In vitro Studies on Biological Control of Drechslera species Causing Brown Spot Disease in Rice Plants
Drechslera species are amongst common fungal pathogens of rice, causing leaf spot diseases. Infection with Drechslera species causes quantitative and qualitative damage to small grains and rice plants. In the present study, rice rhizosphere mold and yeast fungi were isolated from El-Dakahlia and El-Qaliubiya governorates. Results indicated that in case of mold fungi, Fusarium and Aspergillus were the most dominant isolates (520 and 410 CFU per gram, respectively) while Monodictys and Phaeodactylium represented the lowest ones (10 CFU per gram for each). Concerning yeast fungi, Stephomoascus and Candida gave the highest CFU count per gram (90 and 60 CFU per gram respectively). Isolation of pathogens from infected rice leaves and grains from El-Dakahlia and El-Qaliubiya governorates indicated that Drechslera specifier gave the highest frequency percentages (56 % and 53.33 % respectively), while Drechslera rostrate gave 33 % and 26.66 % for both governorates respectively. Penicillium decumbens thom gave the highest antagonistic activity against Drechslera specifier (83.9 %). Biological control of Drechslera species could be successfully applied by using Penicillium decumbens thom as a bio-agent.