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

[z_willus_d]

Originally Posted by Paradajz

hi, N.

no, only myclobutanil is a Triazol there, trifloxystrobin, pyraclostrobin and azoxystrobin are all Strobilurins ( synthetic, but with a fungal ancestry actually ).

if you still chose to test some of those aiming for L.T. my advice is to use myclobutanil, Triazoles are not very likely to cause any resistance that soon.

Strobilurins on the other side are excellent fungicides, not agressive and mainly traveling trough leafs only ( local- systemic is the term in my language ), with extremely broad spectrum ( practically all 4 existing groups of pathogenic fungi ), but with a somewhat less effective action than Triazoles, and highly problematical on the resistance side. therefore, if you use those mix it with mankozeb/propineb at regular doses. my advice there is pyraclostrobin as first choice, although trifloxystrobin has some nice additional effects on a plant ( helps photosynthesis ).
anyway, this group shouldn't be used more than once for P.M. with a strong recommendation for a combination with some broad contact fungicide, and even stronger recommendation of using a fungicide of completely different system of action if there happens to be another treatment for P.M.

br,
ivan

Hi Ivan, thanks for all this great information. I wasn't actually planning to use any of these "atomics," wouldn't know where to find them if I was, but I would like to better understand them, how they're used in industry, their limitations, etc.

From what I gather from your above, the optimal (from the point of view of decimating a P.M. infestation) spray scheme would involve first an application of pyraclostrobin followed up (5-7 days later?) by an application of myclobutanil. The goal being to hit the fungi hard with the broad action pyraclostrobin but also take out the "stragglers" with the myclobutanil, so as to minimize any resistance population. Or were you suggesting the same, but with the first application of pyraclostrobin to include also a tank mix with mankozeb? I know that some of these are used on grapevines here in CA to treat P.M.

Thanks again for the details.
-naysen

[rnewste]

naysen,

I would do some research before using Mancozeb. As I recall, it comes with a 7 day exclusion zone warning against going in the sprayed area. It may be effective, but at what trade-off...

http://www.environmentalcommons.org/...t/mancozeb.pdf

Raybo

[z_willus_d]

Thanks Ray, as I wrote, I'm not planning on using any of the hard stuff (not right now at least). I'm still hoping the OMRI listed Sulfur and greencure can get the job done for me.

On that topic, I might as well post the pics I took from my greencure treated plants this morning. Half were treated two days ago (in the evening) and the rest yesterday evening. You can see how the leaves have "crisped-up" considerably from the pics I posted a couple days back on recommencement of this thread. I'm left to assume that is the result of spraying the greencure fungicide on fungi-infected leaves, but I'm still waiting for a scientific explanation for why the fungicide would accelerate the necrosis of infected leaves/branches. I know these branches/leaves were doomed, but why are they reaching final destination earlier with the fungicide spray? What's the mechanic there?

The first pic is of an outer branch and leaf from my grafted Brandywine Sudduth's that looks like it's about to turn yellow. I thought I'd try and take a picture of the same view every morning to see if the condition progresses there now that I've sprayed, and if it does, how it looks over time (Steve's time-lapse idea).

IMAG0489 shows the now complete devastation of my non-grafted Green Zebra. It's basically a blackened hull holding onto a load of fruit. I should probably just harvest and try and ripen indoors at this point.

So as to show that not everything is doom and gloom, I thought I'd show the Goliath-head sized spaghetti squash my wife found hidden in the shrubs yesterday (IMAG0492) as well as the enormous grafted Madame Jardel's Black plant (IMAG0493) with heavy fruit set and minimal yellowing of leaves. It's on the side that is adjacent to my lawn (rather than the large field of weeds), so perhaps the fungus spores are less able to get to it.

Finally, I threw in a pic from the greenbelt showing what my new bed of tomatoes looks like from down in the ravine. I don't normally see that view, but I was running in the 100+F heat and thought I'd take a breather and try and snap a picture of the plants from afar. It's blurry because of my hand was shaking heavily. That shows what the plants looked like just before they started turning "yellow," but also from afar the plants look better than up close where you can see through the outer canopy and into the heart of madness.
-naysen

[Paradajz]

Originally Posted by z_willus_d

Hi Ivan, thanks for all this great information. I wasn't actually planning to use any of these "atomics," wouldn't know where to find them if I was, but I would like to better understand them, how they're used in industry, their limitations, etc.

From what I gather from your above, the optimal (from the point of view of decimating a P.M. infestation) spray scheme would involve first an application of pyraclostrobin followed up (5-7 days later?) by an application of myclobutanil. The goal being to hit the fungi hard with the broad action pyraclostrobin but also take out the "stragglers" with the myclobutanil, so as to minimize any resistance population. Or were you suggesting the same, but with the first application of pyraclostrobin to include also a tank mix with mankozeb? I know that some of these are used on grapevines here in CA to treat P.M.

Thanks again for the details.
-naysen

hi, N.

it's actually hard to understand the logic of use of chemistry in a world where fungal and other villains change and progress faster than we can even pronounce it.

by the way, although i know i could be cursed for this , those ''atomics'' are actually quite eco- softer than the sulfur you use, Strobilurins especially

no, outdoors L.T. should be done with a single treatment of Triazol ( myclobutanil ) followed by a copper/propineb mix 10-14 days later. if there is a real need for another systemic treatment ( extreme weather conditions favorable to the disease, new outbreak, etc. ) another treatment of Triazol at the appropriate moment ( but not sooner than 7 days after the c/p mix ) would close the issue.
usually ( with a very high percentage ) the first 2 treatments do the job and everything else is chemistry abuse.
it's also a synergietic approach which broadens the protection to almost all manageable fungal diseases, and keeps it there for a very long period of time. it's also highly effective on Alternaria and Septoria side, but if one wanted to get the bacteria also targeted mankozeb should be used instead of propineb.
Strobilurins are always the aces for the finish of such a race ( close to yielding period, when giants like Blights start roaring ) because of it's short restriction period, significantly low- level toxicity and very broad range of protection. only when plants are of low strength i would recommend the second possible systemic treatment to be with trifloxystrobin.

so, once again ( although i feel that nobody will believe me ), L.T. really can make disasters indoors but shouldn't be considered that much of a significant threat in outdoor growing of tomatoes ( grapevines are a very very different issue, there i prefer seeing 3 Blights to 1 Mildew when conditions are favorable ), and therefore the logic is to stop it as early as possible, but also with a minimum level of chemistry.
i also find it highly interesting how much of differences there are between our agricultural practices- in tomato growing it is almost unimaginable to me that 5-7 days treatments with anything ( not saying this because of your question but because i noticed it on quite a number of other threads ) actually exist.
tomato simply is a to intensively growing plant that you can get it covered that way. that's why copper, mankozeb, propineb ( broad, effective and enduring ) and a systemic ( follows the new growth ) make the golden rule of taking a plant to a comfortable set up. in industrial growing of course.

further more, any place with a history of L.T. will have it repeated the following year, and that's where sulfur comes in- as a preventive in very early growing phases.
mostly because it can be highly fito- toxic, just in a way as it is now with those damaged leafs of your plants

br,
ivan


p.s.
i hope you stopped fertilizing those plants, you should also put it to a ''dry procedure'' ( water it at 1-2 days longer periods ), and some 5-7 days before you plan to start harvesting hit it really hard with any sea- weed fert + some potassium ( drench and spray ).
that way you should take the max. possible yields out of those.

p.p.s.
i really won't be writing such a long mails any more, a promise

[z_willus_d]

Ivan,

Please keep the emails long and detailed. The fito (phyto?) toxic effects you see on my pics are from spraying of potassium bicarbonate. I have not yet applied any sulfur to the vines. It's not clear to me that the damage was due to the spray itself or the result of the spray on weakened leaves branches infected with the L.T.? I sprayed on new top growth, and I did not see the same type of damage as on the lower and mid leaves.

On the p.s., I have only "fed" the plants with the manure and ammendments available at planting time, as well as now three doses of quarter-strength feeding of either Fish/Seaweed or a Beet Molasses based Bio Bizz BioGrow fertilizer. I haven't had time this year to mulch (w/ all the spraying, etc.), so I've had to water the plants every other day in the 100-degree heat. They are all indeterminate vines, so I expect/hope to be harvesting over a prolonged period of time. I agree (if I read you right) that withholding water before harvest can intensify flavor, reduce fruit cracking, and make for a nicer produce. I like to spray seaweed as a foliar about once every 2 weeks.

As a side question, it sounds like you feel/believe pyraclostrobin and similar are quite safe and can be sprayed leading up to harvest (but are not generally necessary and temp fate with resistance. How safe, in your opinion, is the myclobutanil; environmental impact? Also, since it is a local systemic, will it traverse from foliage to fruit and thus be consumed if fruit is harvested w/in so many days of spraying?

Thanks for all the information!
-naysen

[Paradajz]

sorry, N., all this time i was under a strange impression that you sprayed those with some kind of ''un-yellow'' sulfur
potassium- bicarbonate most likely additionally doomed the ''waxy'' layer on leafs surface which was already hardly damaged by the disease, and prompted the leafs to drying out. i don't think there is anything with it for you to worry about.

watering is an issue with those plants because of the disease, not cracking or taste. drying will in a way deplete both the plant and the disease, but each watering is a refuel for the disease much more than to the plant. fruits should be the most beneficial users of such a procedure.
fertilizing is a direct atomic fueling of the disease, it progresses on it far more and far faster than the plant itself. nitro is totally out of question especially.
the use of a sea weed/potassium fert is a direct fueling of the fruits, it will benefit from it as long as there are some on the plant.
altogether, such a process should generally make the best of the situation you have with the disease- troubled plants.

Wrong side question for a European guy BTW, have you ever seen the lists of permitted chemical residues in fruits in USA/Europe standards? Those really can confuse a man when compared

Myclobutanil is a very low- level toxicity substance, just as most ( all ) of Triazols are. If i recall well, out of the whole group only difenoconazole showed high toxicity to fish, and none was carcinogenic to mice. Again, if i recall well, all of it could be digested with no serious consequences, and just one or two from the group could cause severe eye irritation.
It doesn't ''leave'' the leafs, the systemic part of it only travels from one side of leaf to the other.

Strobilurins are probably the easiest thing to nature from the whole systemic world ( and much easier than, for example, organics like sulfur or copper ), broad spectrum and really low toxicity makes them great, but resistance development is really an issue with those- e.g. L.T. was found showing it after only 2 years period of use. That's why a contact is a must there.

[z_willus_d]

Yeah Ivan, I mentioned above that was just a diatomaceous earth dusting.

Ok, so I'll conclude that a leaf that has been attacked by fungi will have some protective "waxy" shielding compromised such that a subsequent application of a "caustic" element like potassium bicarbonate will result in the leaf taking additional damage.

I will definitely eliminate N from my feeding regime and focus on only potassium products like seaweed extract.

When you say "why a contact is a must," do you mean the myclobutanil, or are you referring to the more toxic copper/propineb/mancozeb?

Thanks,
Naysen

[Paradajz]

oh, Naysen, you bring me to a situation to earn a status of class 1 Poisoner here...

no, myclobutanil isn't a contact fungicide, i was referring to the more toxic mancozeb or propineb or chlorothalonil ( copper formulations are somehow hard on the mixing side ), out of which i would definitely go with the most horrible one- mancozeb

[rwsacto]

Naysen, et al.

I have had the same problem with yellowing and wilting leaves starting from the ground up. Based on the info in this thread, I believe I have both the LT and OL forms of powdery mildew. I was removing yellowing and wilting leaves every day.

A week ago I sprayed the plants and ground thoroughly with Serenade. That seemed to have stopped the infections. Yesterday, I sprayed with green cure. So far, hardly any yellowing, drying out or dropping leaves after the green cure.

I believe I also have the OL form of mildew as small white spots, primarily on plants that are located near trees. This infection does not seem to spread and these leaves do not yellow, wilt and fall.

Now on to the next challenge, some critter is eating my almost ripe tomatoes in half right on the vine....
Hope this helps,

Rick

[z_willus_d]

Hi Rick, I'm sorry to hear that you've been dealing with similar issues. And I'm glad to hear that you've managed to nip it in the bud with the Serenade and Greencure. I haven't posted on my battles here for a couple days now, but I have been taking time-lapse pictures of a few leaves that show the development of the yellowing/necrosis over time.

I've only sprayed Green Cure once now a week back, and I think it had some positive effect. I went through the entire 8ou container to spray all my plants. Regardless, this last weekend with the 113F temperatures, I lost two plants and most of the rest started showing more of the same issues. The Yellow to dead brown and crispy (or gray/black and crispy on the blacks) was happening in the matter of 24-hours.

Given the loss of plants and other general outbreak, I broke down and ordered a bag of Myclobutani, which I sprayed just this evening. I did 2tsp to 4gal mixed in with a spreader/sticker and a dash of safer insecticidal soap. It took 2 4-gal tanks to cover all the plants in the garden, about two hours of work. Since I have tomato, pepper, and eggplant plants at all levels of maturity and infestation, it should be interesting to see what getting ahead of whatever this is (I'm still banking on P.M.) might mean for control and long-term outlook for the plants.

Please report back on how your vines do as they mature into the season.

Thanks,
Naysen

[z_willus_d]

Riffing off of Steve's (Heritage's) idea from above, I thought I'd try and capture a sequence of photos showing the progression of the "disease" across the same view of a plant leaf/stem, in this case the BW Sudduth's vine. The photo names give the date/time for reference.

I think it's kind of neat to see how the leaf turned yellow and then necrotic brown over the span of just over a week. In that time I sprayed once with GreenCure (around the 5th I think). Clearly it wasn't enough to save that main leaf in the foreground. You can see the demise of the background underbrush somewhat in the progression as well.
-naysen

[Mlm1]

Naysen, those are great time lapse shots. That is interesting to see. There has been a lot of good information on the thread. That would be nice if you could get a definitive diagnosis on your plants. Marla

[z_willus_d]

Hi Marla, yes I agree, this has been an information filled thread. Steve, I'd like to hear how you plants have been doing with the presumed P.M. ? Did you treat with anything? I'm waiting to see how the Myclobutani fares on my plants. That and working with my sewing master mother to sew together some exclusion bags in an attempt to try and save some of the ripening fruit for myself. The birds can't have it all.
-n

[Heritage]

Interesting progression, Naysen, thanks for posting! I'll try to post my finished time-lapse series tonight.

Steve

[Barbee]

There is a bacteria, called Beauveria bassiana, strain GHA, that is pretty effective at warding off some of the harder pests. the product that contains this that I like is called Mycotrol O. It is considered to be a biological pesticide. I see that thrips are one of the pests listed that it will take care of. You may be interested in it. I ordered mine thru Johnny's seeds. It is not cheap and the shelf life is only 6 months as it is a live bacteria.
http://bioworksinc.com/products/mycotrol-o.php