44 research outputs found

    Genotype by environment interaction and grain yield stability of Ethiopian black seeded finger millet genotypes

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    Finger millet ( Eleusine coracana \ua0(L.) Gaertn) is an important cereal widely produced in Ethiopia across diverse agro-ecologies. It is valued by local farmers for its ability to grow in adverse agro-climatic conditions, where other cereals fail. The yield potential of this crop is in the range of 4-5 tonnes/ha, but the current national average grain yield is far below the potential (2.1 tonnes). Lack of improve varieties which are stable, high yielder and stress tolerant is a major limiting factor to production of this crop in Ethiopia. A field experiment was conducted using twelve black seeded finger millet (Eleusine coracana subsp. coracana) genotypes, including local and standard checks (Degu) at two locations (Bako and Gute) in Ethiopia for three years (2014 - 2016). The objective of this study was to identify stable and high yielding genotypes for grain yield and other agronomic traits among the black seeded finger millet genotypes of Ethiopia. The additive main effect and multiplicative interaction (AMMI) model analysis of variance revealed highly significant (P<0.01) differences between environments, genotype, and Interaction Principal Component Analysis (IPCA-I), but significant variations (P<0.05) for G x E interactions. This indicates that the genotypes performed differently over environments and that the test environments are highly variable. Only the first IPCA-I showed high significance (P<0.01) and contributed 48.39% of the total genotype by environment interaction (G x E). Genotypes BKFM0020, BKFM0006 and BKFM0010, which had high grain yield, but with IPCA value close to zero, indicated the wide adaptability/stability. Similarly, analysis using Eberhart and Russell model revealed that these genotypes were within the relatively acceptable range of regression coefficients (bi), approaching to one (0.742, 0.8176 and 1.0578), and deviation from regression closer to zero (s2di) (0.0385, -0.0661 and -0.0248), respectively. This implied that pipeline genotypes were stable, widely adaptable and high yielders than the other genotypes. Genotype and genotype by environment (GGE bi-plot) analysis also revealed that these candidate genotypes were stable and high yielder. Besides, these genotypes showed resistance to blast disease, which is a threat to finger millet production in the study areas. Therefore, these genotypes were selected as potential candidates for possible release in western Oromia and similar agro-ecologies of the country.Le petit mil ( Eleusine coracana (L.) Gaertn) est une c\ue9r\ue9ale importante largement produite en \uc9thiopie dans les diff\ue9rents zones agro-\ue9cologiques. Il est appr\ue9ci\ue9 par les agriculteurs locaux pour sa capacit\ue9 de grandir dans des conditions agro-climatiques d\ue9favorables, o\uf9 les autres c\ue9r\ue9ales \ue9chouent. Le potentiel du rendement en grain de cette culture de mil se situe entre 4 \ue0 5 t ha-1, mais le rendement moyen national actuel est tr\ue8s inf\ue9rieur au potentiel (2,1 tonnes). Le manque de vari\ue9t\ue9s am\ue9lior\ue9es, stables, \ue0 rendement en grain \ue9lev\ue9 et tol\ue9rantes au stress est un t facteur majeur limitant la production de cette culture de mil en \uc9thiopie. Une exp\ue9rience au champs a \ue9t\ue9 conduite avec douze g\ue9notypes des grains noir de mil (Eleusine coracana subsp. Coracana), y compris des contr\uf4les locaux et standard (Degu) \ue0 deux locations (Bako et Gute) en \uc9thiopie pendant trois ans (2014 - 2016). L\u2019objectif de cette \ue9tude \ue9tait d\u2019identifier des g\ue9notypes stables et de rendement tr\ue8s\ua0\ue9lev\ue9 pour le rendement en grain de mil et d\u2019autres caract\ue9ristiques agronomiques parmi les genotypes des grains noir de mil en \uc9thiopie. L\u2019analyse de variance du methode avec effet principal additif et interaction multiplicative (AIM) a r\ue9v\ue9l\ue9 des diff\ue9rences tr\ue8s significatives (P <0,01) entre les locations, le g\ue9notype et l\u2019analyse en composantes principales de l\u2019interaction (IPCA-I), mais des variations significatives (P <0,05) pour G x E interactions. Cela indique que les g\ue9notypes se sont comport\ue9s diff\ue9remment selon les locations et que les locations de test sont tr\ue8s variables. Seule la premi\ue8re IPCA-I a montr\ue9 une signification \ue9lev\ue9e (P <0,01) et a contribu\ue9 pour 48,39% du total des interactions g\ue9notype par la location (G x E). G\ue9notypes BKFM0020, BKFM0006 et BKFM0010, qui avait un rendement en grain \ue9lev\ue9, mais avec une valeur IPCA proche de z\ue9ro, a indiqu\ue9 la grande adaptabilit\ue9 / stabilit\ue9. De m\ueame, une analyse utilisant les m\ue9thodes\ua0d\u2019Eberhart et Russell a r\ue9v\ue9l\ue9 que ces g\ue9notypes se situaient dans la plage relativement acceptable des coefficients de r\ue9gression (bi), se rapprochant de un (0,742, 0,8176 et 1,0578) et de l\u2019\ue9cart par rapport \ue0 la r\ue9gression proche de z\ue9ro (s2di) (0,0385, 0,0661 et -0,0248), respectivement. Cela impliquait que les g\ue9notypes de pipeline \ue9taient stables, largement adaptables et ont eu le rendement tr\ue8s\ua0\ue9lev\ue9 que les autres g\ue9notypes. Les analyses de g\ue9notype et g\ue9notype par la location (bi-parcelle GGE) ont \ue9galement r\ue9v\ue9l\ue9 que ces g\ue9notypes candidats \ue9taient stables et avaient une bonne rentabilit\ue9. En outre, ces g\ue9notypes ont montr\ue9 une r\ue9sistance \ue0 la maladie fongique qui constitue une menace pour la production de mil dans les zones d\u2018 \ue9tude. Par cons\ue9quent, ces g\ue9notypes ont \ue9t\ue9 s\ue9lectionn\ue9s comme candidats potentiels pour une lib\ue9ration \ue9ventuelle dans l\u2019ouest d\u2019Oromia et des zones agro-\ue9cologiques similaires du pays

    Reference soil groups map of Ethiopia based on legacy data and machine learning-technique: EthioSoilGrids 1.0

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    Up-to-date digital soil resource information and its comprehensive understanding are crucial to supporting crop production and sustainable agricultural development. Generating such information through conventional approaches consumes time and resources, and is difficult for developing countries. In Ethiopia, the soil resource map that was in use is qualitative, dated (since 1984), and small scaled (1 : 2 M), which limit its practical applicability. Yet, a large legacy soil profile dataset accumulated over time and the emerging machine-learning modeling approaches can help in generating a high-quality quantitative digital soil map that can provide better soil information. Thus, a group of researchers formed a Coalition of the Willing for soil and agronomy data-sharing and collated about 20 000 soil profile data and stored them in a central database. The data were cleaned and harmonized using the latest soil profile data template and 14 681 profile data were prepared for modeling. Random forest was used to develop a continuous quantitative digital map of 18 World Reference Base (WRB) soil groups at 250 m resolution by integrating environmental covariates representing major soil-forming factors. The map was validated by experts through a rigorous process involving senior soil specialists or pedologists checking the map based on purposely selected district-level geographic windows across Ethiopia. The map is expected to be of tremendous value for soil management and other land-based development planning, given its improved spatial resolution and quantitative digital representation.</p

    Nutrient use efficiency and crop yield response to the combined application of cattle manure and inorganic fertilizer in sub-Saharan Africa

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    Published online: 31 Jan 2018The combined application of cattle manure and inorganic fertilizer has been widely recommended in the context of integrated soil fertility management (ISFM) on smallholder farms in sub-Saharan Africa (SSA). However, the conditions under which this combination (hereafter ISFM) improves nutrient and water use efficiency and crop yields have not been systematically studied. Therefore, we undertook a meta-analysis of studies conducted in rain-fed maize production systems across SSA with the objective of (1) quantifying the magnitude of improvement in grain yield, rain use efficiency (RUE), agronomic efficiency of nitrogen (AEN) and phosphorus (AEP) due to ISFM; (2) determining conditions under which ISFM achieves greater yield response, RUE, AEN and AEP; and (3) compare yield responses to the substitutive and additive approaches of ISFM with sole application of cattle manure. Application of high rates of cattle manure in combination with high N fertilizer rates increased yield response only by 27.5%, but it achieved 47% lower AEN and 27% lower AEP relative to a combination of low manure and low N fertilizer rate. The substitutive approach of ISFM achieved 54% greater AEN and 16% greater AEP than the additive ISFM approach. Yield response and AEN also significantly varied with soil type. On most soil types, AEN was 2–195% lower under sole manure than under ISFM or sole fertilizer. We recommend application of moderate rates of cattle manure (5–10 t ha−1) combined with moderate doses of N fertilizer (< 50 kg N ha−1) on responsive soils to optimize AEN and maize yield response

    Draft genome sequence of Chryseobacterium limigenitum SUR2 T (LMG 28734 T ) isolated from dehydrated sludge

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    The type strain SUR2 of the novel species Chryseobacterium limigenitum was isolated from a dehydrated sludge of the municipal sewage treatment plant in Dogoše near Maribor in Slovenia. The draft genome, with 60 contigs, 4,697,725bp, 34.4% of G+C content, was obtained using the Illumina HiSeq 2500-1 platform. Joint Genome Institute Microbial Genome Annotation Pipeline (MGAP v.4) has identified 4322 protein-coding sequences including resistance genes against arsenic and other heavy metals. In addition, a subclass B3 metallo-β-lactamase, which confers resistance to penicillins, cephalosporins and carbapenems, was also present in the genome. The genome sequence provides important information regarding bioremediation potential and pathogenic properties of this newly identified species
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