** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** WEEDS, ESPECIALLY AMARANTHUS PALMERI (PALMER AMARANTH), REPRESENT A MAJOR BIOSECURITY THREAT TO AGRICULTURE IN THE UNITED STATES CURRENTLY AMOUNTING TO $33 BILLION IN LOSSES ANNUALLY. CLIMATE CHANGE AND HERBICIDE RESISTANT VARIETIES ARE LEADING TO THE SPREAD OF THIS PEST TO NEW US STATES AND THREATENING INTERNATIONAL GRAIN EXPORTS. TO ADDRESS THE LACK OF CHEMICAL HERBICIDES CAPABLE OF ADDRESSING THIS THREAT WE PROPOSE TO DESIGN SAFE AND EFFECTIVE VIRAL HERBICIDES. WE HYPOTHESIZE THIS NEW TOOL WILL BE ABLE TO SELECTIVELY DELIVER RNA TO A. PALMERI THAT INHIBITS ITS HERBICIDE TOLERANCE AND CAPACITY TO GROW WHILE NOT AFFECTING ANY OTHER PLANT IN THE ENVIRONMENT. TO DO THIS WE WILL DESIGN AND TEST A NOVEL FORM OF BIOCONTAINMENT THAT WILL RESTRICT THE VIRUS'S INFECTIVITY TO JUST A. PALMERI, CREATE A NOVEL CLASS OF RNA-BASED TOOLS TO KNOCK DOWN THE FUNCTION OF GROWTH AND HERBICIDE RESISTANCE GENES IN A. PALMERI, AND IDENTIFY MUTATIONS THAT IMPROVE SPREAD OF THE VIRUS THROUGH A. PALMERI. THIS WORK WILL LEAD TO AN IMPORTANT NEW PEST CONTROL TECHNOLOGY TO DEAL WITH A PERVASIVE THREAT TO THE US FOOD SUPPLY, NAMELY HERBICIDE TOLERANT A. PALMERI. ADDITIONALLY, THIS PLATFORM TECHNOLOGY COULD BE EASILY EXTENDED TO OTHER INVASIVE PLANTS THAT THREATEN US FOOD SECURITY IN THE FUTURE. BY ENABLING A REDUCTION IN THE CROP LOSSES TO EMERGING WEEDS THIS TECHNOLOGY WILL INCREASE REVENUES FOR FARMERS AND HELP REDUCE FOOD PRICES FOR AMERICANS, BOTH TODAY AND IN THE FUTURE.