Septoria Experiment

jmsieglaff · June 11, 2020

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!

June 11, 2020	#1
jmsieglaff Tomatovillian™ Join Date: Jan 2014 Location: Southern WI Posts: 2,742	Septoria Experiment 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!