Potential for biological control of Monilinia laxa in peach twigs

The antagonistic effect of four fungi (Aspergillus flavus, Epicoccum nigrum, Penicillium frequentans and Penicillium purpurogenum) against Monilinia laxa on peach twigs was assayed in two field experiments in central Spain in spring and autumn. Results were different in the two periods. In spring, E. nigrum, P. purpurogenum and P. frequentans significantly reduced the success of infection when introduced before inoculation with the pathogen but A. flavus caused only a transient delay in the development of symptoms. However, when inoculation preceded antagonist introduction, only the treatments with P. frequentans resulted in a lasting reduction of symptoms and those with P. purpurogenum merely delayed symptom development. In autumn, only the treatments with E. nigrum resulted in a reduction of M. laxa infection. The potential for practical use of these fungi is discussed.