Re: [compost_tea] Re: adding VAM ?

From: Thomas Giannou <thomas_at_tandjenterprises.com>
Date: Fri, 13 Jun 2003 18:38:17 -0700

Elaine,

Quite often, mycorrhizal inoculum manufacturers have formulated their inocu=
lum ingredients to work efficiently with the spores, hyphae, and host plant=
 root fragments containing spores and hyphae. When those ingredients are m=
ixed into the tea, you lose the biological design of the manufacturer. Mak=
ing probe holes about 10 inches into the soil around the plants and putting=
 about a teaspoon of inoculum down each hole and then pushing the soil in a=
t the top of the hole will work quite well. (Depending upon the manufactur=
er... some may require more inoculum because they have a low spore count.) =
 Where to place the holes has to be thought out too. If a plant was recent=
ly planted, poking holes in the ground a couple feet or more away from the =
plant probably isn't going to be any where near the plant's roots. For mos=
t AM fungi, the hyphae are more infectious than the spores.

Also, if you mix mycorrhizal inoculum into your tea, there needs to be cons=
tant agitation or the spores can settle or float to the top and you will ha=
ve serious application problems. With the inoculum mixed into tea there is=
 also the problem of trying to figure out how much to apply.

For well established plants like trees, a set of holes out at the drip line=
 about 10 inches deep and a foot apart will work fine. I like to get in cl=
ose to the trunk 2-3 feet and put another set of holes in the soil so the m=
ycorrhizal fungi can grow out from the plant as well as get into the feeder=
 roots out around the drip line.

I've found that for well established grapes and roses, six probe holes into=
 the soil close the plants (about 3 inches from the trunk of the plant) wor=
ks quite well.

If a tree is surrounded by turf grass, do a core aeration and mix the inocu=
lum with carrier material (sand or trace minerals) and use a drop spreader =
to apply the inoculum. Then water the area down well. Most grasses will c=
olonize to about 50% and the roots are mingled with the tree roots. The AM=
 fungi will vector over from the grass roots onto the tree roots. Cover cr=
ops in between grape vines (if they are mycorrhizal) can make very nice vec=
toring agents for getting the mycorrhizal fungi onto the underlying grape r=
oots.

The reason we want the inoculum on or as close to the plant roots as possib=
le is that there is a substance called (flavonoids, flavonols, flavonone) w=
hich is part of the exudate coming out of the roots which serves as a trigg=
er to cause the AMF spores to germinate or the AMF hyphae to start growing.=
  In some cases, a combination of carbon dioxide and flavonols are the trig=
gering agents, in other cases, only the flavonols are the triggering agents=
. There is a company in the Midwest that now makes a flavonol product whic=
h can be mixed with water and then put down as a soil drench and will cause=
 a much higher colonization rate with the AM fungi. That product can not b=
e mixed with tea because the bacteria will eat it all up. It also can't be=
 put into the inoculum or it will cause the spores to germinate in the inoc=
ulum or the hyphae to start growing. Once the spores germinate or the hyph=
ae start growing they have a rather short time to work their way into the r=
oots of a plant. It's the plant that feeds the AM fungi and if it doesn't =
get hooked up fairly promptly the fungi will expend it's food and die. Thi=
s is why we want it near the roots of the plant. Probe holes work slick wh=
en you can get in among a bunch of roots. If you take the cover crop treat=
ment approach, those plants can easily be treated and the AMF will be susta=
ined nicely and transferred over to the plant roots you are trying to inocu=
late.

There is another bugaboo to be aware of... well three actually... one has =
to do with phosphorous. If a plant has taken up a lot of phosphorous, then=
 colonization by the AM fungi can be totally inhibited to none at all or a =
very low value. I think this has something to do with a reduction of the f=
lavonols in the root exudates. (This is just my hunch.) I have to do some=
 searching to see if there are any definitive research abstracts available =
to verify my hunch. I'm thinking my hunch is true because of no to low col=
onization rates. That would be expected if a lot of phosphorous presence i=
n the plant would somehow suppress the flavonol production.

The second bugaboo... once the AM fungi is well colonized in a plants root =
system, if a lot of free phosphorous is made available to that system, the =
flow of nutrients through the hyphae of the mycorrhizae will shut down and =
many of the leaves will turn yellow. In a severe case, the plant leaves an=
d stems, etc., will dry up and you can lose the plant... like a reverse osm=
osis. If you make a tea that has a lot of free phosphorous present, this s=
ituation can damage plants that are well colonized with AM fungi. Bird man=
ures can be the source of a lot of free phosphorous. I first experienced t=
his situation when I put some Alaska Fish Pellets around a couple of rows o=
f Raspberry plants. The NPK was 8-5-1. The leaves of the plants yellowed =
up from the ground about 3 feet. A few of the well colonized plants dried =
up and were lost. I scraped the fish pellets away and watered the plants w=
ell and they all recovered except the ones that dried up.

And a third bugaboo.... this probably won't affect people who use compost t=
eas. Strange as it may seem one can work with a grower and AM fungi has be=
en applied and CT is being used and don't be too shocked to find the grower=
 applying some sort of systemic fungicide to his plants as a precautionary =
measure... even after you have spent all kinds of time educating the grower=
 about what to do and what not to do. You just can't predict what people a=
re going to do. Well, certain fungicides are super effective at killing AM=
 fungi and you will have to start all over from the beginning with another =
application. Surprisingly, some fungicides at low levels are actually stim=
ulating to AM fungi.

Just a few tips to consider..
--Thomas Giannou
http://www.tandjenterprises.com


  ----- Original Message -----
  From: soilfoodweb_at_aol.com
  To: compost_tea_at_yahoogroups.com
  Sent: Friday, June 13, 2003 1:16 PM
  Subject: Re: [compost_tea] Re: adding VAM ?


  Mycorrhizal fungal inocula need to be placed next to the roots. Addition=
 to compost usually dilutes the spores too much, unless the compost with sp=
ores is put into deep aeration cores, like 3 to 4 foot deep, into the soil =
the roots are in.

  Addition to tea has to be just before the plant will be put near the spor=
es.

  So, soil injections with tea to which the spores were added work good.

  Root dip into tea with spores (do not add root GELS to get the spores to =
stick. the lack of air that results with the gels we have tested kill the =
fungi).

  Tea with spores applied into aeration holes works great.

  What have I forgotten here? Any other ways to apply tea with spores?

  Elaine Ingham



Received on Fri Jun 13 2003 - 22:08:25 EDT

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