Septoria Experiment

[jmsieglaff]

I came across this powerpoint suggesting a product called MilStop was effective at preventing septoria leaf spot on tomatoes:
https://newenglandvfc.org/sites/newe...TH-organic.pdf

The active ingredient is potassium bicarbonate. I have used the 4 tsp of potassium bicarbonate + a few drops of dish soap in 1 gallon of water as a powdery mildew spray for squash and cucumbers and it was quite effective.

So I decided this year to spray my tomatoes with this to see how it will work. I have always been good about trimming any leaves with even 1 or 2 Septoria spots. I have always been disappointed by how many branches I've had to remove. So this year I'm just removing leaflets with spots instead of the whole leaf with all leaflets--I don't know why I did just do that in the past.

This experiment will be far from scientific--I've sprayed twice so far, both following rainy 2-day periods. I remove any leaflets with spots daily. I have no schedule to spray, just will do it when the weather dictates. A huge factor will be the weather--the last 2-3 years have been very wet, so a drier year should reduce Septoria pressure as well (I'm hoping for drier and it definitely seems like we have fewer rainy days this growing season so far as well as being generally warm, with a few hot days already).

The added benefit of this spray is potassium feeding for tomatoes, via foliar absorption and dripping into the ground.

Fingers crossed! I'd rid the Earth of Septoria even before I'd get rid of mosquitos!

[Labradors2]

That would be great if it works. I'll stay tuned to hear more .

My experience with Septoria (which I get every year) is that, if I remove just one infected leaf, the next time I look the whole leaflet is infected and I always think that I should have saved myself the trouble and removed the whole leaflet the first time around. However, if the spray works, perhaps it will prevent that from happening!

Linda

[RayR]

Potassium bicarbonate fungicides are only registered as a control for Powdery Mildews since they are sensitive to low PH. For Septoria it is possibly helpful as a preventative in a limited way. Septoria is such a sinister pathogen, it's difficult to control once infections start and your plants may be infected even though the spots are not yet visible. A Copper soap fungicide has a better chance of killing Septoria once infection sites are visible. I've searched high and low for controls, biological or chemical and there's no silver bullet. Preventative measures are your best shot.

[Cole_Robbie]

I had a market customer once tell me that the healthiest tomato plant he ever grew was underneath the ladder to his pool and got splashed with pool water every day by his grandkids. It was probably the chlorine.

[jmsieglaff]

I've done copper in the past and it is fairly effective, I'm just looking to try things that are not chemical and trying to not use copper if I can. I may also try the bleach spray. I ordered a new sprayer, 2 gallon with a brass tip, I'm excited to see it in action more than the cheap plastic ones I've been using.

[edweather]

The fungal diseases here in south Georgia are brutal. Am going to give a weak bleach spray a try myself. I had to smile at the previous post talking about not using chemicals, but might give bleach a try

[jmsieglaff]

Ha, well good point. I consider bleach spray far less dangerous than commercial fungicides.