Synthetic disease control

[MsCowpea]

My plants laugh at copper.
I used to squeak by for a whole season and even was a lazy sprayer but last year some plants were getting bad end of Jan.

Today I practically defoliated a couple plants just taking all the diseased leaves off and I have sprayed religiously and it is only Jan 4.

We never disinfected cages or bamboo stakes. Or black plastic edger things I use around the plant stem when planting.
Plus I have grown tomatoes in the same spot for 18 years. All this is bad.

The majority of the plants still look fine but I know how fast things get out of hand.

I grow organically, unless I am experimenting and need synthetic controls for fertilizing only (using containers).

Diagnostics testing says to use copper plus maneb for better control than copper alone on bacterial spot.
Maneb alone is good for Early blight better than Daconil (chlorothalonil sp?)

You can use copper for early blight as well but it is not the greatest.

Of course you can’t use daconil or maneb in organic gardening. But I was wondering if anyone uses them and how do they work. I believe it was Carolyn on gardenweb who said it gives you two extra week which is not that great.

I did buy a Monterey garden fungicide but have not used it yet.

I think it is easy to fertilize and treat pests organically (even prefer to do this) but diseases can overrun you. I may have to plant 100 juliets . It’s bomb proof.

[MissS]

I use daconil on my plants when they need it. I don't always need to spray for disease but when I do I first will spray with milk diluted 50/50 with water and then follow up with daconil if I need to. When conditions are bad I rotate between daconil and copper. This only controls fungal diseases it does not stop them.

[MsCowpea]

That is amazing you don’t always have to spray. Must be those long cold winters. I used milk a few years back. I also tried aspirin and silicon. (Not organic). I can’t remember what the results were. Maybe I should try them again. I know they use milk as a hand disinfectant in some greenhouses So it must have fungicidal properties. Thanks for suggestions.

[Nan6b]

I gave up spraying. When my plants are small, it's OK but with full-sized tomato plants you can go through a lot of bottles quickly. Some varieties just give up under the disease pressure; others do well. I have written off the varieties that struggle too much and go under due to disease. (I think my main disease is Septoria.) Some that do well:

Bajaja
Big Beef
Butter Apple
Crimson Carmello
Dark Galaxy
Dotson's Lebanese Heart
Dr. Carolyn
Early Cascade
Early Girl
Maglia Rosa
Manalucie
Old Brooks
Pomodoro sel. Sorrento
Post Office Runt
Post Office Spoonful
Sungold
Tommy Toe
Velvet Red

Some that did poorly:

Anna Maria's Heart
Fish Lake Oxheart
Keepsake
Kosovo
Mat-Su Express
Medova Kaplya
Orange Russian 117
Orange Strawberry
Park's Whop. CR Impr.
Pink Berkeley Tie Dye
Pomodoro Di Sorrento

[bower]

That is amazing you don’t always have to spray. Must be those long cold winters. I used milk a few years back. I also tried aspirin and silicon. (Not organic). I can’t remember what the results were. Maybe I should try them again. I know they use milk as a hand disinfectant in some greenhouses So it must have fungicidal properties. Thanks for suggestions.

Milk is used for antiviral properties mostly, I think.
An organic alternative to aspirin is to make a brew of willow or Spirea or birch - all are good natural sources of salycilates. I've used it as a soil drench and the plants love it. Maybe it's like being treated to a chicken soup or a spicy guacamole when you have the flu... not a cure per se, but it makes you feel better.
Our climate is really different, but we too can have lots of fungal problems here when it's damp. Sanitation makes all the difference for me. Wipe down those cages with soapy water and a little plain vinegar added (the low pH is antifungal). Last year's tomato leaves and funk should be removed to rot elsewhere, and cover it well with dirt so there are no spores blowing across the garden.
During the season I used to do a quick sanitation round every day before watering, and remove all funky leaves and spent blossoms. Like Nan, the varieties that were "too high maintenance" were not invited to return, and that helps. But removing the sick stuff which is full of spores is key to prevent it from spreading. Also over the years I learned a few tricks to reduce the labor.
One is that the most important sanitation you can do is to remove spent blossoms. They are basically mold bombs, which contain exactly the nutrients that a lonely spore wanted to make a home. The majority of leaf molds are started by blossoms or petals that fall onto the leaf and stay there. Huge difference, if you make removing them a priority clean.
Then while managing my friend's farm tomatoes one season I discovered that it was enough to get rid of old blossoms and any bad leaves once a week while doing the necessary pruning and tying. YMMV, but it was an eye opener for me, that there was no real need to do this every day! Once a week was plenty.
Third lesson for mold prevention was that EB on lower leaves can be prevented by giving the plant a good feed when the fruit begins to ripen. At that time the plant will go looking for N and other nutrients from the lower leaves, and once it starts withdrawing the goodies, the leaves get whatever blight they are susceptible to, EB or grey mold/botrytis. It's like immune support is withdrawn from those leaves too. Extra feeding stopped the problem for me, of EB that turned up at that time in the season.

[Nan6b]

Third lesson for mold prevention was that EB on lower leaves can be prevented by giving the plant a good feed when the fruit begins to ripen. At that time the plant will go looking for N and other nutrients from the lower leaves, and once it starts withdrawing the goodies, the leaves get whatever blight they are susceptible to, EB or grey mold/botrytis. It's like immune support is withdrawn from those leaves too. Extra feeding stopped the problem for me, of EB that turned up at that time in the season.

Oh, that is very interesting, to know the science behind it!

[bower]

Yeah, I don't know why it didn't occur to me that FOOD would cure a disease. But it does!

[MsCowpea]

Nan6B , thanks , it is important to know which tomatoes just aren’t worth the effort.

Bower, many good points in your thoughtful post. At the end of this season those cages and accessories will have to be disinfected —just too lazy in the past - there are so many of them.

I have one of those weeding torches that uses a 5 gal propane tank. That can be used on the cages but sometimes I think I am going to blow myself up. So I have to tell myself -get a grip! I haven’t used it for years but can reacquaint.

I am so glad you mentioned the fertilizing and nitrogen . I read that recently somewhere and it completely went out of my head. All my plants need to be fertilized. I don’t think they explained what is happening with the lower leaves though. Very interesting.

[bower]

Ms. Cowpea, I could hardly believe the connection until I gave the extra ferts and saw the results. Lower leaves stayed green and healthy! Seasoned growers at the Ville have seen it all.. the amount learned from those people I can never sum up.

[MissS]

That is some very good advice Bower. Thank you so much. I never knew that about removing the spent blossoms.

Milk is antiviral and anti fungal. I use it for gray mold and early blight.

[SusieQ]

I have one of those weeding torches that uses a 5 gal propane tank. That can be used on the cages but sometimes I think I am going to blow myself up. So I have to tell myself -get a grip! I haven’t used it for years but can reacquaint.

I love my 'flamethrower', and use it for all sorts of things. A tip I've learned, though... to always make sure the flame is pointed downwind from me. I never want a strong wind blowing the fire back into the wand and up toward the the tank. You can definitely hear the change in propane flow when that happens.

[MsCowpea]

SusieQ- good advice


I found the publication that mentions the nitrogen connection with early blight. I totally forgot that consideration until Bower brought it up.

https://edis.ifas.ufl.edu/pp121


“ To control early blight, start with disease-free transplants and fertilize plants adequately. Inadequate nitrogen levels, in particular, make tomatoes more susceptible to early blight. A persistent problem with early blight might require periodic sprays with an appropriate fungicide.”

[Greatgardens]

That is amazing you don’t always have to spray. Must be those long cold winters. I used milk a few years back. I also tried aspirin and silicon. (Not organic). I can’t remember what the results were. Maybe I should try them again. I know they use milk as a hand disinfectant in some greenhouses So it must have fungicidal properties. Thanks for suggestions.

What is the "silicon" you use?

[Ginger2778]

That is amazing you don’t always have to spray. Must be those long cold winters. I used milk a few years back. I also tried aspirin and silicon. (Not organic). I can’t remember what the results were. Maybe I should try them again. I know they use milk as a hand disinfectant in some greenhouses So it must have fungicidal properties. Thanks for suggestions.

Milk is used for antiviral properties mostly, I think.
An organic alternative to aspirin is to make a brew of willow or Spirea or birch - all are good natural sources of salycilates. I've used it as a soil drench and the plants love it. Maybe it's like being treated to a chicken soup or a spicy guacamole when you have the flu... not a cure per se, but it makes you feel better.
Our climate is really different, but we too can have lots of fungal problems here when it's damp. Sanitation makes all the difference for me. Wipe down those cages with soapy water and a little plain vinegar added (the low pH is antifungal). Last year's tomato leaves and funk should be removed to rot elsewhere, and cover it well with dirt so there are no spores blowing across the garden.
During the season I used to do a quick sanitation round every day before watering, and remove all funky leaves and spent blossoms. Like Nan, the varieties that were "too high maintenance" were not invited to return, and that helps. But removing the sick stuff which is full of spores is key to prevent it from spreading. Also over the years I learned a few tricks to reduce the labor.
One is that the most important sanitation you can do is to remove spent blossoms. They are basically mold bombs, which contain exactly the nutrients that a lonely spore wanted to make a home. The majority of leaf molds are started by blossoms or petals that fall onto the leaf and stay there. Huge difference, if you make removing them a priority clean.
Then while managing my friend's farm tomatoes one season I discovered that it was enough to get rid of old blossoms and any bad leaves once a week while doing the necessary pruning and tying. YMMV, but it was an eye opener for me, that there was no real need to do this every day! Once a week was plenty.
Third lesson for mold prevention was that EB on lower leaves can be prevented by giving the plant a good feed when the fruit begins to ripen. At that time the plant will go looking for N and other nutrients from the lower leaves, and once it starts withdrawing the goodies, the leaves get whatever blight they are susceptible to, EB or grey mold/botrytis. It's like immune support is withdrawn from those leaves too. Extra feeding stopped the problem for me, of EB that turned up at that time in the season.

This post just won the internet! I just learned so so much. Thank you Bower, and with your scientific background, I trust this. Every. Word. Please put a sticky on this thread.. the whole thread is excellent.

[Ginger2778]

Ms. Cowpea, I could hardly believe the connection until I gave the extra ferts and saw the results. Lower leaves stayed green and healthy! Seasoned growers at the Ville have seen it all.. the amount learned from those people I can never sum up.

Me too. I learned most of what I know from them. Some things don't apply to South Florida growing, but most does.

[GoDawgs]

One is that the most important sanitation you can do is to remove spent blossoms. They are basically mold bombs, which contain exactly the nutrients that a lonely spore wanted to make a home. The majority of leaf molds are started by blossoms or petals that fall onto the leaf and stay there. Huge difference, if you make removing them a priority clean.

Are you talking about blossoms that never started becoming tomatoes? I've never paid any attention to that before.

I make it a point to mulch the tops of my pots and limb up any branches whose leaves droop to touch the soil. It seems to help. I also use Serenade, a broad spectrum anti-fungal spray that is OMRI approved. The problem is getting my butt out there to reapply after it rains. Rain seems to be the clarion call for all sorts of problems to come out of the woodwork!

Thank you for the tip on milk! I never knew and will try that in rotation with the Serenade and Daconil (If it gets bad) this summer.

[bower]

[mention]GoDawgs[/mention] both the blossoms that fail to set and the petals that fall or shrivel up as the fruit is starting can be a nurture point for mold. The scientific article that tipped me off about that, I read maybe 6-7 years ago - I will have a dig through and find it at some point so I can share the link. The effects of blossom drops become really noticeable in the enclosed greenhouse environment, which you might never realize outdoors as the wind shakes them off or tucks them in somewhere that afterwards becomes a moldy leaf!
I tip my hat to any gardener with the patience to do spraying. Every time I've done soap spray or similar it's the gateway to despair for me. It's never enough, you always have to repeat. And even worse, it's like putting money in a hose and making a job of wasting it. I know how different it must be in your climate, and you have many more diseases to worry about than we do. Kudos to all of you southern gardeners!

[brownrexx]

Growing in FL is WAY different than growing in PA. I never disinfect any tomato cages. They sit outdoors during the cold, ice and snow. Nothing is going to live on there.

I rotate my tomato planting area every 2 years to try and avoid spores living in the soil.

I usually get Early Blight on the lower leaves way before the plants are blooming or producing fruit so the advice about feeding may not apply to my plants. I do remove all infected leaves.

If I feel like adding Nitrogen I have started using feather meal. It is all Nitrogen. If I use blood meal then the critters (probably skunks) will dig around my plants and they have even dug up seedlings and left them on the ground to die. They really go for blood or bone meal so I don't use them anymore.


Early in the season, I usually spray with a preventative called Actinovate and it really seems to help. If I have problems that I can't control, then I use a light spray of copper.

This works for me but I don't see Septoria until the end of the season and Late Blight does not show up every year and if it does, it comes at the end of the season too.

We don't have as much humidity as the South and I provide plenty of airflow between plants and use cages so I never have mold problems.

[MsCowpea]

Silicon as a foliage spray for plants has been around a very long time. The research seems mixed on its benefits. I have used Dynamite Gro Pro TEK ( potassium and silicon) on tomatoes years ago (off and on ) and tried again this year but I don’t use it enough or with controls to know if it helps or not. My soil is deficient in potassium so perhaps the K would help as much as Si) As mentioned it occurs naturally in horsetail and in comfrey (which is interesting as comfrey tea is sited as beneficial to plants in old gardening books particularly in England.) and still used today.

Apparently it is easy to use too much and interfere with other nutrients. I know you use very very little of the Pro TEK when mixing. And I believe you have to adjust the pH but that is easy to do. If anyone wants to experiment you can get a small amount of the Dyna Gro Pro TEK on Amazon for $10 —it would probably last for years as you use so little. (Not for certified organic growers). There may be better products out there today but you would have to research via google.

Ages ago I was interested in it as something to use against bacterial spot. ( see article below). But I never used it consistently over the years to make a judgement. If it was really effective against BS you’d think it would be used by the commercial growers but I am still intrigued by the claims of its proponents.

https://www.growingproduce.com/vegetabl ... id=1714182

https://www.pthorticulture.com/en/train ... t-culture/

http://www.scielo.br/scielo.php?script= ... 3000500009

[pepperhead212]

Here is a much less expensive source of potassium silicate than the liquid solutions - you just make your own. I use it in the hydroponics, and watering the seedlings, to strengthen their stems. It's interesting to see that it could help in the spraying.


Last year, I had a very bad season with fungus, due to the incredible amount of rain, up to about 7-20, at which time we were well ahead of 2018, which was the 2nd highest on record. Almost every tomato had septoria spot. I tried aspirin, which didn't work at all. Septoria did little, also. Actinovate, which I sprayed early, as a preventative, may have helped for a while, but I didn't have a control group, so no way to tell. It seems that potassium bicarbonate seemed to do best in the past, but it does better in combination with oil, and this fungus came earlier than usual, and in the hottest part of the summer you can't add the oil. It's usually later in the season I have to use it, not this early. Fortunately, it suddenly turned into a drought, for the rest of the summer, and the new growth on most of the tomatoes did well, and I carefully trimmed that diseased growth off them.

This year I'll have to try the silica added to the spraying. Thanks for the input!