Review on Genetic Variation in Potato (Solanum Tuberosum L.) for Processing Quality Traits

Potato (Solanum tuberosum L.) is a versatile food crop and a source of cheap human diet in many countries. It can be used as fresh products and commercially processed foods such as French fries and chips. The genetic makeup is the most important factor that influences quality attributes. Traits that are genetically controlled can be grouped into biological traits (proteins, carbohydrates, vitamins, minerals, reduced amounts of toxic glycoalkaloids), sensorial (flavour, texture, colour), and industrial traits (tuber shape and size, dry matter content, cold sweetening, oil absorption, starch quality). Therefore, the breeding work can successfully meet the needs of a changing and demanding the processing quality. In this review paper discusses some breeding strategies that can be used to create genetic variability and to help the selection programs for internal and external quality traits in potato for processing aspect. The genetic diversity of potatoes grouped in wild and cultivated potatoes. The cultivated potatoes Solanum tuberosum are tetraploid (2n=4x= 48) due to high specific gravity. Varieties with long tubers are used for French fries, while varieties with round tubers are preferred for crisps. A potato variety with dry matter content below 19.5% and 20% is not acceptable for French fries and for chips, respectively. Similarly, a dry matter content of more than 25% is not suitable for French fries manufacturing. The level of reducing sugars that are generally acceptable for chips processing is 0.2–0.3% and for French fries is 0.3–0.5%. Generally, selection of varieties should not be limited only for high yield, but also for internal (specific gravity, dry matter, starch contents) and external quality (tuber shape, eye depth, tuber fresh color and tuber skin color) of tubers. Keywords: Genetic Variation, Processing quality, Tuber quality, Chips, French fries    DOI: 10.7176/JNSR/9-12-05 Publication date:June 30th 201

Assessment Of Production Potentials And Constraaints Of Mango (Mangifera INDICA) At Bati, Oromia Zone, Ethiopia

Production potentials and constraints of mango were assessed at Bati wereda, Oromiya zone, Ethiopia in 2013 using data from sixty randomly selected mango producers in the area. Data were collected using questionnaire and focus group discussion. The result revealed that most of the producers belonged to the age group of 41-50 (28.3%) and 31-40 (266.7%). 95% of the producers were male and the rest 5% were female. Analysis of production system revealed that 90% of the respondents do not use fertilizer; the only 10% of the respondents do use organic fertilizer. All of the respondents use irrigation water; however the source, quantity and quality differ from farm to farm. 85% of the respondents replied that they did not control diseases except birds during the time of fruit maturation. Most of the respondents (95%) did not practice pruning. The orchards branch is so large and weak to support the fruit. Fifty percent of the respondent replied that they harvest the fruit at peak maturity but 33.33% of the respondents replied that the fruit harvest before peak maturity and only 16.67% response that the fruit harvest after peak maturity. The majority of the respondents (46.67) replied that all the listed factors (irrigation water scarcity, pest and disease and technology limitation) can influence the production of mango. The majority of the respondents (66.67) replied that hand picking method of harvesting produce and maintains good quality of fruit and protects the fruit from mechanical damage. Most of the respondents (30%) replied that all the listed (birds, wind, wounding, maturity stage and micro organisms) are major causes of mango production loss. 26.67%, 23.33%, 6.67%, 8.33% and 5% of the respondents response that birds, wind, wounding, microorganisms and maturity stage are the main causes of loss on mango respectively. Most of the respondents (45.00%) replied that major lost of mango occurs during harvesting and before harvesting. The majority (35) of the respondents use both pack animal and human back and shoulder to transport their produce. Most of the respondents (96.67%) sell their products at nearby local marke

Assessing the representation of teleconnective drivers of rainfall over Eastern Africa in global and regional climate models and projected future changes

Climate variability is an important characteristic of regional climate, and a subject to significant control from teleconnections. An extended diagnosis of the capacity of climate models to represent remote controls of regional climate (teleconnections) is vital for assessing model-based predictions of climate variability, understanding uncertainty in climate projections and model development. An important driver of climate variability for Africa is the sea surface temperature (SST) - rainfall teleconnection, such as the El Ni˜no/Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). In this study, an assessment of the teleconnection between tropical SSTs and Eastern African rainfall in global and regional climate models is presented, with particular attention paid to the propagation of large-scale teleconnection signals (as represented by model reanalyses and Coupled Global Climate models (CGCMs)) into the domain of the Regional Climate Models (RCMs). The teleconnection-rainfall relationship with the Eastern Africa region is assessed in two rainfall seasons (June-July-August-September and October-November- December) under present and future periods. Evaluation runs (RCMs driven by reanalysis datasets) and historical simulations (RCMs driven by CGCMs) are assessed to quantify the ability of the models to capture the teleconnection relationship. The future analysis is performed for two Representative Concentration Pathway scenarios (RCP4.5 and RCP8.5) to assess future change in this relationship as a result of global warming. Using ERA-interim reanalysis as perfect boundary conditions, the RCMs adequately simulate the spatial and temporal distribution of rainfall in comparison with observations, although the model performance varies locally and seasonally within the region. Furthermore, the RCMs correctly capture the magnitude and spatial extent regional-scale seasonal rainfall anomalies associated with large-scale oceanic modes (ENSO and IOD). When the lateral boundary conditions are provided by CGCMs, RCMs barely capture the regional teleconnection patterns associated with large-scale modes, and mostly depend on the selection of the driving CGCM. Comparison of the CGCM-driven RCM simulations with the reanalysis-driven RCM simulations revealed that most of the errors in teleconnection found in the RCM simulations are inherited from the host CGCMs. The ERA-Interim driven downscaled results show better agreement with observed spatial teleconnection patterns than the CGCM driven downscaled results. Analysis of the CGCMs and corresponding downscaled results showed that in most cases both the CGCM and the corresponding downscaled simulations had similar teleconnection patterns, but in some cases the RCM results diverge to those of the driving CGCM results. It has been demonstrated that similarities in SST-rainfall teleconnection patterns between the RCM simulations and respective driving CGCM simulations are noted over the equatorial and southern part of the region during OND season, where the rainfall is primarily controlled by large-scale (synoptic-scale) features, with the RCMs maintaining the overall regional patterns from the forcing models. Di↵erences in RCM simulations from corresponding driving simulations are noted mainly over northern part of the domain during JJAS, which is most likely related to mesoscale processes that are not resolved by CGCMs. Looking at the model projections of the future, although the spatial pattern of teleconnections between ENSO/IOD and rainfall still persist, important changes in the strength of the teleconnection have been found. During JJAS, ENSO is an important driver of rainfall variability in the northern parts of the region where dry anomalies are associated with El Ni˜no and wetter anomalies with La Ni˜na. Both regional and global ensemble projections show higher rainfall during La Ni˜na and lower rainfall during El Ni˜no over the northern part of the region compared to the present period. During OND, the teleconnection between ENSO/IOD and rainfall is projected to strengthen (weaken) over Eastern horn of Africa (southern parts of the region) compared to the present period. This implies heavy seasonal rains associated with positive phases of ENSO and IOD will increase in future across the Eastern horn of Africa. The change OND rainfall teleconnections are stronger and also more consistent between the models and scenarios as compared to the change in JJAS teleconnections. These findings have an important implication for the water and agricultural managers and policies in the region to tackle the anticipated droughts and floods associated anthropogenic climate change. Finally, the analysis demonstrated that the largest source of uncertainty in the regional climate model simulations in the context of teleconnective forcing of rainfall over Eastern Africa is the choice of CGCM used to force the RCMs, reinforcing the understanding that the use of a single GCM to downscale climate predictions/projections and using the downscaled product for assessment of climate change projections is insufficient. Simulations from multiple RCMs nested in more than one GCM, as is undertaken in the Coordinated Regional Downscaling Experiment (CORDEX), are needed to characterize the uncertainty and provide estimates of likely ranges of future regional climate changes

Institutional quality and economic growth in Sub-Saharan Africa: a panel data approach

Purpose – The main purpose of this study is to examine the impact of different dimensions of institutional quality indices on the economic growth of Sub-Saharan African (SSA) countries. Design/methodology/approach – The study uses a panel data set of 31 SSA countries from 1991 to 2015 and employs a two-step system-GMM (Generalized Method of Moments) estimation technique. Findings – The study's empirical results indicate that investment-promoting and democratic and regulatory institutions have a significant positive effect on economic growth; however, once these institutions are taken into account, conflict-preventing institutions do not have a significant impact on growth. Practical implications – The study's findings suggest that countries in the region should continue their institutional reforms to enhance the region's economic growth. Specifically, institutions promoting investment, democracy and regulatory quality are crucial. Originality/value – Unlike previous studies that use either composite measures of institutions or a single intuitional indicator in isolation, the present study has employed principal component analysis (PCA) to extract fewer institutional indicators from multivariate institutional indices. Thus, this paper provides important insights into the distinct role of different clusters of institutions in economic growth

Genetic Variability Assessment of Ethiopian Caraway (Trachyspermum ammi L. Sprague ex Turrill) Genotypes at Mersa, Ethiopia

Thirty-six local accessions of Ethiopian caraway were evaluated to assess their genetic variability and to determine their essential oil contents at Mersa, North Wollo using 6 x 6 lattice designs with three replications. Fourteen parameters were recorded and statistically analyzed The analysis of variance for these parameters indicated that the mean squares due to genotypes were highly significant for days to emergence, days to maturity, plant height, secondary branches/plant, seed yield and essential oil content. Genotypic variance contributed the larger portion of the phenotypic variance in all of the parameters. Moderate values of PCV and GCV were noted for number of secondary branches (15.1% and 14.16%), plant height (12.3% and 10.84%) and essential oil content (16.1% and 15.7%); however, the values of PCV and/or GCV were low for the rest of the parameters. Highest value of heritability were observed for essential oil (94.2%) and secondary branches (87.6%).Genetic advance (GA) and GA% were higher for dry matter, seed yield, secondary branches and plant height. Heritability, GA and GA% were higher for number of secondary branches, plant height and essential oil. Significant positive correlations were observed for number of umbel with number of secondary branches (0.98**), number of seeds per umbel (0.6**) and plant height (0.44**).Genotypically seed yield was positive and highly significant with number of primary branches (0.48**), secondary branches (0.5**), number of umbel per plant (0.8**), number of seeds per umbel (0.98**) and plant height (0.79**). Keywords: essential oil, harvest index, heritability, variability, genetic advance, correlation

Postharvest Loss Assessment of Commercial Horticultural Crops in South Wollo, Ethiopia “Challenges and Opportunities”

Postharvest losses assessment of horticultural crops in south wollo, at two districts were investigated using data from220 farmers and 80 traders. Data were collected using structured questionnaire and focus group discussion. The results revealed that the performance of using irrigation water is very interesting (96.4% of respondents) but there is shortage of irrigation water (21.8%). The problem of pest and disease is one of the major production-limiting factors as replied by most of respondents (44.8%) and the problem is severe during winter. The major causes of postharvest losses as replied by the respondents are preharvest infection (46.4%) and others (25%) replied both infection and injury. The general postharvest losses of commodities as replied by the producers is estimated as <5% (50% of respondents) 5-10% (34.1% of respondents) and 10-20% (13.2% of respondents). The losses of individual crops at different stages of handling (farmers level, transportation and storage) is summarized as banana (1.5%,1.2% and 4.5%), orange (3.04%,1.2% and 3.6%), mango (1.6%,1% and 3.7%), papaya (1.5%,1% and 3.3%), tomato (2.5%, 2.5% and 5.9%), onion (3.3%,1.1% and 3.7%), cabbage (4.3%, 2.8% and 4.2%) and carrot (2.8%, 1.2% and 3.8%). Awareness creation about the amount of losses, criteria to be used during selection and other postharvest principles and operations should be given due emphasis to minimize the postharvest losses of perishable horticultural commodities. Key words : Postharvest, horticulture , losses, value chai

Effect of Intra-row Spacing on Growth and Development of Tomato (Lycopersicum esculentum Mill) Var. Roma VF, at the experimental site of Wollo University, South Wollo, Ethiopia

A field experiment was conducted at Wollo University experimental site during March to June 2013 cropping season. The objective of this study was to determine the effect of intra-row spacing on the growth and development of tomato. The experiment was conducted on a randomized complete block design with three replication. Only one variety Roma VF was used on the experiment. The treatment used are 20, 25, 30,35cms spacing between plants with an inter-row spacing of 70cm

Effect of Planting Depth on Growth Performance of Maize (Zea-Mays) at the Experimental Site of Wollo University, Dessie, Ethiopia

The experiment was conducted at the experimental site of Wollo University with the objective of assessing the effect of different sowing depth on growth performance of Maize plant

Shelf-life and post-harvest quality of tomato (Lycopesicon esculentum Mill.) varieties to different packaging materials at Mersa, North Wollo, Ethiopia

Tomato (Lycopersicon esculentum Mill.) has a short shelf life at ambient conditions and is a highly perishable crop. Extreme post-harvest losses occur as a result of the wrong packaging materials. However, by employing the right packing materials, tomato varietals can have longer shelf lives. Globally rising fresh tomato demand has forced the development of essential mechanisms, including packaging materials, to improve shelf life. The current study was initiated to evaluate the quality and shelf-life of tomato varieties in response to packaging materials at Mersa, North Wollo, Ethiopia, during 2021 cropping season. Three replications of a completely randomized design were used to test three tomato varieties (Roma VF, Oval red and Woyno) and seven packing materials [closed carton (CC), open carton (OC), closed wooden box (CWB), open wooden box (OWB), perforated polyethylene bag (PPB), non-perforated polyethylene bag (NPPB) and control (C)] at room temperature (20-22°C). According to the findings, there is a significant (P<0.05) interaction effect between packaging materials and varieties on a number of parameters, including physiological weight loss, decay percentage, disease incidence, total soluble solids (TSS), tomato fruit PH, juice color score, overall acceptability, marketability percentage, and shelf life. Non-perforated polyethylene plastic experienced the highest physiological weight losses of 79.88% and 79.63% after 18 days of storage. Roma VF variety showed the greatest weight loss. In addition, PPB showed the lowest decay percentage (20%) and maximum marketability (20%) during the 18th day of storage. At the end of storage, NPPB with Roma VF and Woyno varieties had a substantially (100%) larger decay loss of tomato fruits. NPPB has been linked to the highest disease incidence (20%). Roma VF and Oval red recorded the highest pH tomato fruit’s color and overall acceptability score on PPB. It can, thus, be concluded that packaging of tomato fruits in PPB can extend shelf-life with better-quality of the produce. However, to develop plausible recommendation, the study should be repeated in multi-location with more packaging methods and varieties over seasons

Phenological and yield response of primed carrot (Daucus carota L) seeds under deficit irrigation

Seedling emergence and stand establishment of carrot seeds are often slow and erratic which results in low productivity. Poor seed quality together with lack of pre-sowing seed treatments and improper irrigation management can be mentioned as the major factors that influence the yield and productivity of carrot. The present study was carried out with the objective to evaluate the effects of different seed priming techniques on early seedling establishment, growth and yield of carrot (Daucus carota L. cultivated variety Nantes) exposed to different irrigation intervals, under field conditions at Gerado, South Wollo, Ethiopia. Four seed priming treatments (no priming, hydro priming, halo priming and hormonal priming) and three irrigation intervals (4, 7 and 10 days) were combined as factorial RCBD in split plot arrangement with three replications. The irrigation intervals were assigned to main plots and the seed priming techniques to sub plots. Result indicated that the interaction effects of priming techniques and irrigation intervals significantly affected the phenological and yield parameters. Distilled water treatment in seven and ten days irrigation interval recorded the highest marketable carrot root yields of 33.73 t h-1 and 30.63 t h-1, respectively. Hence, hydro priming and seven days irrigation interval can be recommended for the production of carrot in the study area and similar agro-ecologies. Given the promising results obtained, further repetitions of the study are recommended to validate the use of these techniques in further locations and in different seasons