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dice · August 21, 2008

I did some Googling for biocontrols for verticillium. There
was a high-chitinase-producing organism mentioned,
streptomyces plicatus, that repressed spore germination
and development of fusarium, verticillium, and alternaria
( http://cat.inist.fr/?aModele=afficheN&cpsidt=13432886 ),
but I did not find any commercial biocontrol preparations
that include it. There were a couple of fungi, trichoderma
viridae and trichoderma harziana, mentioned in other
studies (a lot of sifting to find the information re: verticillium)
that reported some success in repressing verticillium when
found in or added to mature composts.

Perhaps more promising is information from China on using
plant extracts (water or alcohol extracts, I presume) to
repress either mycelial growth or spore reproduction
of verticillium:

http://www.find-health-articles.com/...albo-atrum.htm

A bacterium or micro-fungi organism would in theory be more
efficient (self-reproducing), but it is difficult to look at the soil
and know whether it is still there and alive a few weeks after
inoculating with the organism. A plant extract is more expensive
if you have to grow the plant and then make the extract (or buy
it ready-made), but it does not have to outcompete other soil
organisms to work. That is like fumigating with chemicals, only
in this case the chemicals are organic extracts from plants and
trees. (Anyone have a Chinese magnolia in their yard, for
example?)

There might be some possibilities for growing some of these
plants in and around verticillium invested plots, too. Especially
the Chinese Wild Ginger (asarum sieboldii) might be handy
in no-till plots. It grows in moist, forest soils in winter to
early spring and likes shade. The foliage dies off in the summer
heat, and it goes dormant. Permanently establishing it in no-till
beds where tall winter cover crops like winter rye, rye+vetch,
oats, field peas, winter wheat, etc are grown may give it the
shade it needs in spring, and it may repress verticillium
wherever its roots reach (assuming that whatever verticillium
finds unfriendly in it is found in and around the roots and not
just in the foliage). Even if the unknown anti-verticillium
substance is only in the foliage, that foliage is dead and
decaying in the mulch by summer.

Especially interesting is that extracts of various allium species
were found to repress verticillium mycelium growth more than
50%. That would include onions, garlic, chives, garlic chives,
and various ornamental alliums, any of which could cohabit with
tomatoes in containers and garden beds and could also be used
to make extracts for a soil drench. (Some bugs don't like
alliums, either, a fringe benefit.)

Edit:
PS: Beats the hell out of a 6 year rotation with grains and grasses
in between if you don't have acres of land to grow tomatoes on.

August 21, 2008	#8
dice Tomatovillian™ Join Date: Jan 2007 Location: PNW Posts: 4,743	I did some Googling for biocontrols for verticillium. There was a high-chitinase-producing organism mentioned, streptomyces plicatus, that repressed spore germination and development of fusarium, verticillium, and alternaria ( http://cat.inist.fr/?aModele=afficheN&cpsidt=13432886 ), but I did not find any commercial biocontrol preparations that include it. There were a couple of fungi, trichoderma viridae and trichoderma harziana, mentioned in other studies (a lot of sifting to find the information re: verticillium) that reported some success in repressing verticillium when found in or added to mature composts. Perhaps more promising is information from China on using plant extracts (water or alcohol extracts, I presume) to repress either mycelial growth or spore reproduction of verticillium: http://www.find-health-articles.com/...albo-atrum.htm A bacterium or micro-fungi organism would in theory be more efficient (self-reproducing), but it is difficult to look at the soil and know whether it is still there and alive a few weeks after inoculating with the organism. A plant extract is more expensive if you have to grow the plant and then make the extract (or buy it ready-made), but it does not have to outcompete other soil organisms to work. That is like fumigating with chemicals, only in this case the chemicals are organic extracts from plants and trees. (Anyone have a Chinese magnolia in their yard, for example?) There might be some possibilities for growing some of these plants in and around verticillium invested plots, too. Especially the Chinese Wild Ginger (asarum sieboldii) might be handy in no-till plots. It grows in moist, forest soils in winter to early spring and likes shade. The foliage dies off in the summer heat, and it goes dormant. Permanently establishing it in no-till beds where tall winter cover crops like winter rye, rye+vetch, oats, field peas, winter wheat, etc are grown may give it the shade it needs in spring, and it may repress verticillium wherever its roots reach (assuming that whatever verticillium finds unfriendly in it is found in and around the roots and not just in the foliage). Even if the unknown anti-verticillium substance is only in the foliage, that foliage is dead and decaying in the mulch by summer. Especially interesting is that extracts of various allium species were found to repress verticillium mycelium growth more than 50%. That would include onions, garlic, chives, garlic chives, and various ornamental alliums, any of which could cohabit with tomatoes in containers and garden beds and could also be used to make extracts for a soil drench. (Some bugs don't like alliums, either, a fringe benefit.) Edit: PS: Beats the hell out of a 6 year rotation with grains and grasses in between if you don't have acres of land to grow tomatoes on. __________________ -- alias Last edited by dice; August 21, 2008 at 06:41 PM. Reason: PS: