Treating seeds to kill disease

Hello, I am a student, and I am trying an experiment to find out how to properly treat seeds to kill diseases.

I know this has been discussed here before, but there were never any specifics, which is what I want. I may have even just missed the specifics of other posts, but I have been looking. I am having trouble overall finding information that is more than just do this one thing. I want to know what is best and what works best.

I have been growing my own Zinnias and saving their seeds to grow again every year. So I  am focusing on treating Zinnia seeds to get rid of Alternaria blight (Alternaria zinniae). The top contender seems to be to heat the seed at 100 degrees for 10 minutes, then move to hotter water at 165 degrees for 5 minutes, then instantly cool and dry them. I have also seen that I can dip them into specific types of acid to treat them as well.

I do have some space to experiment with different forms of treating, but as you know, growing seeds takes time and a lot of resources. So I want to make sure I have enough information for my choice on how to treat my Zinnias without killing or damaging them.

Is there any advice someone has? Methods you have tried and worked?

Thank you!

Welcome to Permies!

I am not anywhere near well versed when it comes to plant diseases but this thread has peaked my interest. It is my understanding that diseases like Alternaria blight would exist both potentially on seeds and in the soil.

I'd almost want to skip fiddling with treating seeds and fighting to grow zinnias that might be vulnerable to blight and rather select seeds from my strongest zinnias in an effort to breed a blight-resistant strain that would do well regardless of soil/seed condition.

How long have you been growing your own Zinnias? It sounds like you might be well on your way already to doing that.

Maybe I am missing something, but I'd love to know more about your plans.

Have you tried growing them without treating to see if any of them survive?

If any do, you could save seed from them and develop a resistant strain. Or maybe there are already resistant strains available?

Carol Deppe's book in vegetable breeding goes into detail and has good citations for you to find more info.

Hint, the easiest way is prevention. Next is genetics and selection.  More complicated than just selecting for ones without.  

Treatment includes soil health as many things live in soil over winter.

And laxt of all, treatment of seeds depends on the specific type.  But easier to avoid this step if the other steps can be done first.  

Whatever the choice, don't forget a control section where you don't do the thing.

Seeds do not travel through the world alone. They carry living communities of bacteria and fungi inside them and on their surfaces. Many of these organisms function as endophytes—partners helping with nutrient cycling, plant development, and protection from disease.

Plants have recruited those microbial partners over many generations. Seeds carry an entire ecosystem.

When we apply treatments designed to sterilize seeds—heat, acids, bleach, or other disinfectants—we remove more than the organism we hope to suppress. Those treatments can also remove many of the plant’s long-standing microbial allies.

Rather than trying to sterilize seeds, I focus on maintaining plant diversity and healthy growing conditions so plants and their microbial partners sort things out together. In diverse populations, plants show a wide range of responses to diseases, and the more resilient individuals contribute the next generation of seed.

That approach treats the seed not just as a genetic unit, but as a small traveling ecosystem.