Management of Bipolaris Sorokiniana the Causal Pathogen of Spot Blotch of Wheat by Eucalyptus Extracts

The inhibitory effect of essential oil of flowering buds and potential extracts of Eucalyptus camaldulensis Dehn (leaf, Bark and Flowering Buds) were evaluated on the most aggressive isolate of Bipolaris sorokiniana from wheat crop by agar well diffusion, food poison technique and macro-dilution assay. The mycelial growth was evaluated over four periods (3; 6; 9 and 30 days from incubation) with nine concentrations of essential oils (0.5%; 01%; 2.5%; 05%; 7.5%; 10%; 15%; 50%; 100%) and 3 concentrations (01%; 05% and 10%) of effective extracts. E.oil showed a maximum zone of inhibition of 90 mm diameter and mycelia growth 0.00 ± 0.00 compares to control 40.00 ± 0.00 after 9 days of incubation at 50% and 100% concentration. The extracts of F. buds showed the strongest active values (P<0.05) with a 29.10 ± 0.92 ZOI compared to water extract (19.80 ± 0.33). The ethanol and methanol fruit extracts showed highest minimum inhibitory concentration (08 mg/mL) than water extracts (200 mg/ml) against B. sorokiniana, while minimum fungicidal concentration values for ethanol and methanol fruit extract 40 mg/mL and water extract 300 mg/mL. Extract treated hyphae were collapsed, damaged or thinner when compared with the control. This Study reveals that, F. buds were the potential part of plant. The E.oil and ethanol extract of F. buds were consider most effective that shows considerable potency (up to 97% in-vitro inhibition) than the bark and leaves solvents extracts, while no inhibitory effect was noticed for the aqueous extract of leaves and bark in combating the pathogen.