Oh Oh! I think you've found a topic that none of us knows the answer to. :O
Maybe you could be more specific. What mold control spray recipe are you referring to? I believe there are various horticultural oils--dormant oil for winter or very early spring, and summer oil for (ahem!) summer. But I'm not sure where you would get such a thing. Maybe a web search?
If you are referring to fungal diseases that may occur on tomatoes and plants like that, good ole seaweed sprays have natural fungal control built in it.
Also corn meal is a natural fungicide. You can sprinle corn meal on plants, or make a strong 3-7 day old tea out of it and pour it on the plants as a foliar feed, or on the ground around the roots as a soil drench.
