BIOLOGICAL CONTROL OF SOILBORNE PLANT PATHOGENS IN CONTAINERIZED GROWING MEDIA

DISEASES CAUSED BY SOILBORNE PLANT PATHOGENS IN CONTAINERIZED GROWING MEDIA CAUSE SIGNIFICANT ECONOMIC LOSSES ANNUALLY TO GREENHOUSE INDUSTRIES THROUGHOUT THE WORLD. A WIDE RANGE OF PESTICIDES ARE APPLIED IN AN ATTEMPT TO CONTROL THESE ORGANISMS, BUT PATHOGEN PROTECTION WITHIN THE GROWTH MEDIA, OR RECOLONIZATION BY THE PATHOGEN, RESULTS IN POOR OR SHORT-LIVED CONTROL. SPECIES OF THE NATURALLY OCCURRING SOILBORNE FUNGUS, TRICHODERMA, HAVE BEEN SHOWN TO BE EFFECTIVE ANTA-ONISTS OF SEVERAL FUNGAL PLANT PATHOGENS. RECENT EFFORTS HAVE BEEN MADE TO INCORPORATE BIOLOGICAL DISEASE CONTROL ORGANISMS INTO CONTAINERIZED NURSERY OPERATIONS, HOWEVER, VERY FEW ATTEMPTS HAVE BEEN MADE TO COMBINE THIS WITH OTHER BENEFICIAL ORGANISMS SUCH AS MYCORRHIZAL FUNGI. THIS STUDY WILL EVALUATE SEVERAL ISOLATES OF TRICHODERMA AND ECTOMYCORRHIZAL FUNGUS, LACCARIA LACCATA, FOR THEIR ABILITY TO CO-ESTABLISH AND COOPERATE IN THE CONTROL OF ROOT PATHOGENS IN CONTAINERIZED GROWING MEDIA WITH DOUGLAS FIR. A SERIES OF EXPERIMENTS ARE PLANNED TO ESTABLISH THE METHODOLOGIES NECESSARY FOR THE CO-SELECTION, INOCULATION AND ESTABLISHMENT OF EFFECTIVE BIOCONTROL SYSTEMS FOR THE CONTAINERIZED NURSERY INDUSTRY. DIRECT BENEFITS INCLUDE A LOW COST, LONG-LASTING AND LESS HAZARDOUS SYSTEM FOR THE CONTROL OF SOILBORNE FUNGAL PATHOGENS WHICH WOULD CONTINUE LONG AFTER THE PLANTING STOCK LEAVES THE NURSERY.