Enset (Ensete ventricosum (Welw.) Cheesman) is a perennial staple food crop widely cultivatedrnin the south and southwestern Ethiopia. It supports the lives of approximately 20 million people.rnHowever, its cultivation is impeded by enset bacterial wilt (EBW). Therefore, the aim of thernstudy was to evaluate the antibacterial activity of medicinal plant extracts and antibiotics againstrnXanthomonas campestris pv. musacearum (Xcm); to study induction of resistance in enset byrnleaf extract and evaluate its contribution in controlling enset bacterial wilt disease and torninvestigate growth and metabolic responses of enset clones under different treatments.Thernantibacterial activities of methanol leaf extracts of Achyranthes aspera, Agarista salicifolia,rnDatura stramonium, Melia azedarach, Pycnostachys abyssinica and Vernonia amygdalina andrnsome antibiotics; amoxicillin, cephalexin, chloramphenicol, streptomycin sulphate andrntetracycline were evaluated in vitro. Qualitative analysis of leaf extracts was carried out usingrnstandard methods. Total phenolics content was estimated with Folin Ciocalteau method. Thernantibacterial activity of methanol leaf extracts was evaluated by disc diffusion method. Minimumrninhibitory concentration was determined using agar dilution method. The potential role of A.rnsalicifolia leaf extract to trigger induced resistance, metabolic changes in resistant andrnsusceptible enset clones and the subsequent suppression of EBW was evaluated. Growth, photosynthetic and biochemical responses of the two enset clones, Viz., resistant (Genticha) andrnsusceptible (Midasho) were evaluated 120, 270 and 360 days after treatment application. Thernphytochemical screening results revealed the existence of alkaloids, phenols, terpenoids,rnsaponnins, tannins and glycosides in extract of A. salicifolia in abundant amount. Similar resultrnwas observed in P.abyssinica extract. However, glycosides were absent. Moreover, A. salicifoliarnleaf extract had the highest total phenolics content. It showed a 100, 85.7, 100, 61.2 and 12.3 %rnincrement from A. aspera, A. salicifolia, D. stramonium, M. azedarach, P. abyssinica and V.rnamygdalina. The widest inhibition zone diameter was recorded in A. salicifolia extract followedrnby P. abyssinica. A statistically significant difference in inhibition zone diameter was seenrnbetween species and among serial concentrations within a species extract. The two speciesrnextracts also showed the lowest minimum inhibitory (MIC) and minimum bactericidalrnconcentrations (MBC). Similarly, antibiotics showed antibacterial activity against Xcm.rnHowever, the inhibition zone diameters of antibiotics were significantly higher fivefold timesrnthan leaf extracts. The highest anti-Xcm activity was shown by streptomycin sulphate (50.3 mmrnat 50 mg/mL) followed by amoxicillin (49.7 mm at 50 mg/mL). However, the lowest MIC (0.02rnmg/mL) and MBC (0.049 mg/mL) values of antibiotics were recorded by tetracycline. Inrnaddition, extract treated and Xcm inoculated plants of both clones had an increased activity ofrnphenylalanine ammonia lyase (PAL), peroxidase, polyphenol oxidase and greater amount of totalrnphenolics content (TPC) and total soluble sugars (TSS). Induced plants of the resistant clonernshowed an 8, 4.6, 3, 13 and 4.6 fold increments in PAL activity compared to controls at 24, 48,rn72, 96 and 120 h post treatment, respectively. Infected control plants on the other handrndemonstrated a 7, 3.6, 2.3, 10.6 and 2.4 fold increments compared to controls. Similarly, inducedrnplants of the susceptible clone exhibited 1.5, 1.7, 1.4, 4.2 and 4.4 fold increments in PAL activity compared to controls at 24, 48, 72, 96 and 120 h post treatment, respectively. While infectedrncontrol plants showed a 0, 1.3, 1.4, 3 and 2 fold increments in PAL activity compared to controlsrnat similar sampling time. The activity of tested enzymes and amounts of TPC and TSS werernsignificantly increased in plants of the resistant clone treated with leaf extract and Xcm asrncompared to plants of the susceptible clone. The results of the study suggested that the differencernbetween the two clones was partially caused by variations in biochemical responses. Extractrninduced resistance brought a 33.33 % and 3.1% disease incidence reduction in plants of thernsusceptible and resistant clones, respectively, compared to infected controls. Plants of the twornenset clones also showed variations in growth and physiological responses among themselvesrnand between treatments at different measuring time periods. Nine months after treatmentrnapplication, induced plants of the resistant clone had significantly lower pseudostem (22.2%),rntotal leaf area (6.8%) and leaf area index (32%) than control plants. Similarly, infected controlrnplants of the susceptible clone showed lower pseudostem girth (29.4%), total leaf area (37.3%)rnand leaf area index (37.3%) as compared to controls. Generally, the results suggest that extractsrnof A. salicifolia and P. abyssinica have high potency and the potential for further formulationrndevelopment as biocides with broad spectrum activity. Tetracycline with the lowest MIC andrnMBC values is also a potential alternative in controlling EBW. Moreover, the results also suggestrnthe feasibility of induced resistance to control EBW. However, further research should bernconducted to formulate the extracts, identify the active compounds responsible for thernantibacterial activity of extracts, and evaluate the performance of other application methodsrnunder field conditions. Keywords: Agarista salicifolia, Antibiotics, Assimilation rate, Inhibition zone, Enseternventricosum, Induced resistance, methanol extracts, phenylalanine ammonia lyase, Totalrnphenolic compounds. Xanthomonas campestris pv. musacearum