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 ...
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...
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...
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...
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...
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...
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 ...
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...
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...
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...
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...
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...
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