Use of an anecic earthworm, Pheretima hawayana, as a means for delivery offungal biocontrol agents

Fungal biocontrol agents identified to be antagonistic towards the root-pat hogenic fungi Phytophthora cinnamomi have had limited success when applied in the field. Incomplete delivery of the biocontrol agent into the soil pro file and the plant rhizosphere is partly to blame for this lack of success. Earthworms may help to alleviate this problem though mixing of fungal inoc ula into the soil profile. In this research, Pheretima hawayana, an anecic species of earthworm, was fed oatmeal infested with the biocontrol fungi Tr ichoderma harzianum and Gliocladium virens. The earthworm was used as a vec tor for the transport of the biocontrol agent to the location of P. cinnamo mi infection, the avocado roots. The presence of earthworms in the treatmen t was linked to an increased survival and improved overall health of the av ocado seedling. In addition, earthworms were responsible for augmenting the transport of biocontrol agents into the soil profile, as compared to non-e arthworm treatments. Results suggest earthworms may directly and indirectly contribute towards improved avocado health.