Plantain and Banana Plant Health Initiative Act This bill establishes a research and extension grant program for a plantain and banana plant health initiative. Specifically, the bill authorizes the Department of Agriculture to provide competitive grants for studying potential resistance and tolerance to nonnative diseases and insect pests; increasing research for treatment of pests that affect plantains and bananas; conducting field studies to evaluate plantain and banana cultivars with enhanced resistance to diseases and pests, and adaptability to tropical soils; educating growers on best practices to promote safe production of plantains and bananas; and establishing area-wide integrated pest management programs in areas affected by, or at risk of being affected by, specified pests.