What diseases SPECIFICALLY is it effective on?

Sounds like one of those home brews for Powdery Mildew and similar. It Is worth testing to make sure that FIRSTLY it won't kill your plant.

She told me it prevents all blight.
Anyone try something similar?

She told me it prevents all blight.

Pardon a bit of skepticism - ok a lot of skepticism - but if that was even possibly true then the commercial tomato industry is wasting millions of dollars annually on research and has been for decades..

There are at least 50 home remedy recipes out there that someone swears will prevent all blight. Yet somehow none of them ever seem to be able to hold up to testing.

Dave

Well, since the commercial sprays do not work too well, I may as well give it a try.

There are at least 3 tomato diseases with "blight" in the name. They are entirely different and unrelated diseases.

In addition, some folks use "blight" when referring to other tomato diseases ... or all tomato leaf diseases ... or even all diseases affecting tomatoes. And some use "blight" to describe non-disease conditions which affect tomatoes: for example, leaf miners, sunburn, or herbicide damage.

Any time someone uses the term "blight" generically, you should just assume they don't know what they're talking about.

Well, since the commercial sprays do not work too well, I may as well give it a try.

When I was younger, I grew tomatoes in the Chicago area for 8 summers. The only disease I saw was one summer when one of the plants had Septoria Leaf Spot. I never used any spray. Just lucky.

So keep in mind that if your plants are free of any particular disease this summer, that doesn't mean the spray had anything to do with it.

I have been growing tomatoes here in Charlotte, NC for 12 years and have never had a disease free year. Some years are worse than others. If I can grow tomatoes disease free this year with this spray, then it would be pretty obvious.
I do not really think it will do much either, but then again nothing much else works either. Daconil and Mancozeb will delay disease for a while, but sooner than later it gives in too.