Elucidating the interactions between the rust and a mycoparasite and the coffee plant.

, a fungus associated with pustules of the coffee leaf rust (CLR, ) in Brazil, was tested and to assess its biocontrol potential. The fungus inhibited the germination of rust spores by over 80%. CLR severity was reduced by 93% when was applied to coffee leaf discs inoculated with , whilst a reduction of 70-90% was obtained for experiments. Mycoparasitism was demonstrated through the fulfillment of Koch's postulates. Elucidation of the biochemical interaction between and on coffee plants indicated that the mycoparasite was able to increase plant resistance to rust infection. Coffee plants sprayed with alone showed greater levels of chitinase, -1,3-glucanase, ascorbate peroxidase and peroxidase. Although effective in controlling the rust, fungicide applications damaged coffee photosynthesis, whereas no harm was caused by We conclude that shows promise as a biocontrol agent of CLR.