Background: Ginger bacterial wilt is the most destructive disease that causes qualitative and quantitative rhizome yield losses in Ethiopia. Field studies were conducted to assess yield loss caused by bacterial wilt of ginger in different wilt management systems at Teppi and Jimma, Ethiopia, during 2017. Management systems were host resistance (Boziab and Local) and cultural practices (lemon grass, potassium fertilizer and soil solarization), which were applied as sole and in different levels of integrations. The experiments were factorial arranged in a randomized complete block design with three replications. Disease, growth, yield and yield-related data were collected from central rows of each experimental plot. Data were subjected to analysis of variance using linear general model (GLM) procedure of SAS version 9.3. Mean separation was made using least significant difference test. Correlation among parameters and linear regression of rhizome yield versus final wilt incidence were computed using Minitab 14 statistical package. Results: Analysis of variance indicated that variety, cultural practices and variety × cultural practice interaction effects significantly reduced wilt incidence and increased rhizome yield and its components. Variety Boziab recorded relatively more yield and yield components than the Local variety. Rhizome yield gains of about 51.4% in Local and 51.9% in Boziab at Teppi and 39.4% in Local and 49.1% in Boziab at Jimma were obtained due to integrated application of lemon grass with soil solarization and soil fertilization. The mean relative yield loss calculated for control plots due to bacterial wilt ranged from 51.4 to 51.9% at Teppi and 39.4 to 49.1% at Jimma. The lowest relative yield loss was computed from plots treated with either lemon grass with soil fertilization and solarization or lemon grass with soil fertilization. Final wilt incidence was inversely and highly significantly (P ≤ 0.001) correlated (r = − 0.90** and − 0.88**) with rhizome yield of Boziab and Local, respectively, at Teppi. The slope of the regression line also estimated that for each unit increase in percent of final mean wilt incidence, there was a rhizome yield reduction of 0.18 t ha −1 for Boziab and 0.19 t ha −1 for Local variety at Teppi. Similar trends were observed at Jimma. Moreover, the most integrated treatment provided higher net benefit with optimum marginal rate of return than others. Conclusion: The overall results indicated that integration of host resistance with cultural practices reduces yield loss, improves ginger productivity and significantly reduces bacterial wilt epidemics, and thus, it is recommended in the study areas and other related agroecologies.

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Ginger is one of the most widely cultivated spice grown in various cropping systems and locations throughout the southwestern Ethiopia. Bacterial wilt, caused by Ralstonia solanacearum, is one of the serious diseases of ginger in Ethiopia. Field experiments were conducted during 2019 and 2020 to assess effects of soil amendments on bacterial wilt development and epidemics at Tepi, southwestern Ethiopia. Three soil amendments practices: compost, effective microorganisms and Bordeaux mixture alone and in integration were evaluated. Treatments were arranged in a randomized complete block design with three replications. Compost at the rate of 7 ton/ha enriched with effective microorganisms and Bordeaux mixture treatment significantly reduced ginger bacterial wilt incidence, area under disease progress curve and disease progress rate. This treatment reduced bacterial wilt mean incidence up to 21.08 % as compared to untreated control plot. Compost at the rate of 7 ton/ha also slowed down epidemic progression of bacterial wilt and significantly reduced the disease parameters when effective microorganisms and Bordeaux mixture were integrated. The overall results indicated that integrated compost enriched with effective microorganisms and Bordeaux mixture was effective to slow down the epidemics of ginger bacterial wilt and sustain ginger production and productivity. Hence, integrated compost enriched with effective microorganisms and Bordeaux mixture along with other crop management systems are recommended to improve ginger production and productivity at southwestern Ethiopia and other similar ecologies.

Ginger is a valuable revenue crop for Ethiopian farmers in many sections of the country. In Ethiopia, bacterial wilt disease is a serious constraint to ginger output. Heavy losses are common as a result of the disease, with extra losses happening as a result of the disease's boundaries, which prevent continued production in infested areas. To investigate the impact of soil solarization and botanical mulch on epidemics of bacterial wilt of ginger in Tepi, Southwestern Ethiopia, field studies were done throughout the 2019 and 2020 main cropping seasons. Four different soil solarization periods were used: two weeks, four weeks, six weeks, and eight weeks before planting, with four different botanical mulches: vetivar grass, lemon grass, Chinese chive, and lantana camara added after planting. The control plots were not solarized nor mulched. Treatments were placed in factorial arrangements with three replications using a randomized full block design. In comparison to the control, soil solarization combined with lemon grass mulch treatment dramatically reduced bacterial wilt mean severity by 22.1 percent to 42.2 percent. These treatments also significantly lowered the rate of AUDPC and disease progression. When compared to control, soil solarization for eight weeks combined with lemon grass mulch resulted in the lowest disease severity (42.2%) and AUDPC (33.8%). Overall, the findings of this study showed that using a mixture of soil solarization and botanical mulches to slow down bacterial wilt outbreaks and recover ginger production and productivity, along with other crop management strategies, was effective.