, FRAC U13) and Torino (cyflufenamid) are especially effective during this time and should be utilized in regular rotation when burrs and cones are present.