Archives of Phytopathology and Plant Protection, Jan 27, 2014
ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethan... more ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethanolic extracts of four spices (Allium sativum, Zingiber officinale, Cinnamomum zeylanicum and Capsicum annuum) against the important post-harvest spoilage fungi isolated from diseased fruits. In total, 276 isolates of post-harvest spoilage fungi were isolated from four different fruit types (Persea americana, Musa acuminata, Citrus sinensis and Lycopersicon esculentum), out of which 183 isolates were identified while 93 isolates were remain unidentified. The most dominant post-harvest spoilage fungus was Rhizopus sp. (26.45%), followed by Penicillium sp. (19.93%), Aspergillus sp. (10.86%) and Fusarium sp. (9.06%). Results of disc diffusion assay showed that ethanolic extract of C. zeylanicum was found to be most effective against Penicillium sp., followed by aqueous extracts of A. sativum. The ethanolic extract of C. zeylanicum in agar amended assay and minimal inhibitory concentrations were found to be very efficient (100% inhibition) against all the tested fungi. Results of in vivo study showed that pre-inoculated C. zeylanicum ethanolic extract and A. sativum aqueous extract were found effective in reducing the disease severity (6.24–13.67%) and (7.91–13.15%) against the Penicillium, Rhizopus, Aspergillus and Fusarium sp.
Archives of Phytopathology and Plant Protection, Sep 15, 2016
Abstract The current status of coffee berry disease (CBD) caused by Colletotrichum kahawae was in... more Abstract The current status of coffee berry disease (CBD) caused by Colletotrichum kahawae was intensively assessed and examined in 152 sample coffee farms from 22 districts across major coffee growing regions of Ethiopia. The results showed that CBD was prevalent with significantly (p < 0.001) varied intensity of damage among fields, districts and zones. The highest disease incidence of 70.7, 65.3 and 59.3% was recorded in Hararghe, Gedeo and Jimma, with correspondingly higher severity of 42.7, 46.7 and 32.0%, respectively. The national average incidence and severity of CBD was 52.5 and 29.9% that indicated the present status of the disease is remarkably on increasing trend. The increased intensity of CBD was strongly associated with reduced disease management practices (r = 0.50), altitude (r = 0.42), coffee cultivars (r = 0.23) and production systems (r = 0.28). This empirical evidence shows that CBD is on an upsurge and remains a major challenge to Arabica coffee production in Ethiopia.
Edible mushrooms are seen as a way of increasing dietary diversity and achieving food security in... more Edible mushrooms are seen as a way of increasing dietary diversity and achieving food security in Ethiopia. The aim of this study was to develop substrates using locally available agro-industrial by-products and animal manures to enhance the production of Shiitake (Lentinula edodes) mushrooms in Ethiopia. The hypothesis was L. edodes mushroom production on seven different substrates: 100% sugarcane bagasse (S1), 80% sugarcane bagasse, 20% cow dung (S2), horse manure (S3), chicken manure (S4), cottonseed hulls (S5), sugarcane filter cake (S6), and sugarcane trash (S7). Mushroom yield and biological efficiency were significantly affected by substrate type (p < 0.05). A significantly higher yield (434.33 g/500 g of substrate) and biological efficiency (86.83%) were obtained using substrate S4 while lower yield (120.33 g/500 g) and biological efficiency (24.33%) were obtained using substrate S7 than when using other substrates. The largest first flush of mushrooms was obtained on S4,...
Aggressiveness variation among the population of Colletotrichum kahawae representing seven major ... more Aggressiveness variation among the population of Colletotrichum kahawae representing seven major coffee-growing administrative zones of Ethiopia was studied under greenhouse conditions. The experiment was conducted through cross inoculation of eight Arabica coffee cultivars with seven C. kahawae isolates. The results revealed the presence of significant (p < 0.05) differences among coffee cultivars, isolates and their interactions. However, the large proportion of the variation was due to the main effects of the cultivars and the isolates. The interaction effect between cultivars × isolates was minimal, indicating that variation for virulence within C. kahawae is unlikely to occur. Although all of the isolates were pathogenic to the coffee cultivars tested, isolate CBD07 and CBD68 were the most aggressive followed by CBD184 and CBD156. On the other hand, except the coffee cultivar 741 and 971, the remaining coffee cultivars showed higher susceptibility reactions under greenhouse conditions. Moreover, cultivar 74110 and 1377 were extremely susceptible showing comparable disease reaction with the standard coffee berry disease (CBD) susceptible check ‘cv 370’. The study also showed that the mean disease incidence and severity of 72.5% and 56.2%, 70.7% and 56.2%, 69.6% and 54.4% were obtained with pathogen strains isolated from forest, semi-forest and garden coffee, respectively. Thus, the current variation in pathogenicity among the C. kahawae population is important in the development of disease resistant cultivars by considering the most aggressive isolates for successful screening of coffee germplasms for coffee berry disease resistance.
Microbes are an integral component of the soil ecosystem but degraded soil has few native benefic... more Microbes are an integral component of the soil ecosystem but degraded soil has few native beneficial microbes. This necessitates the characterization of phytobeneficial bacteria having numerous features. The study was initiated to evaluate rhizobacteria enhancing Acacia (Acacia abyssinica) seed germination. Isolates were selected based primarily on phosphate solubilization activity and other traits hydrogen cyanide (hcn), phytohormone, hydrolytic enzyme, siderophore, ammonia. Among isolates, 45% each was categorized as high and medium phosphate solubilizers and the amount was found to range from 195 to 373 µg/mL. The highest solubilization index (SI) 7 was recorded for Acinetobacter BS-27 and 6 for Pantoea BS-38. The maximum P and iaa were produced by Pseudomonas FB-49 (373 and 659.07µg/mL), respectively. Isolates with multiple traits were chosen for seed germination. Accordingly, Agrobacterium RS-79 and Pseudomonas BS-26 showed 100% activity. A 100% seed germination and vigor index...
Purpose Yeast strains tolerant to a wide range of stress conditions are needed for the production... more Purpose Yeast strains tolerant to a wide range of stress conditions are needed for the production of bioethanol from substrates rich in sugar. In our earlier research findings, Meyerozyma caribbica isolate MJTm3 (OM329077) demonstrated remarkable stress tolerance and fermentative activity. The present study aimed to optimize six fermentation parameters to generate conducive fermentation conditions for ethanol production by M. caribbica isolate MJTm3. Method The response surface method (RSM) based on central composite design (CCD) was employed to optimize process conditions for higher bioethanol yield. The optimization process was carried out based on six independent parameters, namely temperature (25-30oC), pH (5.5–6.5), inoculum size (10–20% (v/v)), molasses concentration (25–35 (w/v)), mixing rate (110–150 rpm), and incubation period (48–72 h). Analysis of ethanol concentration was done by HPLC equipped with a UV detector. Result The optimal conditions of the parameters resulting ...
Salt Stress, Microbes, and Plant Interactions: Causes and Solution, 2019
Faba bean is the most vital legume crop in Ethiopia, but abiotic stresses primarily soil acidity ... more Faba bean is the most vital legume crop in Ethiopia, but abiotic stresses primarily soil acidity are an obstacle for its production. Soil acidity disturbs and potentially limits nitrogen-fixing symbiosis. The interruption of nitrogen fixation and faba bean rhizobia interaction as a result of soil acidity leads to decreasing crop production. Sole dependence on chemical fertilizers for agricultural growth would mean further loss in soil quality and increased environmental damage. Rhizobial species show off sizable metabolic abilities to mitigate abiotic and biotic stresses, and mechanisms in stress tolerance are advancing fast, offering a strong foundation for the choice and engineering of rhizobia and legume hosts with better tolerance to soil acidity accordingly. The vast efforts to pick bioinoculants that can restore nitrogen under acid-affected soils are producing competitive crop yields. The main challenge of using single-type bioinoculant in field application can lead to variable and inconsistent outcomes. Co-inoculation of compatible microbes with organic farming which does not involve use of synthetic pesticides and chemical fertilizers is an imperative element in sustainable agriculture. Therefore, the present chapter focuses on the field application of faba bean rhizobial inoculants in acidic soils as a promising potential input in organic farming system. Moreover, the mechanism of N2 fixation and plant growth promotion systems under severe salt, drought, acidity, temperature, and heavy metal stresses is also highlighted.
Archives Of Phytopathology And Plant Protection, 2014
ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethan... more ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethanolic extracts of four spices (Allium sativum, Zingiber officinale, Cinnamomum zeylanicum and Capsicum annuum) against the important post-harvest spoilage fungi isolated from diseased fruits. In total, 276 isolates of post-harvest spoilage fungi were isolated from four different fruit types (Persea americana, Musa acuminata, Citrus sinensis and Lycopersicon esculentum), out of which 183 isolates were identified while 93 isolates were remain unidentified. The most dominant post-harvest spoilage fungus was Rhizopus sp. (26.45%), followed by Penicillium sp. (19.93%), Aspergillus sp. (10.86%) and Fusarium sp. (9.06%). Results of disc diffusion assay showed that ethanolic extract of C. zeylanicum was found to be most effective against Penicillium sp., followed by aqueous extracts of A. sativum. The ethanolic extract of C. zeylanicum in agar amended assay and minimal inhibitory concentrations were found to be very efficient (100% inhibition) against all the tested fungi. Results of in vivo study showed that pre-inoculated C. zeylanicum ethanolic extract and A. sativum aqueous extract were found effective in reducing the disease severity (6.24–13.67%) and (7.91–13.15%) against the Penicillium, Rhizopus, Aspergillus and Fusarium sp.
Archives of Phytopathology and Plant Protection, Jan 27, 2014
ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethan... more ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethanolic extracts of four spices (Allium sativum, Zingiber officinale, Cinnamomum zeylanicum and Capsicum annuum) against the important post-harvest spoilage fungi isolated from diseased fruits. In total, 276 isolates of post-harvest spoilage fungi were isolated from four different fruit types (Persea americana, Musa acuminata, Citrus sinensis and Lycopersicon esculentum), out of which 183 isolates were identified while 93 isolates were remain unidentified. The most dominant post-harvest spoilage fungus was Rhizopus sp. (26.45%), followed by Penicillium sp. (19.93%), Aspergillus sp. (10.86%) and Fusarium sp. (9.06%). Results of disc diffusion assay showed that ethanolic extract of C. zeylanicum was found to be most effective against Penicillium sp., followed by aqueous extracts of A. sativum. The ethanolic extract of C. zeylanicum in agar amended assay and minimal inhibitory concentrations were found to be very efficient (100% inhibition) against all the tested fungi. Results of in vivo study showed that pre-inoculated C. zeylanicum ethanolic extract and A. sativum aqueous extract were found effective in reducing the disease severity (6.24–13.67%) and (7.91–13.15%) against the Penicillium, Rhizopus, Aspergillus and Fusarium sp.
Archives of Phytopathology and Plant Protection, Sep 15, 2016
Abstract The current status of coffee berry disease (CBD) caused by Colletotrichum kahawae was in... more Abstract The current status of coffee berry disease (CBD) caused by Colletotrichum kahawae was intensively assessed and examined in 152 sample coffee farms from 22 districts across major coffee growing regions of Ethiopia. The results showed that CBD was prevalent with significantly (p < 0.001) varied intensity of damage among fields, districts and zones. The highest disease incidence of 70.7, 65.3 and 59.3% was recorded in Hararghe, Gedeo and Jimma, with correspondingly higher severity of 42.7, 46.7 and 32.0%, respectively. The national average incidence and severity of CBD was 52.5 and 29.9% that indicated the present status of the disease is remarkably on increasing trend. The increased intensity of CBD was strongly associated with reduced disease management practices (r = 0.50), altitude (r = 0.42), coffee cultivars (r = 0.23) and production systems (r = 0.28). This empirical evidence shows that CBD is on an upsurge and remains a major challenge to Arabica coffee production in Ethiopia.
Edible mushrooms are seen as a way of increasing dietary diversity and achieving food security in... more Edible mushrooms are seen as a way of increasing dietary diversity and achieving food security in Ethiopia. The aim of this study was to develop substrates using locally available agro-industrial by-products and animal manures to enhance the production of Shiitake (Lentinula edodes) mushrooms in Ethiopia. The hypothesis was L. edodes mushroom production on seven different substrates: 100% sugarcane bagasse (S1), 80% sugarcane bagasse, 20% cow dung (S2), horse manure (S3), chicken manure (S4), cottonseed hulls (S5), sugarcane filter cake (S6), and sugarcane trash (S7). Mushroom yield and biological efficiency were significantly affected by substrate type (p < 0.05). A significantly higher yield (434.33 g/500 g of substrate) and biological efficiency (86.83%) were obtained using substrate S4 while lower yield (120.33 g/500 g) and biological efficiency (24.33%) were obtained using substrate S7 than when using other substrates. The largest first flush of mushrooms was obtained on S4,...
Aggressiveness variation among the population of Colletotrichum kahawae representing seven major ... more Aggressiveness variation among the population of Colletotrichum kahawae representing seven major coffee-growing administrative zones of Ethiopia was studied under greenhouse conditions. The experiment was conducted through cross inoculation of eight Arabica coffee cultivars with seven C. kahawae isolates. The results revealed the presence of significant (p < 0.05) differences among coffee cultivars, isolates and their interactions. However, the large proportion of the variation was due to the main effects of the cultivars and the isolates. The interaction effect between cultivars × isolates was minimal, indicating that variation for virulence within C. kahawae is unlikely to occur. Although all of the isolates were pathogenic to the coffee cultivars tested, isolate CBD07 and CBD68 were the most aggressive followed by CBD184 and CBD156. On the other hand, except the coffee cultivar 741 and 971, the remaining coffee cultivars showed higher susceptibility reactions under greenhouse conditions. Moreover, cultivar 74110 and 1377 were extremely susceptible showing comparable disease reaction with the standard coffee berry disease (CBD) susceptible check ‘cv 370’. The study also showed that the mean disease incidence and severity of 72.5% and 56.2%, 70.7% and 56.2%, 69.6% and 54.4% were obtained with pathogen strains isolated from forest, semi-forest and garden coffee, respectively. Thus, the current variation in pathogenicity among the C. kahawae population is important in the development of disease resistant cultivars by considering the most aggressive isolates for successful screening of coffee germplasms for coffee berry disease resistance.
Microbes are an integral component of the soil ecosystem but degraded soil has few native benefic... more Microbes are an integral component of the soil ecosystem but degraded soil has few native beneficial microbes. This necessitates the characterization of phytobeneficial bacteria having numerous features. The study was initiated to evaluate rhizobacteria enhancing Acacia (Acacia abyssinica) seed germination. Isolates were selected based primarily on phosphate solubilization activity and other traits hydrogen cyanide (hcn), phytohormone, hydrolytic enzyme, siderophore, ammonia. Among isolates, 45% each was categorized as high and medium phosphate solubilizers and the amount was found to range from 195 to 373 µg/mL. The highest solubilization index (SI) 7 was recorded for Acinetobacter BS-27 and 6 for Pantoea BS-38. The maximum P and iaa were produced by Pseudomonas FB-49 (373 and 659.07µg/mL), respectively. Isolates with multiple traits were chosen for seed germination. Accordingly, Agrobacterium RS-79 and Pseudomonas BS-26 showed 100% activity. A 100% seed germination and vigor index...
Purpose Yeast strains tolerant to a wide range of stress conditions are needed for the production... more Purpose Yeast strains tolerant to a wide range of stress conditions are needed for the production of bioethanol from substrates rich in sugar. In our earlier research findings, Meyerozyma caribbica isolate MJTm3 (OM329077) demonstrated remarkable stress tolerance and fermentative activity. The present study aimed to optimize six fermentation parameters to generate conducive fermentation conditions for ethanol production by M. caribbica isolate MJTm3. Method The response surface method (RSM) based on central composite design (CCD) was employed to optimize process conditions for higher bioethanol yield. The optimization process was carried out based on six independent parameters, namely temperature (25-30oC), pH (5.5–6.5), inoculum size (10–20% (v/v)), molasses concentration (25–35 (w/v)), mixing rate (110–150 rpm), and incubation period (48–72 h). Analysis of ethanol concentration was done by HPLC equipped with a UV detector. Result The optimal conditions of the parameters resulting ...
Salt Stress, Microbes, and Plant Interactions: Causes and Solution, 2019
Faba bean is the most vital legume crop in Ethiopia, but abiotic stresses primarily soil acidity ... more Faba bean is the most vital legume crop in Ethiopia, but abiotic stresses primarily soil acidity are an obstacle for its production. Soil acidity disturbs and potentially limits nitrogen-fixing symbiosis. The interruption of nitrogen fixation and faba bean rhizobia interaction as a result of soil acidity leads to decreasing crop production. Sole dependence on chemical fertilizers for agricultural growth would mean further loss in soil quality and increased environmental damage. Rhizobial species show off sizable metabolic abilities to mitigate abiotic and biotic stresses, and mechanisms in stress tolerance are advancing fast, offering a strong foundation for the choice and engineering of rhizobia and legume hosts with better tolerance to soil acidity accordingly. The vast efforts to pick bioinoculants that can restore nitrogen under acid-affected soils are producing competitive crop yields. The main challenge of using single-type bioinoculant in field application can lead to variable and inconsistent outcomes. Co-inoculation of compatible microbes with organic farming which does not involve use of synthetic pesticides and chemical fertilizers is an imperative element in sustainable agriculture. Therefore, the present chapter focuses on the field application of faba bean rhizobial inoculants in acidic soils as a promising potential input in organic farming system. Moreover, the mechanism of N2 fixation and plant growth promotion systems under severe salt, drought, acidity, temperature, and heavy metal stresses is also highlighted.
Archives Of Phytopathology And Plant Protection, 2014
ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethan... more ABSTRACT The experiment was carried out to evaluate the antifungal potential of aqueous and ethanolic extracts of four spices (Allium sativum, Zingiber officinale, Cinnamomum zeylanicum and Capsicum annuum) against the important post-harvest spoilage fungi isolated from diseased fruits. In total, 276 isolates of post-harvest spoilage fungi were isolated from four different fruit types (Persea americana, Musa acuminata, Citrus sinensis and Lycopersicon esculentum), out of which 183 isolates were identified while 93 isolates were remain unidentified. The most dominant post-harvest spoilage fungus was Rhizopus sp. (26.45%), followed by Penicillium sp. (19.93%), Aspergillus sp. (10.86%) and Fusarium sp. (9.06%). Results of disc diffusion assay showed that ethanolic extract of C. zeylanicum was found to be most effective against Penicillium sp., followed by aqueous extracts of A. sativum. The ethanolic extract of C. zeylanicum in agar amended assay and minimal inhibitory concentrations were found to be very efficient (100% inhibition) against all the tested fungi. Results of in vivo study showed that pre-inoculated C. zeylanicum ethanolic extract and A. sativum aqueous extract were found effective in reducing the disease severity (6.24–13.67%) and (7.91–13.15%) against the Penicillium, Rhizopus, Aspergillus and Fusarium sp.
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