Applied Research in Field Crop Pathology for Indiana, 2020 serves as a summary of the applied field crop pathology research trials conducted in 2020 under the direction of the Purdue Field Crop Pathology program in the Department of Botany and Plant Pathology at Purdue University. In Indiana, there are more than 57,600 farms, 16,000 crop producers, and 900 certified crop advisers, Extension educators, and crop-protection industry representatives who manage more than 11.4 million crop-production acres with a total value of $6.3 billion annually. There are more than twenty diseases affecting corn, soybeans, and wheat that may decrease crop production and profitability. In a single growing season in the state, diseases can cause a total estimated loss of more than $400 million, making disease identification and management a primary concern. The goal of this book is to share some of the most current, nonbiased, research-based information to address the management of field crop diseases. This data will support individuals engaged in crop production, helping them select effective, sustainable, and economically sound disease-management practices to implement on their farms.