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Papers by Abuhay Takele
2.3.7 Growth Characteristics 2.4 Discussion 2.4.1 Differences in the environmental stress conditi... more 2.3.7 Growth Characteristics 2.4 Discussion 2.4.1 Differences in the environmental stress conditions between treatments 2.4.1.1 Soil water status 2.4.1.2 Light and air temperature 2.4.2 Differences in the physiological responses to dehydration 51 53 53 53 54 between maize and sorghum 54 2.4.3 Differences between pre and post-flowering growth stages in response to dehydration in maize and sorghum 61 2.4.4 Differences in the physiological responses to rehydration between maize and sorghum at pre and post-flowering stages 64 2.4.5 Conclusions 65 Chapter 3. 3. Antioxidant defense mechanisms and pigment compositions of maize and sorghum after exposure to and recovery from pre and post-flowering dehydration. v 3.2.2.4 Anthocyanin contents 72 3.2.3 Determination of lipid peroxidation 72 3.2.4 Determination of total protein 73 Ub~ n 3.3.1 Antioxidant enzyme activities 73 3.3.2 Non-enzymatic antioxidant contents 84 3.3.3 Lipid peroxidation 97 3.3.4 Discussion 3.3.4.1 Antioxidant responses in maize and sorghum during pre and post-flowering dehydration 3.3.4.2 Antioxidant responses in maize and sorghum during pre and post-flowering rehydration 3.3.5 Conclusions III Chapter 4 4. Seed quality of maize and sorghum harvested from plants after exposure to and recovery from pre and post-flowering dehydration I would like to express my deep gratitude to Assoc. Prof. Jill Farrant for her keen interest and excellent supervision, her encouragement and various supports she provided me during my study and to Assoc. Professor Wiley Stock for his enthusiasm and interest. I am also grateful to Keren for her unreserved technical assistance during my lab work. I thank Clare and Brigitte for some invaluable comments and discussions. A special thanks to Assoc. Professor Wolf Brandt, Dept. of Molecular and Cellular Biology for allowing me to use HPLC machine for a-tocopherol analysis. The staff of Dept. Botany, UCT for technical support, especially Desmond and Gonzalo. Sandy for facilitating my communications with my sponsors. I also thank all my colleagues and friends in both the Dept. of Botany and Dept. of Molecular and Cellular Biology for the unanimous support and sympathy I received throughout my stay. Special acknowledgements to ICRISAT Center, Bulawayo, Zimbabwe and Melkassa Agricultural Research Center, Nazreth, Ethiopia for supplying sorghum and maize seeds, respectively. The Ethiopian Agricultural Research Organization is greatly acknowledged for allowing me to pursue my PhD. study, and financial support. Thanks to the National Research Foundation of South Africa for partially providing running costs to this study. Finally, I am sincerely grateful to my wife Mitin Kebede for her support, encouragements and patience. Also my children Kidus, Fanuel and Gelila for their tolerance for missing my fatherly love and care at their early childhood.
Land Degradation and Desertification: Assessment, Mitigation and Remediation, 2010
Abstract Pastoralist societies in dryland areas anticipate the harsh climatic conditions with mig... more Abstract Pastoralist societies in dryland areas anticipate the harsh climatic conditions with migration patterns that optimise the use of available forage and watering points. Yet, these traditional institutions are under increasing pressure due to a mounting population, encroaching of traditional ...
Journal of Arid Environments, 2009
For nomadic pastoralists in arid environments, judicious migration of the herds is the principle ... more For nomadic pastoralists in arid environments, judicious migration of the herds is the principle strategy for short term survival and long term sustainability. Yet, this efficient mechanism is increasingly challenged by mounting population pressure, appropriation of land and restricted transboundary movements. Lack of information on trekking patterns and grazing areas makes it difficult for government authorities to protect the migration routes. Data are so scarce because the object of measurement is moving in directions no outsider can predict. Consequently, data collection is costly and laborious. The present study suggests the use of satellite telemetry to trace trekking routes in a near real-time mode that can operate without the presence of external observers on the ground. We report on a pilot that tests a remote tracking technique to locate the routing of a nomadic pastoralist during the dry spell, in the Afar region of Ethiopia. From a movement analysis we infer trekking routes and grazing areas as well as the spatial and temporal correlation between the vegetation cover index NDVI, and the visits by the herd. Our first results seem encouraging in that our data collection method can produce unique information relatively quickly and at low cost.
African Crop Science Journal, May 18, 2010
Ethiopian Journal of Agricultural Sciences, May 5, 2021
To feed the ever-increasing population, increase productivity per unit area is one of the most at... more To feed the ever-increasing population, increase productivity per unit area is one of the most attractive strategies. Intercropping is considered a promising system for increasing crop productivity and land-use efficiency. A field study was conducted to evaluate the effect of different crop combinations of wheat-lentil on the productivity of wheat (Triticum aestivum L.) and lentil (Lens culinaris) and land use efficiency under two tillage practices in Minjar district during 2015-2017 cropping seasons. The experiment was carried out using split-plot design with three replications. The treatments consisted of two tillage practices (conventional and minimum tillage) assigned as the main plot and five wheat-lentil intercropping combinations (1:0, 1:1, 2:1, 1:2 and 0:1) assigned as the subplot. The tillage practices and intercropping had significant effect on growth parameters of wheat and lentil. Minimum tillage increased growth parameters for wheat, but reduced growth parameters for lentil. The yield of wheat was non-significantly affected by tillage practices, but the yield of lentil was significantly affected by tillage systems. A higher yield of lentil (1546 kgha-1) was obtained in conventional tillage as compared to minimum tillage practices. Intercropping combination had a significant effect on both growth and yield parameters of both crops. The highest yield of wheat (2932 and 2982 kgha-1) was recorded in sole wheat (1:0) and 2:1 wheat-lentil combination, while the highest Productivity and Land Use Efficiency of Wheat-Lentil Intercropping [46] yield of lentil (1575 kgha-1) was obtained in sole lentil (0:1). Among intercropping combinations, 2:1 wheat-lentil gave the highest LER, ATER, and MAI values. Therefore, 2:1 wheat-lentil intercropping combinations were found suitable for higher productivity and production of component crops and the intercropping system of wheat-lentil in any of the combinations found to be more profitable and productive compared to sole wheat and lentil.
Journal of Stress Physiology & Biochemistry, 2013
Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid... more Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid and semi-arid areas of the world. Sixteen elite sorghum (Sorghum bicolor (L) Moench) genotypes were evaluated for their genetic potential to drought tolerance at callus induction and plant regeneration stage for drought tolerance. The non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress. The factorial experiment was laid down in a completely randomized design which comprised of a combination of two factors (genotypes and five PEG stress level; 0, 0.5, 1.0, 1.5, and 2.0% (w/v) treatments). Data were recorded for callus induction efficiency, callus fresh weight, embryogenic callus percentage and plant regeneration percentage. Significant differences were observed among the genotypes, treatments and their interactions for the evaluated plant traits suggesting a great amount of variability for drought tolerance in ...
Striga hermonthica, is a major constraint to sorghum production in Sub-Saharan Africa. The study ... more Striga hermonthica, is a major constraint to sorghum production in Sub-Saharan Africa. The study was conducted to assess the potential role of intercropping sorghum with different legumes for control of striga. Two types of cropping system (simultaneous and relay) and two row arrangements (single and double alternate) were used for intercropping with groundnut and soybean. The experiment included a standard treatment of sole crop of sorghum, grou dnut and soybean. The experiment was laid out in a randomized complete block design (RCBD) with three replications for two cropping seasons of 2014 and 2015. From the result intercropping of sorghum with soybean and groundnut has significantly reduced the striga counts per plot as compared to sole sorghum. Lowest number of striga count (29.5) at vegetative stage and (19.7) at heading stages was recorded from simultaneous cropping of sorghum-soybean in double alternate row arrangements. The combined analysis result showed that sorghum grain ...
A series of laboratory experiments were conducted during the 2011 and 2012 growing season under i... more A series of laboratory experiments were conducted during the 2011 and 2012 growing season under irrigation using 12 treatment combinations of NP and FYM at Melkassa Research Centre in the Central Rift Valley Region of Ethiopia. The objective of the experiment was to investigate the effect of integrated NP and FYM use on postharvest quality and shelf life of Bombay red onion bulbs. The experiment was laid out as a randomized complete block design with three replications per treatment in the store. Results of the study revealed that combined application of fertilizer at 51.75 kg N+ 69 kg P2O5 + 5 t FYM ha-1 resulted in minimum physiological weight loss of bulbs throughout the whole storage period. Sprouting was lowest in bulbs treated with 51.75 kg N+ 69 kg P2O5 + 5 t FYM ha-1 while it was highest at 138 kg N+ 184 P2O5kg+40 t FYM ha-1. Application of 34.5 kg N+ 46 kg P2O5 + 10 t FYM ha-1 led to minimum bulb rotting. Total soluble solids(TSS) and percent dry matter recorded maximum wit...
Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid... more Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid and semi-arid areas of the world. Sixteen elite sorghum (Sorghum bicolor (L) Moench) genotypes were evaluated for their genetic potential to drought tolerance at callus induction and plant regeneration stage for drought tolerance. The non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress. The factorial experiment was laid down in a completely randomized design which comprised of a combination of two factors (genotypes and five PEG stress level; 0, 0.5, 1.0, 1.5, and 2.0% (w/v) treatments). Data were recorded for callus induction efficiency, callus fresh weight, embryogenic callus percentage and plant regeneration percentage. Significant differences were observed among the genotypes, treatments and their interactions for the evaluated plant traits suggesting a great amount of variability for drought tolerance in sorghum. The correlation analysis also revealed strong and significant association between embryogenic callus percent and plant regeneration percent as well as between embryogenic callus percent and plant regeneration percent. By taking into consideration all the measured traits, Mann Whitney rank sum test revealed that 76T1#23 and Teshale followed by Meko, Gambella-1107 and Melkam showed better drought stress tolerance. Therefore they are recommended to be used as parents for genetic analysis, gene mapping and improvement of drought tolerance while Chelenko, Hormat and Raya appear to be drought sensitive.
Ethiopian Journal of Agricultural Sciences, 2016
Field experiments were conducted at Welenchity experimental field site, Melkassa Agricultural Res... more Field experiments were conducted at Welenchity experimental field site, Melkassa Agricultural Research Center from June to October during the years 2010 and 2011 cropping seasons. The aim of the study was to determine optimum time of intercropping haricot bean into the maize based cropping system under conservation tillage practices, Tied-ridge and Zero-tillage. The experiment was laid out in split-plot design, with tillage practices a) Tied-ridge and b) Zero-tillage as main plot and time of intercropping haricot bean 1) Planting haricot bean simultaneously with maize, 2) Planting haricot bean 15 days after maize was planted and 3) planting haricot bean 30 days after maize was planted as sub-plots. Intercropping was assessed on the basis of the performance of the main and component crops indices as grain yield, biomass weight, partial and total LER and competitive indices such as relative crowding coefficient (K), aggressivity (A), competitive ratio (CR) and system productivity inde...
Tropical Agriculture, 1994
Greenhouse-grown plants of three cultivars of cowpea [Vigna unguiculata (L.) Walp.], with differi... more Greenhouse-grown plants of three cultivars of cowpea [Vigna unguiculata (L.) Walp.], with differing levels of tolerance to waterlogging, were subjected to four cycles of moderate waterlogging (MWL) or severe waterlogging. Leaf relative water content was reduced by waterlogging in the susceptible cultivar while it was increased in the tolerant cultivar, and was associated with a greater increase in stomatal resistance (r s ) and a greater reduction in dry matter production in the former. Leaf water potential (ψ L ), leaf area (LA) per plant, transpiration rate, and net photosynthesis were all reduced by waterlogging with no cultivar difference in response. Leaf weight ratio (LWR) was reduced in the MWL treatment only and to a greater extent in the susceptible cultivar, while stem weight ratio (SWR) was increased by waterlogging and was highest in the susceptible cultivar. After the first cycle of waterlogging there was little change in ψ L , LA, or dry weight of waterlogged plants bu...
Journal of Stress Physiology & Biochemistry, 2013
Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid... more Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid and semi-arid areas of the world. Sixteen elite sorghum (Sorghum bicolor (L) Moench) genotypes were evaluated for their genetic potential to drought tolerance at callus induction and plant regeneration stage for drought tolerance. The non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress. The factorial experiment was laid down in a completely randomized design which comprised of a combination of two factors (genotypes and five PEG stress level; 0, 0.5, 1.0, 1.5, and 2.0% (w/v) treatments). Data were recorded for callus induction efficiency, callus fresh weight, embryogenic callus percentage and plant regeneration percentage. Significant differences were observed among the genotypes, treatments and their interactions for the evaluated plant traits suggesting a great amount of variability for drought tolerance in sorghum. The correlation analysis also revealed strong and significant association between embryogenic callus percent and plant regeneration percent as well as between embryogenic callus percent and plant regeneration percent. By taking into consideration all the measured traits, Mann Whitney rank sum test revealed that 76T1#23 and Teshale followed by Meko, Gambella-1107 and Melkam showed better drought stress tolerance. Therefore they are recommended to be used as parents for genetic analysis, gene mapping and improvement of drought tolerance while Chelenko, Hormat and Raya appear to be drought sensitive.
Agricultural Sciences in China, 2010
Drought stress is often the most limiting factor to maize and sorghum production in the semi-arid... more Drought stress is often the most limiting factor to maize and sorghum production in the semi-arid areas. This study evaluates the response of electrolyte leakage, chlorophyll, carotenoid and anthocyanin contents in maize (cv. Melkassa-2 and sorghum cv. Macia) after exposure to and recovery from pre-and post-flowering dehydration in plants grown in a controlled environment growth chamber under constant environmental conditions (12/12 h day/night, 28-32/17°C day/night temperature, 60-80% RH and PPFD of 1 200-1 400 mol m-2 s-1), at the Department of Botany, University of Cape Town, South Africa. It was revealed that dehydration induced increases in electrolyte leakage was observed in both species during both pre-and post-flowering stages. Electrolyte leakage was however, higher during post-than pre-flowering dehydration in both species. Dehydration during both pre-and post-flowering stages caused a decrease in chlorophyll and carotenoid contents in both maize and sorghum. Chlorophyll and carotenoid contents of both pre-and post-flowering dehydrated sorghum was markedly higher than that of maize throughout the duration of the dehydration period. As opposed to chlorophyll and carotenoid contents, anthocyanin contents increased during pre-and post-flowering dehydration in both species. Differences were however, observed between both species in the response of anthocyanin content to pre-and post-flowering dehydration. Full recovery of chlorophyll, carotenoid and anthocyanin contents were observed in those plants rehydrated during pre-flowering stages. There was however, no recovery in both species during post-flowering rehydration. This study should help understand some adaptive mechanisms developed by maize and sorghum during the dehydration and rehydration periods and contribute to identify useful traits for breeding programs.
Acta Agronomica Hungarica, 2001
This experiment was carried out to evaluate the canopy temperatures and excised leaf water loss (... more This experiment was carried out to evaluate the canopy temperatures and excised leaf water loss (ELWL) of tef cultivars under water deficit conditions at anthesis and to demonstrate that these indices are reliable indicators of plant water stress. Twelve tef cultivars of similar maturity group but diverse origin were grown in each of two seasons under stressed and non-stressed conditions at anthesis. Mean cultivar canopy temperatures ranged from 33.2 to 34.9°C and 32.2 to 33.8°C in 1998 and 1999, respectively. There was also a significant difference in canopy temperature between treatments. The canopy temperature of stressed plants was 10.7% and 11.4% higher than that of non-stressed plants in 1998 and 1999, respectively. Under stress conditions the canopy temperature of the cultivars ranged from 33.6 to 36.7°C and from 33.1 to 37.6°C in 1998 and 1999, respectively, as compared to the non-stressed plants which ranged from 32.1 to 34.5°C in 1998 and from 29.7 to 31.9°C in 1999. There...
Acta Agronomica Hungarica, 2009
Drought stress is often the most limiting factor for maize and sorghum production in the semi-ari... more Drought stress is often the most limiting factor for maize and sorghum production in the semi-arid areas. This study evaluates the enzymatic antioxidant protection mechanism response of maize (cv Melkassa-2) and sorghum (cv. Macia) after exposure to and recovery from pre- and post-flowering dehydration.The response of enzymatic antioxidant protection systems revealed that in both test crops dehydration during both the pre- and post-flowering stages resulted in increased activities of enzymatic antioxidant protection mechanisms (SOD, GR, CAT and APX). There were, however, differences between the species in the type and extent of enhanced developmentally-induced and dehydration-induced antioxidant activities. Differences were also noticed in the relative water contents at which changes in enzymatic antioxidant activities occurred. Under dehydration conditions, sorghum was generally found to have relatively higher enzymatic antioxidant activities, providing it better protection against...
International Journal of Agriculture and Biosciences, 2020
2.3.7 Growth Characteristics 2.4 Discussion 2.4.1 Differences in the environmental stress conditi... more 2.3.7 Growth Characteristics 2.4 Discussion 2.4.1 Differences in the environmental stress conditions between treatments 2.4.1.1 Soil water status 2.4.1.2 Light and air temperature 2.4.2 Differences in the physiological responses to dehydration 51 53 53 53 54 between maize and sorghum 54 2.4.3 Differences between pre and post-flowering growth stages in response to dehydration in maize and sorghum 61 2.4.4 Differences in the physiological responses to rehydration between maize and sorghum at pre and post-flowering stages 64 2.4.5 Conclusions 65 Chapter 3. 3. Antioxidant defense mechanisms and pigment compositions of maize and sorghum after exposure to and recovery from pre and post-flowering dehydration. v 3.2.2.4 Anthocyanin contents 72 3.2.3 Determination of lipid peroxidation 72 3.2.4 Determination of total protein 73 Ub~ n 3.3.1 Antioxidant enzyme activities 73 3.3.2 Non-enzymatic antioxidant contents 84 3.3.3 Lipid peroxidation 97 3.3.4 Discussion 3.3.4.1 Antioxidant responses in maize and sorghum during pre and post-flowering dehydration 3.3.4.2 Antioxidant responses in maize and sorghum during pre and post-flowering rehydration 3.3.5 Conclusions III Chapter 4 4. Seed quality of maize and sorghum harvested from plants after exposure to and recovery from pre and post-flowering dehydration I would like to express my deep gratitude to Assoc. Prof. Jill Farrant for her keen interest and excellent supervision, her encouragement and various supports she provided me during my study and to Assoc. Professor Wiley Stock for his enthusiasm and interest. I am also grateful to Keren for her unreserved technical assistance during my lab work. I thank Clare and Brigitte for some invaluable comments and discussions. A special thanks to Assoc. Professor Wolf Brandt, Dept. of Molecular and Cellular Biology for allowing me to use HPLC machine for a-tocopherol analysis. The staff of Dept. Botany, UCT for technical support, especially Desmond and Gonzalo. Sandy for facilitating my communications with my sponsors. I also thank all my colleagues and friends in both the Dept. of Botany and Dept. of Molecular and Cellular Biology for the unanimous support and sympathy I received throughout my stay. Special acknowledgements to ICRISAT Center, Bulawayo, Zimbabwe and Melkassa Agricultural Research Center, Nazreth, Ethiopia for supplying sorghum and maize seeds, respectively. The Ethiopian Agricultural Research Organization is greatly acknowledged for allowing me to pursue my PhD. study, and financial support. Thanks to the National Research Foundation of South Africa for partially providing running costs to this study. Finally, I am sincerely grateful to my wife Mitin Kebede for her support, encouragements and patience. Also my children Kidus, Fanuel and Gelila for their tolerance for missing my fatherly love and care at their early childhood.
Land Degradation and Desertification: Assessment, Mitigation and Remediation, 2010
Abstract Pastoralist societies in dryland areas anticipate the harsh climatic conditions with mig... more Abstract Pastoralist societies in dryland areas anticipate the harsh climatic conditions with migration patterns that optimise the use of available forage and watering points. Yet, these traditional institutions are under increasing pressure due to a mounting population, encroaching of traditional ...
Journal of Arid Environments, 2009
For nomadic pastoralists in arid environments, judicious migration of the herds is the principle ... more For nomadic pastoralists in arid environments, judicious migration of the herds is the principle strategy for short term survival and long term sustainability. Yet, this efficient mechanism is increasingly challenged by mounting population pressure, appropriation of land and restricted transboundary movements. Lack of information on trekking patterns and grazing areas makes it difficult for government authorities to protect the migration routes. Data are so scarce because the object of measurement is moving in directions no outsider can predict. Consequently, data collection is costly and laborious. The present study suggests the use of satellite telemetry to trace trekking routes in a near real-time mode that can operate without the presence of external observers on the ground. We report on a pilot that tests a remote tracking technique to locate the routing of a nomadic pastoralist during the dry spell, in the Afar region of Ethiopia. From a movement analysis we infer trekking routes and grazing areas as well as the spatial and temporal correlation between the vegetation cover index NDVI, and the visits by the herd. Our first results seem encouraging in that our data collection method can produce unique information relatively quickly and at low cost.
African Crop Science Journal, May 18, 2010
Ethiopian Journal of Agricultural Sciences, May 5, 2021
To feed the ever-increasing population, increase productivity per unit area is one of the most at... more To feed the ever-increasing population, increase productivity per unit area is one of the most attractive strategies. Intercropping is considered a promising system for increasing crop productivity and land-use efficiency. A field study was conducted to evaluate the effect of different crop combinations of wheat-lentil on the productivity of wheat (Triticum aestivum L.) and lentil (Lens culinaris) and land use efficiency under two tillage practices in Minjar district during 2015-2017 cropping seasons. The experiment was carried out using split-plot design with three replications. The treatments consisted of two tillage practices (conventional and minimum tillage) assigned as the main plot and five wheat-lentil intercropping combinations (1:0, 1:1, 2:1, 1:2 and 0:1) assigned as the subplot. The tillage practices and intercropping had significant effect on growth parameters of wheat and lentil. Minimum tillage increased growth parameters for wheat, but reduced growth parameters for lentil. The yield of wheat was non-significantly affected by tillage practices, but the yield of lentil was significantly affected by tillage systems. A higher yield of lentil (1546 kgha-1) was obtained in conventional tillage as compared to minimum tillage practices. Intercropping combination had a significant effect on both growth and yield parameters of both crops. The highest yield of wheat (2932 and 2982 kgha-1) was recorded in sole wheat (1:0) and 2:1 wheat-lentil combination, while the highest Productivity and Land Use Efficiency of Wheat-Lentil Intercropping [46] yield of lentil (1575 kgha-1) was obtained in sole lentil (0:1). Among intercropping combinations, 2:1 wheat-lentil gave the highest LER, ATER, and MAI values. Therefore, 2:1 wheat-lentil intercropping combinations were found suitable for higher productivity and production of component crops and the intercropping system of wheat-lentil in any of the combinations found to be more profitable and productive compared to sole wheat and lentil.
Journal of Stress Physiology & Biochemistry, 2013
Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid... more Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid and semi-arid areas of the world. Sixteen elite sorghum (Sorghum bicolor (L) Moench) genotypes were evaluated for their genetic potential to drought tolerance at callus induction and plant regeneration stage for drought tolerance. The non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress. The factorial experiment was laid down in a completely randomized design which comprised of a combination of two factors (genotypes and five PEG stress level; 0, 0.5, 1.0, 1.5, and 2.0% (w/v) treatments). Data were recorded for callus induction efficiency, callus fresh weight, embryogenic callus percentage and plant regeneration percentage. Significant differences were observed among the genotypes, treatments and their interactions for the evaluated plant traits suggesting a great amount of variability for drought tolerance in ...
Striga hermonthica, is a major constraint to sorghum production in Sub-Saharan Africa. The study ... more Striga hermonthica, is a major constraint to sorghum production in Sub-Saharan Africa. The study was conducted to assess the potential role of intercropping sorghum with different legumes for control of striga. Two types of cropping system (simultaneous and relay) and two row arrangements (single and double alternate) were used for intercropping with groundnut and soybean. The experiment included a standard treatment of sole crop of sorghum, grou dnut and soybean. The experiment was laid out in a randomized complete block design (RCBD) with three replications for two cropping seasons of 2014 and 2015. From the result intercropping of sorghum with soybean and groundnut has significantly reduced the striga counts per plot as compared to sole sorghum. Lowest number of striga count (29.5) at vegetative stage and (19.7) at heading stages was recorded from simultaneous cropping of sorghum-soybean in double alternate row arrangements. The combined analysis result showed that sorghum grain ...
A series of laboratory experiments were conducted during the 2011 and 2012 growing season under i... more A series of laboratory experiments were conducted during the 2011 and 2012 growing season under irrigation using 12 treatment combinations of NP and FYM at Melkassa Research Centre in the Central Rift Valley Region of Ethiopia. The objective of the experiment was to investigate the effect of integrated NP and FYM use on postharvest quality and shelf life of Bombay red onion bulbs. The experiment was laid out as a randomized complete block design with three replications per treatment in the store. Results of the study revealed that combined application of fertilizer at 51.75 kg N+ 69 kg P2O5 + 5 t FYM ha-1 resulted in minimum physiological weight loss of bulbs throughout the whole storage period. Sprouting was lowest in bulbs treated with 51.75 kg N+ 69 kg P2O5 + 5 t FYM ha-1 while it was highest at 138 kg N+ 184 P2O5kg+40 t FYM ha-1. Application of 34.5 kg N+ 46 kg P2O5 + 10 t FYM ha-1 led to minimum bulb rotting. Total soluble solids(TSS) and percent dry matter recorded maximum wit...
Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid... more Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid and semi-arid areas of the world. Sixteen elite sorghum (Sorghum bicolor (L) Moench) genotypes were evaluated for their genetic potential to drought tolerance at callus induction and plant regeneration stage for drought tolerance. The non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress. The factorial experiment was laid down in a completely randomized design which comprised of a combination of two factors (genotypes and five PEG stress level; 0, 0.5, 1.0, 1.5, and 2.0% (w/v) treatments). Data were recorded for callus induction efficiency, callus fresh weight, embryogenic callus percentage and plant regeneration percentage. Significant differences were observed among the genotypes, treatments and their interactions for the evaluated plant traits suggesting a great amount of variability for drought tolerance in sorghum. The correlation analysis also revealed strong and significant association between embryogenic callus percent and plant regeneration percent as well as between embryogenic callus percent and plant regeneration percent. By taking into consideration all the measured traits, Mann Whitney rank sum test revealed that 76T1#23 and Teshale followed by Meko, Gambella-1107 and Melkam showed better drought stress tolerance. Therefore they are recommended to be used as parents for genetic analysis, gene mapping and improvement of drought tolerance while Chelenko, Hormat and Raya appear to be drought sensitive.
Ethiopian Journal of Agricultural Sciences, 2016
Field experiments were conducted at Welenchity experimental field site, Melkassa Agricultural Res... more Field experiments were conducted at Welenchity experimental field site, Melkassa Agricultural Research Center from June to October during the years 2010 and 2011 cropping seasons. The aim of the study was to determine optimum time of intercropping haricot bean into the maize based cropping system under conservation tillage practices, Tied-ridge and Zero-tillage. The experiment was laid out in split-plot design, with tillage practices a) Tied-ridge and b) Zero-tillage as main plot and time of intercropping haricot bean 1) Planting haricot bean simultaneously with maize, 2) Planting haricot bean 15 days after maize was planted and 3) planting haricot bean 30 days after maize was planted as sub-plots. Intercropping was assessed on the basis of the performance of the main and component crops indices as grain yield, biomass weight, partial and total LER and competitive indices such as relative crowding coefficient (K), aggressivity (A), competitive ratio (CR) and system productivity inde...
Tropical Agriculture, 1994
Greenhouse-grown plants of three cultivars of cowpea [Vigna unguiculata (L.) Walp.], with differi... more Greenhouse-grown plants of three cultivars of cowpea [Vigna unguiculata (L.) Walp.], with differing levels of tolerance to waterlogging, were subjected to four cycles of moderate waterlogging (MWL) or severe waterlogging. Leaf relative water content was reduced by waterlogging in the susceptible cultivar while it was increased in the tolerant cultivar, and was associated with a greater increase in stomatal resistance (r s ) and a greater reduction in dry matter production in the former. Leaf water potential (ψ L ), leaf area (LA) per plant, transpiration rate, and net photosynthesis were all reduced by waterlogging with no cultivar difference in response. Leaf weight ratio (LWR) was reduced in the MWL treatment only and to a greater extent in the susceptible cultivar, while stem weight ratio (SWR) was increased by waterlogging and was highest in the susceptible cultivar. After the first cycle of waterlogging there was little change in ψ L , LA, or dry weight of waterlogged plants bu...
Journal of Stress Physiology & Biochemistry, 2013
Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid... more Drought is one of the complex environmental factors affecting growth and yield of sorghum in arid and semi-arid areas of the world. Sixteen elite sorghum (Sorghum bicolor (L) Moench) genotypes were evaluated for their genetic potential to drought tolerance at callus induction and plant regeneration stage for drought tolerance. The non-ionic water soluble polymer polyethylene glycol (PEG) of molecular weight 6000 was used as osmoticum to simulate water stress. The factorial experiment was laid down in a completely randomized design which comprised of a combination of two factors (genotypes and five PEG stress level; 0, 0.5, 1.0, 1.5, and 2.0% (w/v) treatments). Data were recorded for callus induction efficiency, callus fresh weight, embryogenic callus percentage and plant regeneration percentage. Significant differences were observed among the genotypes, treatments and their interactions for the evaluated plant traits suggesting a great amount of variability for drought tolerance in sorghum. The correlation analysis also revealed strong and significant association between embryogenic callus percent and plant regeneration percent as well as between embryogenic callus percent and plant regeneration percent. By taking into consideration all the measured traits, Mann Whitney rank sum test revealed that 76T1#23 and Teshale followed by Meko, Gambella-1107 and Melkam showed better drought stress tolerance. Therefore they are recommended to be used as parents for genetic analysis, gene mapping and improvement of drought tolerance while Chelenko, Hormat and Raya appear to be drought sensitive.
Agricultural Sciences in China, 2010
Drought stress is often the most limiting factor to maize and sorghum production in the semi-arid... more Drought stress is often the most limiting factor to maize and sorghum production in the semi-arid areas. This study evaluates the response of electrolyte leakage, chlorophyll, carotenoid and anthocyanin contents in maize (cv. Melkassa-2 and sorghum cv. Macia) after exposure to and recovery from pre-and post-flowering dehydration in plants grown in a controlled environment growth chamber under constant environmental conditions (12/12 h day/night, 28-32/17°C day/night temperature, 60-80% RH and PPFD of 1 200-1 400 mol m-2 s-1), at the Department of Botany, University of Cape Town, South Africa. It was revealed that dehydration induced increases in electrolyte leakage was observed in both species during both pre-and post-flowering stages. Electrolyte leakage was however, higher during post-than pre-flowering dehydration in both species. Dehydration during both pre-and post-flowering stages caused a decrease in chlorophyll and carotenoid contents in both maize and sorghum. Chlorophyll and carotenoid contents of both pre-and post-flowering dehydrated sorghum was markedly higher than that of maize throughout the duration of the dehydration period. As opposed to chlorophyll and carotenoid contents, anthocyanin contents increased during pre-and post-flowering dehydration in both species. Differences were however, observed between both species in the response of anthocyanin content to pre-and post-flowering dehydration. Full recovery of chlorophyll, carotenoid and anthocyanin contents were observed in those plants rehydrated during pre-flowering stages. There was however, no recovery in both species during post-flowering rehydration. This study should help understand some adaptive mechanisms developed by maize and sorghum during the dehydration and rehydration periods and contribute to identify useful traits for breeding programs.
Acta Agronomica Hungarica, 2001
This experiment was carried out to evaluate the canopy temperatures and excised leaf water loss (... more This experiment was carried out to evaluate the canopy temperatures and excised leaf water loss (ELWL) of tef cultivars under water deficit conditions at anthesis and to demonstrate that these indices are reliable indicators of plant water stress. Twelve tef cultivars of similar maturity group but diverse origin were grown in each of two seasons under stressed and non-stressed conditions at anthesis. Mean cultivar canopy temperatures ranged from 33.2 to 34.9°C and 32.2 to 33.8°C in 1998 and 1999, respectively. There was also a significant difference in canopy temperature between treatments. The canopy temperature of stressed plants was 10.7% and 11.4% higher than that of non-stressed plants in 1998 and 1999, respectively. Under stress conditions the canopy temperature of the cultivars ranged from 33.6 to 36.7°C and from 33.1 to 37.6°C in 1998 and 1999, respectively, as compared to the non-stressed plants which ranged from 32.1 to 34.5°C in 1998 and from 29.7 to 31.9°C in 1999. There...
Acta Agronomica Hungarica, 2009
Drought stress is often the most limiting factor for maize and sorghum production in the semi-ari... more Drought stress is often the most limiting factor for maize and sorghum production in the semi-arid areas. This study evaluates the enzymatic antioxidant protection mechanism response of maize (cv Melkassa-2) and sorghum (cv. Macia) after exposure to and recovery from pre- and post-flowering dehydration.The response of enzymatic antioxidant protection systems revealed that in both test crops dehydration during both the pre- and post-flowering stages resulted in increased activities of enzymatic antioxidant protection mechanisms (SOD, GR, CAT and APX). There were, however, differences between the species in the type and extent of enhanced developmentally-induced and dehydration-induced antioxidant activities. Differences were also noticed in the relative water contents at which changes in enzymatic antioxidant activities occurred. Under dehydration conditions, sorghum was generally found to have relatively higher enzymatic antioxidant activities, providing it better protection against...
International Journal of Agriculture and Biosciences, 2020