Powdery Mildew? Mold? Something Else?

[carolyn137]

Bill, no need to tell me about Daconil washing off and having to repeat sprayings who knows how many times.

But the way I see it Bleach breaks down to oxygen and water as soon as it makes contact with anything organic, like a tomato plant, so how far would one be with Daconil vs bleach in that regard?

[b54red]

Carolyn the advantage of the bleach is that it kills most non systemic diseases and molds upon contact much like when you clean mold in the shower. Another advantage is it is gone very fast so a fungicide that has preventive qualities can be applied soon after the bleach application. The trick is getting the solution to the right strength so it is strong enough to kill most of the bacteria and mold without killing any healthy plant tissue.

I would much rather never have to spray the bleach solution but since I have never found a fungicide that is 100% effective, I use it to slow down disease that is on the plant and use the fungicide as a follow up to prevent re-occurrence. With the constant high humidity and heat down here the occurrence of fungus type diseases is nearly constant so I have used whatever works and the bleach works most of the time. One of the disconcerting things about using the bleach solution the first time is the lose of diseased leaves. Within days of spraying most of the diseased leaves will start shriveling up and dying while the healthy growth is unaffected. I have used it on very small seedlings even before they are set out in the garden. As a matter of fact I like to spray my seedlings before I set them out and then after they are planted follow up with a spray of Daconil as soon as possible.

[JamesL]

Originally Posted by carolyn137

James, the problem that I see is that there are many different genera and species that can cause Powdery Mildew and most are specific to a particular crop.

For instance, in the links you provided milk had some effect on grapevines and courgettes ( summer squash), but the powdery mildew on grapes and summer squash are not the same as those that affect tomatoes.

And not all anti-fungals are effective against the different genera and species of Powdery Mildew.

It's a rough world out there, I tell you.

Hope that helps.

Carolyn,
Thanks. Definitely helpful information. Can never have too much info!

[JamesL]

Originally Posted by b54red

Carolyn the advantage of the bleach is that it kills most non systemic diseases and molds upon contact much like when you clean mold in the shower. Another advantage is it is gone very fast so a fungicide that has preventive qualities can be applied soon after the bleach application. The trick is getting the solution to the right strength so it is strong enough to kill most of the bacteria and mold without killing any healthy plant tissue.

I would much rather never have to spray the bleach solution but since I have never found a fungicide that is 100% effective, I use it to slow down disease that is on the plant and use the fungicide as a follow up to prevent re-occurrence. With the constant high humidity and heat down here the occurrence of fungus type diseases is nearly constant so I have used whatever works and the bleach works most of the time. One of the disconcerting things about using the bleach solution the first time is the lose of diseased leaves. Within days of spraying most of the diseased leaves will start shriveling up and dying while the healthy growth is unaffected. I have used it on very small seedlings even before they are set out in the garden. As a matter of fact I like to spray my seedlings before I set them out and then after they are planted follow up with a spray of Daconil as soon as possible.

Bill,
You use 8oz bleach to the gallon, correct?
When you describe the bleach killing the already infected leaves, I believe I am seeing the same reaction from the potassium bicarbonate (greencure).
I was making the assumption that what is really going on is that infected leaves are throughly infected and the product was really just wiping out the non-visible spores and infection as well. Hence the rest of the visibly unaffected leaf dies, as it would have anyway.
The only other thing I can come up with is the the product is entering the leaf tissue through the open infection site and doing its own tissue damage.

[b54red]

James the amount of bleach I use under ordinary circumstances that I have found effective without doing any damage to the healthy tissue is add 8 ounces of regular bleach (I prefer Clorox because of the consistency) to one full gallon of water. If I am dealing with something devastating like Late Blight or am applying it to wet foliage like right after a rain, I up the ratio just a bit.

I think you may be right about the whole leaf being infected or it could just be that the disease opens the leaf surface so the bleach penetrates too much into it. Either way most leaves infected by a non systemic disease or fungus will dry up. The advantage of the bleach is how fast it works and how fast it also oxidixes so you can follow up without worrying about a chemical reaction with another product. Another advantage is how cheap it is and how often you can use it. I have used it every day for as much as a week with no ill effects during a rainy spell when diseases were devastating my plants.

[rsg2001]

I thought that photo #8 might be fusarium; looked like there were yellowing branches scattered throughout.

The year that I had grey mold -- maybe 5 or 6 years ago - it started on cukes and jumped to the tomatoes. The only thing that slowed it down was Daconil, which I don't regularly use, but I agree it is effective for that. Since then I've been doing more preventive spraying, mainly with Actinovate, which has been helpful. Admittedly in the past month with the intermittent rains I've found it difficult to keep up a regular spraying schedule and I'm paying the price of that. Most of my container plants have various diseases (Early Blight predominantly, even though I changed the soil on all but a couple of the containers). The Ambrosias planted in the ground have fusarium, which Craig said he also experienced with that variety. But the plants in the ground for the main look pretty good, knock on wood, and will give me a later harvest. The container plants have been giving me a good output of cherries and regular tomatoes but not for much longer.

[JamesL]

Bill,
Thanks for the bleach discussion.. It is going into the arsenal if needed.

Rsg,
I original thought it might be fusarium as well, but it doesn't appear to be.

The Greencure appeared to take out the mildew/ mold, and hopefully the Serenade finished the job.

I did some very aggressive pruning and I did do a Milk / Seastart foliar spray.
Milk at 2 cups of 1% to the gallon. Which would put it at a 1 to 8 ratio.
Catch 22 - I won't really know if the milk has an effect, unless the mildew / mold comes back, then I would know that it did not.
I think I will alternate weekends with Actinovate Exel and Serenade and do the Milk / Seastart foliar midweek for the rest of the season.

The Brandywine Suddath's looks real green again - my most important plant right now as it has 32 tomatoes in various stages and about a dozen more flowers. Some flowering on the tops of others, but nothing substantial.

Still need to deal with a little bit of "this" (Septoria) and "that" (EB). (I think)

Tons of Spiders this year. Have been working around several large orb spiders and quite a few greens.
They both have been spreading webs between the planters and containers.
Do my best not to wreck the webs unless needed. But if it is between picking tomatoes and the web.....

Edit- I forgot to include my yellowjacket interaction.
Drinking a can of soda while pruning. I put it down on a fence post and about 30 min later picked it up for a big swig. Something was in my mouth. I quickly spit onto the grass and low and behold, a yellowjacket. He flew away and I went back to pruning - unstung!
I have been stung many times, including a month ago when I stepped on a small bee. No big deal, but in the mouth?

[lakelady]

So how did all of your treatments work James? Plants doing well?

I will vouch that the milk does work for powdery mildew on lilacs, last year my bushes were practically white and the milk helped tremendously. lol, I was using it full strength, so you can just imagine the stink after it started to dry! Had no idea what a sticker was then, so I was spraying like a madwoman. Not sure how it works on tomatoes, but hey, if it's just milk, it's definately worth trying.

[JamesL]

Antoinette,
No reoccurrence of any mildew, so that's good.
I think I will work the milk/foliar spray into the weekly rotation for next season.
Can't believe summer is over. 40 to 50 tomatoes left on the vines.
Figure I need to make it another 3 weeks before my season is a wrap.

[lakelady]

Oh me too. I have a lot of big beefsteaks hanging on for dear life still green, but they are large so I'm expecting them to make it through the season. The plants don't look so hot, but then again, the season is about over so I'm just letting the foliage do its thing. Some plants have dried up dying leaves which I have no idea why, but I'm done spraying for now and ready to clean up the gardens soon.

All in all, it was a MUCH better year than I've ever had, so I'm very grateful!