[Biological Control of Grey Mold Disease Caused by Botrytis Cinerea Pers Using Trichoderma spp. Isolates on Strawberry in the Southern Region of Syria]

The in vivo study was conducted in some fields of south Syria while invitro study and field experiments were conducted in the biological control studies and research center - Faculty of Agriculture - Damascus University in 2010 _ 2012 to investigate the spread of grey mold in Syrian south region and to isolate Trichoderma fungus from Syrian soil for studying the potential of control grey mold disease causes by Botrytis cinerea on Strawberries plants using isolated isolates of Trichoderma and comparing it with fungicide: Bavistin. Eight isolates of the pathogenic fungi were isolated from Damascus, Damascus countryside and Daraa: (Ba-Bb-Bc-Bd-Be-Bf-Bg-Bh) and six isolates of T. harzianum fungi: (T1_T2_T3_T4_T5_T6), isolated from Damascus, Damascus countryside, Daraa and Lattakia and one isolate of T. viride (T7) was isolated from Damascus countryside. Laboratory study was carried out to test the potential of antagonism in petri dish filled with potato-dextrose agar (PDA). The results showed that (T5) of T. harzianum fungus isolated from the soil in the Faculty of Agriculture, University of Damascus gave the highest suppression (93.4%) of the pathogenic fungus isolate (Bf) from strawberry fruit from Erneh in Damascus countryside, while the isolate (T7) of T. viride gave the highest percent of suppression (92.59%) on (Bb) isolate of pathogenic fungus which was isolated from grape fruits from Jillin in Daraa. Field experiment was carried out in the greenhouses of biological control studies and research Center. Inoculums of the pathogenic fungi and suspensions of Trichoderma concentration (106 - 107 conidia/ ml sterile water) from fungal colony two weeks old. The plants were sprayed with suspension of antagonistic, pathogenic fungi and fungicide by aerosol sprayer. After one month of application, the percentage of infected fruits and the efficiency of each treatment was calculated. The results showed that bavistin had the highest efficiency (%92.98) in inhibiting the pathogenic fungus compared to the water, followed by antagonistic fungi T. harzianum and T. viride when they applied together the same treatment and repeat the treatment twice at (17) day intervals (%68.00), whereas T. harzianum fungus had efficiency value (%58.45), followed by T. viride (%47.57).