Early blight and heirlooms

[dirt dauber]

As happens ever year, my plants have early blight. Im almost ready to give up on heirlooms but I've yet to taste a modern hybrid worth growing. I practice trimming the lower leaves and space my plants well for circulation. This year I have gone to growing in earth tainers with soil less mix having thought this was fusarium in the past. I have wanted to stay orgainic but don't believe it to be totally possible in the south east. How did our ancestors ever grow these plants? I have tried strains with Cherokee purple ancestory and they seem more resistant but I still have issues with blight. Same thing with potato leaf types. I've started spraying with Daconil in an attempt to salvage my crop. Is it possible to at least slow down progression of blight? Next year I will follow the practice of early spraying with Daconil. I would appreciate hearing from anyone who has had this problem.Thanks.

[carolyn137]

It's not just about heirloom varieties and foliage diseases,A. solani ( Early Blight) in your case, since neither OP heirlooms OR hybrids have any effective genes for the common foliage disease tolerance,never resistance.

There are a few varieties that do have some tolerance to Early Blight, mainly a coupleof hybrid varieties, but all it means is that instead of spraying every 4-5 days with an anti-fungal one can go a few more days.

And that's a big saving money=wise for the large scale commercial grower.

And that was told to me by Dr. Randy Gardner, a very well know tomato breeder who bred the Mountain series, many more, and more recently Mt Magic, Smarty and PLum Regal, all F1 hybrids.Without checking I think it's Mt Magic and Plum Regal that have some EB tolrance but I've grown both and find the taste of MT Magic to be much better IMO.

Daconil is best used as a preventative once plants go out for the two common fungal foliage pathogens, Early Blight and SeptoriaLeaf pot, but has no action against the two most common bacterial foliagepathogens Bacterial Speck and Spot.

Hope that helps.

Carolyn

[Paradajz]

hi, DD.

oh i agree it's a stubborn bug AS, but no need to be so heartless in the battle with it
and, believe it or not, i have witnessed a garden full of it which overcame it organically. only once, unfortunately.

a couple of suggestions to you, might help.
basically, you need a systemic- integral approach to manage it, and it shouldn't be such a fuss if you do it right.
lets start with the usual stuff:

1. If you do it from your own seed be sure to disinfect it properly ( if you go organic, couple of minutes in a mixed solution of propolis and olive oil do it just perfectly for me ).
2. Use only soil- less mix for growing seedlings and be sure it's done in a protected environment- AS is soil and air borne too, keep your equipment disinfected.
3. Try to eradicate all weeds you can lay your eyes on in your garden.
4. Mulch is an absolute must.
5. Water at a solid distance from the plant and totally avoid spraying water on plant's leafs while doing it ( a big must ).
6. Don't prune anything from your plants at rainy or humid weather. As a matter of fact, avoid touching your plants at such weather.
7. Trimming and spacing you have already named. Trim before any symptoms occur.

Following with more specific stuff and a general overture:

Generally spoken, each tomato plant has a very simple life cycle. To name it in a simple, non- scientific way, 4 phases:
I ROOT phase
II HEAVY VEGETATION phase
III MODEST VEGETATION phase
IV CROP HARVEST phase

The logic here is very simple- when managing any disease one needs to understand those phases and harmonize his actions with it. This means:

1. All your actions in phase I ( completed approx. 10-14 days after transplanting the seedling to the final spot ) need to be concentrated on creating a plant with healthy root system- it's the basic starting goal, if not achieved no further actions will be of any use. If achieved, the fundamental presumption of having a healthy plant is there.
* More specifically and if you chose to use chemistry after all:
- fosetyl aluminium/propamocarb combination ( Bayer's Previcur energy if available ) twice- once at transplanting the seedlings in a pot, once at transplanting to the final place. It's an excellent broad fungus protection, but in addition it significantly ''fuels'' the root system of the plant.
- A mild copper solution spray when the plant develops 2 sets of leafs ( should be 5-7 days after Previcur was used for the first time ).
- Phosphorus fertilizer with a moderate nitro content ( NPK 1:2:1 is ok ) twice: once on 4 sets of leafs, once approx. 7 days after transplanting to the final place.
- Any kind of root system bio- stimulating combination all the way trough the life cycle of a plant ( for example, I use a local product named ''Slavol'', it's a mixture of 6 strains of useful bacteria which inhabit the root system of a plant ).

2. Phase II is actually the phase of spraying.
I have to notice that, from my short experience here, it seems chlorothalonil ( Daconil ) appears mega- used as choice n1 in your agricultural practice, which is ok since it's an excellent substance, but absolutely shouldn't be used in this phase. It's for a very simple reason: the plant is still far away from harvest, and ''golden oldies'' as copper, mankozeb and propineb are at their prime at this phase, while the precious contact ( preventive ) fungicide as chlorothalonil ( with the shorter restrictions attached to it ) should be preserved for later, if needed. Also, the fundamental logical fact which makes using such a substance ( contact ) at this point a pure waste: in this phase the plant will be growing new sets of leafs at ultra speed and the new ones will stay unprotected in no time, or you will have to spray more than you can take. This means that a systemic should be used there.
* Therefore:
- Copper + propineb/mankozeb spray at first prognosis of rain after the transplant to the final spot ( specifically, propineb has been shown to be slightly more effective with AS than mankozeb, although the later in combination with cooper has utmost anti- bacterial and even anti- viral impacts... so it's an extremely tough decision which to use, leave it to you ). And all 3 of them are organic fungicides with long lasting effects and no resistance to it.
- Whatever rain might fall, no need to repeat it in a shorter interval than 7 days, with normal weather 14 days will absolutely do
- In between use difenoconazole ( just once in the cycle should do, twice if extreme weather makes you spend copper/propineb to early ), because it will broaden the protection against mildews. It also specifically targets AS ( in my experience, extremely effective with it and Septoria too ), and it should keep the new growth covered long enough. If not this substance, there are plenty others to chose from.

3. Phases III and IV? No need to do anything specific there, because the job was completed in time... when you create healthy, strong plants in the first 2 phases it should be able to endure whatever might blow their way and still produce yields. It will be up to you and the particular situation if some additional stuff such as chlorothalonil ( or/and something else ) should be used there.
And please note, with such an approach you used mostly organic fungicides, and you also used it in early plant phases when it is most likely that no significant residues will end up in the fruits eventually.

Finally, to be completely honest- such kind of approach isn't solely mine, it's actually scholar in our agriculture, for this purpose I only moderated it for AS slightly, but it will actually cover most of the curable fungal diseases and significantly lower the risk of bacterial ones.
The logic is very simple- just apply the appropriate combinations at appropriate moments, and the result should be minimal chemical investments/health risks with maximal effects. That's why I was a bit surprised at so many mentions of chlorothalonil and such frequent intervals of it's use in tomato growing here, interesting how different our practices are.

br,
ivan

[amideutch]

Here is a link that might interest. Making periodic applications of Actinovate and EXEL LG together as a foliar I have had few problems with foliar disease. Also inoculating seedlings with Mycos and beneficial bacteria make for a healthier plant with increased disease resistance.

Ami

http://www4.agr.gc.ca/AAFC-AAC/displ...36145&lang=eng

[feldon30]

Originally Posted by dirt dauber

I've started spraying with Daconil in an attempt to salvage my crop. Is it possible to at least slow down progression of blight? Next year I will follow the practice of early spraying with Daconil.

If you use Daconil consistently from day one, you will minimize early blight, alternaria canker, septoria, anthracnose fruit rot, etc. to the point where you should get a great harvest. But as you say, you are hoping to go organic.

Originally Posted by dirt dauber

I have wanted to stay orgainic but don't believe it to be totally possible in the south east.

For years, people tried Serenade (OMRI) and while it wasn't as good as Daconil, it provided some control of fungus. However the new kid on the block is Exel LG which is the first systemic fungicide safe for food crops, and it's actually organic to boot. Alternating between Exel LG and Actinovate (beneficial microbes) is gaining a lot of fans here on Tomatoville and has shown itself to be equal to Daconil in a number of gardens.

Basically, early blight and these other fungal diseases are sufficiently preventable and manageable that you should have no trouble getting a good harvest if you start early enough with a spraying regimen. And between Exel LG and Actinovate, you can be completely organic. I should say I have not personally tried this regimen, but people who I trust have, and have gotten great results in very humid years where they normally would have had major outbreaks and crop loss.

Originally Posted by dirt dauber

I would appreciate hearing from anyone who has had this problem.Thanks.

Fungal diseases and blights are a widespread problem in South Carolina, Georgia, Florida, S.E. and Central Texas, Louisiana, southern Mississippi, etc. We all have to deal with these problems.

[RayR]

I totally with Ami on this, the foliar treatments of Actinovate and EXEL LG are good, Actinovate as a direct attack against fungus pathogens, EXCEL LG has only a direct effect against oomycetes pathogens but the suspected triggering of systemic resistance in the plant is a plus against bad fungi too.
The most important but most overlooked part of the defense against common foliar pathogens is that resistance actually begins at the roots with Mycorrhizae, Trichoderma and beneficial bacteria.

[lapk78]

Does anyone know whether or not Actinovate can be mixed with Daconil? Thanks.

[carolyn137]

Originally Posted by lapk78

Does anyone know whether or not Actinovate can be mixed with Daconil? Thanks.

No, you should not add anything to Daconil

Quite a few years ago I contacted Ortho about that and was told that the # of molecules of Daconil had been calibrated to cover the attachment sites on the upper leaf surface after pproper dilution, and anything added would dilute the Daconil and leave unprotected receptor molecules.

To back up a bit, which I already knew, there are specific receptor sites on the upper leaf surface for Early Blight, Septoria Leaf Spot as well as Late Blight (P.infestans). Dacolnil attaches to those sites and thus prevents attachment of the fungal pathogens.

Also, if other stuff is added to the Daconil there can be intermolecular attractions between Daconil and whatever else was added and depeding on the charge they have on them, as + or- clumping can occur.

Hope that helps,

Carolyn

[carolyn137]

That's why I was a bit surprised at so many mentions of chlorothalonil and such frequent intervals of it's use in tomato growing here, interesting how different our practices are.

&&&&&

Ivan, allow me to try and explain.

Dacolnil is the most widely used anti-fungal in the world and has been studied more than any other anti-fungal..so any possible side effects are well known.

Daconil is synthetic but has less toxicity than does Rotenone (organic), which is approved by all organic certifying agencies I know of.

Dacolnil works well and I just explained how it works by blocking receptor sites on the upper leaf surface of tomato leaves in a post I just did here/ So it is not a systgemic anti-fungal.

Daconil iis widely available in a variety of concentrations and names, but for home owners it's the 29.6%concentrated one that needs to be diluted to the effective concentration.

Without using a good antifungal there are some(many?) folks who would never have a goood tomato crop.

My own philosophy is as follows. I don't really care if a product is synthentic or organic b'c my main concern is how toxic a product is to humans, animals, fish, birds and the environment in general. Some organic productgs have toxicities, such as Rotenone, and some synthetic products do as well, but Daconil does not.

It's suggested that Daconl be sprayed from the time that plants are first put out since that's when they are exposed to the fungal spores in the environment, and of course the fungal burden can vary from year to year and region to region.

If plants that have foliage infections with the two most common foliage fungal pathogens such as Early Blight ( A.solani) and Septoria Leaf Spot, the spores can fall to the ground and then in the next season one can see what's called splashback infection after heavy rains or irrigation, but all NEW infections come from spores spread via air and embedded in rain droplets.

Commercial farmers have pesticide licenses and have access to a battery of products; home growers do not.

I haven't addessed the bacterial foliage pathogens and won't in this post.

I use organic fertilizers, I don't use organic seeds b/c it's how a plant is grown that results in organic fruits,and I'm not one to boycott Monsanto or Syngenta b'c of a political philosophy. That doesn 't mean that I agree with everything they do,far from it,it just means that personally I don't subscribe to the vehemence that I see others doing as a general mission.

And while I do know that many will agree with most of what I said above I also know that some prefer on using only organic anti-fungals, and nothing wrong with that either.

Each person has to find out by trial, taking into account their own gardening philosophy and goals, what works best for that person.

Carolyn

[b54red]

If you don't mind a short season and spending an inordinate amount of money on organic solutions you might be able to have a short season down here. If you put out enough plants then some of them will usually survive long enough to make a decent crop. I went totally organic for a few years and did quite well with many crops like brocolli, cauliflower, spinach, lettuce, onions, and some hot peppers. My squash, cucumbers, melons, bell peppers and tomatoes were not so lucky. Worst were the tomatoes. I would usually plant 50 or more tomato plants with most being hybrids only to get what I get off half a dozen plants now. By mid to late June most of my plants were eaten up with foliage diseases that resulted in an early onslaught of spider mites to attack the weakened plants. A peanut farmer friend gave me a Mason jar of Bravo that he used on his peanuts every year after I told him my woes with tomatoes and said to use it on my tomatoes at a rate I can't remember now and to use it every week or 10 days. The chemical in the product was chlorothalonil and for as long as that jar lasted I had good tomato crops with relatively low disease problems. When my bottle of Bravo ran out I decided to go organic again and I tried Seranade after hearing all the glowing reports of how effective it was. I might as well have been giving the foliage diseases food to make them spread faster. That summer was a total disaster. It might be somewhat effective in areas with less disease pressure and lower humidity but I found it totally useless on my tomatoes for that season.

I now depend on chlorothalonil spray as a preventative and a mild bleach solution if any diseases get started despite the Daconil or because of heavy rains stopping its application. Now as long as the fusarium, TSWV, bacterial wilt and such leave my plants alone I usually have a long productive season. I set out plants from March up til August and lose quite a few to fusarium and bacterial wilt but most years I have fresh tomatoes from early June til Christmas.

It is important to prune your plants to a more open growth so that they have decent air flow so they can dry quicker in our humid climate. This also aids in getting good coverage when spraying.

Unless you just have to go organic, I would suggest you keep most of your plants sprayed every week to 10 days with Daconil. If you want to experiment with some of your plants with other methods then you will still have a good shot at having some tomatoes if those methods don't live up to your expectations. It can be daunting dealing with growing in hot humid conditions but the advantage is you have a nice long growing season.

Bill

[Paradajz]

hi, Carolyn.

please note, i haven't been addressing to the substance in a way like ''chlorothalonil is bad, people'', i was actually talking when could be the right ( most effective ) moment to use it, since using it from day 1 in so frequent intervals ( 5-7 days mostly named around here as i noticed ) isn't a justified procedure ( as i said- from the perspective of our agricultural practice, i sincerely don't wish to patronize anybody or anything here ).
the logic of it is very simple: in early vegetation period with tomato, a simple copper/mankozeb combination of contact fungicides will provide a much wider range ( fungal and bacterial ) of protection, and a longer lasting effect. with a systemic added as alternation, a far better protection of rapidly emerging new growth will be provided too.
eventually, this brings us to a very simple account: in this phase of plant's life cycle, 2 copper/mankozeb treatments + 1 or 2 systemic will provide a 30-45 days period of very broad protection, factoring weather conditions. for the same period and at a standard rate, there would be 6-9 chlorothalonil treatments, and at the same time the range of protection would be significantly narrowed.
further more, from a different point of view, conventional agricultural science has certain standards for such stuff. e.g., in growing apples one knows he will complete the cycle with 14-18 pesticide treatments, just as tomatoes go with 5-8
so i was actually commenting on the process how it's used, not the substance. chlorothalonil itself is an excellent substance, as i said- a precious contact fungicide for later ( close to harvest ) periods. also, the system how the substance does the job is unique- it ''messes'' with fungal enzymes, confuses them and eventually starves them to death. beautiful!

as for the rest, allow me to disagree a bit:

i don't know if Daconil, as one of the commercial trade names of chlorothalonil, is the most widely used anti- fungal in the world, but i do know that chlorothalonil isn't. it's actually n3, coming after copper and sulfur.
and by the way, chlorothalonil is widely and extremely successfully mixed with other stuff around the world- e.g., one of the best fungicides i ever met is Syngenta's Ortiva Opti ( azoxystrobin + chlorothalonil )


on the other hand, i personally share exactly the same point of view on organic/synthetic issue as you do, but in the same time i totally cannot agree with the statement that chlorothalonil has no toxicities, since the stuff itself is extremely immobile in practically all types of soil, while it's fundamental degradate is slightly more mobile but hugely more toxic ( some 35 times i believe ).
just as most ( all ) of other pesticides, it brings it's share of risks and one should be careful with it.

about splash- back and new infections, it's a bit of over- simplification. fungus still have to travel to air and rain droplets from somewhere, and that place is usually soil.

finally, i'd like to add my huge personal admiration to your work and efforts in the field of heirlooms to our lovely disagreement

br,
ivan

[amideutch]

one of the best fungicides i ever met is Syngenta's Ortiva Opti ( azoxystrobin + chlorothalonil )

Agree on the above statement. Your preaching to the choir on azoxystrobin. As it is readily available here in Germany in small quantities I used it opposite of my EXEL LG/Actinovate applications normally 3-4 times a season.

The non-availability of azoxystrobin to the backyard gardener in the states is crazy as it is available to commercial growers. Right now the cheapest retail price for Heritage I believe is $80 to $100 which is out of the range most home gardeners are willing to pay.

I even wrote to one of the companies here who sells azoxystrobin and is also in the states as to the reason why they can't sell smaller quantities of azoxystrobin in the states as they do here and they gave no reason except they would look into it.

I don't use chlorothalonil because that is my choice and I try to stay as organic as possible. But some folks in the states are in areas where disease pressure is high like red in Alabama where they don't have access to azoxystobin products and EXEL LG/Actinovate may not be sufficient to handle the disease pressure then I say go for the Daconil or anything else that works in your environment.

But the key is to have a disease control program from the get go and stick to it. Most folks wait till they have disease problems then ask for help and by that time the disease is well established and beyond control.

Plant health is another player in disease resistance and a healthy plant is more able to fight off disease as one that is in stress do to dehydration or lack of nutrients. This is where our PGPR (Plant-Growth-Promoting Rhizobacteria) Biofertilizers and Biopesticides come into play and why we inoculate our plants with on plant out. They fight soil borne disease by what is known as induced systemic resistance ISR when a pathogen is present. Also the bacterial colonization of plant roots aids in mineral and nutrient uptake while pest control is due to activation of ISR.

System Aquired Resistance SAR is another plant defense mechanism which diverts resources from other areas of the plant to the area of the plant under duress. We can use common aspirin which provides salicylic acid as an SAR activator. Put 1 Aspirin in a gallon of water and spray your plants and this will activate the SAR. If you see you plant is under duress from possible disease infection or you are in a drought situation this will activate the plants defense system.

Ami