Biochemical, pathological and genetic characterization of strains of Ralstonia solanacearum (Smith) from Ethiopia and biocontrol of R. solanacearum with bacterial antagonists

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Controlling of Maize Grey Leaf Spot by Interacting Host Resistance and Fungicide Spray Frequency at Bako, Ethiopia

Grey leaf spot (Cercosporazeae-maydis) is major disease affecting maize in western Ethiopia. At Bako National Maize Research Center, a field condition study was conducted to examine the interaction between maize varieties and fungicide spray frequencies on maize GLS and yield, to assess maize yield loss due to GLS, and to conduct cost-benefit analyses of using various fungicide frequencies on maize GLS. The experiment was set up as a factorial combination of 3 maize varieties with 3 tilt 250 EC spray frequencies in a randomized complete block design with 3 replications. The difference between the mean yield of protected plots and unprotected plots of each variety was used to calculate grain yield losses. Finally, correlation and economic analysis were done. Unsprayed variety BH543 had the highest AUDPC value (1676.27%-day), terminal PSI (68.33%), and disease progress rate (0.044500 units-day-1) scored. GLS caused grain yield losses of up to 52.82 % on untreated variety BH543. PSI, AUDPC, incidence and disease progress rate were negatively correlated with yield. The highest marginal benefit (ETB 60486 ha-1), and marginal rate of return (ETB 18.05) were obtained from variety SPRH with once application of propiconazole. Based on current results, one-time tilt 250 EC application was found effective to manage GLS on SPRH1 variety. However, additional experiments should be carried out to verify the current results

Population structure of Gibberella xylarioides Heim and Saccas in Ethiopian forest coffee (Coffea arabica L.) systems

Coffee wilt caused by Gibberella xylarioides (Fusarium xylarioides) is a troublesome soil borne disease of Arabica coffee (Coffea arabica L.) in Ethiopia. It has been known to be prevalent and severe in plantation, garden and semi-forest coffee production systems in that order of importance. A number of recent reports have also indicated that the disease is equally damaging coffee trees with varying intensities thereby endangering the conservation of wild coffee genetic resources in forest coffee systems of the country. However, the reasons for the disease upsurge in the forest remain speculative. Thus, population structure of coffee wilt pathogen was studied by cross inoculating 12 accessions with four isolates collected in the four forest sites, namely, Bonga, Berhane-Kontir and Yayu (southwest) and Harenna (southeast) of Ethiopia. A pathogenic isolate ‘Gx11’ and a moderately resistant coffee cultivar cv. 7440, both from plantation were included as respective standard checks. The cultural and morphological characteristics of 24 isolates from the forests were compared with six strains collected from semi-forest and plantation coffee. The cultural appearance of most isolates from southwest was generally similar in pigments, aerial and radial growths but relatively different from those isolates collected in the Southeast forest site (Harenna). The result of coffee accession by isolate interactions showed that accessions of Harenna (P4, P6 and P11) were resistant to almost all isolates (except to its isolate) with low mean percent seedling deaths (< 31%) while Bonga (P27) and Berhane-Kontir accessions (P34 and P38) were highly susceptible to all isolates with higher seedling deaths of 79.2 to 85.7%. The Harenna isolate was most aggressive (78.7%) followed by Bonga ‘B23’ and Yayu ‘Y21’ isolates which were as aggressive as the one from plantation coffee ‘G11’. In conclusion, the fungus population structure in the forest coffee sites have basically similar cultural and morphological characteristics of the species G. xylarioides (F. xylarioides) with certain differences between southwest and southeast in colony growth nature, pigmentation and aggressiveness. The study evidenced that the pathogen strains in the forest coffee are equally or even more aggressive than those strains in other coffee production systems, thus rapidly threatening Arabica coffee gene pool of Ethiopia.Keywords: Aggressiveness, colony growth, forest coffee, Fusarium xylarioides, coffee production systems, host-pathogen interactionsAfrican Journal of Biotechnology Vol. 12(33), pp. 5157-516

Actors’ post-harvest maize handling practices and allied mycoflora epidemiology in southwestern Ethiopia: Potential for mycotoxin-producing fungi management

Maize plays a key role in household food security in Ethiopia, but its benefit has been limited with high post-harvest losses. This study was initiated to assess post-harvest practices and associated fungi pathogen epidemiology along the maize supply chain in southwestern Ethiopia. The study was conducted in five purposively selected districts and a three-stage sampling procedure was employed for selection of the target groups. In total, 342 participants from different actors were interviewed using a semi-structured questionnaire. Maize samples were collected every month from 63 randomly selected actors for mycological analysis during six months storage period. Post-harvest loss was estimated to be 31% and loss during storage was identified as a critical loss point. Comparing all biological agents, loss due to fungal pathogens in the store ranked on top. Moisture content at loading stage could not increase the shelf life of the commodity. Germination tests showed a significant (P < 0.01) decrease as storage duration increased, while mould incidence on cobs and kernels significantly (P < 0.05) increased. In total, seven fungal genera were isolated, characterized and identified, with Fusarium, Penicillium and Aspergillus being predominant. Most of the post-harvest practices are not effective in reducing post-harvest losses. Especially, farmers’ traditional storage structures can be influenced by external climatic conditions and make the grains liable to develop mould during the rainy season. This research, therefore, highlights the need to design, develop or modify existing storage technologies that reduce post-harvest loss due to mycotoxin-producing fungal pathogens. Furthermore, post-harvest drying to obtain optimum moisture content is also crucial to reduce losses

Household food insecurity and mental distress among pregnant women in Southwestern Ethiopia : a cross sectional study design

Background: There are compelling theoretical and empirical reasons that link household food insecurity to mental distress in the setting where both problems are common. However, little is known about their association during pregnancy in Ethiopia. Methods: A cross-sectional study was conducted to examine the association of household food insecurity with mental distress during pregnancy. Six hundred and forty-two pregnant women were recruited from 11 health centers and one hospital. Probability proportional to size (PPS) and consecutive sampling techniques were employed to recruit study subjects until the desired sample size was obtained. The Self Reporting Questionnaire (SRQ-20) was used to measure mental distress and a 9-item Household Food Insecurity Access Scale was used to measure food security status. Descriptive and inferential statistics were computed accordingly. Multivariate logistic regression was used to estimate the effect of food insecurity on mental distress. Results: Fifty eight of the respondents (9 %) were moderately food insecure and 144 of the respondents (22.4 %) had mental distress. Food insecurity was also associated with mental distress. Pregnant women living in food insecure households were 4 times more likely to have mental distress than their counterparts (COR = 3.77, 95 % CI: 2.17, 6.55). After controlling for confounders, a multivariate logistic regression model supported a link between food insecurity and mental distress (AOR = 4.15, 95 % CI: 1.67, 10.32). Conclusion: The study found a significant association between food insecurity and mental distress. However, the mechanism by which food insecurity is associated with mental distress is not clear. Further investigation is therefore needed to understand either how food insecurity during pregnancy leads to mental distress or weather mental distress is a contributing factor in the development of food insecurity

Evaluation of sorghum genotypes and influence of weather variables on anthracnose (Colletotrichum sublineolum) disease development under field conditions at Jimma, southwestern Ethiopia

The severity and temporal dynamics of sorghum anthracnose on six and nine sorghum genotypes were evaluated on field plots during 2014 and 2015 cropping years in Southwestern Ethiopia, respectively. Anthracnose severity was assessed as the proportion of leaf area affected by the disease. 12 consecutive time point anthracnose severity assessments and their mean severity, disease progress rate, AUDPC, grain yield and yield related components were used to evaluate the response of the genotypes. In the year 2014 and 2015, the mean anthracnose severity was varying from 65 to 79 PSI and 54–82 PSI among six and nine sorghum genotypes, respectively. AUDPC varied from 5063 to 6113%-day and 4171 to 6383%-day in the year 2014 and 2015, respectively. BRC-378 and BRC-245 genotypes consistently had the lowest disease levels and highest grain yields during the two experimental years. The disease pressure was reduced, whereas grain yield and 1000-seed weight of the genotypes were increased in 2015 cropping year. Anthracnose severity was strongly correlated with weather variables and showed strong negative associations with grain yield of all tested sorghum genotypes

Correction to: Diversity and nutrient balances of urban and peri-urban farms in Ethiopia

In the original publication, in Table 6, the asterisks (***) indicating the P values appeared under the column of use efficiency for