Gardening: How to combat plant disease using biology and technology

“I live one mile from the ocean so the evenings can be pretty damp. I have consistently had trouble with powdery mildew and last year had trouble with anthracnose and black spot (early blight) on my tomatoes. None of my crops seemed to do well last year except that I had a bumper crop of lettuces and kale. I would appreciate any advice you could send my way.” – Joan Rowe, Huntington Beach
When it comes to any plant disease problem, there are typically two approaches to sol