Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/27/1998
Publication Date: N/A
Technical Abstract: Soybean seeds, infected with Sclerotinia sclerotiorum, were surface sterilized in NaOC1 (0.53%) and the seed coat was removed from the cotyledon. Mycelia grew both from seed coat and the cotyledons when plated on PDA. Healthy and infected seeds (95:5) were either treated or not treated with thiabendazole (TBZ) (1.32g/kg), Maxim (0.53g/kg), Rival (2.67g/kg), and thiram (1.32g/kg) using 800 seeds per treatment. Percentage of seed with mycelial growth was determined after incubating in a seed germinator for 5 days at 25 C. Rival and Maxim completely inhibited mycelial growth from infected seeds, while thiram and TBZ reduced infection by 90%. In a field test, seed blend with 20% infection was used to test fungicide efficacy. Rival completely inhibited seed transmission (production of sclerotia) in the field, while Maxim and thiram reduced seed transmission by 99.7%. In an additional study, 500 infected seeds were placed in aluminum pans containing field soil to determine if mycclia from infected seed produced sclerotia and apothccia the same year. After 3 months, 553 sclerotia and 10 apothccia were produced. For both of the studies, all infected seeds failed to germinate.