PJ
> -----Original Message-----
> From: John Menge [SMTP:menge@ucr.edu]
> Sent: Wednesday, May 06, 1998 3:46 PM
>> Subject: Re: FW: (Fwd) Avocados and Phosphonic acid
>
> Dear Pat:
> Interesting message. Not too far from the truth. Only thing that
> I object to is the reference that there is anecdotal evidence that organic
> matter reduces disease. There is very hard data both here and in Australia.
> Sounds like a chemical salesman.
> John
>
> At 10:02 AM 4/21/98 -0700, you wrote:
> >FYI
> >
> >> -----Original Message-----
> >> From: Jones, Patricia
> >> Sent: Monday, April 20, 1998 9:21 AM
> >> To: Paswater, Pat;
> >> Subject: FW: (Fwd) Avocados and Phosphonic acid
> >>
> >> I thought that Dr. Menge got his ideas to use mulch to suppress
> >> phytophthera cinnamomi, a root rot fungus, in Australia. Guess not
> >> everybody over there got the message.
> >> PJ
> >>
> >> ------- Forwarded Message Follows -------
> >> From: "Frits v/d Laan" <F.vd.Laan@inter.nl.net>
> >> To: sanet-mg@shasta.ces.ncsu.edu
> >> Date: Sat, 18 Apr 1998 16:22:23 +1
> >> Subject: Re: Avocados and Phosphonic acid
> >> Reply-to: F.vd.Laan@inter.nl.net
> >> Cc: Alenson.Chris.CJ@bhp.com.au
> >>
> >> Chris
> >> > Avocado growers in Australia have problems keeping their trees
> free of
> >> > phytophthera cinnamomi, a root rot fungus. Despite research
> (Baker & Cook) and anecdotal evidence that organic matter, compost, chook
> >> > litter, etc helps to provide a disease suppressive soil the risk
> of tree
> >> > death is very great without the use of Phosphonic (phosphorus
> acid ) which is injected into the trunk.
> >> >
> >> > Our organic growers use sound organic
> >> > management in every way to build healthy biologically active
> soils The
> >> > fact remains that the climatic conditions encourages the root rot
> >> fungus and growers either are faced with choices of either staying
> within the organic guidelines, or using the substance and selling their
> produce on the conventional market which they do not want to do.
> >> >
> >> > I know some would suggest that if the climatic conditions are
> >> conducive to the root rot then perhaps it indicates that the varieties
> should not be grown.
> >> > Look forward to any comments.
> >>
> >> I'm not a Avocado grower but you asked for 'any' comment.
> >> I do grow some plants sensitive to phytophtora but my soil is phyt.
> >> cinn. free. (Phyt. dies if it freezes but spores survive) I do grow
> >> about 100 different plants mostly in relatively small amounts so
> you can say my plants are heavely intercropped. This is what I want to
> say, this problem can be caused or fueled by monocropping. I still
> think the soil is not healthy if you have a problem this way and you
> should also study the possibilities of plants that either influence the
> soil or give shelter to bacteria or fungi that can attack the Phyt.
> Another option could be to graft the Avocados on a better rootstock.
> >>
> >>
> >> Frits v/d Laan
> >> Biologische boomkwekerij/
> >> Organic horticulture
> >> Gouda - Netherlands
> >> http://web.inter.nl.net/users/F.vd.Laan/
> >> f.vd.laan@inter.nl.net
> >>
> >> ------- Forwarded Message Follows -------
> >> From: "Alenson, Chris CJ" <Alenson.Chris.CJ@bhp.com.au>
> >> To: "'sanet-mg@ces.ncsu.edu'"
> >> <sanet-mg@shasta.ces.ncsu.edu>
> >> Subject: Avocados and Phosphonic acid
> >> Date: Fri, 17 Apr 1998 09:34:00 +1000
> >>
> >> Avocado growers in Australia have problems keeping their trees free
> of phytophthera cinnamomi, a root rot fungus. Despite research (Baker
> & Cook) and anecdotal evidence that organic matter, compost, chook
> >> litter, etc helps to provide a disease suppressive soil the risk of
> >> tree death is very great without the use of Phosphonic (phosphorus
> >> acid ) which is injected into the trunk.
> >>
> >> Unfortunately this product is not acceptable under Australian
> organic standards even though the product does not leave residues or
> threaten the environment in any way. Our organic growers use sound organic
> >> management in every way to build healthy biologically active soils.
> >> The fact remains that the climatic conditions encourages the root
> rot fungus and growers either are faced with choices of either staying
> >> within the organic guidelines, not using phosphonic acid and
> perhaps loosing their trees and their incomes or using the substance and
> >> selling their produce on the conventional market which they do not
> >> want to do.
> >>
> >> I know some would suggest that if the climatic conditions are
> >> conducive to the root rot then perhaps it indicates that the varieties
> >> should not be grown. Are there any growers of avocados out there that
> >> have experience in management of this fungus and how do they keep it
> >> at bay without compromising their organic status?
> >>
> >> Look forward to any comments.
> >>
> >> Chris Alenson
> >> Organic Advisory Service
> >> Organic Retailers & Growers Association of Australia
> >>
> >
> *****************************
> Dr. John Menge
> Department of Plant Pathology
> University of California, Riverside
> Phone # (909) 787-4130
> Fax # (909) 787-4132
Pat Jones
pjjones@worldnet.att.net
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