**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THE PROJECT TRIES TO ANSWER A FUNDAMENTAL QUESTION IN THE BIOLOGICAL CONTROL OF PLANT PATHOGENS. IS IT POSSIBLE TO PREDICT DISEASE- OR PATHOGEN-SUPPRESSIVE SOIL CONDITIONS? THESE ARE SOILS WHERE A PATHOGEN OCCURS BUT DOES NOT CAUSE SEVERE DISEASE DESPITE FAVORABLE ENVIRONMENTAL CONDITIONS, A SUSCEPTIBLE HOST, AND A VIRULENT PATHOGEN POPULATION. SUPPOSE WE CAN ACCURATELY PREDICT SUCH SUPPRESSIVE CONDITIONS. IN THAT CASE, WE CAN AVOID USING EXPENSIVE, LESS DESIRABLE MEASURES SUCH AS PLANT PROTECTION COMPOUNDS OR CHANGING THE CROP ROTATION TO LESS SUSCEPTIBLE BUT OFTEN LESS ECONOMICAL CROPS.PREVIOUS RESEARCH IN THE IMPERIAL VALLEY OF CALIFORNIA INDICATED THAT INDIGENOUS FUNGI OF THE H. OVIPARASITICA CLADE COULD EFFECTIVELY ELIMINATE THE CYST NEMATODE'S FEMALES, THEIR EGGS, AND DEVELOPING MALES. WE HAVE FURTHERMORE SHOWN THAT THE FUNGI OCCUR WORLDWIDE. HOWEVER, WE DO NOT KNOW HOW THEY PERFORM UNDER DIFFERENT CLIMATIC CONDITIONS, HOST CROPS, AND PATHOGEN POPULATIONS. A RELATIVELY SIMPLE SOIL DNA EXTRACTION AND PCR TEST ARE REQUIRED TO DETECT THE FUNGI. THIS SEED-GRAND PROJECT WILL INVESTIGATE THE OCCURRENCE AND BIOCONTROL ACTIVITY OF INDIGENOUS HYALORBILIA SPECIES AGAINST H. SCHACHTII IN THE COOLER CALIFORNIA COASTAL CLIMATE AND BROCCOLI PRODUCTION FIELDS.SUPPOSE WE CONFIRM THE ACCURACY OF THE BIOCONTROL PREDICTION UNDER TWO VASTLY DIFFERENT ENVIRONMENTAL CONDITIONS (IMPERIAL VALLEY VS. COASTAL CLIMATE). IN THAT CASE, WE FEEL CONFIDENT TO EXPLORE SEVERAL OTHER PARAMETERS OF THE BIOCONTROL ORGANISMS THAT WILL REQUIRE MORE EXTENSIVE RESEARCH.