The Yissum R&D Company at the Hebrew University in Jerusalem has developed a non-toxic, environmentally friendly agent that controls fungus and bacteria in agriculture. It is derived from yeast isolated from strawberry leaves, and is effective for a large variety of plants.
http://www.jpost.com/Health/Article.aspx?id=288637
http://www.youtube.com/watch?v=t2TWVnoUe6Y