Publications for:

pest = Alternaria (anamorphic genus)
beneficial = Pseudomonas syringae (antagonist)

found 2 publications:

2005

Biocontrol Pseudomonas strains against postharvest pathogens of apple
Journal of Plant Pathology (2005) 87 (4), p. 307
pestinfo wiki

1998

Biological control of core-rot caused by Alternaria alternata on Starking Delicious apples
International Congress of Plant Pathology (1998) 7th meeting, section 5.2
pestinfo wiki