植物病理学および微生物学ジャーナル

概要

Role of Cow Dung on the Transmission of Enset Bacterial Wilt Pathogen (Xanthomonas campestris pv. musasearum) in Ethiopia

Misgana Mitiku*, Alamar Seid, Sadik Muzemil, Zerihun Yemataw, Agdew Bekele

Enset (Ensete ventricosum) (Welw.) Cheesman is a monocarpic, herbaceous plant belonging to the Musacea family and the genus Ensete. All plant parts are utilized for different purposes. Hence, kocho, bulla and amicho are used as human food. By products from the plant is used to make different household items. Despite its importance, enset is constrained by several biotic and abiotic factors that affect its production and productivity. Among the biotic factors, diseases, insect pests and wild animals are important production challenges of enset. But, of all, Enset Bacterial Wilt (EBW) caused by Xanthomonas campestris pv. musacearum (Xcm) is the most damaging constraint contributing a major share to reduction of enset productivity in all enset growing areas of Ethiopia. Concerning sources of inoculum, mode of infection and transmission of Xcm especially of enset in Ethiopia is not yet well studied to the level needed as compared to the seriousness of the disease so, the current study was designed to evaluate the level of enset bacterial wilt pathogen transmission with animal excrete/cow dung. To do this a cow and calf allowed to feed only on the infected enset plant at morning, mid-day and night for seven consecutive days then in the morning and at evening dung and urine samples were collected for seven consecutive days from these animals and a total of 56 samples were collected. Then preparation of suspension and isolation of pathogen was made using standard bacterial isolation techniques. During the course of the experiment and counting of bacterial colony and biochemical test (KOH had been conducted for confirmation. The result of the experiment showed that from the total sample collected from cow and calf dung and urine only 19 or 33.92% were identified as Xanthomonas campestris pv. musacearum (Xcm) which was confirmed based on morphological and biochemical characteristics of the cultured isolates/samples. The rest 37 or 66.07% of the collected samples were didn’t show the specific characteristics of Xanthomonas campestris pv. musacearum (Xcm) so, they are not Xanthomonas campestris pv. musacearum (Xcm). From the total samples the highest average number of colony 19, 17.66, 14.66 and 13 were recorded from samples collected from calf dung at the morning, calf dung at the evening and cow dung at the morning respectively. Whereas the lowest average number of colony 4.66, 3, 2.33, 1.33, and 0.33 were recorded from samples collected from cow dung morning, cow dung morning, calf dung morning, cow urine morning and cow urine morning respectively. So from this study we can conclude that animal excrete both dung and urine have a role in transmitting the bacterial wilt of enset from one field to another at different level of transmission. Also the study depicted that large number of bacterial colony were isolated from dung than urine in the same way from calf than cow; so we should take care-off when we dispose the animal excrete and have to avoid the movement animals and disposing of the their waste materials in enset fields. Since, this is one time study, similar study has to be continued considering the age of animals and enset plant to have a clear understanding and information.