Unique mode of action - FRAC Group U13. GattenĀ® Fungicide has specific activity against the fungal pathogens that cause powdery mildew in several specialty crops. The translaminar movement of Gatten allows for maximum protection on both sides of the leaf surface resulting in improved control, especially in dense canopy situations. Gatten offers a unique mode-of-action for powdery mildew that has no known cross resistance to other classes of chemistry; this makes Gatten an excellent rotational partner for resistance management programs. GattenĀ® CA Fungicide is the same formulation and offers the same excellent benefits as Gatten; however, it is labelled specifically for the state of California for use on apple, cherry, and grape.