Quote:
Originally Posted by 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 |
( oh is this a long quote or what... sorry all
)
hi, N.,
i also like the way you reason with the details very much.
short on time, so i'll try as shortly as possible: this is V. if i ever saw one
( actually, the only other thing i know of which produces such type of leaf necrosis is a very rare type of bacteria which is totally uncommon for solanaceas, and better not to talk about it since it's far worse that verticilliums )
tell- tell signs:
* do not think that the discoloration of a steam is a must, very often you won't be able to see it, what ever you've read about it. there is like a zillion reasons for it: even when noticable it's standardly extremely light, pink, rose, light- brown, even slightly darker green than xylema itself; there is a huuuge number of strains with extremely different levels of pathogenicity, which in combination with tomato sort, plant strenght, weather conditions in past and present, nutrients levels.... well, it's an abnormal number of possible outcomes, out of which each one can produce different visible symptoms
* ''V- resistant'' doesn't actually means 100%, it's actually an average capability of a sort to resist a certain villain
* when you compare L.T. and V. chances, analyse the reason for leaf chlorosis:
- with L.T. chlorosis appears around the spot where pathogen feeds and develops ( this place appears as a necrotic spot ), in other words chlorosis is caused by it. eventually, this chlorosis will be
definite- bordering the spot where pathogen ''works'' with clear margins. it will be only in the terminal leaf stage that you won't be able to tell the margins of chlorosis, just as with about any other disease.
- with V. chlorosis is caused by toxins which the pathogen produces ( the place where it does it is xylema only at the beginning, later the bugger likes to spread to wider territories
) and the weaker ability/or dissability of a normal fluid flow, which with a tomato plant always tends to appear visible at leaf tops as necrotic burn- spots ( toxins ) and fire- like
indefinite chlorosis ( sounds familliar
). there isn't actually that large range of pathogens which can induce indefinite chlorosis.
* cold is a word for V., but it actually needs no more than 24h of cold ( 21-27C is the ideal cold for it ), and it actually needed it some 30-45 days ago when the pathogen in my opinion found the way into your plants.
* ''V- shape'' as the most famous tell- tell sign doesn't actually have to be that often, depend on zillion things, but again- the sole presence of it is a street to look into.
* typical V. appearance time is when the plant is intensively setting fruits- which is late, far after the pathogen entered the host. this works for tomatoes mostly. only very weak or mechanically damaged seedlings will stop growing and dry- out quickly after planting.
* ''droopy'' leafs appearance is a clue.
* initial appearance at higher, partial or midd- sections of a plant is also a clue.
sorry, wanted to add some more but out of time
anyway, in my opinion you actually have just about all signs of V. there, just haven't found the most reliable one yet. still, my advice to you is to test one of those plants.
br,
ivan