Investigation of the physiological responses in soybean and common bean to water deficit

Drought causes considerable reduction of legume productivity and significantly threatens the food security, and this situation is expected to be aggravated due to climate change. In soybean and common bean, water resource capturing through plant root architectural plasticity and the role of symbiotic nitrogen fixation have not been investigated in greater detail yet. This study was therefore conducted to identify and apply useful morphological and physiological performance markers (traits) for selection of drought-tolerant common bean and soybean cultivars under both controlled phytotron and field conditions that might be applicable as markers in future legume breeding programs. In soybean, traits related to above ground performance, such as photosynthesis, biomasses, and stomatal conductance, were related to parameters for nitrogen acquisition in nodules. The ability to maintain vigorous shoot growth under drought-induced nitrogen limitation was identified as an important trait that can be used to select for improved drought tolerance. Further, experiments carried out growing different common bean inbred lines under controlled phytotron conditions revealed the importance of growth and gas exchange parameters as well as nitrogen fixing ability as performance markers to select superior performing bean lines for growth under drought. As a further result, the strong association of symbiotic nitrogen fixation with CO2 assimilation and stomatal conductance was also ascertained. In field experiments the effective use of water through enhanced lateral root development and maintaining the water status of the plant was found to be crucial for enhanced productivity under drought, with root morphology traits (root length, area and volume) as well as root architectural traits (first whorl angle, basal root number and adventitious root branching density) significantly related to seed yield. Measurement of these traits might be added to future bean varietal improvement programs. Further, a direct relationship between both water use efficiency (WUE) estimated using carbon isotope discrimination (CID) and nitrogen fixation (15N abundance) with root morphological and architectural traits (root length, area and volume, basal root number, 1st as well as 2nd whorl angles) was identified. CID (WUE) and 15N abundance (SNF ability) had a direct relationship with each other and also with productivity traits (seed yield and pod harvest index). Soybean field experiments verified the importance of root system architecture and morphology for providing drought tolerance with root architectural traits, tap and lateral roots (diameter and branching density) and morphological traits (root length, surface area and volume) contributing to better performance under drought. Moreover, the strong association of CID (WUE) with ä15N (SNF), root traits as well as seed yield in soybean exposed to drought was ascertained. Findings suggested that higher performance in CID under drought stress may be due to higher CO2 assimilation and better N2 fixation resulting in better root system architecture and morphology of the drought-tolerant cultivar through maintenance of the water status of the plant for efficient biological activity. Overall the study has generated new knowledge about the use of physiological markers (traits) that can be used widely for legume evaluation under drought suitable for both phytotron and field studies.Thesis (PhD)--University of Pretoria, 2012.Plant Scienceunrestricte

The Impact of Public Education Expenditures on Graduate Unemployment: Cointegration Analysis to Ethiopia

Unemployment is amongst most pressing economic challenges the Ethiopian economy has long been experiencing. Though the country succeeded in targeting overall unemployment most recently, graduate unemployment continued trending at higher rates over the years. We examined the impact of government education spending on the rate of graduate unemployment in Ethiopia, using yearly series of data over the periods spanning from 1991to 2019. The results of Augmented Dickey Fuller test revealed difference stationarity for all series of interest; while the suggested order of integration was one. The results of Johnson’s cointegration test indicated the existence of long-run equilibrium relationships among the variables entered the test model. In determining the impacts of inflation rate (CPI), economic growth (RGDP) and public education spending on graduate unemployment, we employed Vector Error Correction Model as it enables us capture the short-run and long-run outputs instantaneously. According to VECM regression results, inflation rate and expenditure on education were found to have significant impact on the long-run growth rate of graduate unemployment. While the inflation rate contributed positively, government expenditure has negative influence on the rate of graduate unemployment towards validating the Keynesian theory of employment. Besides, the impacts of both variables were found to persist in the short-run. Both are estimated significant and consistent in sign in the short-run. However, economic growth was found to have a trivial role in explaining the rate of graduate unemployment in both the short-run and the long-run periods. Moreover, the results of VEC causality analysis revealed a significant unidirectional causality running from economic growth towards public funds available for financing education; but no causality was suggested in reverse. We recommend a drastic measure to advance the education sector through suitable investments in a manner that will help in skills development, productivity enhancement and entrepreneurship growth

Common bean (Phaseolus Vulgaris l.) landraces reaction to field and storage insect pests: baseline data for insect resistant and high-yielding common bean variety development

Common bean is a lowland legume crop that contributes for food security and poverty reduction in Ethiopia. A number of constraints are associated with common bean production in Ethiopia including drought, insect pests, diseases, low number of improved variety, storage practices, storage insect pest management and seed systems among others. Therefore, this study was conducted to investigate the interaction of selected common bean landraces against field and storage insect pests. The field experiment was done at Arsi-Negele in the West-Arsi zone at the sub-center of Melkasa Research Centre (mrc) in Oromia Regional State of Ethiopia. Ten common bean landraces and one improved variety (Beshebeshe) were collected from mrc and evaluated under field and storage conditions. The field experiment was designed in a randomized complete block design in three replications, while the storage experiment was designed in a completely randomized design in three replications. Highly significant variations were observed in the tested common bean landraces in terms of field and storage insect pests. The landraces were not consistent in terms of insect pest reaction across the different plant growth stages and in the storage. This study demonstrated the high potential that existed in common bean landraces in terms of insect pest resistance. Hence, the result of this study calls for a strong collaborative work between common bean breeders and entomologists to develop high yielding and insect resistant common bean varieties

Genotype by Environment Interaction and Yield Stability of Drought Tolerant Mung Bean [Vigna radiata (L.) Wilczek] Genotypes in Ethiopia

A multi-environment evaluation of mung bean genotypes was conducted in six environments across Ethiopia to select promising genotypes. This study was conducted to estimate the magnitude of genotypes by environment interaction (GEI) and seed yield stability of the selected drought-tolerant mung bean genotypes across different environments. A total of fifteen mung bean genotypes were used. Out of these, two released varieties were used as standard checks. The field experiments were conducted during the 2019 main cropping season at six locations namely Humbo, Gofa, Melkassa, Konso, Jinka, and Kako using a randomized complete block design with three replications. Data were subjected to analysis of variance, Additive Main Effects and Multiplicative Interaction (AMMI), and GGE bi-plot analysis. A combined analysis of variance revealed significant variations among the genotype, environments, and GEI for yield and yield-related traits, indicating that seed yield was significantly affected by these factors. Analysis of variance from the AMMI model indicated the contribution of environment, genotype, and GEI was 59.6%, 16.8%, and 14.8% of the total variation in seed yield, respectively. Sum squares of the first and the second interaction principal component axis (IPCA) explained 47.4% and 7.4% of the GEI variation, respectively. The IPCA1 mean square was highly significant (P≤0.01) and that of IPCA2 was significant (p≤0.05), indicating the adequacy of the AMMI model with the first two IPCAs for cross-validation of the seed yield variation. The magnitude of the GEI sum squares was 4.4 times that of the genotypes sum squares for seed yield, indicating the presence of substantial differences in genotypic responses across the environments. The results for the AMMI, Yield stability index (YSI), AMMI Stability Value (ASV), and GGE biplot, analyses depicted that the genotypes G6 (NLLP-MGC-24), G13 (Acc006), and G3 (NLLP-MGC-15) were identified as stable and high yielders across the environments and should be considered for variety release. AMMI1 biplot showed Kako was the potential and favorable environment for mung bean production, while Humbo was an unfavorable for mung bean production

In-vitro evaluation of mung bean (Vigna radiata L., Wilczek) genotypes for drought tolerance and productivity

Drought stress is the most important factor that limits mung bean production and productivity at large in drought-prone areas of Ethiopia. It is hence necessary to identify and verify drought-tolerant and productive varieties of major crops grown in drought areas of the country like mung bean. The present study was conducted to evaluate mung bean genotypes for drought tolerance under in-vitro conditions and to assess the performance of the in-vitro developed regenerants under greenhouse conditions. The in-vitro experiment was thus arranged in a factorial experiment using a completely randomized design with three replications. Three mung bean genotypes, NLLP-MGC-06/G6 (tolerant), VC6368 (46-40-4)/G34 (moderate), and NLLP-MGC-02/G2 (sensitive) and five polyethylene glycol (PEG) levels (0, 0.5, 1.0, 1.5, and 2.0%) were used. The analysis of variance exhibited significant differences among the genotypes for all the studied parameters except the number of roots per shoot. There were significant differences observed among PEG levels for all the studied parameters. Significant genotypes x PEG interactions were observed for all the studied traits except total roots per culture and survival percentage. Increasing polyethylene glycol concentration from 0% to 2.0% in the medium caused a gradual increase in root length from 0.49 cm at 0% PEG to 1.17 cm at 2.0% PEG, respectively. This revealed an adaptive mechanism to the decreased moisture content in the root zones of plants and enhanced increased root length to reach deeper water in the soil. Regenerant from the treatment combinations of G34 (0) exhibited the highest values for the number of primary branches per plant (4.00). Grain yield for the in-vitro regenerated plants evaluated at greenhouse conditions ranged from 552.52 kg ha-1 at the treatment combination of G2 (1) to 996.23 kg ha-1 at the treatment combinations of G6 (0). Most of the regenerants obtained from NLLP-MGC-06/G6 and VC6368 (46-40-4)/G34 showed the best performance under the greenhouse for drought-tolerance under the in-vitro condition, suggesting that the accumulated performance of the tested regenerants under in-vitro conditions was realized under greenhouse conditions. It also indicated that in-vitro culture is an important tool to identify and verify drought-tolerant genotypes and improve desirable agronomical traits. Further study is indeed required to understand the mechanism of drought tolerance for in-vitro-selected somaclones

Factors Affecting the Profitability of Smallholder Common Bean Producers in Central Rift Valley of Ethiopia

አህፅሮት ቦሎቄ ከዋና ዋናዎቹ የጥራጥሬ ሰብሎች የሚመደብ ሰብል ሲሆን ለሀገሪቱ ኢኮኖሚ እንዲሁም ለአርሶ አደሩ የምግብና የገቢ ምንጭ በመሆን ከፍተኛ አስተዋፅዖ ያደርጋል፡፡ በምስራቅና ደቡብ አፍሪካ ውስጥ ኢትዮጵያ በቦሎቄ ምርት የሦስተኛ ደረጃን ትይዛለች፡፡ በ2010 ዓ.ም. ሀገሪቱ 40 በመቶ የሚሆነውን የቦሎቄ ምርት ወደ አለም አቀፍ ገበያ ልካለች፡፡ ቦሎቄ ከፍተኛ የኢኮኖሚ ጠቀሜታ ያለው ሰብል ቢሆንም ሰፊ የሆነ የተሸሻሉ የቦሎቄ ዝርያዎች ስርጭት በተለያዩ ጊዜያት ቢከናወኑም በቅርብ ጊዜ በተለይም በመካከለኛው ስምጥ ሸለቆ ያሉ አርሶ አደሮች ወደሌሎች ሰብሎች ሲያዘነብሉ ይታያል፡፡ ከዚህ ችግር ጋር በተያያዘ ሁኔታ የቦሎቄ ምርት የትርፋማነት ጥናት አለመኖር የመረጃ ጉድለት ፈጥሯል፡፡ አብዛኞቹ ከዚህ በፊት የተደረጉ ጥናቶች የሰብሉን የትርፋማነትና አዋጭነት ጥናት ያላደረጉ ሲሆን ጥናቱ ይህንን ጉደለት ለመሙላት ታስቦ የተተገበረ ነው፡፡ የአርሶ አደሩ ትርፋማነት ለማጥናት ይረዳ ዘንድ የቦለቄ አምራች በሆኑ አካባባዎች አርሶ አደሮች በተለየ የመምረቻ ዘዴ ተለይተው የቅኝት ተሳታፊ ሆነዋል፡፡ የተሰበሰበውም መረጃ ቀለል ያሉ የመረጃ ቀመሮችና እና ለአዋጭነት አስተዋጽኦ ያለቸው ምክንያቶች ትንተና ተደርጎበታል፡፡ የጥናቱ ውጤት እንደሚያሳየው ከሆነ የአርሶ አደሩ ያልተጣራ ጠቅላላ ትርፍ በአማካይ 13486 ብር በሄክታር  ሲሆን ጠቅላላ የተጣራ ገቢ ደግሞ 8127 ብር በሄክታር ይሆናል፡፡ ለቦሎቄ ምርት ትርፋማነት አስተዋዕኦ ከሚያደርጉ አበይት ምክንቶች ውስጥ አርሶ አደሩ ከዋና ገበያ ያለው ርቀት፣ የአርሶ አደሩ የእድሜ ሁኔታ፣ የቤተሰቡ ቁጥር፤ ከግብርና ስራ ውጭ ያሉ ገቢዎች እና የማዳበሪያ ማግኛ ምንጮች አስፈላጊ ሆነው ተገኝተዋል፡፡ በአንጻራዊ መልኩ ሲታይ የወንድ አባወራ አርሶ አደሮች የተሻለ ትርፋማ ሲሆኑ፤ በግብርና ስራ ያለ ልምድ፤ በገበሬ ቡድን አባል መሆንና ምርቱ የተሸጠበት የገበያ ሰንሰለት ዓይነቶች አዎንታዊ በሆነ መልኩ ተጽዕኖ የሚሳድሩ ምክንያቶች ናቸው፡፡ ስለዚህም የቦለቄ አምራች አርሶ አደሮችን ትርፋማነት ለመጨመር፤ አዎንታዊ ምክንያቶችን ከፍ ማድረግና አሉታዊ ምክንያቶችን በመቀነስ የፖሊሲ እርምጃዎችን ማቀናጀት ያስፈልጋል፡፡   Abstract Common bean is one of the major pulse crops which played an important role in the Ethiopian national economy and to farmers as food and cash income. Ethiopia ranked third in common bean production in Eastern and Southern Africa. The country exported 40 percent of its total common bean production in 2010. Despite the wide dissemination of improved common bean varieties and its economic importance, there is a dearth of information on the profitability of smallholder farmers from common bean production. Most of the previous studies on common bean did little on the profitability of smallholder bean producers. This study is designed with the aim of assessing the profitability status of smallholder common bean producers and factors correlated with it. Sample bean producers were selected randomly using simple random sampling. The cross-sectional data collected from sampled households are analyzed using descriptive statistics and Ordinary Least Square (OLS). The result of the study shows that the mean common bean gross margin and net farm income was 13486 and 8127 Birr/ha respectively. Distance from the nearest market, Age, Family size, off farm income and fertilizer source are the factors influencing the profitability of smallholder common bean producers negatively. However, Gender, farm experience, group membership and target market channel had a positive significant influence on smallholder based common bean production profitability. Therefore, in order to enhance the profitability of smallholder households, among others, it is important to improve access to input and output market and collective actions by farmers. There is also a need to minimize the gender gap in the profitability through affirmative action such as the provision of special credit and access to modern technologies by female farmers.  &nbsp

Performance Evaluation of Grain Yield and Yield Related Traits in Common bean Genotypes at Yabello and Abaya, Southern Ethiopia

Common bean is among the major crops grown in southern Ethiopia including Borana zone where the majority of the farmers are Agro-pastoralist and produce the crop mainly for home consumption. The area has potential to the production of common bean for food and nutrition security as well as export commodity. However, scarcity of varieties that fit to the environment is one of the major constraints of production. Therefore, this experiment was conducted to evaluate 36 common bean genotypes including seven released varieties to evaluate performance of genotypes for yield and agronomic traits. The field experiment was conducted in 2015 at two locations (Abaya and Yabello) and genotypes were planted in triple lattice design. Data were collected on yield and important agronomic traits. Analysis of variance computed for individual locations and combined analysis over locations revealed significant variations among genotypes for all traits. Moreover, 16.67% of the genotypes had mean grain yield greater than the best performing released variety across locations and the genotypes showed a grain yield as high as 3.25 tons ha-1. Based on results of this study it is recommended to test the high yielding and early maturing genotypes at many locations to develop preferred varieties across many locations

Identification and Application of Phenotypic and Molecular Markers for Abiotic Stress Tolerance in Soybean

Neurology & clinical neurophysiolog

Grouping of environments for testing navy bean in Ethiopia

Common bean variety selection within its production environment is often challenged by the occurrence of significant genotype-by-environment interactions (GEI) in the variety development process. Grain yield performance of 16 navy bean (Phaseolus vulgaris L.) lines was tested in a multi-environment variety trial during 2010 and 2011 main growing seasons of Ethiopia. Field experiments were conducted in Randomized Complete Block Design (RCBD) with three replications in 14 rainfed environments of the major common bean growing areas. The objectives were to assess the line by environment interactions (LEI), determine stable genotypes, and grouping of test environments. Significant differences were found among the lines for grain yield on each environment and combined over environments. The combined analysis of variance across environments indicated that both environment and LE interactions were significantly influenced lines yield. All interactions in relation to L×E showed high significant difference (P<0.01) for grain yield. Statistical methods as AMMI, GGE and some stability parameters were used to describe the LE interaction and to define stable lines in relation to their yield. The highest yield (2435 kg ha-1) was obtained from the line ICA BUNSI X SXB 405/1C-C1-1C-87. The stability analysis also identified lines ICA BUNSI X SXB 405/1C-C1-1C-87 and ICA BUNSI X SXB 405/1C-C1-1C- 37 as the most stable lines. Lines identified as superior differed significantly from the standard varieties and can be recommended for use by farmers in the bean growing areas of Ethiopia. Cluster analysis, based on grouping of locations showed that Melkassa, Alemtena and Haramaya as potential and high yielding, but Jimma, Bako, Pawe, Areka, Assosa and Sirinka as low to medium yielding locations