BIOLOGICALCONTROLOF ARMILLARIA ROOTROTUSINGSPENTMUSHROOM COMPOST AMENDED WITH COMBINATIONS OF FUNGAL ANTAGONISTS ISOLATED FROM MUSHROOMS F RAZIQ and RTV FOX School of Plant Sciences, The University of Reading, 2 Earley Gate, Reading RG6 6AU, UK Background and objectives < i > Armillaria mellea < /i > is a root rot pathogen of woody and some herbaceous plants. Most infections are not controlled effectively at present [1,2]. A number of fungal antagonists with different modes of action were applied in combination in order to improve biological control. < b > Materials and methods < /b > Compared to many woody plants, strawberry roots are highly susceptible to < i > Armillaria mellea < /i >, and so potted strawberries were chosen as the test plants. In order to investigate biological control, a number of fungal antagonists isolated from commercial mushrooms were tested for their activity against this white rot pathogen by competition and antibiosis, in addition to parasitism. As a result of laboratory studies, < i > Dactylium dendroides , isolated from < i > Lentinus edodes < /i >, the Shii-take Mushroom, was chosen as an effective competitor and the < i > Trichoderma < /i > spp. as producers of antibiotics. < b > Results and conclusions < /b > < i > Dactylium dendroides < /i >, grown on sterile mushroom compost, allowed 41% of the strawberry plants to survive for over 75 weeks after inoculation with < i > Armillaria mellea < /i > which killed over 83% of the plants not protected with the antagonists. This antagonist interacted synergistically with several strains of < i > Trichoderma harzianum < /i > and < i > T. viride < /i > resulting in increased survival of the test plants. These additional fungi were ineffectual when used by themselves < i > in vivo < /i > despite showing substantial antagonistic activity < i > in vitro < /i >. < i > T. hamatum < /i > gave a similar level of protection in combination with < i > D. dendroides < /i > but was more effective when applied alone, while < i > Chaeton-lium olivaceum reduced the activity of < i > D. dendroides < /i >. These results show that prospects of biological control of < i > A. mellea < /i > can be increased by prudent combinations of fungal antagonists with several modes of action. < b > References < /b > 1 . Fox R T V, McQue A M, West J S, Raziq F, 1994. Proceedings Brighton Crop Protection Conference: Pest and Diseases, pp.1115-1120. 2. Fox R T V, Sanson S, 1996. Mycological Research 100, 318-320.