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940Re: [fukuoka_farming] On Fungus - Arbuscular Mycorrhizas

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  • Don Graves
    Sep 4, 2002
      Hello Robin & Jamie...& all
      in fact NOT ALL fungi are decomposers, (saprotrophic).. parasitic or disease
      causing...

      The oldest mycorrhiza group (Zygomycetes) , aka ARBUSCULAR MYCORHIZAS,
      Glomales or Glomalean fungi are BIOTROPHIC organisms ... BIO ~ = living,
      TROPHIC = feeding
      Arbuscular mycorrhizas cannot be grown in lab dishes on non-living media,
      (without living plant root hosts)...
      as can the Basiodimycete & Ascomycete mycorhizal fungi
      Arbuscular mycorrhizas (AM) are biotrophic organisms that feed on energy
      from healthy plants
      ... in (bidrectional) exchange for minerals (& perhaps water) obtained from
      thread-like networks of hyphae (fine fungal tubules) in the soil. Hyphae
      occupy smaller soil spaces & a larger total soil volume compared to plant
      roots only.

      regards
      Don


      ----- Original Message -----
      From: "jamie" <jamie@...>
      To: <fukuoka_farming@yahoogroups.com>
      Sent: Wednesday, September 04, 2002 11:35 PM
      Subject: Re: [fukuoka_farming] On Fungus


      > Hello again Robin, I find it useful to consider fungal problems as
      > indicating a general problem in the health of my plants, the fungus just
      > doing what it is supposed to do, decompose dying or unhealthy plants. To
      put
      > it more simply it's not the fungus that is the problem. But then I think
      you
      > probably know this already. But thinking like this will help you avoid
      > spraying your veg with the copper sulphate that I'm sure is what your
      local
      > viticulters are spraying on their crops. It does indeed work well against
      > certain fungal and bacterial attacks such as mildew, however, copper
      enters
      > the soil and then remains there, as the concentration increases through
      > respraying it reaches a level of toxicity toward earthworms. Here is some
      > more information on copper compounds and their effects on plants (sorry I
      > don't have the www address);
      >
      > >copper compounds. Copper is a foliar fungicide with protective action.
      > Copper compounds can be highly toxic to many fruit crops and must be used
      > with extreme care. Copper >sulfate is soluble in water. This high degree
      of
      > solubility is the fundamental cause of toxicity problems, which copper
      > sulfate can cause to all fruit crops. Fixed coppers have been >developed
      > that are relatively insoluble and therefore less toxic to plants. However,
      > fixed coppers can also result in phytotoxicity under certain conditions.
      The
      > fungicidal activity of >copper is based on its ability to destroy proteins
      > in plants. This is true for all plants, fungi, and fruit plants. When lime
      > is combined with copper compounds, it reacts with the copper
      > >making it more stable. Thus, copper compounds in the presence of lime
      would
      > generally produce lower, more uniform concentrations of free copper, which
      > in turn would be less apt >to injure plant tissues than if no lime were
      > used. Because copper has the ability to kill all types of plant tissue,
      the
      > use of copper fungicides carries with it the risk of causing injury to
      > >fruit plants. Ideally, copper on the leaf or fruit surface should be high
      > enough to kill the fungus or bacteria but low enough not to cause injury
      to
      > the plant. Factors that can promote >injury include: failure to use enough
      > lime; cold, wet weather conditions that apparently increase copper's
      > solubility, allowing more into the plant and resulting in toxicity; and
      > >application of excessive rates of copper. Even when no injury is evident
      on
      > the plant, subtle effects of the copper on the plant may be occurring. In
      > addition, to reduce growth and >yields, it has been shown that the use of
      > copper fungicides can reduce the maturity of the fruit as well as that of
      > the shoots. Copper fungicides can have subtle, chronic negative >impacts
      on
      > fruit plants. Copper provides low to moderate control of many fungal and
      > bacterial diseases. Fixed coppers, plus lime, are safer than Bordeaux.
      They
      > may be used for >leaf curl control on stone fruits and pre- and
      postharvest
      > leaf spot control on tart cherries. Copper compounds should not be applied
      > in a postharvest spray without adding lime. If >copper is applied without
      > lime, orchards will show toxicity symptoms such as chlorosis (yellowing),
      > leaf drop on tart cherries, and necrosis (browning) on sweet cherries. If
      a
      > >copper material is applied without lime and yellowing and leaf drop
      occur,
      > an application of lime within 2 to 3 weeks after the copper application
      may
      > prevent further yellowing and >leaf drop.
      >
      >
      > I've used cardboard also this year to inhibit the growth of plants in an
      > area I'm now preparing for winter veg. It has certainly worked well,
      > allowing minimal 'weeding' before I seed the surface with things like
      > spinach, chicory, lettuce etc. I declined the offer of manure earlier
      this
      > year after it being suggested by Emilia that the best way to improve the
      > fertility of the soil and keep it in balance was by simply using plants,
      > just as happens in nature. I'd think you might very well be able to plant
      > much of your land this winter with a cover crop that you could scythe and
      > leave as a green mulch on the surface when you plant your veg next spring
      or
      > even interplant amongst a cover crop such as white clover. You might want
      to
      > look at http://www.sare.org/handbook/mccp2/index.htm for a cover crop that
      > will suit your climate which, I suspect, is very similar to Southern
      > California in this cover crop database (I've just remembered this one
      also,
      > should just be what your looking for as it's aimed specifically at
      > California http://www.sarep.ucdavis.edu/cgi-bin/ccrop.exe). Have a look
      at
      > that earlier discussion on this list (from message 330 the thread is
      called
      > to souscayrous, emilia and all and then Soil Amendments).
      >
      > You seem to be taking a patient approach to your land so rather than go in
      > spraying, see if you can't ameliorate the worst of your conditions by
      simply
      > following nature's lead by rebuilding the natural fertility of your soil
      > through plants. I'm about to build some raised beds for next years crops
      and
      > I intend planting the beds this winter with cover crops to stop erosion,
      > keep the soil loose, feed the soil microorganisms and build up plant
      > available nutrients. Why not order Emilia's video (which I'm sure she has
      in
      > Spanish and I know she has in English) and we can compare notes on
      progress
      > and keep in contact with Emilia via this group to keep us on the right
      path.
      > Whilst the beds take a little work to build and there is some weeding
      > through the first couple of season's, once the beds are established you
      will
      > have the soil in as natural and 'wild' a state as is possible and thus a
      > healthy soil that produces nutritious crops that come to resist pests and
      > diseases.
      >
      > Jamie
      > Souscayrous
      >
      >
      >
      > ----- Original Message -----
      > From: Robin Fernández-Medina <flyingdebris1@...>
      > To: <fukuoka_farming@yahoogroups.com>
      > Sent: Wednesday, September 04, 2002 11:10 AM
      > Subject: Re: [fukuoka_farming] On Fungus
      >
      >
      >
      > Thanks to all those responses on the issue of Fungus. I agree with Jamie
      and
      > others on the result of an imbalanced ecosystem being conducive to fungal
      > outbreaks. The land I am currently mulching and cultivating on was and is
      on
      > what has always been an olive tree orchard and almond trees. Both dry
      > tolerant. I know the old owner was using foliar sprays and this must have
      > impacted the surroundings in ways I can only dread. Since we purchased the
      > land two years ago we have done nothing in the line of fertilizing or
      > clearing or anything out of choice to see what direction things took. The
      > prescence of certain weeds indicated patches of poor soil, and the sun
      burn,
      > drought, salting and mineral deficiency look was apparent. Last year we
      > started laying cardboard and manures down on the areas we were preparing
      to
      > grow veggies in the future (which turned out to be this summer). The
      aphids
      > were all over in the beginnig and they thinned out to manageable levels
      > alone, but it took a long time to see ladybugs so I am not sure what
      > happened there. The plants showed deficiencies and the latest (which was
      my
      > comment on fungus) was the spread of leaf rot and just plants dying and
      > noticing that the fungus were clearly invading. I try to limit my watering
      > hours and always in summer wet the soil and not the leaves. I am thinking
      > that perhaps the close by piles of fresh grass clippings has been the
      focal
      > point of this invasion. Not sure but a hunch. Its the first time I have
      seen
      > dill get decimated in this fashion.
      > We have a very dry climate here during our summer months. Borderline
      drought
      > and drought prone areas.
      > Either way, I really am just standing by and watcing how all these
      processes
      > unfold during these years as the land continues to go untouched.
      > Here on the grape vines we use a blue dust that suppreses rot on the
      grapes.
      > I dont know what its called but the farmers tell me that it is
      innofensive.
      > Is this so? Can I apply it to the area under fungal attacks as a solution?
      > I would be intereseted to hear of your comments.
      > Regards,
      > Robin
      >
      >
      >
      >
      >
      >
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