Apple bitter rot is a destructive fruit rot of apple worldwide. Because of recent advances in postharvest
biological control as an eco-friendly and a potent alternative of fungicides, the present study evaluated
the antagonistic activities of more than 100 Actinomycetes isolated from apple orchard soils of Kerman
city (Iran) against causal agent of the disease. In vitro bioassays revealed that six of the isolates had
significant inhibitory effects against the mycelial growth of the pathogen. Postharvest in vivo
experiments were performed with either direct application of antagonists spore and mycelial mat or
suspensions of their crude extracts. Statistical results indicated that antagonists inhibited rotting of apple
fruit (p < 0.01) either by inhibition of disease onset or preventing further expanse of diseased fruitlesions.
Molecular identification of the antagonist performed based on 16S rDNA nucleotide sequence,
and identified as Amycolatopsis sp. The present study is a preliminary step toward production of an
applicable eco-friendly biocontrol product. Future larger scale postharvest evaluations would reveal such
feasibility.