Arbuscular mycorrhizal association of indigenous agroforestry tree species and their infective potential with maize in the rift valley, Ethiopia

Tree species in agroforestry are important source of inoculum for companion agricultural crops. Agroforestry trees can serve as a source of Arbuscular mycorrhiza (AM) inoculants to intercropped annuals. We studied spore abundance, root colonization of Albizia gummifera (J.F. Gmel.) and Croton macrostachyus (Hochst Ex Del.) trees and their effect on colonization of maize. Soil and root samples were collected from field standing trees from under and outside the canopy of trees and maize crops in the main rainy season. The number of spore count was significantly higher under the canopy of A. gummifera (791/100 g of dry soil) and C. macrostachyus (877/100 g of dry soil) trees than outside the canopy (547 and 588/100 g of dry soil, respectively). The level of root colonization of C. macrostachyus (45 %) was higher than A. gummifera (41 %). Root colonization of maize crops grown under the canopy of A. gummifera and C. macrostachyus trees was significantly higher than outside the canopy (P < 0.001). Maize seedlings grown on non-sterilized soils collected under and outside the canopy of A. gummifera and C. macrostachyus trees recorded higher root colonization, plant height, shoot and root dry weight than grown on sterilized soils (P < 0.001). The percentage of AM colonized roots of Zea mays seedlings was significantly positively correlated with the number of spore counts for field soils. The rhizospheres of indigenous agroforestry perennial species are important source of inoculum for annuals. The integration of perennials and annuals in an agroforestry system enhances the maintenance of soil quality in the tropics.     

First confirmation of foot and mouth disease virus serotype SAT-1 in cattle and small ruminants in Ethiopia in 2007/08

The study was conducted in three regional states of Ethiopia: Amhara, Oromia, and the Southern Nations Nationalities and people regional state from August 2007 to April 2008 with the objective of identifying the foot and mouth disease virus (FMDV) serotypes circulating in the region. Two serotypes were recorded from epithelial tissue and oesophageal–pharyngeal (OP) fluid that were taken from outbreaks in study regions of Ethiopia. Serotype O FMDV was identified in Girar Jarso, Yabello, and Ankesha Guagusa districts while SAT-1 was isolated in Surma and Maji districts from tissue samples and this was the first report of the FMDV serotype in Ethiopia. Similarly, the OP fluid samples were found positive for SAT-1 FMDV in Maji and Surma districts.     

Micro-nutrient composition and end-user acceptable quality in potato in Ethiopia

Micronutrient deficiencies in diets, including iron (Fe) and zinc (Zn), are an important public health problem across population in Ethiopia. Potato is a modest source of dietary nutrients. The purpose of this study was to assess the mineral (Fe & Zn) composition of potato germplasm in Ethiopia and grower's willingness to try new potato types. The Fe and Zn contents were assessed in peeled tubers of popular farmer varieties, and newly introduced Andean diploid group Phureja accessions and improved tetraploid clones grown in multi-location trials. Grower's preferences for the new potato types was assessed using a participatory approach. Significant variations in mineral and tuber yield traits exist among the germplasm assessed and broad-sense heritability appears to be high for most traits measured, suggesting that progress through breeding can be made among these materials. However, the slightly negative correlation of tuber yield with Fe and Zn content and user appreciation traits found in this study suggests that progress in improving crops for yield and enhanced Fe and Zn concentrations with end-user acceptable quality will be challenging. The results from this study provide baseline information on Fe and Zn composition of many popular farmer varieties in Ethiopia and end-user preference criteria for evaluating new potato varieties that would help to orient the biofortification breeding to the conditions and preference of farmers.     

Labile, recalcitrant, and microbial carbon and nitrogen pools of a tallgrass prairie soil in the US Great Plains subjected to experimental warming and clipping

Carbon (C) and nitrogen (N) fluxes are largely controlled by the small but highly bio-reactive, labile pools of these elements in terrestrial soils, while long-term C and N storage is determined by the long-lived recalcitrant fractions. Changes in the size of these pools and redistribution among them in response to global warming may considerably affect the long-term terrestrial C and N storage. However, such changes have not been carefully examined in field warming experiments. This study used sulfuric acid hydrolysis to quantify changes in labile and recalcitrant C and N fractions of soil in a tallgrass prairie ecosystem that had been continuously warmed with or without clipping for about 2.5 years. Warming significantly increased labile C and N fractions in the unclipped plots, resulting in increments of 373 mg C kg⁻¹ dry soil and 15 mg N kg⁻¹ dry soil, over this period whilst clipping significantly decreased such concentrations in the warmed plots. Warming also significantly increased soil microbial biomass C and N in the unclipped plots, and increased ratios of soil microbial/labile C and N, indicating an increase in microbial C- and N-use efficiency. Recalcitrant and total C and N contents were not significantly affected by warming. For all measured pools, only labile and microbial biomass C fractions showed significant interactions between warming and clipping, indicating the dependence of the warming effects on clipping. Our results suggest that increased soil labile and microbial C and N fractions likely resulted indirectly from warming increases in plant biomass input, which may be larger than warming-enhanced decomposition of labile organic compounds.     

Increased grain protein content and its association with agronomic and end-use quality in two hard red spring wheat populations derived from Triticum turgidum L. var. dicoccoides

Suitability of wheat (Triticum aestivum L.) for many food products depends on its unique protein. Elevated grain protein content (GPC) and its quality influences the bread making properties of wheat. The objective of this study was to examine the association of elevated GPC with agronomic and end-use quality in two hard red spring wheat recombinant inbred (RI) populations derived from wild emmer (Triticum turgidum L. var. dicoccoides). The two hard red spring populations (ND683/Bergen and Glupro/Bergen) were developed using a single-seed-descent method. ND683 and ‘Glupro’ are high in GPC (180 g kg^-1), presumably due to the introgression of gene(s) from Triticum turgidum L. var. dicoccoides and ‘Bergen’ is low in GPC (145 g kg^-1). From each of the two populations 12 high- and 12 low-GPC RI lines (F_5:7) were selected for replicated testing at two North Dakota (ND) locations in 1995. In both populations, the high-GPC lines had significantly (p < 0.05) higher values compared to the low-GPC lines for mean GPC and water absorption. Mean grain yield of the high-GPC lines was not significantly different from the low-GPC lines in both populations. In the ND683/Bergen population, the high-GPC lines had significantly (p < 0.05) higher values than the low-GPC lines for mean plant height, days to heading, and flour extraction. GPC was significantly (p < 0.05)and negatively associated with test weight and also significantly (p < 0.01) and positively associated with water absorption in the Glupro/Bergen population. In these populations, results suggested that it may be possible to select lines that combine higher GPC and acceptable yield level, but later in maturity and taller in plant height. This revised version was published online in July 2006 with corrections to the Cover Date.     

Prevalence of Bovine tuberculosis in Ethiopian slaughter cattle based on post-mortem examination

A study aimed at describing the magnitude and distribution of gross lesions compatible with bovine tuberculosis (BTB) in Ethiiopian slaughter cattle in five abattoirs (four municipal and one export) located in various cattle husbandry systems in Ethiopia was carried out from July 2006 to January 2007 using detailed meat inspection procedure. Five representative abattoirs (four municipal and one export) located in distinct livestock management systems were selected. A total of 3322 cattle; 2876 (86.6%) male, 446 (13.4%) female; 3094 (93.1%) indigenous zebu, 140 (4.2%) crossbred and 88 (2.7%) pure exotic cattle were included in the study. A nine-year meat inspection record was also analyzed to elucidate the trend of BTB in the local cattle population.Of the carcasses inspected, 337 (10.2%, 95%CI= [9.2–11.2]) had lesions suggestive of tuberculosis, 69 (20.5%) generalized and 268 (79.5%) localized.TB prevalence showed a marked variation between categories of age, breed, class of animals, abattoir, geographic origin and husbandry system. It was higher in old and young animals than middle age group; in exotic than local breed; in calves than other classes of animals. The highest and lowest prevalence of TB was recorded in Adama (24.7%, 95%CI= [21.1–28.7]) and Yabello abattoirs (4.2%, 95%CI= [2.6–6.6]), respectively. Cattle whose origin was from Addis Ababa and its surrounding areas had higher prevalence of TB infection (23.9%, 95%CI= [17.6–31.5]).Cattle maintained in dairy farms had high degree of exposure (23.9%, 95%CI= [16.7–32.9]) to the infection than those maintained in other types of management system. Analysis of meat inspection records also revealed an increasing incidence of TB over the years. Our study demonstrated a high prevalence of tuberculosis in Ethiopian slaughter cattle and this could infer to similar scenario in a reference cattle population in the country. In view of Ethiopia’s increasing involvement in livestock export trade, the reported high prevalence of tuberculosis could be a major obstacle, particularly at this moment when sanitary requirements from importing countries are so much strict. Furthermore, the growing concern over increasing incidence of tuberculosis/HIV/AIDS co-infection, the high incidence of extra- pulmonary tuberculosis and a high risk of acquiring zoonotic tuberculosis among the majority of the population emphasize the need for paying the necessary attention towards the control of bovine tuberculosis.     

Australopithecus garhi: a new species of early hominid from Ethiopia

The lack of an adequate hominid fossil record in eastern Africa between 2 and 3 million years ago (Ma) has hampered investigations of early hominid phylogeny. Discovery of 2.5 Ma hominid cranial and dental remains from the Hata beds of Ethiopia's Middle Awash allows recognition of a new species of Australopithecus. This species is descended from Australopithecus afarensis and is a candidate ancestor for early Homo. Contemporary postcranial remains feature a derived humanlike humeral/femoral ratio and an apelike upper arm-to-lower arm ratio.     

On-farm tree species diversity and management in semi-arid of Lemo district,Southern Ethiopia

Agroforestry Systems - Despite the emerging and promising of on-farm trees to the biodiversity conservation, economic and ecological importance, there is still a dearth of empirical scientific...