Linking indigenous with scientific knowledge about enset (Ensete ventricosum) disease management in Gamo highlands of Ethiopia: Evidence from local people response, soil physicochemical and microbial dynamics

Abstract

CONTEXTEnset (Ensete ventricosum) is a staple food for millions in Ethiopia and characterized by climate resilient crop, but enset bacterial wilt (EBW) disease caused by Xanthomonas is the major threat to enset growing regions in the country that puts the food security of smallholder farmers at risk. Enset is a drought tolerant plant used for nutritional, medicinal and cultural activities for over 20 million people in Ethiopia. However, enset bacterial wilt (EBW) disease is a serious challenge. Although there is a good EBW disease management system from local people, the link between indigenous and scientific knowledge is not explored. OBJECTIVEThis study aimed to assess indigenous-scientific knowledge nexus about enset (Ensete ventricosum) disease management in Gamo highlands of Ethiopia using data generated from local people response, soil physicochemical and microbial dynamics. METHODSSamples (soil and plant) were collected from different farm sites (with no enset, with enset and with enset-medicinal) at three districts for physicochemical, antibacterial and microbial analysis. We considered various physicochemical parameters (moisture, temperature, pH, macro- and micro-nutrients); extracted phytochemical compounds from medicinal plant leaves using different solvents (water, ethanol, methanol and n-hexane); and 16S rRNA gene sequence using Illumina sequencing technique. RESULTS And CONCLUSIONSWe found that farmers have no knowledge gap in classifying healthy enset from sick/infected one. However, farmers were unable to classify the different stages of infected enset. Farmers were able to recognize that farm tool > animals > plant debris > air as a means of disease transmission. Nearly all respondents (97.3%) did not use chemicals to control EBW, rather they remove infected enset by uprooting. We found that farm tool cleaning, crop rotation, wrapping, bone smoking, and inter-planting medicinal plants were the main local EBW disease management practices employed by farmers. Medicinal plant extracts (E. abyssinica > D. afromontana > P. fruticosus) showed promising antibacterial activity (1.33 ± 0.28–8.81 ± 0.32 mm) against Xanthomonas. Planting medicinal plants with enset also significantly enhanced some soil physicochemical parameters and shifted the soil bacterial abundance from Proteobacteria to Firmicutes. Although indigenous practice enhanced soil physicochemical parameters and non-pathogenic microbial community in the soil, integrating it with modern knowledge (applying chemicals) were recommended as an effective EBW management strategy. SIGNIFICANTSoil physicochemical and microbial shift due to inter-planting medicinal plants with enset indicates that medicinal plants may have means of protection against EBW disease through optimizing soil physicochemical and microbial dynamics in the Gamo highlands. Additionally, the inhibition of medicinal plants against Xanthomonas suggests the inclusive influence of medicinal plants on the EBW causing bacteria.