Any late blight treatment-prevention sprays????

[RomanX]

My county is a hotspot for late blight. Here, it's not IF your plants get LB -it's WHEN. Last year's season (my first) ended in September because of LB (it was agonizing to watch my green tomatoes get diseased and become inedible.)

So, for NEXT year (2016), I am growing mostly LB-resistant hybrid tomatoes.

But I'm smart enough to realize that "resistance" doesn't mean my plants won't get it! A preventative treatment is necessary - but ignorant as to what is effective! Your'alls advice is needed!

Totally Tomatoes has one: Serenade Garden Disease Control. It claims that since it's organic, it can be safely used up to and including the day of harvest (????). It seems that the word "safe" - repeatedly stated - is enough. But as a wily consumer, I'd be more impressed with the word "effective".

Is there any EFFECTIVE preventative sprays for LB?? (Whether or not the product is organic is not important: EFFECTIVE is!!)

[Cole_Robbie]

bleach


http://www.tomatoville.com/showthread.php?t=15548

[RomanX]

Originally Posted by Cole_Robbie

bleach


http://www.tomatoville.com/showthread.php?t=15548

II used bleach last year, once my plants got late blight. I had searched here, found the bleach advice and faithfully used it. I sprayed, pruned and picked, sprayed, pruned and picked, sprayed, pruned and picked . . .and despite this, my plants never recovered. The green fruit continued growing larger but slowly became discolored and were discarded; the few that ripened alMOST to picking stage, rotted from the bottom.

You know that SOME of the plants I'LL grow this year are NOT LB resistant, so I need to be prepared THIS year!! last year, I went to the county Extension for formal diagnosis and treatment remedies. They got quite alarmed when I told them I was using a bleach solution: they said it was against the law and it wasn't approved, so STOP! (which I didn't) While they said I could try one of the approved copper fungicides, my plants probably wouldn't recover and this was the end of my tomato growing season. (which it was)

If I go get a copper fungicide and do preventative spraying. . . would this be effective (or merely labor intensive and costly?). . . .what would a good preventative spraying program look like (starting WHEN to spray, spray after rains or weekly etc ?)

[Cole_Robbie]

Originally Posted by RomanX

last year, I went to the county Extension for formal diagnosis and treatment remedies. They got quite alarmed when I told them I was using a bleach solution: they said it was against the law and it wasn't approved, so STOP!

I would like to see the statute to which they are referring. I doubt it exists.

When diluted enough to still be a disinfectant, bleach actually meets the requirements to be USDA certified organic.

[b54red]

The biggest problem in controlling Late Blight with anything once it gets started is early recognition. If you wait til all your plants are infected and it has gone inside the plants no control will work. It doesn't seem to take long for LB to become systemic once the spores get on the plants. In my experience the only time I have had any good results controlling it were when I saw it at it's earliest stages on just a couple of plants and then treated my whole garden very aggressively with the bleach spray. If you wait til all or most all of your plants are showing LB symptoms then it is probably going to be a losing proposition though you may save a few of the least infected plants. The first time I tried the bleach spray I didn't start until at least half my plants were visibly infected. I lost all or most all of those plants and a few others. I sprayed relentlessly and upped the dosage of bleach to no avail on the sicker plants and ended up losing over 2/3rds of my plants. The next time I started much sooner and had far better results. I made sure to spray everything in the garden including the mulch under my plants and all nearby plants. I also sprayed with a strong permethrin spray to knock out any insects that would help spread the spores. The last two times I saw it even earlier and sprayed very aggressively and removed the few plants that I was sure had it after the first bleach spray and they were the only ones I lost. Of course this last time I saw it was this past summer and I spent weeks worrying that it would show up again but it never did. I also used copper and Daconil as a preventative after using the bleach spray for a week or so.

The first time I had LB I lost every single plant though I used every fungicide in the book. I think what has helped me spot it so early is my constant battle with Gray Mold which shows up every summer and can be deceptively similar in appearance to one who hasn't experienced the horror that is full blown Late Blight. I have found that LB seems to almost always show up first on the upper third of the plant whereas Gray Mold almost always starts lower on the plant and deeper in the foliage. I have found that GM if left untreated and the conditions are right will also become systemic and all treatment is futile after that point but it isn't nearly as aggressive nor does it spread like LB.

I don't know if any fungicide will prevent it but I keep using them but I quickly jump to the bleach at the first sign of either LB or GM. The biggest difference in treatment is that I will go to the stronger solution immediately if I suspect LB because I would rather have a few slightly burned leaves than lose my whole crop of tomatoes.

Bill

[Fusion_power]

There are two products you should investigate. The first is Abound which contains azoxystrobin and is rated for vegetable use. Please investigate it VERY carefully before purchasing. Quadris is another product that contains azoxystrobin but with another fungicide to increase efficiency. The second is Agri-fos which is based on phosphorus the best I recall. These should be used alternating to give best control. As with most fungicides, they MUST be used before an infection, there is no such thing as "curing" late blight once it has reached threshold levels.

You may get recommendations for chlorothalonil, copper, neem, etc. These are at best moderately effective though neem alternated with copper can be a useful combination.

[ContainerTed]

Don't wait to see that the plants are affected. Do preventative spraying every two weeks or so. Mote often if you have a lot of rain. I use a product called "Garden Safe". I usually get mine as a concentrate from Walmart. If you wait until LB or any other fungal disease is present, it is nearly impossible to get rid of.

If's just the old saying, "An ounce of prevention ......"

[amideutch]

The regimen I have been using for the past years has been alternate applications of Actinovate plus Agri-fos (Phosphorous Acid) and Azoxystrobin. These are applied as a preventative and is the only way you can control disease. As Darrel said once the plant is infected it's history.

Azoxystrobin products here in Europe have been available for years at affordable prices in small quantities but in the states is a different story which is geared for commercial users. The patent on azoxystobin ended in 2014 so hopefully Azoxystrobin product prices will decrease and become available to the home/hobby gardeners. Or the TVille members can get together with others in your area and split the cost.

Inoculating your plants with Myco's and beneficial bacteria on plant out will also help and make for a healthier plant better able to resist disease and drought and reducing plant stress.

The one thing about strobilurins is applications need to be limited to 6-8 per season or the disease you are trying to eradicate can develop a resistance to it as what happens with antibiotics. One of the reasons why I alternate my applications with Actinovate and Agri-Fos.

Here are some links on the subject.

Ami

http://www.agf.gov.bc.ca/pesticides/...oxystrobin.pdf

http://www.tomatoville.com/showthrea...ht=late+Blight

http://www.tomatoville.com/showthrea...ht=late+Blight

http://www.mississippi-crops.com/201...bound-quadris/

[clkeiper]

I am trying Oxidate this year.

[RomanX]

Last year was my first year growing tomAtoes and I didn't know to expect ANY kind of diseases etc. I admit I am rAther a "helicopter" grower, spending anywhere between 3 and 5 hours every day tending and inspecting my eight tomatoes plants. Last year,all my plants were healthy, green, bushy and happy One day. . . the next morning when I went out to tend them, they were NOT! Horrible big black splotches on ALL the stems, brownish dead looking leaves: the Late Blight had struck overnight!

I HAD no warning.

So this year, I want to be pro-active. I don't want to watch my beauties die a long, slow death ever again!

[b54red]

Originally Posted by RomanX

Last year was my first year growing tomAtoes and I didn't know to expect ANY kind of diseases etc. I admit I am rAther a "helicopter" grower, spending anywhere between 3 and 5 hours every day tending and inspecting my eight tomatoes plants. Last year,all my plants were healthy, green, bushy and happy One day. . . the next morning when I went out to tend them, they were NOT! Horrible big black splotches on ALL the stems, brownish dead looking leaves: the Late Blight had struck overnight!

I HAD no warning.

So this year, I want to be pro-active. I don't want to watch my beauties die a long, slow death ever again!

I hate to break it to you but it is more than likely you will see your beauties hit by various diseases that can result in death if you keep growing tomatoes. The worst is Late Blight but Tomato Spotted Wilt Virus can devastate tomatoes though it doesn't show up every year at least not heavily. Bacterial Wilt can shock you with the speed it can kill a very healthy green plant. Nematodes and fusarium wilt can also be serious problems in some locations. The various foliage diseases that can devastate like Septoria and other spot and speck diseases along with Gray Mold show up almost every year down here and even Early Blight can be bad under the right conditions.

No matter what fungicides you use, you do need to use them regularly for them to be at all effective. Even with regular use some diseases will get through your defenses especially if you have hot humid conditions. Keeping your plants pruned to allow better air flow and sunlight penetration can be very efficacious. Mulching to stop splash back on your plants will also help. Use of beneficial insects and sometimes pesticides can help stop insect devastation. Learning how to use the diluted bleach spray correctly and in a timely manner can be a real plant saver. Here is a link to a good discussion with a thorough explanation on how to use it.
http://tomatoville.com/showthread.ph...t=bleach+spray

I do all of these things to slow disease and prolong my season but even with these steps I still have loses from mild to severe every year. A year with constant rain and super muggy conditions make matters much worse down here. The more I use the techniques listed above the longer my plants are productive on average. Years where I neglect my plants too much are usually the shortest seasons and since you like to baby yours and you aren't dealing with too many plants you should be able to maintain your plants better than most.

Bill

[loulac]

Originally Posted by b54red

I hate to break it to you but ... Bill

No problem, you are just honestly speaking the truth. Which leads me to wonder if it’s worth using strong fungicides. We know that Cl2 from bleach will quickly evaporate, but what do we know about azoxystobin etc.? Will the molecule be destroyed once sprayed on the plant or washed into in the ground ? are we going to ingest it either on the tomato or with the following crops ? Personally I prefer to play safe and lose the last tomatoes of the season.

[amideutch]

but what do we know about azoxystobin etc.?

Azoxystrobin is in the chemical family of Strobilurins. They are
based on naturally occurring wood-decaying mushrooms.

Ami

[loulac]

Thanks for the add-on, Amideutch, but I'm only slightly relieved : I suppose it's being synthetised now and I can't help thinking of neonicotinoids that are a d_ nuisance. Nicotin, after all, is a perfectly natural product too...

[Jwb4707]

I used daconil last season, seemed to keep the blights at bay, I lost the whole crop the previous season. There was some mystery ailment that took a few of my heirlooms, but it didn't seem like blight.