An Autumn Tomato

Soon this tomato season will be over.  I only planted
four this summer, but they have been great producers.
I went out after heavy rains and captured this "turning"
tomato.  Each year my tomato leaves get a leaf
blight from the bottom up; it is a slow process but
I am sure it affects tomato production.  Do any of you
have a wholistic approach to this??  I need a recipe to
mix for spraying the leaves when the blight starts.  I
am against harmful chemicals!  Any thoughts you
have would be appreciated!