** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** HERBICIDE-RESISTANT ITALIAN RYEGRASS POSES A SERIOUS THREAT TO GLOBAL AGRICULTURE, ESPECIALLY IN WINTER CROP PRODUCTION. IN ADDITION TO THE GENETIC FACTORS AND UNRESTRICTED HYBRIDIZATION, SEVERAL UNIQUE ECOLOGICAL TRAITS MAKE ITALIAN RYEGRASS A ROBUST INVADER AND A RESILIENT AND HERBICIDE-RESISTANCE-PRONE WEED AT A GLOBAL SCALE. IT HAS BEEN REPORTED THAT A SPECIFIC MICROBIOME, E.G., A SYMBIOTIC-ENDOPHYTE EPICHLOË SPP. PROVIDES ITALIAN RYEGRASS WITH INCREASED TOLERANCE TO MANY ABIOTIC STRESSES, INCLUDING DROUGHT, COMPETITION, AND SOMETIMES HERBICIDES. ADDITIONALLY, THERE IS EVIDENCE THAT CERTAIN ENVIRONMENTAL FACTORS CAN INFLUENCE THE STRESS RESPONSE IN WEED SPECIES AND, SUBSEQUENTLY, THE HERBICIDE EFFICACY, LEADING TO AGGRAVATED IMMUNITY OF THE WEEDS TO MULTIPLE HERBICIDE CHEMISTRIES. ALTHOUGH DISCUSSIONS WITH GROWERS IN EXTENSION MEETINGS AND FIELD VISITS TO WHEAT-PRODUCING COUNTIES IN ALABAMA INDICATE THAT SEVERAL ITALIAN RYEGRASS POPULATIONS ARE APPARENTLY SURVIVING SOME OF THE COMMONLY USED HERBICIDES APPLIED AT PREEMERGENCE AND POSTEMERGENCE STAGES IN THE REGION, NO WORK HAS BEEN DONE TO DOCUMENT THE CURRENT HERBICIDE RESISTANCE STATUS IN THIS WEED IN ALABAMA OR TO UNDERSTAND THE INFLUENCE OF KEY DRIVING FORCES TRIGGERING HERBICIDE RESISTANCE DEVELOPMENT AND SPREAD IN ALABAMA AND BEYOND. THIS PROJECT AIMS TO EVALUATE THE ABUNDANCE AND ASSOCIATION OF EPICHLOË SPP. TO HERBICIDE RESISTANCE DEVELOPMENT IN ITALIAN RYEGRASS POPULATIONS IN ALABAMA AND UNDERSTAND THE INTERACTIVE EFFECTS OF SOIL MOISTURE, TEXTURE, TEMPERATURE, AND CO2 LEVELS ON HERBICIDE RESISTANCE DEVELOPMENT. OUR OVERALL GOAL IS TO UNDERSTAND THE DRIVING FORCES OF HERBICIDE RESISTANCE ACQUISITION AND EXPRESSION IN ITALIAN RYEGRASS TO HELP DEVELOP INFORMED MANAGEMENT STRATEGIES FOR DEACCELERATING THE RESISTANCE EVOLUTION AND SPREAD.

Auburn University, Auburn AL

Investigators