RE: [compost_tea] Re: Phytopathology journal article on compost tea, November 2004

From: Ryan, Matthew <matthew.ryan_at_rodaleinst.org>
Date: Mon, 25 Oct 2004 17:03:29 -0400
      Hi Ted, Tom, Titel, and others.

     

      It’s been a while since I posted las= t, but I do still read the posts and I thought that I could shed some light= on this subject of powdery mildew and compost tea.  First off, you gu= ys are talking about different pathogens.  Grape powdery mildew caused= by Uncinula necator, which is different from the powdery mildew on roses w= hich is caused by Sphaerotheca pannosa.  Thus you can't really compare= the effects from tea on the powdery mildew on these different plants becau= se were talking about different pathogens.  Second, since powdery mild= ew usually prefers dry weather and does not like rain, it is possible that = spraying just plain water will result in a reduction of infection. &nb= sp; 

     

      In our research at Rodale we found that ACT = did suppress grape powdery mildew at one of the vineyards in one of the two= years were experimented, but this was only about 50% suppression and was n= ot adequate from the grower’s perspective.  In the second year= we did not observe any powdery mildew suppression at any of the three vine= yards we were collaborating with.  So it seems like there is potential= , but ACT for disease suppression really needs some major developments befo= re it can be recommended with confidence (ie. purchase crop if suppression = fails like Ted mentioned) to growers.

     

      I also wanted to mention that Tom has a good= point - "As hard as I search I still haven’t found an article= on disease suppression supporting ACT by your methodologies".

     

      I hope that I have not offended anybody, jus= t wanted to shed some light in a constructive sense. 

     

      Matt Ryan

      The Rodale Institute

     
     
      -----Original Message-----
      From: Ted Peterson [mailto:ted.peterson_at_tcsn= .net]
      Sent: Thu 10/21/2004 2:19 AM
      To: compost_tea_at_yahoogroups.com
      Cc:
      Subject: Re: [compost_tea] Re: Phytopatholog= y journal article on compost tea, November 2004
     
     
      ----- Original Message -----
      From: Titel Ryzhomer <mailto:thegoodjob_at_h= otmail.com> 
      To: compost_tea_at_yahoogroups.com
      Sent: Wednesday, October 20, 2004 4:15 PM =
      Subject: [compost_tea] Re: Phytopathology jo= urnal article on compost tea, November 2004

     
      Hi Ted,
     
      Yes, I've actually observed with magnificati= on the powdery mildew
      structure breaking down after spraying (unde= r magnification it has a
      building block, almost geodesic (sp) structu= re) and eventually
      disappearing, sometimes leaving a scar. This= efficacy has not been
      apparent with every batch of CT, however oth= er batches have helped
      to control it as you have indicated regardin= g grape plants. I am
      aware that there are many types of powdery m= ildew and perhaps this
      CT is working only on the variety we have gr= owing here on
      delphineas, roses, some herbs, Indian Hemp o= r Dogbane {Apocynum
      androsaemifolium} and a weed that appears to= belong to the Evening
      Primrose family. It has been quite easy to i= nduce the powdery mildew
      (for research purposes) through use of poor = growing conditions, etc.
     
      I hope this helps to clarify.
     
      Regards,
      Titel
     
     
     
      Well, I will have to say this is amazing.&nb= sp; In all the tests I have run here I have seen nothing like this.  W= e have several vinyards using different brewers from different makers and s= ome home ones knocked off of mine and Earth Works and a lot of different re= cipes.  I haven't heard reports like yours from any of them.  Mos= t vinyards use Roses as indicator plants because powdery mildew will usuall= y show up there before grapes. If the vinyard people see it on the roses th= ey can be pretty sure it's in the vines.  I tried spraying right on th= e roses with full strength tea and it did nothing to the mildew that was al= ready there.  It did prevent the mildew from spreading but did absolut= ely nothing to the existing mildew on the plant.  In addition, I had t= o spray every day to prevent the spread.  When I stopped spraying, the= mildew started spreading in 1 to 2 weeks depending on mildew pressure. =
     
      Do you have controls?  Did you try spra= ying with just molasses or just water?  Could it be that there was a r= esidue of fungicide that was activated when you sprayed?  Was the spra= yer you used completely clean of fungicides?  Did you add anything to = the tea that was a form of organic fungicide that you didn't explain in you= r message? 
     
      Here is the problem I have:  I did not = see and have not seen anything even close to what you are describing. = If I believe what you say and go to a vinyard and present CT as able to cu= re powdery mildew and it doesn't, I am financially responsible for their lo= ss of product.  Are you sure enough of what you posted about eradicati= on of powdery mildew to back up that claim to a grower?  Would you be = willing to go to a grower and state if he follows your directions and the m= ildew does not subside that you would compensate him for the loss?
     
      The tests I made were on conventional vines,= organic vines and patches that were separated by enough distance to give p= retty accuract results.  One vinyard was in a medium to high mildew pr= essure area and the other was in an area that was traditionally low mildew = pressure.  I did see the outbreaks controlled in every vinyard I have = applied tea instead of conventional fungicide but even in the most successf= ul vinyards, we got minor outbreaks.  I treated those with fungicide a= fter I determined that tea could do nothing to eradicate the mildew.  = So your post is very interesting to me.  Do you have any lab test to s= ubstantiate what you say?  Would you be willing to let me contact the = grower and find out his/her impression of what happened?  If what you = say is true, you may have found something worth a fortune to organic grower= s. 
     
      I now have contracts with 5 vinyards and hav= e sprayed a lot of tea over almost three years.  I have done a lot of = tests and am still unprepared to make the statement you have made after 7 m= onths so I am very interested to learn where you are having success when no= body I know, even other consultants, are having the same results.
     
      You mentioned inducing mildew as the result = of poor growing conditions.  The spread of mildew has not been the res= ult of poor growing conditions as far as I can tell.  It attacks both = conventional and organicically managed plants with equal vengence.  I = have seen it attack in extremely well managed vinyards and skip poorly mana= ged vinyards and vice-versa.
     
      Ted Peterson
      EW/SOE

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Received on Mon Oct 25 2004 - 17:48:32 EDT

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