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

[aclum]

Hi Naysen,

Your disease problems sure sound discouraging. I don't know enough about such things to venture an opinion on what to do (seems like you've tried about everything), but you might go to the following link, and then click on the appropriate links to get to your country extension contacts. (I didn't link directly to this as I though you might find some of the intevening info of interest).

http://www.wrpmc.ucdavis.edu/

When you get to the county extension info part of it says:
********************************
University Extension in my State



Extension services vary by state and county. Local knowledge can often be the best resource for your specific questions. You will need to check with your local Extension office to determine what expertise is in your area, but traditional services that Extension may provide include:

• Pest identification and/or plant disease diagnostic services
• Pest control recommendations
• Soil testing to determine fertilizer needs

****************************************

I'd give them a call. I'm guessing that their services are probably free or very inexpensive and they could probably solve your problem pretty quickly or maybe refer you to someone at Davis who could. I think that since the tomato industry is so important to the central valley, they really are interested in finding out what sort of problems home gardeners are having so they can pin point outbreaks of things to alert the industry if necessary.

Good Luck!

Anne

[z_willus_d]

Hi Anne, I haven't given the UE a try, but it may be time I do. I feel like a I need a master gardener science team to take a field trip over to my place to get to the bottom of this once and for all. It's the not knowing that kills me.

Thanks for the idea.
-naysen

[ginger2778]

Nansen, I hope you find out, because I had the exact same weird leaf yellowing on a few of mine here in south Florida. Please post your answer.
Marsha

[beeman]

Originally Posted by ginger2778

Nansen, I hope you find out, because I had the exact same weird leaf yellowing on a few of mine here in south Florida. Please post your answer.Marsha

I hate to say it, but it looks like my problem that I suffered with for years. I can't be absolutely sure as you grow a lot more vegetation than I do on my single stems.
My final answer late last year, from a professional source here in Ontario, Corky Root Rot.
Seems it is all over the USA/Canada, often diagnosed incorrectly as Fusarium/Verticillium wilt.
You have to 'Dig' a plant out, so you can examine the root ball, or in my case the lack of it. An examination of the plant stem shows a brown spongy dying end, where the root ball should be.
The only thing keeping my plants alive was the new roots formed up the buried stem, and even those were brown and dying.
Healthy roots should show a lot of white, mine have always been brown and shrivelled.
I do have photos if you want to see them, just ask.

[DavidP]

I'd try looking thru the UC IPM site for tomatoes, you've probably already done that but thought I'd mention
http://www.ipm.ucdavis.edu/PMG/GARDEN/VEGES/tomato.html

Also give your local Sacramento master gardener hot line a call

http://cesacramento.ucanr.edu/Contact_Master_Gardeners/
They may ask you to email a photo or send in a sample

[Heritage]

Naysen,

I get the same (or very similar) on my tomatoes starting about this time of year. I don't have a positive ID on mine but I've been calling it 'Leveillula taurica' (Powdery Mildew). A photo of early infection is shown here:
http://www.ipm.ucdavis.edu/PMG/r783100411.html
It seems sulfur is an effective control so, on at least a few plants, you might want to discontinue any of the oil sprays in your spray rotation in anticipation of applying sulfur.

Good luck, keep us posted,
Steve

[z_willus_d]

Hi Beeman, I surely hope I do not have what you've had. I've heard of Corky Root Rot, but it's certainly not been on the top of my list. Last year Root Knot Nematode came up as a potential issue, so I pulled a number of my plants. I did the analysis and didn't find evidence of the RKN problem. I think the Corky Root Rot would prefer cooler/moister conditions than I've had, but I'll keep it on my list of things to check for, especially if I have a chance to pull a plant, which I may soon.

Here's a pic from last year of the roots of one of my plants that went down to this problem:
http://www.tomatoville.com/attachmen...3&d=1338436905

Thanks,
Naysen

[Paradajz]

when you examine the whole garden, is there plenty of those ''v'' shaped chlorosis/necrosis leaf spots?

what ever it is ( and it definitely suggests verticillium very much ), do not fertilize any more- nitro would be like an atomic disease- fuel here, sterilize your hands and equipment when working with plants, do not work on plants on humid weather, etc.... and take one of those plants for a test somewhere
if you still can't make a positive lab- test, you may pick one of the plants which has only started developing symptoms and drench it with 2-3l of 1% copper oxychloride + 0.25% mankozeb mixture ( just as a test, both are organic fungicides and shouldn't make your honey kill you ). the test would most probably show some fito- toxicity ( mostly depends on the flowering stage of the plant ), but if it's verticillium it should also contain the disease to some point ( not fully, it would continue developing after some time ). anyway, such test could help you confirm/exclude this bugger if you don't have any other way to do it.

br,
ivan

[Paradajz]

a p.s.

i almost forgot- with plenty of strains, when verticillium develops in late stages of plant cycle ( which actually happens when you have raised strong and healthy plants and/or it's transmitted by pests and not soil ), the tell- tell sign won't be always low, but a very very light browning would be easier found in the branches where it has developed.

[z_willus_d]

Steve, you've certainly piqued my interest. I've haven't really noticed the "powdery" part of the description, nor the gray mycelium or anything that looks like a colony of mildew, but I would say some of the description matches well what I'm seeing. What's more, I've tackled just about every other possible source for this issue in past attempts, so as I've not really tried to address a mildew issue in the past, it may very well be that this is what I'm dealing with. When I look at the photos for the condition, I see some that seem to match my plants quite well, while others with the white "fuzz" don't look anything like it. Do you know if the condition would cause a potato leaf to wilt and become droopy/rubbery? I see that on a few of my plants.

Is there a way I can examine a leaf, perhaps under high magnification, to get a positive ID?

DavidP, I may just give one of the master gardeners a call next week to see if they have any ideas or can help me get a positive ID on the mildew.

I want to thank everyone for helping me narrow down on this. Steve, you're always an extreme help.
-naysen

[Heritage]

Naysen, I just took another look at your photos and I'm wavering on the Powdery Mildew diagnosis. My tomato leaves are showing more spotty areas of bright yellow than yours and don't get entirely yellow until the spots converge. But I do see some leaves that look exactly like mine. I also see some with the V-shape that Paradatz mentions and is a sign of verticillium. So, I'm only guessing...

Paradatz might be correct with the verticillium diagnosis, except I thought it was a cool weather disease. Also, with verticillium you should see darkening of the stem tissue, similar to fusarium (only lighter) and you didn't see any signs of it.

Did you graft anything onto rootstock with resistance to all 3 races of fusarium or just the 2?

Steve

[Heritage]

Also, how fast did the disease progress?

[z_willus_d]

Ok, lots of good stuff here... I love the deep dive into details.

First, let me thank Paradajz for the contribution. On the question of Verticillium, I will say that was one of the systemic diseases that I focused on heavily last year, along with Fusarium. I, ultimately decided that Verticillium was even less likely than Fusarium given the climate here, the low incident rate of V, lack of any darkening signs in the stem, etc. Now this year, since I'm grafting onto Maxifort, that seems even less likely. The Johnnies lists Maxifort with the following resistances:
* F2 Fusarium Wilt (Races 1 & 2)
* FOR Fusarium Crown and Root Rot
* N Nematodes
* PL Corky Root Rot
* TMV Tobacco Mosaic Virus
* V Verticillium Wilt

So with the "V" it would seem less likely than even last year that I have Verticillium. I will say that the look of the leaves does quite mimic that of V, which is why I latched onto it before.

Steve, I mainly grafted onto Maxifort, and a small handful got Beaufort. I note that some of the regular leaf types just seem to turn yellow, while the larger potato leaves have the characteristic yellow splotches, turning to necrotic brown.

Something else I noticed this evening was that the yellowing mainly appears within the cover of the plants outer foliage. That is to say, the outermost leaves and branches show the problem less than those within. That's not a rule, but it does hold sway. I also noticed that this same problem seems to be hitting my peppers now as well as the tomatillo plants (actually, I first noticed specific leaves turning yellow on the tomatillos several weeks back.

To the question of disease progression, I would comment from recent experience and last year that it seems to appear first on plants that have been out in the garden for the longest period of time, hence also those which are generally most mature. It seems like I notice it first on a single plant, but then a couple weeks on it is apparent on numerous. I think that in the matter of a couple days it went from not that noticeable to very noticeable on a few. On others it's been an escalating progression. For instance, my Wes was showing it weeks ago on the lowest branches, but not it's 65% consumed to within a quarter of the top of the plant. The older branches and leaves have turned to brown dust.

Frankly Steve, I'm really inclined to thing you hit the nail just about on the head. It would jive with what I've read about the mildew; the fact that I've been spraying so moist under leaves; that I let my plants bush out, so they're quite compacted in their cages. The only thing I don't really notice is the white fuzz and sporulations, though perhaps given the hot dry climate here, they can't quite coalesce to that stage.

I'm zeroing in on a couple products. Comments?
- http://www.domyownpestcontrol.com/hi...ay-p-2325.html
- http://www.amazon.com/BONIDE-PRODUCT...eywords=sulfur

I wonder, besides the sulfur, if there's something else I should try. It seems that sulfur will deter the mildew, but it is hard to impossible to get rid of. I feel that quick action is required here, and that time is of the essence."

Thanks all.
-naysen

[Heritage]

Naysen, with that, you've moved me back into the Powdery camp. There are two different Powdery Mildews and the one we're talking doesn't have the fuzzy white growth:
http://ag.arizona.edu/plp/plpext/dis.../tomato/pm.htm

The high humidity inside the plant canopy would be ideal for mildew and the thick growth probably kept your preventative sprays from protecting the leaves.

Any sulfur formulation labeled for tomatoes and powdery mildew should help. I know you are aware of the caveat "do not spray when it's hot (>90F, especially if low humidity) or use sulfur if you have used oil sprays in the last 2 weeks (some say a month)". I sprayed my worst looking row of plants tonight with flowable sulfur. It's amazing how fast that yellow creeps up the plants.

As far as other organic fungicides for mildew, I have had good luck with Neem, but I know that is in your spray arsenal already and not been a great help. I would also like to know of an alternative to sulfur, maybe Paradatz, or others, can suggest an organic cure?

Steve

[LDx4]

Naysen and Steve,

I have the exact same problem down here. Based on information online, I had narrowed it down to powdery mildew. It seems to hit the most mature plants at a certain stage - I had several plants that looked all green and fine last week and now this week they're starting to show the familiar yellowing that moves up the plant. Most of my oldest plants that I put out in the beginning of March have it. One of my Zolotoe Serdtses that I got from you, Steve, has it bad. As soon as the last tomatoes start to blush, I'm going to pull that plant. This is a problem that I deal with every year, though, and so far, nothing I've tried has cured it. I'm trying to stay as organic as possible, since I sell at farmers markets, and even though I'm not certified organic, I want to stay as organic as possible.

Naysen or Paradatz, if you find a workable cure, let us know!

One of the drawbacks of living in a temperate climate like California!?

Lyn