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Background: Shrinking of rangelands/natural grasslands has led to various inter-communal conflicts and loss of livelihoods among pastoralists in Ethiopia. Restoring the rangelands is an important step to be taken to alleviate the problem. Various aggressively spreading invasive weed species are threatening the existence and sustainability of rangelands/natural grasslands. In addition, moisture stress is a major hindrance to any efforts made to restore the rangeland/natural grasslands. The role of Arbuscular mycorrhizal fungi (AMF) in establishing plant seedlings and regenerating natural grasslands through enhancing water and nutrient uptake is well documented. Objective: The main objective of this study was to investigate the influence of land use and soil types on abundance and diversity of AMF in semi-arid rangeland areas of the Middle Awash Basin in the Ethiopian Rift Valley region. Materials and Methods: Representative rhizosphere soil samples were taken from different land use types (cultivated, open grassland, shrubland, and prosopis-invaded land) and used to assess AMF diversity and abundance in relation to soil physical and chemical characteristics. The same soil samples were used to establish trap cultures for spore formation and colonization assessment. Results: In the present study, morphological analysis from field soils and trap cultures revealed 16 distinct morphotypes belonging to 10 genera including Glomus (3), Claroideoglomus (3), Funneliformis (2), Rhizophagus (2) and one from each of Acaulospora, Entrophospora, Gigaspora, Sclerocystis, Scutellospora and Septoglomus. Spore abundance significantly varied, ranging from 265–481 and 319–488 (100-g-1) in trap culture and field soil samples, respectively. Grassland soil samples displayed the highest spore abundance, followed by soil samples from shrubland and cultivated fields, with the lowest records from prosopis-invaded land use type. However, sporulation and level of colonization were higher in cultivated lands, which have lower spore abundance than open grass and shrublands. Conclusion: The results of the study indicated that converting land use from traditionally managed rangelands/grazing system to cultivated lands leads to encroachment by Prosopis spp. on the lands and significantly reduces AMF spore abundance, diversity, and percentage root colonization. Thus, the ever-expanding encroachment of prosopis on the open grasslands and croplands around the Awash River necessitates implementing strict measures to decrease pressure on the soil biota underneath., East African Journal of Sciences, Vol. 15 No. 1 (2021): East African Journal of Sciences

There are growing demands for high quality coffee in the international market today. This has given coffee producing countries an impetus to increase the quality as well as the quantity of coffee they produce. For improving coffee quality and meet market demands, attention has been given to exploring genetic and environmental factors as well as agronomic and other coffee management practices. However, little information is available in Ethiopia regarding effect of environmental factors such as altitude and coffee management practices such as shading and processing methods on the quality and biochemical composition of green coffee beans. This problem has constrained efforts being made in the country to further exploit the growing demands for quality coffees in the international market. Therefore, a study was conducted during the 2010/11 main cropping season to determine coffee quality attributes as a function of altitude, shade, and processing methods. Red ripe coffee cherries were handpicked from three coffee farms in south-western Ethiopia located at altitudes of 1150, 1545 and 1802 meters above sea level, which represented lowland, midland, and highland coffee growing areas, respectively. The coffee cherries were obtained from both shaded and unshaded farms in each of the aforementioned coffee growing areas. The green coffee beans were subjected to both wet and dry coffee processing methods. A total of 36 coded samples (18 washed and 18 unwashed green coffee beans) with a moisture content of about 10.5% were subjected to cup and laboratory tests. Coffee cup test was done according to the procedure of Ethiopian Commodity Exchange (ECX) using 36 green coffee bean samples. Contents of caffeine, trigonelline, and chlorogenic acids were determined using HPLC/THERMO. Sucrose was determined using GC VARIAN 3800. Univariate analysis of variance and stepwise multiple regression analyses were conducted using SPSS 16 v2. The results revealed that coffee beans originating from the high altitude had significantly higher first grade and Q1 grade points than coffee beans originating from the low and middle altitudes. Unshaded and unwashed coffee grade was better than the washed and shaded coffee grade. Caffeine content of the beans was affected neither by altitude, shading, nor by the processing method. Shading affected only the content of bean caffeoylferuloylquinic acids (CFQA), which was found to be significantly higher for the unshaded coffee bean samples than the shaded coffee bean samples. Contents of 4,5-dicaffeoylquinic acid (4,5-DCQA), feruloylquinic acids (FQA), and total chlorogenic acid (TCGA) were significantly higher for coffee beans originating from the low and middle altitudes than those originating from the high altitude. Similarly, coffee beans that originated from the low altitude had significantly higher contents of 3,4- dicaffeoylquinic acid (3,4-DCQA), caffeoylferuloylquinic acids (CFQA), and trigonelline than coffee beans that originated from the high altitude. However, coffee beans that originated from the high and middle altitudes had significantly higher contents of chlorogenic acids, i.e., 3-caffeoylquinic (3-CQA) and 5-caffeoylquinic acid (5-CQA) than coffee beans that originated from the low altitude. The sucrose content of coffee beans that originated from the low latitude was significantly higher than the sucrose content of coffee beans that originated from middle and high altitudes. Washed coffee beans contained significantly higher amounts of dicaffeoylquinic acid (4,5-DCQA), caffeoylquinic acid (5-CQA), chlorogenic acid (TCGA), and trigonelline than unwashed coffee beans. However, unwashed coffee beans had significantly higher 3-caffeoylquinic (3-CQA) and caffeoylferuloylquinic acids (CFQA) contents than washed coffee beans. Unwashed coffee beans had higher values for primary defect, secondary defect, odour, total-point and preliminary grade whilst washed coffee beans had better scores for acidity, body, and flavour attributes, which distinctly influence the ultimate taste profile of coffee origins. It is concluded that coffee bean quality attributes and contents of the associated chlorogenic acids improved in response to increased altitude under both shaded and unshaded conditions regardless of the type of processing method used. The results imply that growing coffee plants in the highlands and midlands rather than in the lowlands as well as washing the beans results in the production of coffee beans with high quality attributes and chlorogenic acid contents that could meet the rising international market demands for high cup quality., East African Journal of Sciences, Vol. 12 No. 2 (2018): East African Journal of Sciences

Low soil fertility and poor soil fertility management practices constrain crop production in Ethiopia. Diagnosing soil fertility problems and characterizing soils are a prerequisite for formulating appropriate soil fertility management practices. However, most soil fertility problems in Ethiopia are not diagnosed, and the soils are not characterized. This invariably leads to lack of documented information for judicious application of soil ameliorative measures to increase crop yields. This study was, therefore, aimed at characterizing soil of Jijiga Plain in the Somali Regional State of Ethiopia on which wheat is commonly grown. The study was conducted during the main cropping season of 2012/2013. The study area was stratified in to three altitude categories 1650 - 1700, 1750 - 1800, 1850 - 1900 meters above sea level prior to sampling. Then, a total of 3 x 2 x 30 x 3 = 540 disturbed soil samples were collected from the surface (0-15 cm) and subsurface (15-30 cm) layers across the altitude categories. The samples were composited treatment-wise to 3 x 6 = 18 sub-samples. The composite soil sub-samples were analyzed for selected soil physico-chemical properties. The data were analyzed using descriptive statistics. The results indicated that both the surface and subsurface soils are clayey in texture. The pH of the soil at the layer of 0 - 30 cm ranged from 8.37 to 8.82 and is rated as strongly alkaline. The exchangeable Ca2+ contents of the soil at the surface and subsurface soil layers were 24.52 and 30.52 cmol+/kg, respectively, which is rated as very high in both soil layers; the exchangeable Mg2+ content is 7.36 cmol+/kg in the surface soil layer, which is rated as high, but 10.21 cmol+/kg in the sub-surface soil layers, which is rated as very high. The exchangeable Na+ content of the soil ranges from 0.33 to 2.16 cmol+/kg, which is rated as medium to high. The exchangeable K+ contents of the surface and subsurface soil layers are 1.1 and 1.4 cmol+/kg, respectively, which are rated as high and very high in the surface and sub-surface soil layers. The cation exchange capacity of the soil ranges from 37.17 to 40.49 cmol+/kg, which is rated as high to very high. The percent base saturation in the surface soil is 89.63% whereas that in the sub-surface soil is 109.23%, which is rated as very high. The contents of soil organic carbon (1.81%) and total nitrogen (0.13%) in the surface soil layer were found to be medium whereas those of the sub-surface soil layer were found to be low. However, the available phosphorus contents of both the surface (2.4 mg kg-1 soil) and sub-surface (1.87 mg kg-1 soil) soil layers were found to be very low. It could, thus, be concluded that, the soil of the study area is characterized by strong alkalinity with high contents soluble calcium carbonate, very low content of plant-available phosphorus, and medium contents of soil organic matter as well as total nitrogen. However, the texture and other chemical properties of the soil do not appear to limit crop production. Therefore, there is a need to take ameliorative measures aimed at lowering the pH and increasing availability of soil phosphorus, soil organic carbon, and total nitrogen to improve wheat and other crop yields in the study area., East African Journal of Sciences, Vol. 12 No. 1 (2018): East African Journal of Sciences

Sorghum (Sorghum bicolor L. Moench) is one of the leading drought-tolerant crops often used to mitigate droughts for meeting household food security in Ethiopia. However, poor stand establishment is one of the major factors that constrain productivity of the crop. Poor stand establishment of sorghum is affected by certain conditions after sowing, which have a large influence on speed of germination and seedling emergence that determine successful establishment of the crop under adverse growing conditions. Therefore, an experiment was conducted to elucidate the effect of seed priming on germination and seedling vigor of seeds of six sorghum varieties under a laboratory condition. The experiment was conducted during the 2014 main cropping season on the campus of Haramaya University. The treatments consisted of six sorghum varieties (Abshir, Dekeba, Macia, Meko-1, Melkam and Teshale), three priming media (water, 9 g urea L-1, and 0.2 g ZnSO4 L-1) and five priming durations (0, 5, 10, 15 and 20 h). The experiment was laid out as a completely randomized design (CRD) in a factorial arrangement and replicated four times per treatment. The results showed significant (P < 0.05) main effects of the treatments and interactions between priming media and duration, and variety and priming duration for all the traits studied. The highest improvements in final germination percentage (FGP) (6%), germination-index (GI) (8.4%), germination time (MGT) (4%), emergence-percentage (EP) (20%), seedling-length (SL) (12.5%), seedling-dry-weight (SDW) (26.5%), seedling-vigor-index-1 (SVI-1) (33.1%) and seedling-vigor-index-2 (SVI-2) (49.7%) were recorded in response to seed priming using ZnSO4 followed by priming with Urea and water for 10 h priming over the unprimed seeds (control treatment). Likewise, the highest varietal performance was recorded for Melkam followed by Teshale and Dekeba with 10 h priming. The reduction in MGT and the increments in FGP, GI, EP, SL, SDW, SVI-1, and SVI-2 due to variety Melkam with 10 h priming respectively were 5.7, 7.7, 3.8, 22.7, 13.6, 30.2, 38.1, and 58.8% over the unprimed seeds. Therefore, the priming sorghum seeds for 10 hours with ZnSO4 followed by Urea and water significantly improved germination, seedling growth, and seedling vigor under laboratory conditions, implying that the practice priming seeds with each of the media based on availability and affordability could be used by farmers to enhance sorghum seed germination, field stand establishment, and yield., East African Journal of Sciences, Vol. 12 No. 1 (2018): East African Journal of Sciences

Potato (Solanum tuberosum L.) is an important food security and cash crop in Ethiopia. However, the yield of the crop is low in the country due to a number of factors among which poor soil fertility management is a major one. Therefore, a field experiment was conducted on the main campus of Haramaya University in the 2009/10 cropping season to elucidate the effect of mineral nitrogen and potassium fertilizers on growth and tuber production of the crop. The treatments consisted of five rates of nitrogen (0, 50,100,150, and 200 kg N ha-1) and three rates of potassium (0, 100, and 200 kg K2O ha-1). The experiment was laid out as a randomized complete block design in a factorial arrangement and replicated three times per treatment. The results of the experiment revealed that nitrogen had significant main effects on all parameters except tuber specific gravity whilst potassium did not influence any of the parameters studied. The maximum marketable ware potato tuber yield (21.4 t ha-1) was obtained in response to the application of 100 kg N ha-1. However, the highest yield (12.7 t ha-1) and number (5.2 tubers hill-1) of medium-sized tubers, which are appropriate for planting as seed, were attained at the rate of 200 kg N ha-1. Thus, it could be concluded that the rate of nitrogen fertilizer required to enhance seed tuber production was found to be higher than that required to optimize ware potato production, and potassium application was not necessary to produce the crop. Â Keywords: Soil properties; Solanum Tuberosum L.; Tuber number; Tuber Size Distribution; Tuber Yield Â, East African Journal of Sciences, Vol. 8 No. 2 (2014): East African Journal of Sciences Volume (8) N0 2

The dangerous tomato leaf miner pest (Tuta absoluta), which was reported to have crossed into Ethiopia via the Sudan in 2012, has scared tomato producing farmers across the country. Therefore, a study was conducted using pheromone traps to elucidate the occurrence of the insect pest and to monitor its population build-up in eastern Ethiopia. Pheromone traps were placed in the greenhouse for two months (February - March 2014) and in the open-field tomato crops for one week to monitor the tomato leaf miner moth. Examination of the traps was carried out at seven-day intervals, and the dispenser was replaced every 15 days. There was a linear increment in the number of captured moths during the surveyed time both in the greenhouse and in the open-field tomato crops. The number of moths captured ranged from 27 - 47 and 103 - 255 in the open-field and in the greenhouse, respectively. Thus, based on the examination of the traps, the presence of Tuta absoluta was confirmed for the first time in eastern Ethiopia. In the greenhouse, the larvae of the tomato leaf miner inflicted a heavy damage on young tomato plants. As a result, young plants died before flowering. The results of the study have revealed that the pest is likely to cause heavy losses in tomato crops on an unprecedented scale in the Eastern part of the country. Therefore, monitoring the pest in all tomato producing regions of the country is a vital step towards early detection and decision-making to take integrated management measures against the outbreak of the infestation. Keywords: Larvae; Leaf Miner; Moth; Pheromone Trap; Population Dynamics; Pupation; Tomato;Â Tuta absoluta, East African Journal of Sciences, Vol. 8 No. 1 (2014): East African Journal of Sciences Vol (8) No 1

Chelenko I (G-147-2/94) garlic variety was released in 2013 for mid to high altitude garlic growing areas of eastern and western Hararghe Zones in Ethiopia. The variety was developed through selection from a collection of 252 cultivars/genotypes obtained from Debre-Zeit Agricultural Research Centre in central Ethiopia and Haramaya district in the eastern part of the country. The released garlic variety was shown to have superior yielding ability and other desirable traits over the standard check ‘Tsedey’ cultivar. Moreover, the yield of the new variety was found to be stable over seasons and locations in the eastern highlands of the country. Therefore, the variety could be cultivated sustainably by smallholder farmers in the area and other places with similar. Keywords: Bulb yield; Bulb weight; Stability test; Yield trials; Tsedey variety; Haramaya, East African Journal of Sciences, Vol. 8 No. 1 (2014): East African Journal of Sciences Vol (8) No 1

Haramaya I is the common name for the carrot (Daucus carota L.) variety with the original collection name AUA-108. The variety was developed through selection in the eastern highlands of Ethiopia. It was selected from 64 carrot genotypes collected from Haramaya woreda (district). The genotypes were maintained by farmers for a long period of time through an open-pollinated seed production system. The released carrot variety was found to be superior in marketable and total root yields and other desirable traits to the commercial Nantes variety, which was used as the standard check, and a famers’ open pollinated cultivar, which was used as a local check. Furthermore, this variety was superior to the Nantes variety and the farmers’ open-pollinated cultivar in terms of producing lower proportions of small-sized, cracked, forked, and hairy roots. The variety had also a margin of seed production potential amounting to 11.81% over the Nantes variety. Moreover, its root yield was found to be stable over seasons and locations. Therefore, it could be cultivated sustainably by smallholder farmers in the highlands of eastern Ethiopia and in other places with similar agroecology. Keywords: Core-size; Farmers’ cultivar; Nantes variety; Root yield; Seed yield; Yield stability, East African Journal of Sciences, Vol. 8 No. 1 (2014): East African Journal of Sciences Vol (8) No 1

Coffee beans with unique flavour profiles that are produced in special geographical microclimates are known as specialty coffees. Specialty coffees have high niche markets and fetch premium prices. Bean quality attributes of coffees produced in Ethiopia are often determined based on results of green coffee bean assessment done on arrivals in the central market by Ethiopian Commodity Exchange (ECX) Company. This research was, therefore, conducted with the objective of studying bean quality attributes of coffees originating from distinct major and minor coffee growing regions in Ethiopia and to explore the potential for finding new specialty coffees using the methods employed by the Ethiopian Commodity Exchange (ECX) company and those employed by Efico (Belgian coffee company). Seventy coffee bean samples were collected from 24 locations representing four traditional coffee producing regions in Ethiopia (south-western, southern, western, and eastern regions) and one newly emerging (north-western) region. Red coffee cherries were collected by handpicking. The green coffee beans were sun-dried, hulled, and subjected to sensory evaluation using the aforementioned methods. The results revealed that location did not have significant effects on all coffee quality attributes (cup cleanness, acidity, body, flavour, total point, preliminary grade, aroma, aftertaste, balance, perfumed, and overall attributes) except hundred bean weight and bean moisture content. The preliminary quality attributes for the unwashed coffee samples indicated that more than 65% of the samples attained the grade point 2. Most of the specialty coffee quality attributes attained high score points for all regions. Thus, based on the cup quality test done by Efico, about 75.7% of the samples fitted specialty grade 1, 18.6% fitted specialty grade 2 (premium grade), and 5.7% fitted specialty grade 3 (commercial grade). Furthermore, based on this test, four additional specialty coffees, namely, Kabo, Kossa, Gore, and Anfilo were identified. However, based on the cup quality test done by Ethiopian Commodity Exchange (ECX) company, only 7% of the samples fitted specialty grade 1, 40.1% specialty grade 2, and the remaining 48.6% fitted specialty grade 3 (commercial grade). In conclusion, the study revealed that almost all coffee beans originating from the distinct coffee growing geographical regions in the country have comparably superior bean quality attributes, with about 3/4th of the samples falling in the category of the specialty grade, and there is high potential to discover new specialty coffees in the regions using the Efico method rather than the ECX method. Â Keywords: Coffee origins; Coffee industry; Commercial grade; Cup quality test; Efico; Ethiopian Commodity Exchange (ECX); Specialty grade. Â, East African Journal of Sciences, Vol. 9 No. 2 (2015): East African Journal of Sciences Vol (9) No 2

Common bean (Phaseolus vulgaris L.) is an important food crop in Southern Ethiopia. However, the productivity of the crop is constrained by low soil fertility, particularly, phosphorus deficiency due to soil acidity. Therefore, field experiments were conducted to study the response of the crop to phosphorus application on Nitisols at Areka Agricultural Research Centre and Kokate research station in southern Ethiopia. The treatments consisted of three common bean cultivars (Hawassa-Dume, Nasir, and Red-Wolaita) and five phosphorus fertilizer rates (0, 23, 46, 69, and 92 kg P2O5 ha-1). The experiments were laid out as a randomized complete block design in a factorial arrangement and replicated three times per treatment. Analysis of the data indicated that the main effects of cultivar and phosphorus significantly (P < 0.05) influenced grain yield, number of pods per plant, seed weight, leaf area index, and above-ground dry biomass yield. The interaction effects of cultivar and phosphorus rate also significantly (P < 0.05) influenced the number of pods produced per plant at one location (Areka). At Areka, Nasir produced a significantly higher grain yield (2504.8kg ha-1) than Hawassa-Dume (1951 kg ha-1)and Red-Wolita(2198 kg ha-1). However, at Kokate, the grain yields of the three common bean cultivars were in statistical parity. Application of 69 and 23 kg P2O5 ha-1 resulted in the optimum grain yields of the crop at Areka (2498 kg ha-1) and Kokate (2219 kg ha-1), respectively. The results of the economic analysis indicated that cultivar Nasir produced the highest net benefit (15903 Birr ha-1). It could, thus, be concluded that cultivating Nasir at the rates of 69 P2O5 ha-1 at Areka and 23 kg P2O5 ha-1 at Kokate is most economical for smallholder farmers in the study area. Â Keywords: Biomass yield; Economic analysis; Grain yield; Phaseolus vulgaris L., East African Journal of Sciences, Vol. 9 No. 1 (2015): East African Journal of Sciences Vol (9) No 1

Although a number of improved wheat varieties have been released in Ethiopia, most farmers continue cultivating local varieties, which are low yielders and highly susceptible to diseases. The low adoption rate of improved wheat varieties is attributable mainly to farmers’ uncertainty about the expected benefit. Hence, on-farm trials consisting of three improved bread wheat varieties [Madda Walabu (HAR-1480), Digalu (HAR-3116), Danda’a], with one local variety as a control treatment, were conducted in Gurawa district in the highlands of eastern Ethiopia in the 2012 and 2013 cropping seasons. The objective of the trials was to evaluate the varieties for agronomic performances jointly with farmers’ research groups, researchers, and experts of agriculture in the region. Visual observation and data collection were done from planting up to harvesting. The visual assessment revealed that the growth performances of the improved varieties were superior to that of the local variety. The analysis of variance showed that the grain yields of the improved varieties significantly exceeded that of the local variety. Thus, the improved varieties Digalu, Danda’a, and Madda Walabu produced grain yields of 7432.5, 7193.7, 6502.5 kg ha-1, which exceeded the grain yield produced by the local variety (4835 kg ha-1) by about 54, 49, and 34%, respectively. Digalu and Danda’a were also unaffected by diseases compared to the other varieties. Eventually, the farmers selected Digalu and Danda’a, but rejected the improved Madda Walabu variety and the local one. It could be concluded that farmer participatory evaluation of existing improved wheat varieties is a vital pre-condition for adoption and scaling up of production of the crop in the region., East African Journal of Sciences, Vol. 7 No. 2 (2013): East African Journal of Sciences Vol (7) No 2

Aflatoxigenic fungal invasion and aflatoxin contamination of groundnut can occur during pre-harvest as well as post-harvest stages of production. Therefore, a field experiment was conducted in the 2010 cropping season with the objective of evaluating the effect of biofumigation and soil solarization on the population of Aspergillus spp. in treated soil, and to determine the effect of combined use of biofumigation and/or soil solarization and fungicide seed treatment on invasion of the crop by the fungus and its yield. The treatments consisted of solarization, biofumigation, solarization+ biofumigation and untreated control as a main plot and carbendazim, mancozeb, carbendazim + mancozeb fungicide seed treatment and untreated control as a sub-plot. The experiment was laid out as a split-plot design with three replications near Babile and Dire Dawa towns in eastern Ethiopia. Seeds of the Shulamit groundnut variety were used for the experiment The results revealed that fungal population densities in the soil were reduced drastically due to soil solarization. Integration of soil solarization + biofumigation with mancozeb + carbendazim seed treatment significantly reduced infections by A. flavus and A. parasiticus, and increased seed yield by 42.1% and 70.9% over the control treatments at Babile and Dire Dawa, respectively. Soil solarization + biofumigation in combination with fungicide seed treatments increased seed yield by up to 19.4- 42.1% at Babile and by 53-70.9% at Dire Dawa with decreased A. flavus and A. parasiticus seed infections. It could be concluded that seed treatment using carbendazim at the rate of 2 g kg-1 seed and mancozeb + carbendazim at the rate of (1+2) g kg-1 seed could be recommended as the best management option for controlling invasion of groundnut by A. flavus and for increasing the yield and quality of the crop in the region., East African Journal of Sciences, Vol. 7 No. 2 (2013): East African Journal of Sciences Vol (7) No 2