Agree there are many OMRI approved fungicides but you need to understand that fungicides aren't a cure. They are a preventative so most effective when applied before the disease appears, and yes you spray the entire plant to protect it. Also keep in mind that none of the organics test out as effective at control as the synthetics, primarily Daconil. So for next season you'll want to consider a preventative spray program from day one of plant out.

That said your choice include several different copper-based fungicides in addition to the ones already mentioned. Some are more readily available locally, some not. So that should be your focus - get something ASAP. You can always change to another fungicide later.

Purdue Univ. - Using Organic Fungicides

Also check out these discussions of this question:

http://forums.gardenweb.com/discussions/2176791/best-fungicide-to-use?n=14

http://forums.gardenweb.com/discussions/2178808/that-old-question-about-the-best-organic-fungicides?n=11

Dave

I've had good results using Serenade for rust on roses.

That's septoria and it's quite a lot worse than early blight. I don't know of any organic in nature sprays that are proven to actually work. People say nettle sprays or neem work (I have big doubts), but if you want to slow down that thing you'll need at least copper, which is organic gardening approved at least.

I think it looks like septoria as well, but both diseases have a range when it comes to how they can appear.

Septoria isn't worse than EB in my garden. Both are about the same in terms of disease progression and speed. Both can be slowed down enough to get a decent harvest and keep plants going until frost with diligent spraying and pruning. But I imagine things might be different in other conditions. I prefer septoria simply because I've never seen it affect fruit at all.

I use organic copper soap against it. Although this year, I'm trying out a B. amyloliquifaciens biological product and may just use that all season to see what happens.

Yeah as I initially said - there are signs of both - and in many cases they do go in hand as they only need the right climate conditions to become active. In variably those climate conditions develop in the spring's inconsistent weather.

But like gb said, I find little evidence that septoria is "a lot worse than early blight" in its effects on the plant. The synthetic Daconil is much more effective on septoria from what I have read and seen but so-called "organic" fungicides combined with good plant hygiene can slow it down.

Ideal solution for both is preventative spraying from day one.

Dave

I've used Serenade for a couple years. It's a very good preventative against bacterial speck, and it's an OK preventive spray overall, but once a plant has EB or septoria, it's not as good as copper, in my experience.

But copper, even organic copper, can have detrimental effects on aquatic life, so if your development has a pond or something it's trying to protect, it may not allow organic copper. It will probably be better than nothing. Spray all your plants with it to prevent or delay spread to them.

A lot of times, organics and biologicals can't prevent disease entirely but they can significantly delay onset of foliage diseases. The later foliage diseases strike, of course, the more production and the higher the chance your plants will make it to frost.

"They also made me hopeful that because of the different varieties of tomatoes planted it will not likely spread to all of them because of the different disease resistances. (Not sure if that's true but one can hope :)"

Hate to burst your bubble but don't hold your breath on that. ;-) And don't refrain from spraying all the plants in that hopes that it might be true. It is one of those claims that sounds good in theory but doesn't hold up in practice.

Dave

i use neem oil religiously.. it is the best fungicide/pesticide in my opinion and even acts as a rodent repellent. i use the Bayer/Natria brand it is concentrated. the bottle really goes a long way and last me 3-4 years at 1-2 tablespoons per gallon.. it already has a emulsifier in it so no need to add anything to it besides water.

BUT, as some mentioned, it is not a cure all and for it to be most effective it should be applied BEFORE diseases set in as preventative maintenance, around every 1-2 weeks.

it is extremely effective. i've been using it for around 5 years now.. i just recently used it for a beetle problem eating my Kale and beets. last week i used it as a fungicide and today i am applying it to repel squirrels and skunks from digging on my soil bed (i just spray it over the soil/hay) and they stay away. the skunks digging for worms and grubs and the squirrels looking for buried nuts or stashing them.

i've yet to find another product that can be used this way., it's also one of the safest, since it's basically like any other oil we eat (oil that comes from a seed or nut) just neem oil as some extra properties that grape seed oil does not have ;-)

there is a lot more research now on neem and it neem has even been found to be beneficial to the soil as a conditioner and oddly enough, as a earthworm promoter.

good luck with it. just be sure to apply it early next season and every once in a while after that and after rains.

I use neem sparingly because it's broad spectrum. Anything that is that broad spectrum is not going to distinguish between beneficials and pests, and I've invested a lot of time and effort on a strategy of letting nature do most of my pest control for me. You'd think something "natural" and so safe for humans would be compatible with a "natural" strategy, but that's not always the case. It depends on the strategy and your priorities.

I'd probably use daconil before neem for disease prevention/control because chlorathonil has no insecticidal properties, whereas neem does. But as it is, I stick to biologicals and then copper toward the mid-late season as diseases ramp up. I will use neem on my squash and cukes if the powdery mildew starts getting bad and is no longer controlled well by other options.

For pest control, I hand-pick as long as I can, use plain water for aphids, and use BT for caterpillars if there's a growing infestation. I'm very comfortable with BT because it's so specific to just caterpillars. I use spinosad, which is broader spectrum than BT, selectively on the bases of my cucurbits (for SVBs) and on tomato fruits that have set and some of the foliage around tomato fruits. I will sometimes use neem in a soap/oil spray to knock down pests that cluster in ways that make it easy to target only small areas of plants.

Of course, if I got a bad case of mites or thrips, all bets would be off. These are not common problems where I am, though.

i think it's widely known that neem is non-toxic for most beneficial. everything about it points to even being save around bees and ladybugs.
i even drench my soil with it once or twice a season (beginning/end) and my soil bed have earthworms and insects crawling everywhere.
most of neem insecticide properties come by ingestion in the larvae stage and almost every bug out there that has a soil-larvae stage is harmful to the garden.. simply spaying it on an insect isn't going to kill it.

i even find its citric-like scent rather pleasant. i also believe the scent alone does a lot. beetles tend to not even get near the kale after i spray them, yet i see the common white butterfly strolling around unphased.

in the soil, it's actual shown to promote activity rather than kill.
the benefits far outweigh any slight downside it may have, which i have not even found any.

here is very extensive study on neem and earthworms:
https://www.hindawi.com/journals/aess/2011/925950/

its a long study, skim to the bottom for the conclusion. in short, only really high concentration doses irritated earthworms and didn't even kill them at high concentration. i have several other studies showing it boosted earthworm population by 25%.

There's more to garden fauna than earthworms. Much more.

Claims that neem is harmless to beneficials 1) don't make sense and 2) are not based on any actual evidence.

When neem is actually studied experimentally, it has been shown to have sublethal but harmful effects on the health of bees, for example. And I garden to attract and nurture native bees among other creatures. It has also been shown to reduce lady beetle reproduction as well. Most of the studies on its effects on beneficials have never been done.

Anything that eats a pest that has ingested or been coated with neem is also eating the compounds in the neem. Nobody has explained to my satisfaction how something that harms such a wide variety of creatures knows not to harm those that are beneficial. Neem does not have a brain.

I'm not saying neem is bad across the board. Everything has its place. But it depends on what you're trying to accomplish in your garden, and I've finally reached a point in my garden where I have to use almost no insecticides at all. I'm not about to throw that out the window by introducing widespread, indiscriminate use of a broad-spectrum insecticide, no matter how organic it is.

i suppose if you spray an aphid with it and a ladybug happens to come along and eat the aphid,. but that would be pure speculation and what are chances you have aphid infestation, spraying neem, and also have ladybugs eating the aphids..

since earthworms have no exoskeleton, they are usually very sensitive. that is why there is more research for worms than there are for other insects.
no one will probably every know exactly what neem will and won't kill, but so far more research point to it being very safe around beneficial ecosystem, and i'll go with it until i see otherwise, that's how i see it. nothing so far that i've read point to any real harm. more good than bad.. i still see carpenter bees going from tomato flower to tomato flower every single day of the entire summer, they don't even seem to mind the scent. ;-)

Earthworms are also in a completely different phylum than most beneficial predators and pollinators.

stevie: but so far more research point to it being very safe around beneficial ecosystem, and i'll go with it until i see otherwise

Multiple Routes of Pesticide Exposure and the Risk of Pesticides to Biological Controls: A Study of Neem and the Sevenspotted Lady Beetle (Coleoptera: Coccinellidae)

Biological Effects of Neem ( Azadirachta indica ) Seed Oil on an Egg Parasitoid, Trichogramma chilonis

Effects of neem-treated aphids as food/hosts on their predators and parasitoids

Lethal and sublethal effects of azadirachtin on the bumblebee Bombus terrestris (Hymenoptera: Apidae)

" and what are chances you have aphid infestation, spraying neem, and also have ladybugs eating the aphids.."

Quite common actually. Not to mention that the use of Neem for aphids is unnecessary when plain water works just as well.

Earthworms are a totally separate class and are not considered nor included in beneficial insects research. They aren't an insect, they don't live on the surface but deep in the soil, they don't eat the plants or come into direct contact with the Neem so they have nothing in common.

When it comes to insects Neem has been proven to:

• Disrupt or inhibit the development of eggs, larvae, or pupae (aka kill them);

• Block the molting of larvae or nymphs;

• Disrupt mating and sexual communication;

• Repel larvae and adults;

• Deter females from laying eggs.

  This is not to say the Neem has no role in pest control. It does. But use of Neem in an indiscriminate fashion is your choice of course but advocating that type of use to other less informed individuals, in light of all the research done on its effects on beneficials, isn't justified.

  Dave

there are far worse things your next door neighbor might be using. besides, it's whats more safe for me. i would rather ingest some neem oil with my kale than BT, or many other pesticides that might be considered organic (copper?) yeah go ahead, eat some metal with your fruit ;-)

i'm for the environment and its ecosystem more than the majority of people.
if my use of neem oil accidentally killed 1000 ladybugs that ate neem-coated aphids, but managed to killed 100,000 beetle grubs from drenching my soil, then i succeeded eliminating a big threat to my garden as well as all the surrounding houses in my neighborhood. the beetles would have done a lot more bad than the good the ladybugs would have done..

when a creditable study comes along that say neem is killing the typical beneficial garden insect (bees, etc), then i'll reevaluate ;-)

OP - look at my recent tomato plant post. very wet, cloudy and cool spring. weekly/biweekly use of neem since transplant..

Whatever your reasons are, it's your decision. Nobody's trying to tell you what to do. But if you recommend it as being completely harmless to the ecosystem, you are not making a correct representation of the situation, period.

I don't know what you consider "creditable" if study after study on ladybugs, bees, and parasitoids isn't enough.

Granted, there are many more beneficial insects that haven't been studied on this issue, but since we understand quite a bit about what neem does to a wide spectrum of insects which are considered pests, there's really no reason to think that just because humans classify others as "not-pests" that neem is going to treat them differently.

stevie: besides, it's whats more safe for me. i would rather ingest some neem oil with my kale than BT, or many other pesticides that might be considered organic (copper?)

BT is a harmless bacterium to humans. In addition, any residue washes off very easily unless you use a sticker. Copper is toxic in high doses, yes, but the amounts you'd get even if you didn't wash vegetables would be well within the margin of safety for most people, and organic formulations wash off very easily. Neem, meanwhile, is not always harmless to humans. Plus, neem is an oil, which won't rinse off easily with just water, so you're much more likely to consume neem residue than BT residue or copper residue. In the end, none of these choices is likely to harm you, but you'll be consuming more of the neem than the other applications.

Once again, you decide the way you want to decide. But don't misrepresent facts out of ignorance to other people. People need to be given accurate information so that they can make their own decisions.

stevie: there are far worse things your next door neighbor might be using.

I try not to use what everyone else does as a basis to rationalize choices that I personally feel I shouldn't be making.

I'm just not crazy about neem as the first time I used it I ended up burning the leaves on some of my plants. That said, I'm probably going to give my cruciferous veggies a spray later today. GB, I'm curious - you said that you switched to copper mid to late season. When exactly would that be for you?

generalfactotum: GB, I'm curious - you said that you switched to copper mid to late season. When exactly would that be for you?

Yeah, that's not really a precise description. I guess I meant more mid-season for fruiting. So that would be around beginning-mid August for me here in PA, depending on the weather. Sooner if more rain and humidity. If I start seeing signs of early disease, I'll work in some copper applications earlier.