Responses requested - Fusarium in pot grown tomatoes?

[nctomatoman]

Hello, all - I decided to start this thread after a discussion with Carolyn earlier today. Many of you know that I plant quite a few tomato plants in pots, using fresh metroMix and composted cow manure (Wallace Farms) - with the pots bleached prior to planting.

Well, it is happening again this year, only earlier than usual. Citron Compact, Black Altai, Kimberly, New Big Dwarf, several of Patrina's F1 dwarf crosses, coming down with what appears to be Fusarium wilt (a few or many branches or main stems suddenly going bright yellow - then wilting, even when well watered - plants no longer taking up water, etc.)

The key question - research/information indicates that Fusarium should not be transmittable to pot grown tomatoes unless the soil in the pots is from infected soil. I have a suspicion that it can be spread by insects if they chomp on infected plants, then move on to the potted plants. Who amongst you have experienced Fusarium in your potted plants where there appears to be no possible vector for transmission other than wind borne spores or insects????

Will be looking for this to be an interesting, interactive dialogue with Keith, Carolyn and others chiming in.

Editing with the status of my driveway, potted plants:

Still very healthy, no signs of disease/wilt: Sneezy, Katinka, Marmande, Mexico Midget, Red Robin, Lime Green Salad, Saucy Green, Granny Cantrell.

Touch of wilt: Earl's Faux, Sleazy, Doc, Anna Banana, Sophie's Choice, Sleepy, Witty, Grumpy, Taxi, Kimberly

Significant Wilt: Dopey, Bashful, Black Altai

Nearly Dead - severe wilt: Happy, Silvery Fir Tree, Citron (which looks worst of all - for the second year in a row).

[Lee]

Pill bugs! Hmmm.... Now that's an intersting theroy.
I've had a large number of pill bugs in the garden this year,
and they've been regularly chomping on the live tomato
plants. Usually, I've only seen them on decaying foliage....

They also love the climate in the bottom of my pots, as there are plenty of them that come out when the dirt is
dumped at the end of the season.

If Fusarium can be spread by mechanical cutting instruments, why not the organic cutting instruments of
these insects.....

I have seen a good share of Fusarium in potted plants, however I can't claim the soil, cage, pot are not the source.

Lee

[Suze]

Craig/Lee, here's some things for you to ponder.

What about your stakes, do you bleach them also? Are you still using any wooden ones in containers? And if so, I wonder that even if one bleaches them, would the porosity make it impractical to really remove all fusarium? Or would some of it still remain in the stake, only to potentially 'bleed out' later?

Wheelbarrow/tools -- Do you bleach those too?

Compost -- I really wonder if this might be a factor. Is it a local source? Does their composting process dependably kill fusarium? And, do you really need to use the compost for containers in the first place? I myself prefer not to add anything to the ProMix (or equivalent) I use for containers, except dolomitic lime and time release ferts. I want the starting situation to be as 'clean' as possible. However, I do occasionally foliar feed with seaweed and/or fish emulsion for trace elements. So maybe try a few containers next year without the compost and see if it makes a difference.

Pill bugs and other crawlies -- If you suspect that as a possible factor (and I think it's reasonable to do so) I guess you could cut pieces of fine mesh screen to size for the bottoms of a couple of containers to keep them from crawling up through the drain holes.

Keith mentioned the dust, but what about fusarium being carried by rain droplets, wonder if that's possible and/or documented? Early blight can be.

Possible ways to 'clean' the soil -- There's some information on google re using hydrogen peroxide as a soil drench to rid soil of fusarium (type in tomatoes hydrogen peroxide fusarium). I haven't had a chance to read and digest much of it, though. Might be one of those things that sound good "in theory", but wouldn't be easily implemented. I've used 3% h2o2 at 1:10 to 1:15 many a time to water seedlings, and they actually seem to like it. So I don't think it would hurt for you to at least try something like that with a container or two. But once the plant is infected, don't know how much good it would do.

[MsCowpea]

(EDIT Suze--I must have been typing while you were posting. Oh well, great minds think alike)


As you mentioned, fusarium is not considered to be spread by insects. As there are other, more likely , possible sources of infection (even in containers bleached and filled with new mix) not sure how it would be possible to eliminate the 'usual' culprits and place the spread of fusarium on insects.

Do you water with city or well water? I have read that fusarium can be carried in the irrigation water. I was wondering if you reuse your tomato stakes? Fusarium can be transmitted on those and hand tools. Even by dust. Also it is is aggravated by use of ammoniacal nitrogen.

This is from Kansas State University:
"Fusarium can be spread on seed, stakes, soil, infected transplants, equipment, tools and shoes/clothing. Long distance spread is through seed, transplants or infected soil. Fusarium can even spread in the wind with dust particles. It is not considered to be spread by insects."

What a frightening thought that fusarium could be carried by insects--sure hope that it not the case. I would take TSWV over fusarium any day as it does not persist in the soil for years and years.

I was wondering--When you cut into the stem do you see the brown streaks that is shown in all the pictures?

Even though you seem sure as to what it is--have you ever considered sending it to a lab for verification. You just take in the whole plant (shake off most of the dirt). Doesn't cost much money. I believe there is a univ.based lab in Raleigh.
I know you have the bright yellow leaves and wilt -symptoms of fusarium. If it is fusarium you feel very bright that you diagnosed it correctly. However, though the chances may be slim, it might be something else.

Wondering what percentage of cow manure you use in the pots as that stuff is very dense and reduces drainage considerably even when mixed with potting mix. Too much would certainly compromise the roots as I am sure you know-leading to yellowing and decline.

(http://www.kdcomm.net/~tomato/Tomato.../fusarium.html)

http://www.ces.ncsu.edu/depts/ent/cl...mit/submit.htm

[Lee]

Lots of good thoughts to ponder. Thanks so much for
listing that.
I may try some preventive techniques next season to see what happens.
The idea that it could spread on wooden stakes and cages is another safe bet.
As I said, I don't do anything to prevent retransmission,
such as bleaching, so I can't say for sure that the container, or cages are not the source.

I also can't say that I've ever used just pure sterile potting mix to grow in either, as I've always used at least 1/2 of the container filled with cheap organic humus or the like.

However, I do find the statement from Kansas State to be
very odd. It can be transmitted by essentially everything except insects??? (My interpretation....) My guess is there
is a little truth to all of it.....


MsCowpea, I'll take that trade! Your point about it's longevity in the soil is a good one. However, I'd rather live with the fusarium, since with that, I know I can grow and get fruit off of tolerant varieites such as
Cherokee Purple, Cuostralee, and Big Beef. With TSWV.... all dead no fruit possible.....


Lee

[Love2Troll]

Put me down as one that believes the possibility of insect vector theory. Thrips and froghoppers are my main suspects.

After years of carefully bleaching tools, cages, pots & using new ProMix BX I've finally given up and accept that will have some evidence come July and plants will be dead starting sometime in August.

This year 7 of 20 plants show early signs. 4 are mail order Marianna's Peace, 1 is a started from seed Maxifort/Polish Dwarf graft and 2 are mail order regular leaf Dora.

Maybe next year I'll try bagging entire plants and sterilize everything again.

http://www.fototime.com/F966B5F49B76ED9/orig.jpg

http://www.fototime.com/8FD8C467A20C586/orig.jpg


jt

[mdvpc]

jt-What are you using as your blossom bag? Very nice-it almost looks like agribon or something similiar.

[Love2Troll]

Michael,

It's called tule. I buy it in the fabric dept at Wally*World. Very, very inexpensive.



jt[/url]

[MsCowpea]

Lee, hope I don't live to regret my words--but after a horrible year with TSWV I then went on to a great year with little problems. I just hope that I can continue to control those thrips. I just hate the thought of any serious soil-borne disease--I would have to move.

I have never seen fusarium in person--I know the symptoms seem very specific and distinct but I would still want confirmation. Love to Troll , are you sure you have fusarium? Sure glad I don't own a lab and depend on forum posters for business.

My husband was 'allowed' to fill some containers in my absence--put in alot of dense compost along with good potting mix . Those containers weighed a ton and did absolutely LOUSEY compared to the containers that had a mix like pro-mix and soilless Miracle Gro. Heavy containers don't need near as much water. Your 50% inexpensive humus stuff
would really effect drainage in a container. If I used something like that I would add tons of perlite to the mix.

http://www.ces.ncsu.edu/depts/ent/cl...mit/submit.htm

[rsg2001]

It has been three years since I had fusarium (and I had it to varying degrees for three years). One of the last straws for me was when one container plant came down with it -- and I had used fresh sterile mix in it. The only vectors I could think of were the cage (I re-use my cages) or the air.

I had lessened the incidence of fusarium through a variety of things -
1- mulching practices. I started using grass mulch, although I don't mulch the containers.
2- Soilgard, a product that Gardens Alive used to carry, but no longer does. This year I was not get it from the manufacturer, nor could the manufacturer find a distributor for me in the Northeast who would sell a relatively small amount. I'm very nervous that, come the dog days of August, the plants will get sick again.
3- Avoiding varieties that in my garden seemed more prone to getting sick (those included Anna Russian and Caspian Pink).

Last year, and this year, I've been using Messenger (along with Serenade to protect against foliage disease). I suppose it's possible that these practices might help, since Messenger supposedly boosts a plant's immune system. I just hope that I can avoid fusarium.

[Love2Troll]

Love to Troll , are you sure you have fusarium?

MsCowpea,

No, not 100% sure. If I lived in North Carolina would take in a sample. There is a country extention office only 2 miles away and maybe should make a trip there and see if they do testing.

Thanks

jt

http://www.csrees.usda.gov/Extension/index.html

[MsCowpea]

Love to Troll, what state do you live in?

Most extension offices do not actually do laboratory testing. They will try and diagnose your problem but whether of not they get it right depends on the expertise of the person looking at it. I prefer the lab especially when the results dictate very specific measures that should be undertaken. And it costs very little--why not take advantage of the service. The biggest expense would be mailing something to them but many have a univ.based lab close by.

If you got the diagnosis correct you have the pleasure of coming on the forum to say I TOLD YOU SO.

Extension offices should be able to tell you where you can actually take or send a plant for very basic tests (not the super expensive tests) The inexpensive tests may not be 100% accurate but better than guessing.

The reason I am so big on testing is I think some of the 'diseases' people think they have are caused by their own growing methods.

You may not want to test if you just have a few plants but if the same thing happens year after year I would evaluate everything I was doing and then get help.

[Love2Troll]

Love to Troll, what state do you live in?

Misery... near Kansas City

[JBinKC]

Troll it isn't that Miserable here. It could be worse you could actually be IN KC )) I'm near KC also and that's close eough for us )

[mdvpc]

JT-thanks for the info.