Antimicrobial and Antifungal Effect of Ginger Zingiber Officinale , Green Tea Camellian Sinensis and Neem Azadirachta Indica on Selective Bacterial and Fungal Pathogensof Crop Plants: A Comparative Study

Plants have been a source of food, medicines and many other daily life products since primitive times. Bacterial and fungal pathogen attack reduces crop yield. Phytochemicals as biocides can kill microbes. In this study extract of Zingiber officinale rhizomes (Ginger), leaves of Azadirachta indica (Neem) and Camellian sinensis (Green tea) applied on bacterial strains, Xanthomonas syringae, and fungal pathogen, Alternaria alternata, to check their antibacterial and antifungal activity respectively. Ethanolic and aqueous extracts were prepared. Ethanolic and aqueous extracts showed a different yield. The bacterial pathogen was grown on ?Nutrient Agar media (NA)? and the fungal pathogen was grown on ?Potato Dextrose Agar media (PDA)?. Antibacterial and antifungal potential of plant extracts were observed at two different stages (at the time of inoculation and after growth of pathogen on media). The method used for assessing the inhibition zone was ?Agar Well Diffusion method?. MIC was also measured by ?Micro Broth Dilution Method?. Ethanolic extract of green tea showed the highest inhibition zone on Xanthomonas compestris was 12.5?1.0mm while lowest inhibition zone of 6.0?0.5mm was due to the aqueous extract of green tea. Antimicrobial activity of other extracts was in between these two ranges. Antibacterial and antifungal activity of ethanolic extract of ginger rhizome and neem leaves was 11.5?1.0, 6.0?1.0, 11.5?1.0, and 7.5?0.5, respectively. Aqueous extract of ginger rhizome showed no antifungal activity while antibacterial activity was 3.0?0.5mm. The lowest antibacterial activity was shown by the ethanolic extract of neem and the lowest antifungal activity was also due to the aqueous extract of neem with the inhibition zone of 0.8?1.0 and 1.0?0.5mm, respectively. Highest antibacterial and antifungal activity were shown by aqueous extract of green tea leaves with the inhibition zone of 12.5?1.0 and 3.0?0.6mm, respectively. MIC values of aqueous extract of ginger rhizome and green tea leaves were 158.3mg/ml for Alternaria alternata, which is the highest MIC for the fungal pathogen. However, the lowest MIC value for Alternaria alternata was 75mg/ml by ethanolic extract of neem leaves. The others extract showed antifungal MIC value in between these two ranges. Findings of the study will help in agriculture disease control management on pathogens of wheat such as X. syringae, and A. alternata. Advance researches are obligatory to explore interaction and microbial growth inhibition mechanisms of divergent phytochemicals from different plants. The awareness of the effectiveness of pooled extracts can be expanded from food implementations to the pharmacological and chemical field.