I tried spraying a baking powder spray prophylactically on tomatoes and beans, didn't do the job. Getting a few yellow leaves on the tomatoes. Bad sign. Usually gets worse. I really want tomatoes this year! Getting a few yellow leaves with brown edges on the McCaslan beans. How are you Southern gardeners fighting fungus??? Struggling here in N. MS zone 7. I ordered an organic copper spray. Will this help? Never tried it before.