A comparative analysis of agricultural knowledge and innovation systems in Kenya and Ghana: sustainable agricultural intensification in the rural–urban interface

Agriculture remains the backbone of most African economies, yet land degradation severely hampers agricultural productivity. Over the last decades, scientists and development practitioners have advocated integrated soil fertility management (ISFM) practices to improve soil fertility. However, their adoption rates are low, partly because many farmers in sub-Saharan Africa are not fully aware of the principles of this system innovation. This has been attributed to a wide communication gap between farmers and other agricultural actors in agricultural knowledge and innovation systems (AKIS). We add to the literature by applying innovation system approaches to ISFM awareness processes. This study aims to assess if AKIS are effectively disseminating ISFM knowledge by comparing results from two sites in Kenya and Ghana, which differ in the uptake of ISFM. Social network measures and statistical methods were employed using data from key formal actors and farmers. Our results suggest that the presence of weak knowledge ties is important for the awareness of ISFM at both research sites. However, in Kenya AKIS are more effective as there is a network of knowledge ties crucial for not only dissemination but also learning of complex innovations. This is largely lacking in Ghana where integration of formal and informal agricultural knowledge systems may be enhanced by fostering the function of informal and formal innovation brokers.     

Farmers’ knowledge of crop diseases and control strategies in the Regional State of Tigrai, northern Ethiopia: implications for farmer–researcher collaboration in disease management

Differences in perceptions and knowledge of crop diseases constitute a major obstacle in farmer–researcher cooperation, which is necessary for sustainable disease management. Farmers’ perceptions and management of crop diseases in the northern Ethiopian Regional State of Tigrai were investigated in order to harness their knowledge in the participatory development of integrated disease management (IDM) strategies. Knowledge of disease etiology and epidemiology, cultivar resistance, and reasons for the cultivation of susceptible cultivars were investigated in a total of 12 tabias (towns) in ten weredas (districts). Perception of diseases involved both scientific and spiritual conceptual frameworks. Of the more than 30 crop diseases recorded on the major crops in the region, only rusts and powdery mildews (locally called humodia) and a few root rots were considered by farmers to be important. Farmers’ awareness of other diseases was extremely low; some highly damaging but less conspicuous diseases, such as faba bean chocolate spot and chickpea ascochyta blight (also called humodia), were not regarded by farmers as disease but as problems caused primarily by excessive soil moisture. Considering that some of these “unrecognized” diseases can cause complete yield loss and genetic erosion in epiphytotic years, there is an urgent need for bringing together farmers’ and scientists’ knowledge to complement each other. Even when farmers had access to disease-resistant or disease-tolerant cultivars, they grew susceptible local varieties because of multiple criteria including earliness, good yield in years with low humodia severity, suitability for home consumption, market demand/quality, and low soil fertility and land management requirements. Farmer innovation and knowledge were evident in their use of diverse disease control measures, but these were a mixture of the “useful and the useless.” Our findings stress the necessity for extension workers and researchers to understand and improve farmers’ knowledge of crop diseases, and farmers’ ability to observe and experiment, through the Farmer Field School or a similar experiential learning approach. These insights about farmers’ knowledge of crop diseases provide a basis for further collaborative maintenance of crop genetic diversity, development of germplasm, and IPM-related research in Africa.

A food politics of the possible? Growing sustainable food systems through networks of knowledge

There is increased recognition of a common suite of global challenges that hamper food system sustainability at the community scale. Food price volatility, shortages of basic commodities, increased global rates of obesity and non-communicable food-related diseases, and land grabbing are among the impediments to socially just, economically robust, ecologically regenerative and politically inclusive food systems. While international political initiatives taken in response to these challenges (e.g. Via Campesina) and the groundswell of local alternatives emerging in response to challenges are well documented, more attention is needed to the analysis of similarities between community approaches to global pressures. While we are not suggesting the application of a template set of good practices, the research reported in this paper point to the benefits of both sharing good practices and enabling communities to adopt good practices that are suited to their place-based capacities. The work also suggests that sharing community-derived good practices can support and reinforce global networks of sustainable community food systems, foster knowledge co-creation and ultimately cement collective action to global pressures. In turn these networks could enhance the sustainability and resilience of community food systems and facilitate wide scale food system transformation.     

Mycoparasitism of Gliocladium isolates in China Mycoparasitism of Gliocladium isolates in China

During an investigation of mycoparasitic fungi on sclerotia of Sclerotinia sclerotiorum in China, Gliocladium species was consistently encountered and isolated from natural soils collected over the country. Colonization frequencies on sclerotia of S. sclerotiorum by the fungi ranged from 40% to 100% when the sclerotia were introduced into soils and coincubated at 22-24 ℃ for 4 weeks. Identification showed that G. roseum, G. virens and G. catenulatum were the dominant species amon…     

Regulation of leptin in involution of mammary gland

Leptin,a protein hormone produced and secreted predominantly by white adipose tissue,has a critical role in the regulation and coordination of energy metabolism.Leptin is produced in the mammary gland by the fat tissue or by the mammary epithelium.In vitro study has shown that leptin triggers apoptosis in mammary epithelial cells.Mammary gland involution is characterized by extensive apoptosis of the epithelial cells.At the onset of involution,STAT3 is specifically activated.Various studies show that leptin act as a paracrine and autocrin factor to influence mammary epithelial cell proliferation and differentiation.This paper reviewed the function of leptin to the involution of mammary gland.     

Summarize in the Study of 3-S Cultivating Technique of Rice in Cold Zone

水稻三超栽培技术针对寒地稻作再高产的障碍因素,利用大钵盘超早超稀定位播、培育均质多蘖壮秧,宽行单本适期移栽,深施肥、控灌水等强化及安全栽培措施,延长水稻生育期、扩大营养空间、释放个体生产潜力,开发低节位优势分蘖,从而形成具有高光效、超高产群体的栽培技术体系。     

Cultural styles of participation in farmers’ discussions of seasonal climate forecasts in Uganda

Climate change is confronting African farmers with growing uncertainties. Advances in seasonal climate predictions offer potential for assisting farmers in dealing with climate risk. Experimental cases of forecast dissemination to African rural communities suggest that participatory approaches can facilitate understanding and use of uncertain climate information. But few of these studies integrate critical reflections on participation that have emerged in the last decade which reveal how participatory approaches can miss social dynamics of power at the community level and in the broader context. Furthermore, neither climate application research nor theoretical critiques of participation fully examine the culturally constructed nature of participation. Drawing on sociolinguistic analysis, in-depth interviews, and ethnographic observation, this paper examines how Ugandan farmers engage in participation in the context of discussions of seasonal climate forecasts. Forecasts were presented to farmers groups whose members were then asked to discuss the forecast among themselves. In doing so, groups sought to develop a common understanding of the forecast and consensual plans for response strategies. Focusing on one particular group meeting as an example, we show how different cultural styles of participation affect the interpretation of the forecast and the formulation of response strategies. Group interaction is shown to be mostly structured around two styles of participation. On the one hand, there is the “Western” style advocated by NGOs and the government, which centers on ensuring that all individuals who are present have opportunities to speak during discussion and to vote on group decisions. On the other hand, a “Kiganda” style of participation emphasizes the importance of affirming ties to a collectivity, respect for social hierarchy, deployment of good manners, and consensus building. The case study illuminates how the performance of different styles of participation is grounded in localized frameworks of language and culture but also draw on political and policy discourses at the national level. Although a cultural high value on consensus may work in favor of prominent members, the availability of multiple styles of participation also enables group members to exercise their agency in positive ways. Attention to the interplay of different styles of participation throws light on the subtle social processes that shape how knowledge is assessed, which sources are trusted, which and whose interpretations prevail, what options are deemed viable, how costs and benefits are calculated, and whose resources are mobilized in the effort to reduce vulnerability to climate risk. These are key questions for an assessment of the role of boundary organizations, such as farmer associations, in the communication and application of climate forecasts in agriculture.     

Character of viral clones in serial passage of a nuclear polyhedrosis virus in vitro

In this paper,the character of viral clones from early and late passages after serial passages of Trichoplusia ni single nuclear polyhedrosis virus in a Tn 5B1-4 cell line is described.It demonstrated that no significant difference was observed in the infectivity of the cell culture supernatants of various passages to the cell line.The number of polyhedra produced in a cell and infectivity of polyhedra to T.ni larvae declined strikingly with the increase of passages.The polyhedra without virions began to increase from passage to passage.The result of restriction enzyme digestion showed that the DNA restriction fragments of the clones were different from wild virus DNA,although they came from a homogeneous viral DNA.The mutation of viral DNA resulted in the in crease of noninfectious polyhedra without virions and in the increase of the number of polyhedra produced in cell line as well as virulence of the polyhydrosis inclusion bodys to T.ni larvae after prolonged passages of Tn SNPV in the cell culture.     

Dynamics of Mineralization of Organic N in Red Soil

通过测定加有黑麦草的土壤样品在不同培养时间产生的硝态氮、亚硝态氮、铵态氮和氨态氮数量的变化，研究了有机氮在二种红壤（红砂土和黄筋泥）中的矿化动态．有机氮在红壤中的矿化结果主要是铵的生成和氨的挥发，培养后５ｄ，明显发生铵的释放，红砂土在培养后１５～２０ｄ，铵的释放达到最大值，黄筋泥则是在培养后３０～３５ｄ．在培养的前２０ｄ，红砂土中铵的释放多于黄筋泥，但在３０ｄ后，情况相反．培养期间有机氮矿化释放的氨用２％硼酸溶液吸收，以这种形式损失的有机氮，红砂土多于黄筋泥     

Necessity and Strategy of Development of Energy-Oriented-Agriculture in China

中国已成为继美国之后的全球第二大能源消费国,能源问题已成为制约一个国家经济发展的首要因素之一。目前,中国在解决能源问题方面,所采取的措施尚不能从根本上解决这一问题。提出能源农业的概念,系统阐述了能源农业的特点以及中国在发展能源农业方面所要采取的能源作物的筛选、培育、标准化栽培管理制度的建设、加工设备和加工工艺、能源转化设备转化效率和转化机制以及区域发展规划制定等一系列的基础及基础应用研究措施。     

Studies on the Situation of Soil Organic Carbon Storage in Croplands in Northeast of China

This paper aims to estimate the soil organic carbon (SOC) storage in Northeast of China, identify its balance situation and changing trends under current cropping systems, and finally put forward some strategies to keep the SOC in balance. A biogeochemical model (DNDC) for agro-ecosystem was employed to predict SOC dynamics in agricultural ecosystems at regional scale. Data on climate, soil properties, cropping systems, acreage, and management practices at county scale were collected from various sources and integrated into a GIS database to support the model runs at the regional scale.The model predicted results revealed that (1) Total SOC storage in agricultural lands in Heilongjiang, Jilin and Liaoning provinces in Northeast of China is about 1243.48 × 106 t (0-30cm soil layer), respectively occupying 58.4, 25.5 and 16.1%;(2) Under the current cultivation systems, SOC is in a situation of net loss with carbon losing at a high rate of 31.22 ×106 t a-1 (respectively 59.3, 25.9 and 14.8% in Heilongjiang, Jilin and Liaoning provinces) and 2.05 t ha-1 a-1, the situation is more serious in Heilongjiang and Jilin provinces; and (3) Protective cultivations, such as manuring, returning more residue of crop to the field, adopting no-till, are very useful for the accumulation of SOC in these regions.     

Adsorption-Desorption Characteristics of Chlorimuron-Ethyl in Soils

The adsorption-desorption characteristics of chlorimuron-ethyl in soils were investigated to provide the basic data for evaluating the safety in field and the risk to water resource. The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques; furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils. The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for the Freundlich model well, and the physical reaction presents the main contribution during the adsorption-desorption process. The adsorption values （Kads-f） of chlorimuron-ethyl in 8 types of soil ranged from 0.798 to 6.891. The isotherms of 2# （Jiangxi clay） and 3# （Jiangxi sand loam） soils belong to the S-type curve, while the isotherms of another 6 type soils belong to the L-type isotherm. The results of desorption indicated that the hysteresis phenomena appeared during the desorption process, and the hysteresis coefficients （H） of the herbicides in 8 soils varied from 0.259-0.980. Furthermore, Kads-f and desorption values （Kads-f） increased with the OM （%） and the clay content increasing, while the values decreased with the soils pH increasing. The H values decreased with the OM and the clay content increasing, and increased with the soils pH increasing. It can be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which will induce the great translocation of the herbicide after application in field. It can be transported to ground or groundwater causing risk to environments. The physical and chemical properties of soils, including the OM, the clay content, and the pH of soil were the dominating factors during the adsorption-desorption.     

Golf course superintendents’ knowledge of variability within fairways: a tool for precision turfgrass management

Precision Agriculture - Golf course superintendent’s knowledge of variability may be an overlooked and underutilized tool for precision turfgrass management (PTM). This case study used a...     

Testing of Seedborne Fungi in Wheat Germplasm Conserved in the National Crop Genebank of China

There is a primary understanding of the dominant fungi in wheat seeds conserved in the National Crop Genebank of China （NCGB） and an evaluation of the healthy status of wheat germplasm propagated in different regions. A total of 1 465 wheat accessions were detected for seedbone fungi by blotter, agar plate, and wash tests. By blotter test, 17 genera of fungi, including more than 30 species, were detected in 712 wheat accessions from Shaanxi, Hebei, and Qinghai provinces, China. Alternaria was the most frequently detected in wheat seeds from Shaanxi Province, followed by Rhizopus, Penicillium, Aspergillus, Bipolaris, Cladosporium, Gonatobotrys, Chaetomium, and others. Seedborne fungi in wheat seeds from Hebei Province, with relatively high incidence were Alternaria, Rhizopus, Penicillium, Aspergillus, Bipolaris, Cladosporium, and Fusarium. In the seeds from Qinghai Province, Alternaria, Rhizopus, Bipolaris, Cladosporium, and Trichothecium are important seed-borne fungi. The seed germination was reduced substantially when seeds were infected by Fusarium verticillioides （syn. F. moniliforme）, Bipolaris nodulosa, and Cladosporium herbarum. Eighteen genera and 25 species of fungi were identified in 353 accessions from Shaanxi Province using the agar plate test. The dominant fungi were Alternaria, Aspergillus, Bipolaris, Gonatobotrys, Penicillium, and Fusarium. The smut fungi, Ustilago tritici, was detected by the wash test in 400 accessions, but it was low in incidence in 300 seed samples from Shaanxi Province （1.3%）, and in 100 samples from Hebei Province （2.0%）. Totally 19 genera of fungi were detected in wheat seed samples, and some seedborne fungi were saprophytic and others were biotrophic which could cause seedborne diseases in the field.     

Development of hybrid rice in China

The success achieved in development of hybrid rice is a great breakthrough in rice breeding which provides an effective way to markedly enhance rice yield on a large scale. China is the first country in the world to exploit rice heterosis commercially. Research on hybrid rice was initiated in 1964. The genetic tools, viz, cytoplasmic male sterile(CMS), maintainer and restorer lines (or A, B and R     

Diversity of Trichoderma in greenhouse soil

The protected agricultural production has become one of the fast growing and wid espread cultivation technology in the north parts of China. Continuous cultivati on of single crop or less rotation of crops usually resulted in the large amount of accumulation of soilborne pathogens and serious crop diseases in the greenho use. After a few years of investigation of soilborne fungi in the north parts of China, nearly one hundred species of mictosporic fungi have been identified by the authors.…     

Optimization of ISSR-PCR system in licorice

甘草是中国最大宗的药材之一,具有重要的药用、生态及工业价值。利用ISSR技术对甘草种质资源的遗传多样性进行深入研究,对甘草物种生物多样性的保护及新品种培育具有重要意义。研究了影响甘草ISSR-PCR扩增效果的一些因素,实验结果表明:最适宜用于甘草ISSR PCR分析的反应条件为:20μl反应体系中,1×TaqDNA聚合酶配套缓冲液(10mmol/LTris-HCL,pH9.0,50mmol/LKCL,0.1%TritonX_100,2.0mmol/LMg2 ),0.8UnitTaqDNA聚合酶,0.4μmol/L引物,200μmol/LdNTP,10ng模板DNA。     

Alleviation of Al Toxicity in Barley by Addition of Calcium

The potential mechanism by which Ca alleviates Al toxicity was investigated in barley seedlings. It was found that 100 Al-alone treatment inhibited barley plant growth and thereby reduced shoot height and root length, and dry weights of root, shoot and leaf; promoted Al accumulation but inhibited Ca absorption in plant tissues; and induced an increase in the activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） and in the level of lipid peroxidation （MDA content） in leaves. Except for the increase in Ca concentration in plant tissues, treatment with 0.5 mM Ca in the absence of Al had less effect on the above-mentioned parameters, compared with the control. Addition of Ca efficiently reduced Al toxicity, which is reflected by the promotion of plant growth, reduction in Al concentration and MDA content, increase in Ca concentration and in SOD, POD, and CAT activities compared with the Al-alone-treatment; with increase in Ca level （3.0 raM）, the ameliorative effect became more dominant. This indicated that the alleviation of aluminum toxicity in barley seedlings with Ca supplementation could be associated with less absorption of Al and the enhancement of the protective ability of the cell because of increased activity of the antioxidative enzyme.