East African Journal of Sciences

Evaluating Rumen Fluid-Inoculated Lignocellulosic Substrates for Biogas Production

2021-05-13T19:34:11+00:00

Background: The continuous decline in reserves of fossil and petroleum-based fuel and its undesirable environmental effects is a major problem faced by humanity. Biofuel production from lignocellulosic biomass such as agricultural, forest and crop residues, food waste and energy grasses is cost effective and could provide a sustainable solution to the problem. However, since a lignocellulosic substrate is recalcitrant, the choice of more effective digestion inoculums is crucial to achieve an improvement in the efficiency of digesting the substrate. Microbial community present in rumen is efficient in hydrolysis of complex organics at mesophilic temperature.
Objective: The objective of this study was to evaluate and compare biogas production potential of watercrown, potato peel, wheat and sorghum straw and sugarcane bagasse separately inoculated with rumen fluid of cow, goat and sheep.
Material and Methods: Total solid, volatile solid, C/N ratio and pH of the slurry before and after anaerobic digestion were determined following standard procedures. The volume of biogas produced was measured using water displacement method for 32 days and energy was estimated from a general methane composition of biogas and 1 m3 of methane contains 34 MJ of energy.
Results: The initial C/N ratio of slurries of potato peel ranged from 15.33 to 16.33. The highest cumulative biogas yield of 1318.83 mL g-1 VSadded-1 was obtained from potato peel inoculated with cattle rumen fluid. The cumulative biogas yield of watercrown inoculated with cattle and sheep rumen fluid was higher than that of all the slurries of sugarcane bagasse and wheat straw.
Conclusions and implications: Slurries of potato peel and watercrown grass produced the highest amount of biogas and could be used potentially for biogas production at the pilot scale.

Adaptation of Food Oat (Avena sativa L.) Genotypes in Amhara Region, Ethiopia

2021-05-13T19:34:12+00:00

Background: Oat is one of the soil acidity tolerant crops among cereal crops. In Ethiopia, However, it is mainly cultivated for animal feed using local cultivars with poor agronomic and soil management practices in soil acidity prone areas.
Objective: There are a lot of improved and commercial oat varieties released by European countries that are recommended for both food and feed. Therefore, the study was conducted to identify high-yielding and disease-resistant oat genotypes in acid soil highland areas of Amhara region.
Materials and Methods: The study was conducted at Adet, Banja, Fajie, Farta, Geregera, Sekela, Sekota and Sinan in the Amhara Regional State of Ethiopia. Thirteen introduced food oat genotypes and one local cultivar as a check were used as experimental treatments. The experiment was laid out as a randomized complete block design with three replications.
Results: The combined analysis of variance showed significant (P≤0.05) differences for grain yield and yield related traits of among genotypes, environments, and their interactions. The combined grain yield performance range was 3904 kg/ha to 3045 kg/ha in food oat genotypes. Food oat genotypes G4, G5, G10, G2, G13, G8 and G12 showed higher interaction to the environmental factors and also higher in grain yielding performance than the remaining tested oat genotypes across the tested environments. Therefore, these genotypes are relatively wider in adaptation across the tested environments. However, food oat genotypes only Goslin (G4) and Souris (G12) were more both widely adaptable and resistance to oat diseases over the local cultivars.
Conclusion: Among the 13 introduced food oat genotypes, Goslin (G4) and Souris (G12) were higher in grain yield performance, with a grain yield advantage of 26.93% and 18.16% and resistance to oat diseases over the local cultivars. Therefore, Food oat genotypes Goslin (G4) and Souris (G12) should be demonstrated and scaled out in soil acidity prone high land areas of Banja, Fajie, Farta, Geregera, Sekela and Sinan districts and in areas with similar agro-ecologies of Ethiopia.

Determinants of Export Performances of Major Spices (Turmeric and Korarima) in Ethiopia

2021-05-13T19:34:12+00:00

Background: Ethiopia has comparative advantages in the production of exportable spices due to existing rich genetic resources, diverse agro-ecological condition and abundant arable land and labour. However, despite their high potential and opportunities for export, most spices including turmeric and korarima are not fully utilized.
Objective: This study was intended to analyze the determinants of export performance of major spices (turmeric and Korarima) in Ethiopia.
Material and Methods: The random effect GLS gravity model was selected as an analytical tool to estimate the determinant of major spices export performance between Ethiopia and nine sampled spices trade partners using annual panel data collected for a period of 2005 to 2015/2016.
Results: The results indicated that Ethiopia's population, foreign direct investment, real exchange rate and institutional quality, the importers' GDP, GDP per capita and population, geographical distance and the dummy variables (COMESA membership and sharing common borders) had significantly affected turmeric and Korarima export performances, at different level of significance level, with their expected sign or effect. However, the variables intuitional quality and being COMESA membership were found to have unexpected negative influences on the export performance of major spices (turmeric and Korarima).
Conclusion: The finding of the study implied that there is a need to formulate policies and strategies that would promote institutional quality, improve supply capacity, attracting foreign direct investment, strengthen trade liberalization, deepening economic integration and targeting export destination that could reduce transportation costs in order to improve the export performance of those spices.

Effects of Telecommunication Mast Electromagnetic Radiation (EMR) on Exposed Rats (Rattus norvegicus)

2021-05-13T19:34:12+00:00

Background: The safety of electromagnetic radiation (EMR) from modern telecommunication devices is controversial as some studies reported negative effects, while others reported no effects. Thus, more studies are necessary to clear the controversy, so as to design appropriate precautionary and palliative measures if found toxic.
Objective: This study was conducted to determine the effects of telecommunication mast EMR on selected health indices of rats (Rattus norvegicus).
Materials and Methsod: Twenty-four (24) rats were divided into two groups of 12 rats each. Group 1 was made the control, while group 2 was exposed to 18000 MHz EMR at 50 m from a telecommunication mast. The weight, body temperature, reproductive activities, and reactions of the rats were observed for 60 days. Thereafter, the rats were sacrificed and their blood parameters, liver function, and histology were examined.
Results: The exposed rats were less active, weighed and reproduced less, had lower offspring survival rates and insignificantly (P > 0.05) elevated body temperature. The white blood cells (WBC) of the exposed rats were significantly increased (P < 0.05), while the packed cell volume (PCV), hemoglobin (Hb), red blood cells (RBC), and lymphocytes were reduced. The aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and total protein (TP) of the exposed rats were significantly increased, while the albumin (ALB) was significantly reduced. The ovary, lung, and kidney tissues of the exposed rats showed no abnormalities, but necrosis of the hepatocytes and fat were observed in their livers and the skins, respectively.
Conclusion and Recommendation: It is concluded that electromagnetic radiation (EMR) from modern telecommunication devices harmed the health of exposed rats. It is inferred from the results that EMR has negative effects on the health of mammals. Hence, it is advisable not to site telecommunication masts close to dwelling places.

Effects of Nitrogen Fertilizer Rate and Cutting Height on Morphological Characteristics and Yield of Elephant Grass (Pennisetum purpureum L.)

2021-05-13T19:34:13+00:00

Background: Elephant Grass (Pennisetum purpureum L.) is a forage grass with high potential to improve livestock production. However, the dry matter yield of the forage crop is low because of poor agronomic and soil fertility management practices.
Objectives: This study was, therefore, conducted to evaluate the effects of nitrogen fertilizer rate and cutting height on morphological characteristics and yield of elephant grass (P. purpureum L.).
Materials and Methods: Treatments were arranged in a 3 x 4 factorial arrangement in a randomized complete block design with three replications (3 cutting heights i.e., 7.5, 15, and 22.5 cm; and 4 nitrogen fertilizer rate i.e., 0, 69, 115, and 161 kg N ha-1). Data on morphological characteristics and yield of elephant grass (P. purpureum L.) were collected and subjected to the analysis of variance using the general linear model procedure of the statistical analysis system version 2004.
Results: Most morphological characteristics of elephant grass increased (P < 0.05) as cutting height and nitrogen fertilizer rate increased, except for weight per tiller, tiller diameter, and internode length. Forage dry matter yield was in the order of 0 < 69 < 115 = 161 kg N ha-1 and 7.5 < 15 = 22.5 cm. Looking at the combination of the two factors 115 kg N ha-1 x 22.5 cm and 161 kg N ha-1 x 15 cm treatments resulted in greater dry matter yield of 6.25 and 6.45 ton DM ha-1 cut-1, respectively, and 115 kg N ha-1 was economically feasible.
Conclusions: This study suggests that the rate of 115 kg N ha-1 x 22.5 cm cutting height is optimum for intensive cultivation of the forage crop with high dry matter yield at reduced nitrogen fertilizer cost.

Producing, Processing, Marketing and Hygiene of Cow Milk in the Supply Chain of Girar Jarso District of Oromia Regional State, Ethiopia

2021-05-13T19:34:15+00:00

Background: Production and productivity of dairy is very low in Ethiopia. This problem is exacerbated by high contamination with microorganisms and other contaminants during production, procurement, processing and distribution. To tackle the problem, understanding the production, processing and microbial load of raw milk and measuring its hygiene quality is necessary.
Objectives: The study was conducted with the objective of assessing milk production, handlings, constraints of milk production and marketing, and its hygiene in urban and peri urban areas of Girar Jarso district of Oromia Regional State, Ethiopia.
Materials and Methods: A total of 150 respondents were interviewed using pretested questionnaire to collect data on dairy cattle management, milk production, hygienic conditions, milk production constraints and marketing. Moreover, 60 milk samples were collected and analyzed for mean aerobic mesophilic bacterial count (AMBC), total coliform count (TCC), and spore forming bacterial count (SFBC).
Results: The major feed resources were communal grazing land, crop residues, grass hay, concentrate feeds and non-conventional feed such as atella. The mean estimated daily milk yield/day/cow was 12.15 ± 0.26 and 2.69 ± 0.04 liters for crossbred and local cows, respectively. Average lactation lengths of local and crossbred dairy cows were 6.58 ± 0.22 and 9.19 ± 0.11 months, respectively. Shortage of feed, lack of clean water, appropriate utensils and adequate markets during fasting season were the major constraints to dairy production in the study area. The mean AMBC, TCC and SFBC for milk samples collected from producers at farm gates were 6.42 ± 0.07, 4.49 ± 0.09 and 2.59 ± 0.05 log10 cfu ml-1, respectively.
Conclusion: It is concluded that dairy productivity in the study area is low and of poor quality as a result of different constraints and therefore good dairy husbandry and hygienic milk handling practices should be promoted to improve milk productivity and milk quality in the study area.

A Robust Method of Computing the Annual Rate of Land Use/Land Covers Change in Landscapes

2021-05-17T13:59:06+00:00

Background: Several earlier studies have used different formulae to compute the annual rates of land use/land covers changes in landscapes. Moreover, the magnitudes of the land use changes from two time points (i.e., initial and recent) only have been used to compute the annual rates. However, the use of different formula by itself is confusing and the failure to take into account the instantaneous changes in magnitude of the land use changes from the intermediate time points along the time period may lead to either overestimation or underestimation of the annual rates.
Objective: A formula to compute the annual rate of change in land use/land cover in a robust method was suggested based on the property of the function of instantaneous change in slope and law of compound interest in economics.
Materials and methods: The property of instantaneous changes in slope was integrated with the formula of compound interest in economics to derive the formula of calculating the interest rate of change in land use. With the application of this approach, the differential effects of the drivers of land use change along long temporal scale can be taken into account by converting the magnitude of the changes into change factors. Here, data are “scaled” to change factors from the ratios of the mid points (tangent lines) to the consecutive intermediate initial time points along the time period and these change factors are again averaged over number of time intervals of change detection to enhance the precision of calculating annual rates.
Result: The annual rate of change in land use should be computed as,
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Conclusion: For both short and long time periods, the present formula can be applied as standard and such computation is an ideal input for planning biodiversity conservation and development strategies.

Registration of a new Triticale Variety: ‘Kombolcha’

2021-05-17T14:00:37+00:00

Background: Triticale (X-Triticosecale Wittmack) is a hybrid of wheat (Triticum sp.) and rye (Secale sp.) It combines yield potential and grain quality of wheat with the diseases and environmental tolerance including adaptability to marginal soils, diseases resistance and low-input requirements of rye. The crop has demonstrated high yield potential under marginal growing conditions and could a very attractive alternative for raising cereal production in the globe, involves Ethiopia.
Objective: To evaluate and release stable high yielding and disease resistant/tolerant Triticale variety for the western highland of Oromia and other similar agro-ecologies
Material and Methods: Twelve triticale genotypes including the standard check “Moti” were evaluated across two locations for three years (2015-2017). Eventually, two promising genotypes, “Acc 2012 MS #51 and Acc.2012 MS #59” were selected and promoted to variety verification trail with the standard check ‘’Moti” during the 2018/19 cropping season. The national variety release technical committee evaluated the two candidate varieties both at Gedo and Shambu on research stations and farmers’ fields.
Results: Among the two evaluated varieties, ‘Kombolcha’ is well adapted to altitudes ranging between 2244 and 2784 meters above sea level and characterized by amber seed color, longer panicle and gave high seed yield (6184.8 kg ha-1) and stable performance across years and locations. It has about 13% yield advantage over the standard check variety, “Moti”. The variety is also resistant to major diseases such as steam rust (Pucinia graminis f.sp. tritici), yellow rust (Puccinia striiformis f.sp. tritici) and Septoria tritici (Mycosphaerella graminicola).
Conclusions: “Kombolcha” (Acc. 2012 MS #51) is released for the highlands of western Oromia and similar agro-ecologies for its stable and high grain yield, and resistant to major diseases. Therefore, farmers in western highlands of Oromia and similar agro ecologies particularly those inhabiting marginal and acid prone areas can produce “Kombolcha” variety with its full management recommendation.

Registration of ‘Diga-2’ Finger Millet (Eleusine coracana sub.spp. coracana) Variety

2021-05-17T14:01:02+00:00

Background: Finger millet is an important staple food crop widely grown in Ethiopia. The national average yield is far below the potential yield of the crop. Limited availability of stable, high yielding and disease tolerant finger millet varieties is one of the major production constraints in the country.
Objective: The objective of this study was to identify stable high yielding and diseases tolerant genotypes for production.
Materials and Methods: twelve black seeded pipeline finger millet genotypes were evaluated under a regional variety trial at Bako and Gute research stations from 2014 to 2016 main cropping seasons including the standard (Degu) and local checks using randomized complete block design. Diga-2 variety is black seeded finger millet (Eleusine coracana sub.spp. coracana) with the pedigree of Acc. BKFM0010 has been collected from Beneshangul Gumuz Regional State by Ethiopian Institute of Biodiversity.
Results: The results from Additive Main effect and Multiplicative Interaction (AMMI) and Eberhart and Russell regression stability models as well as Genotype and Genotype by Environment interaction (GGE) biplot analysis revealed that Diga-2 variety was relatively stable and high yielder (2.38 t ha-1) among the tested genotypes. The new variety, Diga-2 had a yield advantage of 33.7% over Degu, the standard check variety used for multi-environment evaluation.
Conclusion: Among the tested genotypes, Diga-2 finger millet variety was selected and released in 2018 for its high grain yield potential, stable and resistant against finger millet blast (Magnaporthe oryzea) disease which is the most important finger millet production constraints in Ethiopia in general and western Oromia in particular.