Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/29/1996
Publication Date: N/A
Technical Abstract: Commercial interest in using fungal conidia and blastospores as biopesticides for controlling insects, weeds, and plant pathogens is dependent on the availability of low-cost methods for producing effective spore preparations. Liquid culture and solid-substrate production methods are being developed to maximize spore yield, stability, and biocontrol efficacy. Nutritional conditions during culture growth and submerged culture sporulation have been shown to affect the spore "fitness" of biopesticides by altering spore morphology, composition, germination rate, and desiccation tolerance. Our studies have focused on optimizing nutritional conditions for the liquid culture production of spores of the potential bioherbicide Colletotrichum truncatum and of the potential bioinsecticide Paecilomyces fumosoroseus. While the carbon-to-nitrogen (CN) ratio of the sporulation medium was shown to affect numerous spore attributes of C. truncatum, CN ratio was not a significant nutritional factor during the growth and sporulation of P. fumosoroseus. The nitrogen content of the medium affected spore yield and spore desiccation tolerance in P. fumosoroseus cultures. Data will be presented on the impact of nutrition on the "fitness" of liquid culture-produced spores of C. truncatum and P. fumosoroseus. Additionally, the relevance of these data to the commercial production of fungal spores for use as biopesticides will be discussed.