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Winter soil treatment

Posted by marullo pa (My Page) on
Tue, Sep 6, 11 at 14:48

Garden overcome by septoria leaf spot. I tried spraying with copper fungicide which helped a little. Was this the right treatment? Secondly, I know it is wise not to plant tomatoes in same location year after year but I have no options to rotate. I remove all debris and dispose of it. Is there a treatment that I can apply now in order to avoid this problems next year?


Follow-Up Postings:

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RE: Winter soil treatment

Septoria is one of the two most common fungal foliage diseases.

At this point spores have fallen to the ground from your infected plants. So I suggest turning over the soil as deeply as you can so as to bury those spores.

No, there is no winter soil treatment, but when you put out plants next year please consider using Daconil from the minute you put out those plants which is much better than Copper and it can be used to the day of harvest which tells you it isn't that toxic, actually Rotenone is more toxic. It covers the specific attachment sites on the upper leaf surface so that the spores of Early Blight ( A. solani) and Septoria Leaf spot have problems infecting the leaf surface.

The fungal foliage pathogens are spread by air and embedded in rain droplets , they aren't soil borne systemic pathogens, so new infections can happen all the time.

The bit about not planting tomatoes in the same place every year is a bit of a myth when folks thought that they depleted nutrients in the soil. The only reason to NOT plant in the same place year after year is for disease concerns, not nutritional ones.

So dispose of the infected plants, turn that soil over deeply, and I don't mean with a tiller, I mean with a spade that goes deep. And then in the Spring don't turn it over again or all you'll do is bring some of the spores back to the top.

And doing that can cause what's called splashback infection where rain or too much irrigation lets spores that have fallen to the ground or come up to the tops after burying them, can splashback on plants initiating infections from the base of the plant which moves upwards.

Infections from rain or air usually infect the most exposed leaves at the top of the plants.

Carolyn


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RE: Winter soil treatment

chlorothalonil (aka Daconil and found in Ortho Max Garden Disease Control) will help. I think if you are going to do a soil drench, it needs to be more concentrated than if you are doing a foliar spray.


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RE: Winter soil treatment

Carolyn, are you sure there isn't a soil drench that can get down in the ground and kill the Septoria spores for those of us who don't want to spend all fall deep digging?


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RE: Winter soil treatment

Even though we call these products fungicides, I am not sure that technically they are. A fungicide means an agent that can kill a fungus and I am not sure if these agents actually kill the fungus let alone a fungal spore. Fungal spores are incredibly hardly.

I think most if not all of these agents are fungistatic - meaning that they inhibit the growth of the fungus but don't actually kill it. That is why you need to start these preventatively - because they don't actually kill the fungus let alone the spores.

So I am not sure a soil drench over the winter will help, although a soil drench after transplant may.


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RE: Winter soil treatment

"But in the Spring don't turn the soil over again" seems like a difficult option. Am I to just plant in winter hardened soil?


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RE: Winter soil treatment

No, I'm not suggesting that you plant in winter hardened soil. You're in PA, I'm in upstate NY, and when the ground thaws in the Spring it isn't hard at all. Sometimes compacted a bit from snow cover but the ground loosens up quickly. If at that time you want to run a tiller over it shallowly, that would be fine as well.

Fungicides.

I can't think of one fungicide that kills naked spores. The vegetative forms yes, but not naked spores which is what falls to the ground from previously infected plants.

Daconil is not used as a soil drench for tomato foliar pathogens b/c, as I posted above, it only works by covering up the specific protein attachment sites on the upper leaf surface of live plants. It cannot kill naked spores.

I'm sure most of you know that many tomato pathogens can exist in the soil for many years, most of the systemic disease ones once there usually stay there and the foliage pathogen ones for up to maybe 5 years.

And that means they are very resistant to environmental insults.

Spores need to germinate to form the vegetative forms of the specific diseases before they can infect and there are conditions that allow for that and some that don't.

Just think of the conditions that are needed when fermenting tomato seeds that allow for the removal of the spores of several diseases to be lessened on the seed coat surface and I think you'll appreciate the acidic conditions that exist in the fermentation as well as all the enzymes that are needed, and all in the warmer temps of fermentation containers.

Yum made a good comparison above when she spoke to fungistatic which just slows growth of the vegetative forms of fungi as opposed to fungicidal which kills the vegetative forms, not the spores, of some fungal pathogens.

The same obtains with bacteriostatic and bacteriocidal, but those terms are used more in the sense of human infectious diseases. In that regard fungistatic and bacteriostatic products are used in humans to slow down multiplication of the pathogens so that the human immune response can get activated and help to control infection.

Tomatoes do not have anything like a human immune response.

A wee anecdote.Those who read romance novels or historical fiction know of the scene where the beautiful lady is prone in bed and suffereing mightly. By her side with one knee on the floor is her husband to be pledging his love and support if only she will live.

All of a sudden her fever goes down and her skin retains it's normal color and he is delighted.

So what happened? Her immune system, both the T and B cells kicked in and she recovered. No antibiotics back then you know. LOL

Carolyn, retired Microbiologist with a concentration in infectious diseases who taught med students most of her life who thoroughly enjoys talking diseases, whether human or otherwise. Just don't get her talking human parasitic diseases, nasty critters that they are. Jean and I used to spend hours upon hours in the Pest and Disease Forum here but that was years ago, for me at least, and so sometimes I feel like and have time to answer and sometimes I don't b'c I also read/post at other sites as well and I do have another life ya know( smile)


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RE: Winter soil treatment

Maybe next year a mulch would be useful to help control splashback. I prefer an organic mulch which also improves the soil, but plastic is sometimes better in the Spring because it helps warm the soil faster.

If you have a small garden and usually turn the soil with a spading fork in the Spring you can get by with just aerating it a little with the fork without turning it over; just push the fork in and pull back to crack the soil but don't mix it all up.

Bob B.


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RE: Winter soil treatment

  • Posted by lois PA Zone 6 (My Page) on
    Thu, Sep 8, 11 at 20:49

Will the spores that you bury by turning over the soil be dead by the time you turn over the soil again next year?


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RE: Winter soil treatment

Lois - I think the septoria spores can last up to 3 years in the soil. Early Blight, up to one year.

Here is a link that might be useful: Septora and Early Blight


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RE: Winter soil treatment

I can't seem to cut and paste from the article just linked to but if you look under CONTROL it's suggested that Solanceous crops be rotated every 3-4 years. But nothing was said about that suggestion in terms of how the soil was or was not treated as to Fall plowing or spading or the extent to which foliar sprays were used.

And that article was written for those in WI as it noted and while most of the article is just fine one can't always extrapolate from areas where the ground freezes deeply in the winter and those areas where that's not true when it comes to suggesting how long spores can remain in the soil.

Lois, there's a difference in burying spores deeply such that they have no chanace to germinate against spores that fall to the ground from an infected plant.

For many years I grew my tomatoes and much more in a 1/4 acre field where the young man who was renting land from us plowed my field deeply along with the others in the Fall, then planted winter rye, then just disced and smoothed in the Spring.

I grew in that same field for about 15 years and didn't have problems with splashback infection, was sprawling my tomatoes and used no mulch.

I had virtually NO splashback infection but of course would always have new infections spread by air and rain. That's a given, which is why I think it's important to use a vigorous foliar spray program with an effective anti-fungal for the plants, starting from when they are put outside.

Does that answer your question?

Carolyn


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RE: Winter soil treatment

  • Posted by lois PA Zone 6 (My Page) on
    Sat, Sep 10, 11 at 10:39

Thanks.. The part about burying the spores confused me because it seemed the spores you buried the year before would resurface when you turned over the soil the next year, germinate the following spring, and reinfect the plants.


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RE: Winter soil treatment

Thanks.. The part about burying the spores confused me because it seemed the spores you buried the year before would resurface when you turned over the soil the next year, germinate the following spring, and reinfect the plants.

*****

True enough Lois but my assumption is that the next year Daconil would be used to prevent any new infections so nothing to fall to the ground.

And if the ground is worked up again the next Spring, but seldom to folks plow or spade that deeply, that a mulch could be used to prevent splashback infection.

And if spraying with Daconil each year is continued the initial spores buried deeply would be non-viable in a few years and constant attention to spraying would help prevent new infections.

Carolyn


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RE: Winter soil treatment

if i have access to fresh or dry manure from cow / horse etc
should i mix into my soil any at all?
if yes, which is best?
also, is it better to mix in soil now before winter or in spring?
lastly - should i go for fresh or dry?

thank you so much


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RE: Winter soil treatment

Lois
2 yrs ago we had a very bad blight here in R.I., everyone called it late blight. Almost everyone I talked to lost their whole crop late in the season, ( I have a store and there is always a lot of garden talk).Even picking the tomato's green,they just rotted. Mine did not. I did not get the blight.

When I plant I always use Daconil. I make up a large bucket of water w/ the write amount of water verses Daconil and I drench the roots of the tomato plants in this before I plant. I was given this tip by an old timer gardener.
Then after planting I water them in with the Daconil mixture.Ratio on bottle.

My brother got the blight, after destroying the plants that fall he sprayed the ground w/copper, then turned the soil over. The next yr. he used the Daconil method the way I do and used weed prevention cloth in the whole garden. He had a very good crop last yr.

Daconil also helped get rid of downy mildew on my flowers. It took several yrs. I spray very early before anything comes up and several times thru out the season. I also spray at the end of the season. This yr I was lax. and it's coming back on some flowers. So I will be spraying at the end of season. Daconil is a great product.

For manure I use dry chicken manure, I put it down in the fall because it is very strong and I like to over winter it.
I also amend my soil in the spring w/ composted manure w/humus,peat,perlite if needed and fertilizer 10-10-10.

I plant my tomato's in the same place every yr. I think if you amend your soil every yr. you are replacing the nutrients and as long as you feed them you can plant in the same place.

My problem this yr. and last yr. was white fly infestation.
Last yr not as bad, this yr. very bad. I bought live lady beetles in 3 series along w/ lace wings and no help. Don't know what to do to avoid it for next yr. I'm thinking of burning the ground. Has anyone ever don't this?

Karen


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RE: Winter soil treatment

  • Posted by lois PA Zone 6 (My Page) on
    Sun, Sep 11, 11 at 11:59

Thanks, Carolyn and nerak, that makes sense now.


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RE: Winter soil treatment

Carolyn puts it through her own words like she has lived and loved life. To the point of belief. Good post.

And for the skeptics, nevermind.


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RE: Winter soil treatment

Thanks, Carolyn and nerak, that makes sense now.

Unfortunately, some of what nerak said doesn't make sense. Since it's been 36 hours and none of the experts have come along to point this out, I will try.

Daconil used as a soil drench to prevent Late Blight is just a waste of time and money (see Carolyn's earlier posts on this thread). There are two reasons what that is the case.

First reason: There are two possible types of pathogens which can cause Late Blight. One might exist in Florida, but so far as the scientists know, can't exist anywhere else.

If nerak's profile is up-to-date, she doesn't live in Florida (no zone 6 in Florida), so her tomatoes are in no danger from that pathogen.

Although the Florida-only Late Blight pathogen is able to overwinter in the soil, the only Late Blight pathogen known to occur in the other 49 states doesn't overwinter except in living tissue of plants susceptible to Late Blight (in colder regions, only in-ground potato tubers). You can read about this in Cornell's Late Blight FAQ:
http://www.longislandhort.cornell.edu/vegpath/lbfaq.pdf

Second reason: Daconil doesn't kill the Late Blight pathogen! It offers partial prevention of infection by the pathogen. The pathogen can only infect a tomato plant in certain locations on the leaves; Daconil attaches to the plant at those locations, preventing the pathogen from attaching there.

So drenching the soil with Daconil in Florida wouldn't even help against the type of Late Blight pathogen that can overwinter in the soil.

Yes, nerak drenched the soil with Daconil and didn't get Late Blight. But she'd have had the same result if she'd drenched the soil with olive oil, water, or Coca-cola. Or not drenched the soil with anything.

===

Likewise, Nerak's brother's additional preventives had nothing to do with his plants not contracting Late Blight the following year.

Spraying the ground with copper had no effect, since the Late Blight pathogen would not survive the winter anyway. Ditto for turning over the soil (to bury the pathogen?). And ditto for using "weed prevention cloth."

===

If any experts happen along, I beg that they will correct anything I may have gotten wrong.


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RE: Winter soil treatment

Expert? I don't know about that but when I have time I will get back here to hopefully clarify a few points and post a link or two to back up those points.

Carolyn


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RE: Winter soil treatment

I was also curious about burning the ground with a torch to kill fungal spores. They make relatively cheap propane torches that you could just pass back and forth over the top layer of dirt to kill any spores that would have fallen from the infected plants. I would have to re-think wooden raised beds and probably move to block beds, but do you think it would be effective? (Carolyn) Propane is pretty cheap so it would not be an expensive solution, plus, who doesn't like to use a flame thrower.


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