Showing papers in "East African Journal of Sciences in 2011"
TL;DR: In this article, the authors investigated the impact of topography on soil development and characteristics and revealed the existence of three different soil orders along the toposequences in an area that was previously mapped as Eutric Nitosols.
Abstract: In developing countries, where research funds are limited, the availability of pedogenic information and proper classification of soils will be of great importance. The soils of Kindo Koye watershed were fully characterized along east and west facing toposequences that formed a catena and classified according to the Soil Taxonomy and the WRB Legend to assess the impact of topography on soil development and characteristics. The morphological and physiochemical properties of seven pedons located at the upper, middle and lower slopes of the two toposequences and at the depression were studied. The study revealed the existence of three different soil orders along the toposequences in an area that was previously mapped as Eutric Nitosols. The pedons on the upper and middle slopes of both east and west-facing toposequences and the pedon on the east-facing lower slope were categorized under Ultisols, whereas the pedons on the foot slope west-facing and the depression were categorized under Inceptisols and Entisols, respectively. The Ultisols, Inceptisols and Entisols were further categorized as Acrisols, Cambisols and Fluvisols major groups according to the WRB Legend, respectively. This detail survey and classification of soils shows that topography has a great influence on soil development and characteristics. Keywords: Catena; Toposequence; Pedon; Soil Taxonomy; WRB Legend
34 citations
TL;DR: Earlliness coupled with high biomass yield could be considered as an indirect selection criterion for durum wheat grain yield improvement in moisture stressed areas.
Abstract: A field experiment was conducted at Geregera (110 45’ N latitude and 380 45’ E longitude) in north Wollo, Ethiopia during the 2003 cropping season with the objectives of estimating genotypic variability, heritability, genetic advance and associations among yield and yield-related characters of durum wheat. Forty four randomly taken Ethiopian durum wheat accessions were evaluated using randomized complete block design in three replications. Analysis of variance showed significant differences (p < 0.05) among the durum wheat accessions for all the characters considered. Genotypic coefficients of variation (GCV %) were medium for spike length (12.5%) and kernel yield plant-1 (12.3%). Broad sense heritability were high for spike length (89.2%), plant height (87.1%) and thousand kernels weight (80.2%), indicating that these characters were predominantly controlled by genetic factors. Maximum heritability in broad sense coupled with high genetic advance were exhibited for spike length, plant height and thousand kernels weight, implying that phenotypic selection could identify superior genotypes for these traits. Genotypic correlation analysis revealed that grain yield had strong positive associations (p < 0.01) with kernel yield plant-1 (rg = 0.89), plant height (rg= 0.84), thousand kernels weight (rg = 0.82), biomass yield (rg = 0.80) and number of kernels spike-1(rg = 0.78), where biomass yield and harvest index exerted maximum positive direct effects on grain yield. On the other hand, days to heading had a significant negative correlation (p < 0.01) with grain yield (rg = -0.75) which exerted maximum negative direct effect on grain yield. Therefore, earliness coupled with high biomass yield could be considered as an indirect selection criterion for durum wheat grain yield improvement in moisture stressed areas.
17 citations
TL;DR: The observed heterogeneity of forest coffee populations to leaf rust in the field under native agro-ecology provides an opportunity to develop resistant varieties among the enormous forest coffee genetic resources and at the same time calls for strategic multi-site in situ conservation to rescue and maintain the present genetic variation and enhance co-evolutionary processes.
Abstract: Coffee ( Coffea arabica L.) is native to southwestern Ethiopia growing as understory of the rainforests that harbor huge floral and faunal diversities. Besides drastic reduction in the forest cover and low average yield, the crop is attacked by several diseases among which coffee berry disease, coffee wilt disease and coffee leaf rust caused by Colletotrichum kahawae , Gibberella xylarioides and Hemileia vastatrix , respectively, are the major fungal diseases contributing to reduced yield in the country. The epidemics of coffee leaf rust (CLR) was monitored between July 2007 and April 2008 in Bonga, Berhane-Kontir and Yayu montane coffee forest populations of southwest Ethiopia to determine the incidence and severity of CLR and its seasonal variation in the forest coffee populations and their reaction to leaf rust in the natural habitat. Thirty coffee trees were selected from each forest (three sites within a forest) coffee population to record incidence (percent rusted leaves), severity (percent leaf area damaged) and sporulated lesion density (number of lesion per leaf, SLD) from selected six branches per tree. An average of 10-12 leaves per branch was considered to determine each disease parameter. The data were analyzed using nested design (tree under location) using SAS statistical package. The occurrence of CLR significantly varied with locations and seasons. Overall mean incidence of 31.1, 21.4 and 7.9 and SLD of 2.7, 1.8 and 0.86 occurred in Yayu, Berhane-Kontir and Bonga montane coffee forest populations, respectively. Leaf rust was low (13.9%) in July 2007 and high (29.6%) in January 2008. Significant variation observed among each coffee tree within a location and season significantly interacted with both location and coffee trees within a location. The mean rust incidence varied from 0.36 to 18.5% in Bonga, 1.8 to 49% in Berhane-Kontir, and 11.8 to 62.6% in Yayu forest coffee populations. The corresponding severity ranged from 0.08 - 1.2%, 0.24 - 1.7% and 0.91 - 3.3% whereas the SLD varied from 0.08 - 1.9, 0.33 - 3.65 and 1.5 - 5.9% in that order. The observed heterogeneity of forest coffee populations to leaf rust in the field under native agro-ecology provides an opportunity to develop resistant varieties among the enormous forest coffee genetic resources and at the same time calls for strategic multi-site in situ conservation to rescue and maintain the present genetic variation and enhance co-evolutionary processes. The selected forest coffee trees that showed promising results should be further investigated for their possible value for future utilization. The location-season and coffee tree-season interaction effects necessitate characterization of Hemileia vastatrix races prevalent at each location and insist strategic variety development for contrasting environments. Keywords: Coffee Leaf Rust; Ethiopian Coffee; Epidemics; Hemileia Vastatrix ; Incidence; Seasonal Variation; Severity
15 citations
TL;DR: Bariso was the most stable and high yielding genotype and was therefore released for the western Ethiopian highlands and other areas with similar agroecologies, implying that genotypes suitable for specific environments can be selected.
Abstract: The performance of a given genotype depends on its genetic potential and the environment upon which it is grown. In this study, sixteen genotypes of field pea ( Pisum sativum L. ) were tested over locations (Shambu and Arjo) for three years (2000-2002) and at Gedo (2002) with the objectives of identifying high yielding, stable and adaptable varieties for the Western highlands of Ethiopia. Regression and additive main and multiplication interaction (AMMI) analysis were computed to identify stable genotypes across multienvironments (location-year combinations). Analysis of variance revealed highly significant difference among genotype and genotype x environment (G x E) interactions, implying that genotypes suitable for specific environments can be selected. Regression and AMMI analysis were employed in order to determine the stability of genotypes. The two models regression analysis and AMMI revealed similar result in that Bariso, EH92049-1-2-1 and EH92049-2-2 were stable and widely adapted genotypes. However, the genotypes EH92049-1-3-1 and EH92039-1 are sensitive to changes in environmental conditions. Bariso was the most stable and high yielding genotype and was therefore released for the western Ethiopian highlands and other areas with similar agroecologies. Keywords : AMMI; Genotype x Environment; Pisum sativum; Regression; Stable
14 citations
TL;DR: The observed significant G x E interaction for tuber yield and dry matter content suggests that potato breeders should give special emphasis for G X E interaction while developing stable and high yielding genotypes in terms of tuber yield, dry matter and specific gravity.
Abstract: A study was conducted to determine stability of tuber yield, dry matter content and specific gravity, and the nature and magnitude of genotype x environment (G x E) interaction in elite tetraploid potato genotypes. Eleven potato genotypes including two standard checks were evaluated in the eastern part of Ethiopia at Haramaya, Langae, Kulubi, Hirna and Arberekete during 2008 and 2009 cropping seasons under rainfed condition. There were significant variations among genotypes with respect to tuber yield and dry matter content while the genotypes exhibited comparable tuber specific gravity values. Significant G x E interaction was observed for tuber yield and dry matter content and G x E mean square for tuber specific gravity was not significant indicating that G x E has negligible influence on the trait. Partitioning of the G x E interaction for both tuber yield and dry matter content indicated the presence of both linear and non-linear types of G x E interactions. None of the genotypes were found to be stable and ranked at the top for tuber yield, dry matter and specific gravity. The stability and responsiveness appeared to be specific for specific character within a single genotype. Genotype CIP-392640-528 is stable for specific gravity, average responsive for tuber dry matter content and above responsive for tuber yield. Highly significant positive correlation (r = 0.99) was obtained between specific gravity and dry matter content proving that specific gravity is a true indicator of tuber dry matter content. The observed significant G x E interaction for tuber yield and dry matter content suggests that potato breeders should give special emphasis for G x E interaction while developing stable and high yielding genotypes in terms of tuber yield and dry matter content.
11 citations
TL;DR: Analysis of variance components showed that variance of GCA was higher than SCA in the case of days to flowering, plant height, leaf number per plant, leaf length, leaf width, leaf area, panicle length and 100 kernel weight indicating that additive type of gene action was playing a greater role in the inheritance of these traits.
Abstract: Crossing sorghum [Sorghum bicolor (L.) Moench] obtained from different areas of Ethiopia were done in 2004/05 cropping season. In 2005/06 evaluation of 15 F1s with their parents were done in a randomized complete block design with three replications at Bako. The study was conducted to estimate combining ability and determine type of gene actions involved in the inheritance of yield and yield components traits. Analysis of variance revealed that mean squares due to genotypes, parents and crosses were highly significant (P<0.01) for all the traits except for 100 kernel weight that were significant for crosses. Mean squares due to general combining ability (GCA) and specific combining ability (SCA) were highly significant for all characters studied, except non significant SCA for 100 kernel weight. For yield, three of the parents, 212646, 69543 and 69193 had the best general combiner and incorporating these parents for grain yield per panicle in sorghum breeding may be importatnt. Based on specific combining ability analysis for grain yield per panicle five hybrids 69543 x 223506, 212646 x 223506, 97MW5122 x 212646, 97MW5122 x 69543 and 212646 x 69193 were the best in the experiment. The estimate of variance components showed that the variance due to SCA was higher in magnitude than GCA in the case of days to maturity, panicle width, panicle weight, kernel number per panicle and grain yield. Therefore, these traits were predominantly under the control of non-additive type of gene actions. Whereas variance of GCA was higher than SCA in the case of days to flowering, plant height, leaf number per plant, leaf length, leaf width, leaf area, panicle length and 100 kernel weight indicating that additive type of gene action was playing a greater role in the inheritance of these traits. Keywords: Combining Ability; Diallel; Gene Action; Sorghum bicolor
11 citations
TL;DR: In this paper, the main purpose of the study was to identify factors that affected the adoption of improved sorghum varieties in Awbare District of Somali Regional State, Ethiopia Individual interviews were conducted to collect data from 180 households in eight kebeles.
Abstract: The main purpose of this research was to identify factors that affected the adoption of improved sorghum varieties in Awbare District of Somali Regional State, Ethiopia Individual interviews were conducted to collect data from 180 households in eight kebeles Descriptive statistics and mean comparisons using a t-test and chi-square test were employed to analyze data The findings indicated that the adopters of improved sorghum varieties were more educated, younger in age, had a larger farm size, had more shoats, lived in a better house, owned a radio and had a positive attitude towards improved sorghum varieties when compared to the non-adopters The results of the study confirmed that a farmer who had better economic status (as evidenced by larger farm size, more shoats and a better quality house) and had access to market information might be a greater technology adopter Moreover, targeting younger educated farmers may enhance the adoption of new agricultural technology in the area High priorities to promote technology adoption are the provision of extension agents with transportation facilities and the establishment of community radio stations
11 citations
TL;DR: It is concluded that vetch hay could substitute 50% of the concentrate mix without compromising feed intake and digestibility of nutrients as well as milk yield and composition of lactating Boran x Friesian cows.
Abstract: The experiment was conducted with the objective to assess the effect of replacing vetch for concentrate mix on feed intake and digestibility as well as milk production and composition in lactating crossbred (Boran x Friesian) cows kept on a basal feed of urea- molasses treated wheat straw (UMTWS). Eight crossbred cows of similar milk yield (8-10 kg d-1), body weight (BW) and stage of lactation (early lactation), but differing in parities were arranged in 4 x 4 double Latin square design. The treatments included offering urea molasses treated wheat straw basal diet ad libitum and supplementation with concentrate mix (T1), and replacement of the concentrate mix with vetch (Vicia dasycarpa) hay at the level of 25% (T2), 50% (T3) and 75% (T4). The concentrate mix consisted of 74% wheat bran, 25% noug seed (Guizotia abyssinica) cake and 1% common salt. The CP content of UMTWS was 86.7 g/ kg dry matter (DM), whereas that of vetch hay and the concentrate mix were 199 and 225 g/ kg DM, respectively. The contrary was true for neutral detergent fiber (NDF) content which was 767 g/ kg DM in UMTWS, and 545 and 479 g/ kg DM in vetch hay and the concentrate mix respectively. In sacco degradability studies showed that the concentrate mix and vetch were similar in rumen degradability parameters, except that rate of degradation was relatively faster for vetch hay. Total DM intake was higher (P 0.05) among treatments, except for cows in T3 that had higher (P 0.05) for cows in the different treatments. It is concluded that vetch hay could substitute 50% of the concentrate mix without compromising feed intake and digestibility of nutrients as well as milk yield and composition of lactating Boran x Friesian cows.
9 citations
TL;DR: There was significant difference in the storability of paddy seeds under different storage conditions as well as the incidence of seed mycoflora and fungal incidence, which were significantly higher in seeds stored under LTLH conditions and in jute bags.
Abstract: Storage conditions, storage containers and seed treatments prior to storage are important factors responsible for retaining seed longevity. But ideal storage environment are seldom available for the precious seed, especially under tropical conditions. Maintenance of seed germination in vulnerable parental lines IR 58025A (6A) and IR 58025B (6B) of paddy ( Oryza sativa L.) during storage was investigated using integration of different treatments as storage containers (jute bags/ polylined jute bags), storage conditions (ambient/LTLH i.e. low temperature, low humidity or controlled) and seed dressings (captan/thiram) at Karnal seed godowns in North India during 2000-2007. Ten kg of seed was stored per treatment. Seed was taken from the fields of Indian Agricultural Research Institute, Regional Station, Karnal (India). The initial moisture content of paddy seeds was kept 13% which is a standard. The results revealed that there was significant difference in the storability of paddy seeds under different storage conditions. Under LTLH storage conditions (temperature:15 °C and relative humidity:30%) paddy seeds maintained germination above the minimum seed certification standards (80%) up to 60 months after seed treatment as against 24 months when stored under ambient conditions. The germination of seeds stored under LTLH conditions (86.1%) and in polylined jute bags (75.3%) was significantly higher than seeds stored under ambient condition (61.9%) and in jute bags (72.8%) after 60 months of seed treatment. Treatment with thiram/captan also showed improved seed germination by 7% as against untreated control. Seed vigour also followed a trend similar to seed germination. The incidence of seed mycoflora was 54.8% and 45.2% in seeds of 6A and 6B, respectively. This was significantly higher in seeds stored under LTLH conditions (62.1%) and in jute bags (39.1%) compared to seeds stored under ambient condition (64.7%) and in polylined jute bags (47%). In all 16 fungi were found associated with paddy seeds. However, the fungal incidence in treated seeds was 29.2% as against 70.8% in untreated control. Seed moisture content did not vary much amongst different treatments though it was higher in seeds stored under ambient storage conditions (11.7%) as against seeds stored under LTLH- low temperature, low humidity conditions (9.2%). Keywords: Paddy-Rice; Seed Germination; Seed Mycoflora; Seed Storage; Storage Condition
6 citations
TL;DR: The survey revealed high occurrence and distribution of faba bean rust in the study area and the need for effective and feasible management options to be developed.
Abstract: Disease survey was conducted in Hararghe highlands of Ethiopia during the 2009 cropping season to determine the incidence and severity of faba bean rust (Uromyces viciae-fabae) in major growing districts of Hararghe highlands, and its association with environmental factors and cultural practices. A total of 90 faba bean fields were surveyed in six districts. Sample plants were systematically selected in an “X” fashion. In each field, 10 plants were sampled for disease assessment. During the survey, altitude, type of cropping system, weed management practices, crop growth stage, previous crop in the field and sowing date were recorded. Significant differences among locations were indicated with respect to altitude, sowing date, crop growth stage and field management practices. The mean incidence of the disease varied from 44.6% in Bedeno to 98% in Tullo, while severity of the disease varied from 12.7% in Bedeno to 65% in Gorogutu and Kurfachale districts. Logistic regression analysis for the association of rust incidence and severity with environmental factors and cultural practices as independent variables showed rust incidence below 80% had a high probability of association with Deder district, areas with altitude above 2450 m.a.s.l. and when faba bean was planted after July 25. Rust incidence above 80% had a high probability of association with Gorogutu, Kurfachale, Tullo districts; altitudes below 2450 masl, and when faba bean was planted from the end of June up to July 25. Similarly, disease severity below 40% had a high probability of association with Bedeno district, flowering growth stage, altitude above 2450 m.a.s.l., and when weeds were managed properly. Disease severity greater than 40% had a high probability of association with Gorogutu, Kurfachale, Tullo, Deder and Metta districts, altitudes below 2450 m.a.s.l., podding and late podding growth stages, and where poor weed management was practiced. The survey revealed high occurrence and distribution of faba bean rust in the study area and the need for effective and feasible management options to be developed. Keywords : Disease Incidence; Disease Severity; Faba Bean Rust; Uromyces viciae-fabae; Weed Management
6 citations
TL;DR: Investigation of the presence, intensity and damages caused to coffee berries by major insect pests of coffee in wild coffee populations in Afromontane rainforests of Southwestern Ethiopia found difference in occurrences of insect pest incidences between and within forest coffee populations was observed.
Abstract: A study was conducted to investigate the presence, intensity and damages caused to coffee berries by major insect pests of coffee in wild coffee populations in Afromontane rainforests of Southwestern Ethiopia. The parasitoids associated with those insect pests were also studied. Based on ecological descriptions of forest coffee population, each forest locality was stratified in to three forest sites. In each stratum, 40 coffee trees were randomly taken for insect pests and parasitoids collection; whereas 16 random coffee trees were used to study the incidence of the pests on coffee berries at different phenological stages. Fifteen insect pest species in 10 families under five orders were recorded. Among the insects recorded, Ceratitis fasciventris (Bezzi) and Ceratitis anonae Graham were new records for Ethiopia. Similarly, Prorops nasuta and Psyttalia spp. were new parasitoids reported for the first time in Ethiopia. The damage caused by coffee berry moth was low and analysis of variance revealed that there is a significant difference (P 0.05) among the forest coffee populations. Fruit fly mean incidences on ripen coffee berries reached 52.12% ± 14.31, 71.08% ± 4.48 and 82.73% ± 3.61 at Yayu, Berhane-Kontir and Bonga, respectively. Mean damage by Hypothenemus hampei was less than 10% in most of the forest coffee populations, which is relatively low incidences in less disturbed ecosystem. In general, difference in occurrences of insect pest incidences between and within forest coffee populations was observed, which could be due to variations in ecology, and diversity of the insect pests and their parasitoids. From the results, it is thought that these forest coffee sites would be used as the main genetic resources for exploration of insect pests and their natural enemies in the future, which undoubtedly needs detailed research work.
TL;DR: The results of this study suggested selection of parents on the basis of their quality performance regardless of their origin and crossing among them is an appropriate breeding method to improve target region coffee quality.
Abstract: In view of the lack of study on heterosis and combining ability in coffee quality breeding programs of Ethiopia, the present study was conducted on six distinct Coffea arabica L . lines in origin and 12 hybrids made among them in half diallel fashion to evaluate coffee hybrids for Sidamo coffee quality, to estimate heterosis effects for different coffee quality parameters and to determine the gene actions involved in controlling the quality parameters. Coffee samples were prepared during the 2002/2003 cropping season from hybrids and parents planted at the Wonago Agricultural Research Sub-station (06o 03’ N and 38o 03’ E) in Sidamo following a randomized complete block design. The coffee samples were evaluated for Sidamo coffee quality at the National Coffee and Tea Liquoring and Inspection Center. The hybrids exhibited positive and significant heterosis that ranged from 14 to 33% relative to the commercial Sidamo coffee variety for most of the parameters studied. Two hybrids; 7440 x 75227 and 744 x 1681, evaluated as having highly acceptable Sidamo coffee quality were the best specific combinations and heterotic for all coffee quality parameters. Two Kaffa coffee parents namely, 7440 and 75227 were good combiners and produced hybrids better than the commercial Sidamo coffee variety for Sidamo coffee quality. Predominance of non-additive gene actions were detected for acidity, body, cup quality and overall Sidamo coffee quality and additive gene action was important for the expression of flavor. The results of this study suggested selection of parents on the basis of their quality performance regardless of their origin and crossing among them is an appropriate breeding method to improve target region coffee quality. This study was conducted using coffee parents obtained only from two coffee growing regions and the results might not be sufficient to reach at a general conclusion for all coffee types in Ethiopia. However, the present findings can be used as good evidence for the possibility of using coffee lines of diverse origin and their crosses to improve unique coffee quality of the target region. Keywords : Additive Gene Action; Coffea arabica; Combining Ability; Heterosis; Non-additive Gene Action; Sidamo Coffee Quality
TL;DR: In this article, the effects of feeding different levels of concentrate mixture to sheep fed urea treated maize stover basal diet on feed intake, digestibility, and nitrogen balance were evaluated at Haramaya University.
Abstract: The effects of feeding different levels of concentrate mixture to sheep fed urea treated maize stover basal diet on feed intake, digestibility, and nitrogen balance were evaluated at Haramaya University. The experiment was conducted in a randomized complete block design using twenty male Hararghe Highland sheep with a mean initial body weight (BW) of 17.2 ± 1.74 (mean ± SD) kg. The animals were grouped into five blocks based on their initial BW and randomly assigned to four treatments within the block. The levels of supplementation were 0 g (control, T1), 150 g (low, T2), 250 g (medium, T3) and 350 g (high, T4) of the concentrate mix prepared from brewers dried grain, peanut cake and wheat bran at a ratio of 1:1:3 on dry matter basis, respectively. Hundred kg (dry matter basis) of chopped maize stover was treated with 4 kg of urea dissolved in 100 liters of water and ensiled for 21 days before used as a basal diet. The urea treated maize stover (UTMS) was offered ad libitum and water and mineral block were available to the experimental animals all the time throughout the experiment. Intake trial was conducted for 90 days. Digestibility and nitrogen balance trials were carried out for 7 days following 3 days of adaptation to the metabolic cage and carrying of the fecal collection bag following 15 days of adaptation. Urea treatment improved the crude protein (CP) content of maize stover by about 33% (from 5.8 to 7.7%). The UTMS intake was lower (P < 0.05) for the sheep in T4 (665 ± 16 g DM day-1) than in T1 (768 ± 16 g DM day-1) and T3 (754 ± 16 g DM day-1). Daily DM intake per kg W0.75 was higher (P < 0.01) for T3 (105.7 ± 1.7 g day-1) and T4 (104.1 ± 1.7 g day-1) than T1 (91.9 ± 1.7 g day-1). Total CP intake per kg W0.75 (7.8, 10.4, 12.7, and 13.8 (SEM = ± 0.16), for T1, T2, T3, and T4, respectively) increased with increasing level of supplementation (P < 0.01). Crude protein digestibility was lower (P < 0.05) in non-supplemented sheep (0.42 ± 0.04) than the supplemented sheep (0.65, 0.71, and 0.70 (SEM = ± 0.04) for T2, T3 and T4, respectively). Nitrogen intake during digestibility trial (6.4, 11.2, 14.4, and 17.5 (SEM = ± 0.3) g day-1 for T1, T2, T3 and T4, respectively) increased with increasing levels of supplementation (P < 0.001). Nitrogen retention was positive and higher in the supplemented groups (8.2, 7, and 4.4 (SEM = ± 0.63) for T4, T3, and T2, respectively) than in T1 (-0.02 ± 0.63 g day-1), which has a negative nitrogen balance (P < 0.01). The result indicated that supplementation improved feed intake, digestibility and nitrogen balance, but feeding sole urea treated maize stover failed to support sufficient nitrogen intake which might have resulted in body reserve mobilization to meet the maintenance requirement of the animal.
TL;DR: In this paper, a study was made to compare efficiency and capacity of two types of granular activated carbon (GAC), Calgon F200 and Norit GCN1240, for removal of Trihalomethanes (THMs) in water and to examine the competition of one adsorbate in the presence of another.
Abstract: A study was made to compare efficiency and capacity of two types of granular activated carbon (GAC), Calgon F200 and Norit GCN1240, for removal of Trihalomethanes (THMs) in water and to examine the competition of one adsorbate in the presence of another. Coconut based Norit (GCN1240) and bituminous based Calgon F200 GACs were selected for the study. Multi-component adsorption isotherm models were established for both GACs using same model water containing chloroform (2.54 mg L -1 ) and bromoform (1 mg L -1 ). After sample bottles were agitated at the speed of 25 rpm in a mechanical shaker for 15 days, measurements were taken using gas chromatography. The results obtained were checked with Freundlich adsorption isotherm model. This model expresses well adsorption of one THM species in the presence of another with R 2 > 0.95. Based on the model, adsorption capacity of Calgon F200 and Norit GCN1240 were found higher for bromoform than chloroform. Calgon F200 showed a higher adsorption capacity compared to Norit GCN1240 for a lower equilibrium concentration (< 3 μg L -1 ). However, for equilibrium concentrations in the range of 3 - 200 μg L -1 , both Calgon F200 and Norit GCN1240 showed similar capacity for competitive adsorption of THMs. Keywords: Granular Activated Carbon; Adsorption; Bromoform; Chloroform; Trihalomethane
TL;DR: The biomass production and nutritive value of the natural pasture of Umbulo Wacho watershed in Southern Ethiopia were studied and the interactions among closed or open areas, sampling time and altitude were significant for most of the nutrient content and yield parameters.
Abstract: The biomass production and nutritive value of the natural pasture of Umbulo Wacho watershed in Southern Ethiopia were studied. The upper and medium altitudinal zones had an open area and areas closed for 2, 3 and 4 years and the lower altitude had an open area and an area closed for 2 years. In each of the open and closed areas, three sites were selected (9 in open, 21 in closed) at each of which exclusion cages (30) were fixed. The re-growths of forage samples were cut at 30 days interval from May up to November from the exclusion cages. The overall dry matter (DM, %), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), ash, calcium (Ca) and phosphorus (P) contents of the forages were 30.8, 83.9, 12.7, 66.7, 32.6, 4.5, 16.2, 0.6 and 0.3%, of the DM, respectively; in vitro DM digestibility (IVDMD) was 72.1% and DM yield (DMY) was 71.34 g/1.21 m/30 d (0.59 tones/ha/30 d). The natural pasture (117.1 ha) produced 829.07 tones of DM/year (0.59 * 117.1*12) which can only meet 8.20% of the total DM requirement (10,107.11 tones/year) of the tropical livestock unit (4431) found in the watershed. Closing an area for long duration decreased (P < 0.01) CP, P, DMY and IVDMD, but increased ADF and ash. Advance from the rainy season towards the dry period reduced (P < 0.01) DM, DMY, CP, ADF, ash and P. With increasing altitude, DM increased (P < 0.01) but DMY, NDF and P decreased. The IVDMD was positively correlated with DMY and negatively correlated with NDF and ash (P < 0.05). The interactions among closed or open areas, sampling time and altitude were significant (P < 0.05) for most of the nutrient content and yield parameters. The forages could be cut twice (middle and end of the rainy season) when the nutrient contents are optimal. For integrated and sustainable use of forages in the watershed, further study in improvement of quality and utilization is suggested. Keywords: Forage; Dry Matter; Watershed; Natural Pasture
Journal Article•
TL;DR: Both additive and non additive gene actions were important in controlling days to 50% flowering, pod length, percent oil content, plant height, length of main shoot, seed yield per plant, biological yield, harvest index, and number of primary and secondary branches in Brassica carinata A. Braun.
Abstract: This study was conducted to estimate general and specific combining ability variances and potential heterosis in Brassica carinata A. Braun. Seven parental lines along with their 21 F1 crosses were planted in 2009/2010 and 2010/2011 at the G.B. Pant University Crop Research Centre, India using randomized block design with three replications in three rows for each accession per replication. Data recorded for 14 traits were subjected to the Griffing (1956) method II model I genetic analysis and estimate of heterosis. Standard heterosis of the crop parameters ranged from -8.22% for harvest index to 191.57% for number of pods per plant, while for seed yield per plant it ranged from -16.64 to 66.09%. Both additive and non additive gene actions were important in controlling days to 50% flowering, pod length, percent oil content, plant height, length of main shoot, seed yield per plant, biological yield, harvest index, and number of primary and secondary branches. Additive gene action was important for the expression of days to 90% maturity, seeds per pod and thousand seeds weight. Non-additive gene actions were important in controlling the expression of pods per plant
Journal Article•
TL;DR: The results showed distant parents in origin produce hybrids with higher standard heterosis in magnitude in a greater number of hybrids, and revealed the possibility of improving target region coffee quality through selection of parents on the basis of their leaf tip color for crossing regardless of their origin.
Abstract: This study was conducted to generate information on the effects of distant parents in origin, growth habit and leaf tip color on the magnitude of standard heterosis (SH) in Coffea arabica L. hybrids for yield and quality in 34 hybrids generated from 15 parents in Ethiopia. The results showed distant parents in origin produce hybrids with higher standard heterosis in magnitude in a greater number of hybrids. It was observed that 16 and 11 out of 17 between and within region hybrids exhibited standard heterosis ranging from 0.8 to 52.8% and from 3.58 to 44.95%, respectively, for fresh cherry yield. In comparison, hybrids obtained from crossing distant parents in all factors (origin, growth habit and leaf tip color) registered the highest magnitude of SH, which ranged from 21.05% (clean coffee yield) to 52.80% (fresh cherry yield) with mean SH of 36.64 and 28.95% for fresh cherry and clean coffee yield, respectively. For coffee quality parameters, the effect of parents’ leaf tip color on the magnitude of heterosis was observed to be more important than the parents’ geographical origin. Five out of six hybrids having both parents green leaf tip color (Kaffa x Kaffa and Kaffa x Sidamo) exhibited SH of 1 to 16% for the overall coffee quality. These hybrids also exhibited positive and significant SH (14 to 33%) for 6 out of 8 coffee quality parameters. The results of this study suggested the importance of including distant parents in all possible factors to produce greater number of high yielding hybrids with highest magnitude of standard heterosis in Ethiopia. The results further revealed the possibility of improving target region coffee quality through selection of parents on the basis of their leaf tip color for crossing regardless of their origin. Keywords : Distant Parents; Growth Habit; Hybrids; Leaf Tip Color; Origin; Standard Heterosis
TL;DR: Investigation of the relationships between aboveground plant biomass and species richness in three farming systems and four grazing management systems found that species richness was observed first to ascend along with biomass increment up to 1932 kg ha -1 and then declined at constant increase of biomass.
Abstract: The study was conducted in a montane grassland of Kokosa District, West Arsi Zone of Oromia Region, southern Ethiopia. The objective of the study was to investigate the relationships between aboveground plant biomass and species richness in three farming systems and four grazing management systems. A total of 180 quadrats (each 1 m x 1 m) were sampled in the three farming systems (dominant livestock- enset , enset -livestock and enset -livestock-cereal) and four grazing management systems (communal, enclosure, stream bank and benchmark). All the farming system and grazing management have different management practices. Plant species composition and aboveground plant biomass at different sites were quantified. Altogether 50 plant species (34 grasses, 4 legumes, 3 sedges and 9 forbs) were recorded in the montane grassland of Kokosa District. Even though the majority of the plant species share the different farming systems and grazing management practices, the highest number of species (39) was recorded in the enset -livestock farming system, whereas the lowest (33) species were recorded in the enset- livestock-cereal farming system when all the grazing management and farming systems were combined. Significantly, the highest species richness (4.9 species m -2 ) was recorded in the enclosure grazing management site whereas the lowest (3.4 species m -2 ) was recorded in the benchmark grazing site when all grazing sites and farming systems were combined. The relationship between species richness and biomass was detected in the montane grassland. There was significant difference (P ≤ 0.05) in species richness for a combination analysis of farming system by grazing management system of the montane grassland. The highest biomass was recorded in the benchmark grazing management sites while the lowest was recorded in the communal grazing sites. On the contrary, maximum species richness was found in the enclosure grazing management sites which had intermediate biomass yield and the lowest species richness was recorded in the benchmark grazing areas with the maximum biomass records. Thus, species richness was observed first to ascend along with biomass increment up to 1932 kg ha -1 and then declined at constant increase of biomass. An increase in biomass in the benchmark grazing sites was not accompanied by an increase in species richness suggesting the dominance of few species in these sites. The rationale behind this might be due to the competitive exclusion of the less competent species from the community at peak biomass production. Keywords: Biomass; Farming System; Grazing Management; Montane Grassland; Species Richness
Journal Article•
TL;DR: In this paper, the authors evaluated the variation in morphological traits of hexaploid wheat accessions across different regions and altitudes using frequency and Shannon-Weaver diversity index.
Abstract: Variable climatic factors, i.e. rainfall, relative humidity and temperatures across regions and altitudes resulted in a high genetic diversity in wheat species. The objective of the study was to evaluate the variation in morphological traits of hexaploid wheat accessions across different regions and altitudes using frequency and Shannon-Weaver diversity index. Polymorphism was observed in all traits with the exception of glume hairiness. More than 85% of the collections contained medium to large and plump seed types. Over all accessions diversity indices ranged from 0.03 for glume hairiness to 0.85 for beak length. Average regional diversity indices for all traits ranged from 0.47 for Group II (accessions from Gojam and Gonder) to 0.57 for Group III (accessions from Shewa). Traits diversity in altitude ranged from 0.44 for altitudes > 2800 masl to 0.63 for altitudes . 2200 masl. Within regions and within altitudes diversity accounted for 89% and 93% of the total variation, respectively. Hence, emphasis should be given to have more samples within one and the same region and range of altitudes to capture more genetic diversity and use it as breeding material for variety improvement programmes. Keywords : Ethiopia; Phenotypic Diversity; Triticum aestivum
TL;DR: It appears that geographical origin has no or little effect in determining the pattern of genetic diversity observed among the accessions, and the greatest variability among accessions was observed for characters such as biomass, ear weight and grain weight, which highly dictated the differentiation of accessions into clusters.
Abstract: Finger millet ( Eleusine coracana L.) is one of the important indigenous crops of Africa. The productivity of the crop, however, is very low owing to several factors including the inherent low-yielding potential of the cultivars. Information on genetic diversity among the available germplasm collections is very useful for breeding programs utilizing the materials as germplasm source. An experiment was conducted at Arsi Negele and Bako, Ethiopia, in 2000 main season to study the extent of genetic variability present among sixty-four germplasm accessions collected from the Eastern and Southern Africa and maintained at the Institute of Biodiversity Conservation, Ethiopia. The accessions were planted in three replications at both locations using a randomized complete block design. Data were recorded on eleven morpho-agronomic characters. Analysis of variance at both locations showed that the mean squares due to genotype and genotype by location interaction were significant (P ≤ 0.05) in almost all the cases. Broad-sense heritability values at each location and combined over locations were higher (> 80%) for most of the characters, indicating the existence of a wealth of genetic variability among the population for most of the morpho-agronomic traits. Cluster analysis grouped the accessions into four clusters of different sizes. It appears that geographical origin has no or little effect in determining the pattern of genetic diversity observed among the accessions. The greatest variability among accessions was observed for characters such as biomass, ear weight and grain weight, which highly dictated the differentiation of accessions into clusters. Genetic distances between cluster IV and all other clusters were significant indicating that crosses between selection from members of cluster IV with the rest of the clusters may provide desirable recombinant in breeding efforts. Parental selection should also be based on the existence of optimum level of the desired traits. Keywords: Eleusine coracana ; Germplasm Collections; Genetic Diversity; Geographic Origin
TL;DR: Kulumsa-1 was selected, developed and released by Kulumsa Agricultural Research Center for major linseed growing areas of Ethiopia and proved to be more resistant to powdery mildew and pasmo diseases than the checks.
Abstract: Kulumsa-1 is a common name for the linseed variety developed through selection from the variety known as Chilallo, the linseed variety released nationally in 1992, which is a population. Kulumsa-1 was selected, developed and released by Kulumsa Agricultural Research Center for major linseed growing areas of Ethiopia. Specifically, it was tested at Kulumsa, Bekoji, Asasa, Sinana, Holetta, Adet and Areka for three years (2002/2003-2004/2005) and verified in 2005/2006 on these locations for official release. Consequently, Kulumsa-1 consistently produced better mean seed yield than the standard check ( Belay-96 ) and the local check over three years. Likewise, it proved to be more resistant to powdery mildew ( Oidium sp .) and pasmo ( Septoria linicola ) diseases than the checks. The results of the multi-location trials revealed that Kulumsa-1 was superior in seed yield performance across years and locations. Besides, it is stable variety based upon the two stability parameters, deviation from regression (S 2 di ) and coefficient of determination (R 2 i ). Keywords: Edible Oil; Kulumsa-1 ; Linseed; Variety Registration
TL;DR: It was concluded that two cycles of S 1 recurrent selection have brought significant genetic improvement in grain yield and major agronomic traits in UCB and was fully released and recommended for commercial production in the mid-altitude agro-ecologies of Jimma and Illu Ababora Zones, and similar areas in the south-western areas of Ethiopia.
Abstract: S 1 recurrent selection was carried out to improve grain yield, plant height, ear placement, resistance to lodging and other desirable agronomic traits in Ukiriguru composite B (UCB) maize variety. This paper presents the genetic gain and progress made in improving these traits through two cycles of selection. Three hundred and sixty, and 254 S 1 families were evaluated in three environments and 36 and 25 families were selected following 10% selection intensity during the first (C 1 ) and the second (C 2 ) cycles, respectively. The selected families were recombined in isolated half-sib recombination blocks using remnant seeds. The progress made through selection was determined by evaluating the parent population (UCB C0), the first (UCB S 1 C 1 ) and the second (UCB S 1 C 2 ) selection cycles in six environments in a randomized complete block design in four replications. Commercial open-pollinated and hybrid varieties were included as checks. UCB S 1 C 2 produced mean grain yield of 8.7 t ha -1 and had a significant (P < 0.01) genetic gain of 30% (2.0 t ha -1 ) with mean gain of 15.0% (1.0 t ha -1 ) cycle -1 . The selection also resulted in short plant height and low ear placement with significant (P < 0.01) genetic gain of 9.6% (30.8 cm) and 19.6% (39.6 cm), respectively, and superiority in tolerance to diseases and resistance to lodging. Still selection had significant (P < 0.01) grain yield benefit of 35.0% (3.1 t ha -1 ) and 29.3% (2.6 t ha -1 ) relative to Gibe Composite 1 and Kuleni, respectively, and showed comparable yield potential with commercial hybrids, BH660 and BH670. It was concluded that two cycles of S 1 recurrent selection have brought significant genetic improvement in grain yield and major agronomic traits in UCB. Hence UCB S 1 C 2 was fully released and recommended for commercial production in the mid-altitude (1600-1800 masl) agro-ecologies of Jimma and Illu Ababora Zones, and similar areas in the south-western areas of Ethiopia. After release, it was named as ‘Morka’ meaning ‘competent’, to express its yield potential which is comparable to the yield potential of popular hybrid varieties in the zones. Keywords: Genetic Gain; Morka ; Recurrent Selection; Response to Selection; Ukiriguru Composite B
Journal Article•
TL;DR: In this paper, the authors studied the grain quality, proximate composition, gluten isolation and characterization of three bread wheat varieties namely Pavon 76, HAR 2501 and HAR 2536 grown in Arsi and Bale areas of Ethiopia.
Abstract: The aim of this research was to study the grain quality, proximate composition, gluten isolation and characterization of three bread wheat varieties namely Pavon 76, HAR 2501 and HAR 2536 grown in Arsi and Bale areas of Ethiopia. The wheat varieties had a protein content of 10.60, 11.53 and 10.70% while the wet gluten content of their flours were 29.87, 34.6% and 29.83% for Pavon 76, HAR 2501 and HAR 2536; respectively. The yield (extraction rate) of gluten powder was 10.30% from Pavon 76, 11.34% from HAR 2501 and 9.62% from HAR 2536; respectively. The farinographic performance analysis showed that water absorption corrected to 14% moisture basis was 60.1% for Pavon 76, 58.6% for HAR 2501 and 64.2% for HAR 2536. The protein content of gluten powder on dry matter basis extracted from the three varieties were 82.17% from Pavon 76, 86.21% from HAR 2501 and 80.93% HAR 2536. The grain quality and gluten powder characteristics of the three wheat varieties were acceptable and can be utilized for gluten powder production to be incorporated in pasta, noodle, bread and other food products. Keywords : Bread Wheat; Farinographic Qualities; Gluten Powder; Grain Quality
TL;DR: In this paper, the effect of repeated tillage and weed control methods on weed infestation and grain yield of wheat was evaluated at Arsi Negelle, southern Ethiopia, from 1993 to 1995 cropping seasons.
Abstract: The effect of repeated tillage and weed control methods on weed infestation and grain yield of wheat was evaluated at Arsi Negelle, southern Ethiopia, from 1993 to 1995 cropping seasons. Five tillage practices (zero, one, two, three and four times tillage) as main plot and four weed control methods (Duplosan sprayed at 2.5 l ha-1, Duplosan plus one hand weeding at 30 days after emergence (DAE); one and two hand weeding at 30, and 30 and 60 DAE, respectively) as subplots were arranged in split plot design with three replications. Broadleaf weeds comprised 73% of the total weed population in the experimental plots. Effect of tillage and weed control was dependent on year. Increased frequency of tillage reduced weed infestation (r = -0.34**) and increased plant height (r = 0.42**), biomass (r = 0.51**) and grain (r = 0.43**) yields of wheat. Weed density in zero-till and three times plowing was 78 and 35%, respectively, more than four times. Weed density in plots treated with Duplosan alone and its combination with 1HW was 38.4 and 19.5% more, respectively, while it was 5.9% less with 1HW alone compared with 2HW. About 33 and 26% of the total variations in weed infestation were due to tillage and weed control methods, respectively. Grain yield reduction in zero-till and three times plowing was 59 and 21%, respectively, compared with four times’ plowing. Twice weeding reduced weed population by 28% and increased wheat grain yield by 3.3% compared to Duplosan alone. Fifty five, 95 and 43% of the total variations in wheat grain yield in 1993, 1994, and 1995, respectively, were attributed to the regression. Frequent tillage reduced weed infestation and increased grain yield by 11 and 21.9%, respectively, compared to weed control. Generally, four times plowing significantly reduced weed infestation and increased wheat grain yield with considerable economic benefit.
Journal Article•
TL;DR: Although it is not stable for tuber yield, Bubu exhibited high sensitivity to environmental change and a better adaptation to high-yielding environments and the taste of boiled tubers was rated as very good by the farmers.
Abstract: An improved potato (Solanum tuberosum L.) variety, Bubu (CIP-384321-3), is developed by the Root and Tuber Crops Improvement Program of the Haramaya University, Ethiopia and approved by the National Variety Release Committee in 2011. The performance of the variety was evaluated at five locations in the eastern part of Ethiopia from 2006 to 2009. The mean performance of Bubu over locations and years indicated that it gave 11.5% more tuber yield over the standard checks (Harchassa and Gabissa). Although it is not stable for tuber yield, it exhibited high sensitivity to environmental change and a better adaptation to high-yielding environments. Bubu is a medium maturing variety with tuber size and shape preferred by the farmers. The taste of boiled tubers was rated as very good by the farmers. The variety is recommended for the highlands of Eastern and Western Hararghe Zones with an altitude ranging from 1650-2330 meter above sea level. Keywords : Bubu; Hararghe; Potato; Stability; Tuber Yield
Journal Article•
TL;DR: In this paper, a direct questionnaire survey involving 743 respondents from seven major cities in Ethiopia was performed to explore consumers' attitudes and market potential for a fermented dairy product-kefir, which was also intended to produce experimental kefir and undertake nutritional, microbial, texture and viscosity analyses as well as sensory quality evaluation.
Abstract: This study was conducted to explore consumers’ attitudes and market potential for a fermented dairy product-kefir. It was also intended to produce experimental kefir and undertake nutritional, microbial, texture and viscosity analyses as well as sensory quality evaluation. In order to meet the objectives, a direct questionnaire survey involving 743 respondents from seven major cities in Ethiopia was performed. The results revealed that the respondents indicated very high interest in kefir and are willing to purchase in case of availability in the market suggesting existence of an opportunity for dairy processing industries in Ethiopia to introduce kefir to the market and meeting the increasing demand for diversified dairy products in urban areas. In an attempt to meet the second objective, experimental kefir was produced under laboratory scale at the Food Engineering Laboratory of Addis Ababa Institute of Technology, Addis Ababa University and then after the end product was analyzed for proximate chemical composition, microbes, texture and viscosity. Added to this, evaluation for sensory qualities by panelists selected from consumers group and people who are familiar with quality attributes of dairy products was performed. The results revealed that kefir can be processed with the existing technologies in the Ethiopian context and has good nutritional composition and the processing technology provided microbiologically non-hazardous end product. Keywords : Consumer Attitudes; Dairy Diversification; Kefir; Market Potential; Microbiological Analysis
TL;DR: Three vetch varieties named as Gebisa, Lalisa and Abdeta were selected and developed in 2010 by the Sinana Agricultural Research Center for the Bale highlands and similar agro-ecologies and performed better in yield and important agronomic parameters as compared to their respective checks.
Abstract: Three vetch varieties named as Gebisa (common vetch variety with Acc. No. 62632), Lalisa (woolly pod vetch variety with Acc. No. 6792DLot-2) and Abdeta (narbon vetch variety with Acc. No. 118) were selected and developed in 2010 by the Sinana Agricultural Research Center for the Bale highlands and similar agro-ecologies. These varieties were tested for 12 environments, at four locations (Sinana, Robe, Dinsho and Agarfa) for three years (2006/2007-2008/2009) to see their adaptability to soil and climate, to evaluate for yield and other agronomic parameters. Due to their superior performances, the three vetch varieties were selected and verified at four locations during the Bona 2009/2010 cropping season and released for production. Gebisa is characterized by growth habit of straggling or semi-climbing. The growth habit of Lalisa is crumbling and climbing whereas that of Abdeta is erect/upright growth habit striking similar to faba bean. The seed colors of Gebisa, Lalisa and Abdeta are pink, black and reddish brown, respectively. They performed better in yield and important agronomic parameters as compared to their respective checks. They were also better resistant to major diseases and have good nutritional quality. Moreover, the varieties were well adapted to the highland agro-ecologies of Bale. The introduction of these newly released forage varieties could contribute in mitigating the scarce feed resource conditions in the small-scale farmers of the highland agro-ecologies.
TL;DR: It can be concluded that Lantana camara, Eucalyptus globules and Pyretherum flowers could be used to protect seed potatoes from potato tuber moth damage in diffused light storage in Bako Agricultural Research Center.
Abstract: Lantana camara, Eucalyptus globulus, Tagetus minuta, Pyretherum flowers and Azadiractha indica, were evaluated against potato tuber moth damage including two checks (Diazinon 60% EC and untreated check) at Bako Agricultural Research Center in 2003/2004 and 2004/2005 cropping seasons. A total of twenty-one huts were constructed from locally available materials. Inside each store, 1m2 bed storage sacks were constructed 65 cm above the ground. Six hundred and fifty (650) numbers of potato tubers were stored on the bed of each hut in two layers one over the other. The treatments were arranged in a randomized complete block design with three replications. Plant powder and Diazinon 60% EC were applied at the rate of 50 g/bed and 3.5 ml/bed respectively at two months interval. The treatments that showed promising effects were further advanced on a large bed (2 m x 3 m) without replication. Data was collected for the number of potatoes infested and damaged by potato tuber moth, and number of potatoes damaged by some factors other than potato tuber moth. Evaluations were made at an interval of fifteen days for seven consecutive months. Analysis of variance showed that there were significant differences among the treatments. Number of potatoes infested and damaged by potato tuber moth was significantly (P < 0.05) lower in Lantana camara, Eucalyptus globulus and Pyretherum flowers than the other treatments. Percent of potatoes infested and damaged by potato tuber moth on a large bed were lower for Lantana camara, Eucalyptus globules, Pyretherum flowers and Diazinon , while higher for the other treatments. Percent of potatoes damaged by diseases and other factors were significantly high in all treatments and non-significant differences were observed among them. From this study it can be conclude that Lantana camara, Eucalyptus globules and Pyretherum flowers could be used to protect seed potatoes from potato tuber moth damage in diffused light storage.
Journal Article•
TL;DR: Obsa and Dicho were by far greater than the standard check, Abasena, in terms of grain yield, disease resistance, tolerant to shattering and non-lodging, and the average oil contents and average oil yields.
Abstract: Obsa and Dicho are the names assigned after release for sesame ( Sesamum indicum L.) varieties with accession number Acc. EW004 and Acc. EW015, respectively. Both varieties were by far greater than the standard check, Abasena, in terms of grain yield (by 142.06 and 135.98%, respectively), disease resistance, tolerant to shattering and non-lodging. The average oil contents and average oil yields for Obsa and Dicho were 51.45 and 53.8%, and 498.4 and 503.9 kg ha-1, respectively. Keywords : Dicho; Obsa; Sesamum indicum ; Variety Registration
TL;DR: In this article, the authors proposed a method to perform two-dimensional forward and inverse gravity data modeling that can be used to interpret the subsurface geologic structure by assigning variable densities to the different prisms.
Abstract: The implementation of a tool to perform two-dimensional forward and inverse gravity data modeling that can be used to interpret the subsurface geologic structure is presented in this article. The approach subdivides the subsurface into regular shape prisms and reconstructs the geologic structures by assigning variable densities to the different prisms. To obtain the subsurface density distribution one will first use the forward modeling tool and generate a plausible model of the subsurface to use it later as the initial model in the inversion program. The inversion tool makes use of the compact gravity data inversion algorithm to iteratively model the subsurface. The advantage of this approach is that the desired geological characteristics are automatically incorporated into the model with a minimum subjective judgment on the part of the interpreter. The method was demonstrated by inversion of synthetic and real data. The synthetic data is generated from a two–dimensional model consisting of a regular array of identical blocks whose densities can be individually specified. While testing the application on real data that were collected around Filwoha (Addis Ababa), the resulting subsurface structural model produced gravity data that matched with the observed gravity data, within a predefined acceptable root mean square error.