735 research outputs found

    Fungal Endophytes from the Aerial Tissues of Important Tropical Forage Grasses \u3cem\u3e Brachiaria \u3c/em\u3e spp. in Kenya

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    Most, if not all plants in natural ecosystems are symbiotic with mycorrhizal fungi and/or fungal endophytes. This association between plant and fungi is believed to be over 400 million years old when plants first colonized the land (Redecker et al., 2000). These fungal symbionts play important roles on plant ecology, fitness, and evolution; shaping plant communities; and the community structure and diversity of associated organisms. The importance of fungal endophytes in cool season grasses production and effects of endophyte on the livestock health (Examples fescue toxicosis and ryegrass staggers) have been extensively investigated (Smith et al., 2009; di Menna et al., 2012). However, current understanding of fungal endophyte community of warm season grasses (including Brachiaria spp.) and the impact of these endophytes on livestock production is very limited. Therefore, this study aims to analyse fungal endophytes community inhabiting in the aerial tissues of important tropical grasses Brachiaria species from Kenya, an East African country representing place of origin for most of the Brachiaria species

    Establishment and Early Growth of Improved Brachiaria Cultivars in Different Agro-Ecological Zones of Kenya

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    Livestock feed scarcity is a salient feature in East Africa (Njarui et al., 2011) and it is a major constraint to livestock productivity particularly during the dry seasons. The recent interest in livestock development in Kenya fueled by rising demands of animal products has led to research in identifying drought tolerant, productive and persistence forages to support livestock productivity. Brachiaria grasses have shown a great potential in South America and Australia as livestock feed. It is the most widely cultivated forage in tropical America, with estimated acreage of 99 million hectares in Brazil alone (Jank et al., 2014), supporting a highly vibrant beef industry. Although the Brachiaria genus is native to East and Central Africa, its potential as livestock feed has not been exploited in the region because of limited research on its benefits. Several Brachiaria cultivars selected and improved in South America were introduced in East Africa and are being assessed for their contribution to livestock feed base in Kenya and Rwanda. This paper reports on preliminary results on establishment and early growth of eight Brachiaria cultivars under different climatic and soils in Kenya

    Effects of Storage Structures and Moisture Contents on Seed Quality Attributes of Quality Protein Maize

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    The study was aimed to examine the effects of various storage structures and moisture contents on seed quality attributes of quality protein maize seed. The quality protein maize (QPM-1) seed was tested in conventional seed storage containers (Fertilizer sack and earthen pot) and the improved hermetic ones (Metal bin, Super grain bag, and Purdue Improved Crop Storage (PICS) bag) at Seed Science and Technology Division, Khumaltar, Nepal during February, 2015 to January 2016. Ten treatments comprising 5 storage devices in two moisture regimes (11% and 9%) replicated thrice and laid out in Completely Randomized Design (CRD). Data on temperature, relative humidity (RH), germination, electrical conductivity (EC), seed moisture content (MC) were collected bimonthly. The conventional containers were found liable to the external environmental condition whereas the hermetic structures observed with controlled RH level below 40% in all combinations. Electrical conductivity (EC) for seed vigor showed that hermetic containers provide higher seed vigor than the conventional ones. Up to 4 months all treatments were found statistically at par for germination. A significant difference was observed in each treatment after 4 months where PICS bag & Super grain bag showed best germination followed by metal bin while fertilizer bag & earthen-pot showed poorer and poorest germination respectively till one year. Almost all treatments with lower MC showed better results than the treatments with higher MC. A negative correlation (R2=69.7%) was found between EC and Germination. All six figures from 2 to 12 months on MC showed statistically different where hermetic plastic bags were found maintaining MC as initial whereas MC of fertilizer bags and earthen pot was spiked than the basal figure. The finding evidenced that the hermetic containers and low MC are the seed storage approaches for retaining the quality of seed even in an ambient environmental condition for more than a year

    Effect of controlled artificial disorder on the magnetic properties of EuFe2(As1−xPx)2 ferromagnetic superconductor

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    Static (DC) and dynamic (AC, at 14 MHz and 8 GHz) magnetic susceptibilities of single crystals of a ferromagnetic superconductor, EuFe2 (As1−xPx )2 (x = 0.23), were measured in pristine state and after different doses of 2.5 MeV electron or 3.5 MeV proton irradiation. The superconducting transition temperature, Tc (H), shows an extraordinarily large decrease. It starts at Tc (H = 0) ≈ 24 K in the pristine sample for both AC and DC measurements, but moves to almost half of that value after moderate irradiation dose. Remarkably, after the irradiation not only Tc moves significantly below the FM transition, its values differ drastically for measurements at different frequencies, ≈16 K in AC measurements and ≈12 K in a DC regime. We attribute such a large difference in Tc to the appearance of the spontaneous internal magnetic field below the FM transition, so that the superconductivity develops directly into the mixed spontaneous vortex-antivortex state where the onset of diamagnetism is known to be frequency-dependent. We also examined the response to the applied DC magnetic fields and studied the annealing of irradiated samples, which almost completely restores the superconducting transition. Overall, our results suggest that in EuFe2 (As1−xPx )2 superconductivity is affected by local-moment ferromagnetism mostly via the spontaneous internal magnetic fields induced by the FM subsystem. Another mechanism is revealed upon irradiation where magnetic defects created in ordered Eu2+ lattice act as efficient pairbreakers leading to a significant Tc reduction upon irradiation compared to other 122 compounds. On the other hand, the exchange interactions seem to be weakly screened by the superconducting phase leading to a modest increase of Tm (less than 1 K) after the irradiation drives Tc to below Tm . Our results suggest that FM and SC phases coexist microscopically in the same volume

    Identification of Niches for Integration of Brachiaria Grasses in Smallholder Mixed Crop-Livestock Farming Systems in Kenya

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    Inadequate quantity and quality of feed is the major constraint to livestock productivity in Kenya. Low rainfall, lack of adapted forages and poor management of sown forages are major factors that affect feed resources production. In most of the farming systems, forages are relegated to the less fertile and degraded soils resulting into poor growth. As a result the growth is poor resulting in deficient in minerals content, low crude protein (CP) and energy. The situation in exacerbated by climate variability and frequent drought. On the other hand, feed resources derived from crop residues, particularly cereals are of poor quality and not sufficient to meet animal production (Njarui and Mureithi, 2006). A research programme was initiated in 2012 to explore superior feed resources and increase availability of high quality forages to increase livestock productivity in East Africa. The program focuses on evaluation of drought and marginal soil adapted improved Brachiaria cultivars from South America. The genus Brachiaria is predominantly an African grass with about 100 species. The Brachiaria grasses are the most widely grown forages in South America (Miles et al., 2004). These grasses produce high biomass, enhance soil fertility and reduce greenhouse gas emission (Peters et al., 2012), are highly nutritious and are known to increase milk (Njarui, pers. comm.) thus suitable for different farming systems of Kenya. However, before integration of these grasses into farming systems, it was imperative to identify suitable niches suitable for growing these grasses. The knowledge gained from the study will facilitate development of suitable approaches for promoting these grasses across diverse production systems of Kenya

    Analysis of the London penetration depth in Ni-doped CaKFe4As4

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    We report combined experimental and theoretical analysis of superconductivity in CaK(Fe1x_{1-x}Nix_x)4_4As4_4 (CaK1144) for x=x=0, 0.017 and 0.034. To obtain the superfluid density, ρ=(1+ΔλL(T)/λL(0))2\rho=\left(1+\Delta \lambda_L(T)/\lambda_L(0) \right)^{-2}, the temperature dependence of the London penetration depth, ΔλL(T)\Delta \lambda_L (T), was measured by using tunnel-diode resonator (TDR) and the results agreed with the microwave coplanar resonator (MWR) with the small differences accounted for by considering a three orders of magnitude higher frequency of MWR. The absolute value of λL(TTc)λL(0)\lambda_L (T \ll T_c) \approx \lambda_L(0) was measured by using MWR, λL(5 K)170±20\lambda_L (\mathrm{5~K}) \approx 170 \pm 20 nm, which agreed well with the NV-centers in diamond optical magnetometry that gave λL(5 K)196±12\lambda_L (\mathrm{5~K}) \approx 196 \pm 12 nm. The experimental results are analyzed within the Eliashberg theory, showing that the superconductivity of CaK1144 is well described by the nodeless s±_{\pm} order parameter and that upon Ni doping the interband interaction increases.Comment: 8 pages, 5 figure

    ‘Agents-in-focus’ and ‘Agents-in-context’: The strong structuration analysis of central government accounting practices and reforms in Nepal

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    Drawing on Stones’ (2005) strong structuration theory, the paper unfolds why and how the key stakeholders of central government accounting in Nepal are involved in the reproduction of routinised accounting practices, resisting the externally-propagated changes. Government accountants (the agents-in-focus) through their capability to control the budget routines have enjoyed a powerful social position in their position–practice relations with the agents-in-context, i.e. professional accountants and international consultants, higher-level officers and administrators, auditors, and politicians. Social position along with historically-imbued dispositions and their conduct and context analysis have enabled government accountants to strategically exercise their agency. Government accountants have articulated duality and a dialectic relation with the agents-in-context, which have resulted in the reproduction of everyday accounting practice and the resistance to the World Bank-led reforms, such as accrual accounting and, more recently, the Cash-Basis IPSAS

    Climate-Smart \u3cem\u3eBrachiaria\u3c/em\u3e Grasses for Improving Livestock Production in East Africa

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    Climate change is a global phenomenon with negative impacts severely felt by poor people in developing countries (Morton 2007). Across many parts of Africa, rural poor communities rely greatly for their survival on agriculture and livestock that are amongst the most climate-sensitive economic sectors. Climate-smart agriculture helps farmers to increase food production, become more resilient to climate change and reduce greenhouse gas (GHG) emissions. The main anthro-pogenic GHGs are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O); they are critically important for regulating the Earth’s surface temperature. Inadequate quantity and quality of feed is a major constraint to livestock production, particularly during the dry seasons across Africa. The overall objective of this inter-institutional program is to increase feed availability in action areas of the target countries in East Africa (e.g. Kenya, Rwanda) by use of climate-smart Brachiaria forage grasses (Rao et al. 2011) for increased animal productivity and for generation of extra income to smallholder famers. An innovative programmatic approach will be used to reintroduce high quality, persistent and productive Brachiaria genotypes that were selected and improved in Latin America (Miles et al. 2004) back to Africa. These forage grasses will contribute to alleviate feed shortages, increase income to resource poor farmers, improve soil fertility, adapt to and mitigate climate change, increase milk and beef production, and as a result improve livelihoods and protect the environment

    Climate-Smart \u3cem\u3eBrachiaria\u3c/em\u3e for Improving Livestock Production in East Africa: Emerging Opportunities

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    Brachiaria grass is an important tropical forage of African origin with desirable attributes of agricultural and environmental significance. Brachiaria has been extensively cultivated as a pasture across the tropics except in its endemic provenance of Africa. In 2013, a collaborative research program was initiated in Kenya and Rwanda with the aim of improving the availability of quality livestock feeds adapted to drought and low fertility soils using Brachiaria. The outcomes sought were increased livestock productivity leading to improved farmer income and the development of seed production opportunities. The program has identified five preferred cultivars, and four of them are currently being evaluated on-farm by over 2000 small-holder farmers in Kenya and Rwanda for livestock productivity. Preliminary milk production data has shown a 15 to 40% increase in milk production in Kenya and an average increase of 36% in Rwanda. The substitution of Napier grass by Brachiaria in the feed has increased average daily body weight gain of cattle by 205g during a 12 week period. Kenyan farmers reported increased on-farm forage availability by three months after Brachiaria introduction. The program has also worked to determine the role of endophytes and plant associated microbes for the improvement of biomass production and adaptation of Brachiaria to biotic and abiotic stresses. A diverse group of fungi and bacteria were isolated, identified and characterized, and the role of these microbes on plant growth and plant pathogen suppression is being investigated. This paper discusses the rationale for selecting Brachiaria as potential forage for eastern Africa and highlights current achievements, and identifies areas for future research
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