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1.
Journal of Crop Science and Biotechnology - Knowledge on the extent and pattern of diversity in crop species is a precondition for any crop improvement as it helps breeders in determining apt...  相似文献   
2.
• Livestock manure was the main organic waste in urban and peri-urban areas.• Manure production will increase by a factor of 3–10 between 2015–2050.• Only 13%–38% of excreted N by livestock will be recycled in croplands.• Intensification of urban livestock production greatly increased N surpluses.• Reducing population growth and increasing livestock productivity needed.Urban population growth is driving the expansion of urban and peri-urban agriculture (UPA) in developing countries. UPA is providing nutritious food to residents but the manures produced by UPA livestock farms and other wastes are not properly recycled. This paper explores the effects of four scenarios: (1) a reference scenario (business as usual), (2) increased urbanization, (3) UPA intensification, and (4) improved technology, on food-protein self-sufficiency, manure nitrogen (N) recycling and balances for four different zones in a small city (Jimma) in Ethiopia during the period 2015-2050. An N mass flow model with data from farm surveys, field experiments and literature was used. A field experiment was conducted and N use efficiency and N fertilizer replacement values differed among the five types of composts derived from urban livestock manures and kitchen wastes. The N use efficiency and N fertilizer replacement values were used in the N mass flow model.Livestock manures were the main organic wastes in urban areas, although only 20 to 40% of animal-sourced food consumed was produced in UPA, and only 14 to 19% of protein intake by residents was animal-based. Scenarios indicate that manure production in UPA will increase 3 to 10 times between 2015 and 2050, depending on urbanization and UPA intensification. Only 13 to 38% of manure N will be recycled in croplands. Farm-gate N balances of UPA livestock farms will increase to>1 t·ha−1 in 2050. Doubling livestock productivity and feed protein conversion to animal-sourced food will roughly halve manure N production.Costs of waste recycling were high and indicate the need for government incentives. Results of these senarios are wake-up calls for all stakeholders and indicate alternative pathways.  相似文献   
3.
Chickpea (Cicer arietinum L.) is a dry season food legume largely grown on residual soil moisture after the rainy season. The crop often experiences moisture stress towards end of the crop season (terminal drought). The crop may also face heat stress at the reproductive stage if sowing is delayed. The breeding approaches for improving adaptation to these stresses include the development of varieties with early maturity and enhanced abiotic stress tolerance. Several varieties with improved drought tolerance have been developed by selecting for grain yield under moisture stress conditions. Similarly, selection for pod set in the crop subjected to heat stress during reproductive stage has helped in the development of heat‐tolerant varieties. A genomic region, called QTL‐hotspot, controlling several drought tolerance‐related traits has been introgressed into several popular cultivars using marker‐assisted backcrossing (MABC), and introgression lines giving significantly higher yield than the popular cultivars have been identified. Multiparent advanced generation intercross (MAGIC) approach has been found promising in enhancing genetic recombination and developing lines with enhanced tolerance to terminal drought and heat stresses.  相似文献   
4.
Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement.  相似文献   
5.
Cross-sectional studies were conducted in tsetse and non-tsetse-controlled areas of the Southern Nation Nationalities and Peoples Regional State (SNNPRS) of Ethiopia to determine the prevalence of bovine trypanosomosis as well as drug sensitivity tests on Trypanosoma congolense in both naturally and experimentally infected cattle and mice, respectively. A total trypanosome prevalence of 4.8% (95% CI: 1.8-7.5) and 20.4% (95% CI: 14-26.8) were recorded in the tsetse-controlled study area of Humbo district and the non-tsetse-controlled area of Mareka district, respectively, indicated statistically significant difference between the two areas (P<0.001). The mean PCV value for Humbo and Mareka was 26.2 (95%: 25.7-26.7) and 22.7 (95% CI: 22.1-23.3), respectively, which were also statistically significant (P<0.001). The prophylactic activity of isometamidium chloride (ISMM) was observed in Humbo on nine naturally positive zebu cattle. Breakthrough infections were recorded in (6/9) 66.7% of the cases in less than 5 weeks. A qualitative assay on mice was conducted on two T. congolense isolates obtained from the breakthrough cases with ranges of doses of ISMM and diminazene diaceturate (DA). Thereafter the mice were followed for relapse infection. ISMM at doses 0.5-4 mg/kg body weight (bw) and DA at doses of 3.5-28 mg/kg bw failed completely to cure T. congolense infections in any of the mice. A quantitative assay on mice was conducted on four T. congolense isolates obtained from Mareka. The four isolates were pooled into two pools (Pool-1 and Pool-2) for the quantitative assay on mice. The pooled isolates were tested with the same trypanocidal drugs and ranges of doses as it was used for the qualitative assay on mice. The minimum curative dose (MCD) of ISMM that cleared T. congolense infected mice was 4 and 2mg/kg bw for Pool-1 and Pool-2, respectively, whereas MCD of DA was 28 and 14 mg/kg bw, in Pool-1 and Pool-2, respectively. Although cloned populations were not used to prove whether the observed resistance was at the individual level or not, the results show that there is resistance to both ISMM and DA; failure of the "sanative pair".  相似文献   
6.
Abstract

The experiment was conducted at Kulumsa, South East Ethiopia, using four levels of nitrogen (N) (0, 50,100 and 150?kg N ha?1) and four levels of phosphorus (P) (0, 35, 70 and 105?kg P2O5 ha?1) fertilizers arranged in 4?×?4 factorial arrangements in randomized complete block design with three replications. The available P was increased after harvest due to the application of N and P fertilizer at the rates of 100 or 150?kg N ha?1 and 70 or 105?kg P2O5 ha?1. More specifically, nutrients concentration and nutrient uptake were significantly (p?<?.01) varied among treatment combinations and nutrient use efficiency was declined by increasing N and P after optimum rates. The higher physiological efficiency of N (53.47?kg kg?1) and P (580.41?kg kg?1) and the highest apparent recovery of N (19.62%) and P (2.47%) was recorded from application of 50?kg N ha?1 and P at 70?kg P2O5 ha?1 and the highest agronomic efficiency of N (10.78?kg kg?1) and P (15.25?kg kg?1) was recorded from N at the rate of 50?kg N ha?1 and P at 35?kg P2O5 ha?1, respectively. The combination of N at 100?kg N ha?1 and P at 70?kg P2O5 ha?1 was promising combination that generated highest net benefit 488,878.5 ETB (Ethiopian birr) ha?1 with the highest marginal rate of return (36638%) and gave the highest seed yield (1858.82?kg ha?1) with yield increment of about 57.72% over the control.  相似文献   
7.
Chemical and other selective insecticides are annually used as foliar treatments against defoliating Lepidoptera in the southern Spanish open woodland (known as dehesa), one of the largest forest ecosystems in the Mediterranean basin. In order to analyse the negative impact of these treatments on beneficial arthropods, the toxic effect of the three authorised insecticides on Philodromus buxi Simon (Araneae: Philodromidae), the most abundant tree canopy spider in southern Spain, was tested under laboratory conditions. Cypermethrin was the most harmful insecticide 96 hours after application, causing around 90% corrected mortality, while flufenoxuron (an insect growth-regulator) prompted around 45% mortality, and Bacillus thuringiensis caused no mortality at all. In addition, flufenoxuron produced a clear alteration in the predatory capacity of P. buxi, increasing the reaction times of treated specimens, and additional mortality associated with the moulting process. Bacillus thuringiensis caused no effects in reaction times, growth or moulting. The results obtained clearly indicate that B. thuringiensis is the most suitable of the authorised insecticides for conserving populations of P. buxi in dehesa woodland in southern Spain.  相似文献   
8.
A cross sectional sero-prevalence study was conducted on 1,595 cattle in Jimma zone, Ethiopia to investigate the status of bovine brucellosis and identify potential risk factors. Sera samples were analyzed using Rose Bengal Plate Test (RBPT) and Complement Fixation Test (CFT). The overall individual and herd level sero-prevalences were 3.1% (n = 1,595) and 15.0% (n = 227), respectively. The sero-prevalence of bovine brucellosis at individual animal level was significantly higher in non-pregnant (11.18%) than pregnant (2.77%) and lactating (22.35%) than non-lactating animals (2.46%). Moreover, significantly higher sero-prevalence was observed in herds of larger sizes. Individual animal sero-prevalence was also positively associated with the occurrence of abortion (26.98 and 1.54% in those with and without previous history of abortion, respectively). Generally, the sero-prevalence of bovine brucellosis found in Jimma area was not high and the sero-prevalence was closely associated with some of the risk factors considered at individual animal and herd level.  相似文献   
9.
There are several hurdles to ensure sustainable seed production and consistent flow of improved legume varieties in sub‐Saharan Africa (SSA) and South Asia (SA). The unreliable demand, autogamous nature of most of the grain legumes, and slow variety replacement rate by smallholder farmers do not provide strong incentive for private seed companies to invest in legume seed business. Unless a well thought‐out and comprehensive approach to legume seed delivery is developed, current seed shortages will continue, eroding emerging market opportunities. The experiences reported here are collated through a 10‐year partnership project, the Tropical Legumes in SSA and SA. It fostered innovative public–private partnerships in joint testing of innovative market‐led seed systems, skills and knowledge enhancement, de‐risking private sector initiatives that introduced in new approaches and previously overlooked entities in technology delivery. As new public and private seed companies, individual seed entrepreneurs and farmer organizations emerged, the existing ones enhanced their capacities. This resulted in significant rise in production, availability and accessibility of various seed grades of newly improved and farmer demanded legume varieties in the target countries.  相似文献   
10.
Journal of Crop Science and Biotechnology - Chickpea (Cicer arietinum L.) is one of the most important food legumes in the world. However, Fusarium wilt is one of the major yield limiting factors...  相似文献   
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