Is this little thing really what's destroyed my gardens?

[aclum]

Hi Naysen,

Not to further confuse the issue but have you considered a 10% milk spray? Check out this thread - lots of good info on the subject (although some differences of opinion, as usual <g>).

http://www.tomatoville.com/showthrea...ght=milk+spray

Relatively early on in season (but after fruit set as I recall), I suspected powdery mildew on some of my plants, but not sure and tried Neem Oil - which didn't have much effect. Then I found the thread above and tried the dilute milk and it seemed to work!

However, I keep getting the some affected leaves here and there and now just cut them off and forget about it LOL! I really hate spraying, mostly because I'm just lazy (or think I have other, better, things to do LOL!) and don't want to take the time to lift up and spray the underside of all the leaves!

So far, knock on wood, the plants don't seem to suffer from having the leaves cut off and they keep growing new, good, green leaves.

(But I still think an on-site inspection and diagnosis by the University Extension people is your best bet .

Anne

[b54red]

Have you used a copper fungicide? If you think you have powdery mildew it is supposed to work to prevent as well as stop it. I always use my bleach solution when I get powdery mildew and it is very effective; but any affected leaves will die and dry up within a few days. I have used it successfully on squash, melons, tomatoes, and cucumbers for getting rid of powdery mildew. The bleach spray has worked for me to kill or stop any kind of fungal disease but it has no preventative use so a fungicide would be useful afterwards to prevent further outbreaks. If it is not fungal or bacterial and is some kind of systemic disease like fusarium then the bleach spray will have no affect.

Did you check for spider mites? They will cause yellowing and can really sneak up on you because they are so hard to see.

I hope you can find out for sure what you are dealing with. Right now you remind me of when years ago I first encountered TSWV. I tried everything in the book and watched in frustration as one plant after another died from it before I knew what it was. Hopefully your problem is more amenable to a solution.

Bill

[z_willus_d]

Hi Anne, I hadn't considered milk. Hell, I don't even drink the stuff anymore. We're all almond now. I'll definitely give the thread a read, as it sounds interesting enough.

Ivan, points taken. I still have a bit of a hard time believing that every one of my beds, containers, Earth/Inn-Tainers have been contaminated and for two years running. For instance, the EarthTainers got brand new Sunshine Advanced mix. Other InnTainers got Ocean Floor mix, the hillside half-barrels were loaded up with a fresh dump of peat, manure, and bark fines. The new raised bed was a different load of stuff. The old bed was a different load but polluted with soil from my old garden in Sacramento proper. In short, I have seen this issue for two years straight on all of my plants in greater or less greater but significant amounts. And the beds don't all share soil sources.

Well, as I said I take your points. I need to have a test run to get to the bottom of the problem, rather than keep running around spraying this and that like a crock chicken farmer with his head cut-off.

Thanks for the long post and your time.
-naysen

[lycoperson]

I've read through all the disease discussions, but my first thoughts on seeing the pics was a nutrient issue, especially if you are growing in containers. Have you done a tissue test? For $15 plus shipping send leaf samples to a lab. Then you can know exactly what nutrients are in the leaves, and if these levels are very low, low, good, high, or very high. If you haven't done this and are interested, I can post how I do this.

Paul

[z_willus_d]

Hi Paul, all these plants are in deep raised beds. I grew tomatoes last year in 25-gal half-barrels as well as Raybo's EarthTainer and InnTainer SWC designs. This year, however, I grow the tomatoes only in the raised beds. I reserve peppers for the SWCs, and Eggplants for the half-barrels.

What I'd like to do next, I think, is test for the Powdery Mildew fungus. It shouldn't be a hard test to check for that, and if it's there I've got an answer. If not, we're back to things like V or perhaps a nutrient issue. I was very careful when developing my soil mix for the raised beds to include things like Compost (home-made Earthworm castings), Forest Humus, peat, green sand, azomite, tomato tone, decomposed granite, hort sand, perlite, rabbit manure (which the worms love), alfalfa pellets, etc. I spent a good deal of time researching the correct ratios for these. In any case, I can't image how I would be deficient in any of the macro-nutrients, and the micros aught to be covered as well.

Despite all that self-certainty, I'll certainly fall back to testing for nutrients if I can't nail down the pathogen as DM (LT) or perhaps V, though I'm still dubious of the latter.

Thanks for the idea.
-naysen

[lycoperson]

Sounds like you have a good strategy to proceed. Growing in raised beds with organic amendments makes deficiencies the less likely cause. And excess micronutrients would probably have shown up earlier. When you image search powdery mildew tomatoes, is that what your plants look like?

[z_willus_d]

Originally Posted by lycoperson

When you image search powdery mildew tomatoes, is that what your plants look like?

Well, yes they kind of do when you compare to the Leveillula taurica (Oidiopsis sicula) variant of the fugi. Here are a couple web pics by example, which may be compared to the pics of my plants I've already posted. I owe Steve (Heritage) credit for making this link, albeit yet to be confirmed.
--naysen

http://ag.arizona.edu/plp/plpext/diseases/vegetables/tomato/PM1.jpg


http://ag.arizona.edu/plp/plpext/dis...tomato/PM2.jpg


http://www.ipm.ucdavis.edu/PMG/IMAGE...TAU-FO.001.jpg

[z_willus_d]

Originally Posted by aclum

Hi Naysen,

Not to further confuse the issue but have you considered a 10% milk spray? Check out this thread - lots of good info on the subject (although some differences of opinion, as usual <g>).

http://www.tomatoville.com/showthrea...ght=milk+spray

Anne

So I read through the thread Anne. It looks like 2cup of 1% milk to the gallon can help illiminate some forms of powder mildew, specifically those attacking grapevines. Unfortunately, we didn't get any real feedback on how it worked on how well it works on the tomato strains. I'd like to see a study on that.
Thanks again for posting.
-naysen

[Paradajz]

hi again.

you are welcome, Naysen, but no need to thank me, i enjoy conversation with people who have a tendency of knowing what they are talking about, like you and Steve, and plenty of others here, of course
thanks, Steve, but very far from an expert i am. ages and ages ago i have studied with one though, and i would so much wish that you could hear the speech he would have given on those photos... 10sec after it Naysen would go ''all in'' for verticillium, i guarantee it

about the subject:

Naysen, i have noticed that you use raised beds with various soil compositions.
but please note, verticillium is one of the hardest villains to recognize, treat, predict or prevent. the nature of it is to unstable and hard to understand, e.g. much different than fusarium. as a matter of facts it's been almost a decade since i've seen a case where so many reliable symptoms appeared as with your plants.
as simply as i can:
* it's not determined how many strains, V.albo- atrum and V.dahliae are just general division for plenty of happy families.
* albo- atrum is commonly heavier but somehow more predictable, can survive in soil in various forms ( mycelium and mycosclerotias ), dahliae on the other hand prefers leafs and weeds for it's mycosclerotia, both can easily survive up to 50cm deep in soil, bla bla bla... anyway, mostly dahliae ( but a.a. not excluded ) can produce such splash- back infections starting from a simple tiny piece of weed that you wouldn't believe it. also your hands and tools and other equipment can- the bugger can survive on a piece of metal up to 6 months, in just about any organic environment 2 years minimum.

as for L.T. this isn't it. believe me you would know an explosive outbreak of L.T. if you had one- i have often witnessed plants which were hardly recognizable no more than 8-10 hours after the initial symptoms appeared in favorable conditions for the disease.
again, just as it was the case on the photos of L.T. you posted- the chlorosis is definite and clearly borders the infected spots. further more, it's a disease ''of a specific spot'' and not systemic, which results in another definite sign- the necrosis won't appear the same on both sides of an infected leaf ( at initial disease stages especially ), while with V. it will.
further more, leaf margin's necrosis is much wider/variable with L.T. than with V., meaning that you will most often meet it at leaf tops just the same as at leafs sides.
more, it will start as small whitish/grayish spots on leafs front side which you can easily distinct.
and the easiest of all, i believe that you are experienced enough to detect a living fungus appearance at leaf surface, with or without a lens, which with a V. you won't be able to do.

finally, if it was a nutrient thing, it would be on the excess side and not a deficiency, and it would go for potassium ( or boron, which is almost impossible ), but it would have appeared much earlier, also on fruits ( pre- maturation ) and flowers ( dropping/burning ), and it would also stop after some time and not develop extensively further.

vau, time to sleep, good night all,
ivan

[z_willus_d]

Hi Ivan, as much as I'm still not sure I agree with your conclusion (based on the limited available data I provided with my pics and posts), I find I am learning a great deal from your posts about these difficult conditions. I will say that we had 2 days of 100+ F degree temperatures here, and in those two days, the vines I mentioned above (about half the tomatoes in the garden) have advanced from perhaps 10-15% lower leaves showing the yellow spots, necrosis, etc. to now I would estimate 50-65%. The intensity has accelerated as well. I spent some time with the vines this evening, and it was astonishing how, for instance, the lush and vital Brandywine Sudduth's has become a mess of yellow and brown. As I stated earlier, from afar it's not always obvious, the destruction, since the external branches and leaves are less affected and block easy internal canopy viewing. Always those within the 18" cage, beneath the canopy, always those are the affected leaves. They see less sunlight, less airflow, probably retain more moisture...

Well, but I have an open mind still and I'm retaining all that you've written to test against and use in the future and now.

As for today, I waited until near dusk and sprayed the following concoction. I spent too much time focusing on good coverage, and simultaneously ran out of sprayand daylight; thus only half of my tomato plants were sprayed, and not the peppers, cucs, squash, eggplants, etc. Here's the mix (4 gal total):
+ 1.5 TBS/gal Green Cure (Potassium Bicarbonate)
+ 0.5 tsp/gal Actinovate
+ 3 TBS/gal Monterey Spinosad solution (for thrips)
+ .5TBS/gal Mycotrol O (for thrips, etc.)

Tomorrow evening, I will spray the same on the remaining plants. I have an order in for "Kumulus DF Fungicide - 30 LB (Cert Organic Sulfur)," from:
http://www.keystonepestsolutions.com...FWKCQgodYgQAXw

...which I will spray as soon as it arrives. In the meantime, I'll be contacting the UE office to see what they have to say about the area, my problem, etc. I may also try and have some tests run to get positive ID for V or PM or ???

So that's where I stand. I might try posting more pictures of the carnage and (hopefully) eventual recovery, so experts like Ivan and Steve have more data.

Thanks all.
-naysen

[Heritage]

Here's a couple of photos of what I've been calling Leveillula taurica, and some comments:

Photo 1 - two leaves from the same plant - the leaf on the left looks how I think of something systemic might possibly look - maybe V on this one, except the leaf on the right shows necrotic spots surrounded by yellow margins - maybe L.T. on this one.

Photo 2 - detail of the necrotic spots from the right leaf in photo 1.

Photo 3 - typical symptoms on two leafs from a PL plant. Again, I see possibilities of both L.T. and V.

I removed a lot of yellow leafs today - the leafs in the worst condition were, as Naysen also noted with his, inside the canopy where preventative sprays didn't reach and humidity is probably higher. This seems to indicate L.T. - I don't see how V. symptoms could be affected by canopy location.

Ivan, is L.T. identification something easily accomplished with a microscope and a few spare minutes in the evening, or would it require in-depth knowledge of fungi and more than a few hours of reading?

Thanks,
Steve

[LDx4]

Steve,

Your photos look pretty much just like my plants do.

Paradajz mentioned "more, it will start as small whitish/grayish spots on leafs front side" and I've seen some of those spots on leaf stems on some of the most interior leaves.

Plus, at the San Diego County Master Gardeners website, they indicate that L.T. is the predominate fungal problem for our county, so I'm still of the mind that the problem is L.T.

I discovered in my gardening cabinet that I had a jar of Green Cure and a bottle of Liquid Copper Fungicide (both organic) and not used yet, that I must have bought last summer, probably at the height of the L.T. outbreak last year. The L.T. must have eased up before I had a chance to try them last year. So now I think I'll try spraying the copper instead of going with the sulfur, since I just sprayed Neem Oil last Friday and it's too soon to use the sulfur. The instructions on the copper spray say to use it either before or after the presence of L.T., so maybe it will still work to stop the spread.

I hope we can all find a workable solution for this!

Lyn

[z_willus_d]

Hi Lyn, my research has suggested that Copper isn't the best for powdery mildew, but UCD does list the Potassium Bicarbonate (Green Cure) as a measure for L.T. in peppers (should also apply to tomatoes). See here:
http://www.ipm.ucdavis.edu/PMG/r604100111.html

I think the Copper Fungicide works better on other types of fungi. I'd go with the green cure and move on to the sulfur, but I guess I'd already written as much above.

Good luck whatever you choose.
-naysen

[z_willus_d]

Steve, superb photos. You must a have a studio. What you've shown there matches well many of my plants. Some show more of a full leaf yellowing, but most match your photos.
Thanks for sharing.
-naysen

[Heritage]

Lyn, thanks, it's good to know L.T. is a common fungi in S.D. county, I think I prefer it over V. (if I could choose). Good luck with your control measures, please post your spray results. I decided to spray sulfur on just one row (50 plants) as a test. Maybe, for us, control is mostly a waiting game until the 'June Gloom' passes. Also, this is the first year I haven't pruned indeterminates to a single stem, and, since it is the first year I have seen these symptoms, I can't help but think there must be some correlation - lack of airflow, no spray penetration...

Steve