THIS PROPOSAL IS A PLANT HEALTH AND PRODUCTION AND PLANT PRODUCTS AREA OF THE CRITICAL AGRICULTURAL RESEARCH AND EXTENSION (CARE) PROGRAM PROJECT REQUESTING $296,048.CORN IS PLANTED ON OVER 89.7 MILLION ACRES IN THE U.S. WITH A VALUE OF MORE THAN $52.9 BILLION IN 2019. IN 2018, AN EPIDEMIC OF A NEW DISEASE, TAR SPOT CAUSED BY PHYLLACHORA MAYDIS, OCCURRED IN SIX STATES IN THE MIDWEST. FIELDS IN THE MOST SEVERELY AFFECTED REGIONS REPORTED 1345-4035 KG/HA (20-60 BU/A) YIELD LOSS. THE IMPACT ON U.S. CORN PRODUCTION FROM 2018 TO 2020 IS ESTIMATED AT A 241 MILLION BUSHEL LOSS WITH A VALUE OVER $895 MILLION. TAR SPOT CONTINUED TO SPREAD THROUGH THE U.S. AND IS NOW CONFIRMED IN TEN STATES. THERE IS A LACK OF UNDERSTANDING OF TAR SPOT EPIDEMIOLOGY AND HOW THE IMPLEMENTATION OF IPM TACTICS CAN MANAGE TAR SPOT IN CORN.THIS PROPOSAL AIMS TO ADVANCE THE UNDERSTANDING OF THE EPIDEMIOLOGY OF PHYLLACHORA MAYDIS ON DENT CORN AND DEVELOP AN EFFECTIVE, ECONOMICAL, AND COMPREHENSIVE IPM APPROACH TO CONTROLLING TAR SPOT OF CORN IN THE U.S. THE OBJECTIVES OF THIS PROPOSAL ARE: 1) EVALUATE THE SUCCESS OF A TAR SPOT INTEGRATED MANAGEMENT PLAN THAT INCLUDES RESISTANT HYBRIDS, FUNGICIDE APPLICATION, AND TIMING (BASED ON AN ADVISORY TOOL); 2) DEVELOP AN IMPROVED UNDERSTANDING OF THE EPIDEMIOLOGY OF PHYLLACHORA MAYDIS ON CORN; AND 3) DEVELOP AN INNOVATIVE SUITE OF EXTENSION TOOLS AND OFFER HANDS-ON TRAINING IN TAR SPOT IDENTIFICATION AND BEST MANAGEMENT PRACTICES FOR TAR SPOT THAT INCLUDES FACTSHEETS, WEBINARS, AND WEB-BASED CONTENT.