37 research outputs found
Consumer awareness and attitudes toward GM foods in Kenya
A survey of 604 consumers was conducted in Nairobi, Kenya, in November and December 2003, at three points of sale (supermarkets, kiosks, and posho mills) to determine consumer awareness and attitudes towards genetically modified (GM) foods. Above a third (38%) of the respondents were aware of GM crops, mostly from newspapers, television and radio. Others had learned about GM crops at school. Newspapers and television were more important to higher-income and more educated consumers. Consumers acknowledged the technology’s potential positive impacts, with more than 80% agreeing that it increases productivity. Sixty-eight percent said they would buy GM maize meal at the same price as their favorite brands, although many had concerns; half of the respondents feared that GM technology could lead to a loss of biodiversity and affect non-target insects; while more than one- third (37%) had concerns about the effects of GM food on human health. We conclude that GM technology has a role to play in food security in Kenya. However, consumers need more information about the technology, which can be provided through established sources of information. Finally, consumer attitudes should be studied regularly, and the survey population broadened to include rural consumers
Biocontrol-based strategies for improving soil health and managing plant-parasitic nematodes in coffee production
Open Access JournalCoffee is an important commodity for Kenya, where production is steadily declining, despite a global rise in demand. Of the various constraints affecting production, plant-parasitic nematodes are a significant, but often overlooked, threat. As a perennial crop, treating plantations once infected with nematodes becomes difficult. The current study evaluated the drenching application of two biocontrol agents, Trichoderma asperellum and Purpureocillium lilacinum, for their nematode control efficacy, as well as their impact on the soil nematode community structure on mature, established coffee trees in Kenya. Seven Arabica coffee field trials were conducted over two years on trees of various ages. All the fields were heavily infested with Meloidogyne hapla, the first report of the species on coffee in Kenya. Both fungal biocontrol agents were detected endophytically infecting roots and recovered from soil but not until six months after initial applications. The population densities of M. hapla had significantly declined in roots of treated trees 12 months after the initial application, although soil nematode density data were similar across treatments. Based upon the maturity index and the Shannon index, treatment with T. asperellum led to improved soil health conditions and enrichment of diversity in the microbial community. Application of P. lilacinum, in particular, led to an increased abundance of fungivorous nematodes, especially Aphelenchus spp., for which P. lilacinum would appear to be a preferred food source. The soils in the trials were all stressed and denuded, however, which likely delayed the impact of such treatments or detection of any differences between treatments using indices, such as the functional metabolic footprint, over the period of study. A longer period of study would therefore likely provide a better indication of treatment benefits. The current study positively demonstrates, however, the potential for using biologically based options for the environmentally and climate-smart management of nematode threats in a sustainable manner on established, mature coffee plantations
The Pochonia chlamydosporia Serine Protease Gene vcp1 Is Subject to Regulation by Carbon, Nitrogen and pH: Implications for Nematode Biocontrol
The alkaline serine protease VCP1 of the fungus Pochonia chlamydosporia belongs to a family of subtilisin-like enzymes that are involved in infection of nematode and insect hosts. It is involved early in the infection process, removing the outer proteinaceous vitelline membrane of nematode eggs. Little is known about the regulation of this gene, even though an understanding of how nutrients and other factors affect its expression is critical for ensuring its efficacy as a biocontrol agent. This paper provides new information on the regulation of vcp1 expression. Sequence analysis of the upstream regulatory region of this gene in 30 isolates revealed that it was highly conserved and contained sequence motifs characteristic of genes that are subject to carbon, nitrogen and pH-regulation. Expression studies, monitoring enzyme activity and mRNA, confirmed that these factors affect VCP1 production. As expected, glucose reduced VCP1 expression and for a few hours so did ammonium chloride. Surprisingly, however, by 24 h VCP1 levels were increased in the presence of ammonium chloride for most isolates. Ambient pH also regulated VCP1 expression, with most isolates producing more VCP1 under alkaline conditions. There were some differences in the response of one isolate with a distinctive upstream sequence including a variant regulatory-motif profile. Cryo-scanning electron microscopy studies indicated that the presence of nematode eggs stimulates VCP1 production by P. chlamydosporia, but only where the two are in close contact. Overall, the results indicate that readily-metabolisable carbon sources and unfavourable pH in the rhizosphere/egg-mass environment may compromise nematode parasitism by P. chlamydosporia. However, contrary to previous indications using other nematophagous and entomopathogenic fungi, ammonium nitrate (e.g. from fertilizers) may enhance biocontrol potential in some circumstances
InfluĂȘncia da densidade do solo infestado por nematoide no desenvolvimento inicial de cana-de-açĂșcar
Consumer preferences of genetically modified foods of vegetal and animal origin in Chile
Effect of soil fertility management practices on nematode destroying fungi in Taita, Kenya
The effect of soil fertility management practices on nematode destroying fungi was investigated for three seasons in Taita, Kenya. The study aimed at identifying soil fertility practice that promoted nematode destroying fungi in the soil. Field experiments were established in Taita district, the treatments comprised of Mavuno fertilizer, Triple super- phosphate and calcium ammonium nitrate (TSP+CAN), cow manure and a control where no amendments were applied. This experiment was replicated in ten farms and repeated in three planting seasons. Isolation of nematode destroying fungi carried out was using the soil sprinkle technique and the isolates were identified using the key described by Cooke and Godfrey (1964). There were significant difference (P= 1.705 x 10-06) in occurrence of the nematode destroying fungi between soil fertility treatments. The highest mean (1.6) occurrence of nematode destroying fungi was recorded in soils amended with cow manure and the least (0.7) was recorded in soils from the control plots. A mean of 0.78 was recorded in soils from both TSP+CAN and Mavuno fertilizers. Plots amended with cow manure presented the highest diversity of nematodes followed by the control, then TSP+CAN and least in Mavuno with shannon indices of 0.34, 0.15, 0.13 and 0.11 respectively. Sixty percent of all the isolated nematode destroying fungi genera were from plots treated with cow manure and only twenty percent were from plots amended with the inorganic fertilizer. The control plots recorded higher number of nematode destroying fungi compared to the soils that received inorganic fertilizers
Ethno-pharmacological practices in management of livestock helminthes by pastoral communities in the drylands of Uganda. Livestock Research for Rural Development
Abstract A two stage sampling ethno-pharmacological study was carried out with agro-pastoralists in Nakasongola district involving two sub-counties namely; Nabiswera and Nakitoma. Participatory methods were used to establish a livestock disease inventory, ethno-diagnosis, medicinal plants used and implication for livestock-based livelihoods. Fourteen focus groups discussion comprising of 198 persons and 32 key informant interviews were conducted. Trypanosomosis (20.9%), East cost fever (15.5%) and helminthosis (12.8%) were found to be the most prevalent of the twenty five diseases affecting different livestock species in the area. Thirty seven plants species belonging to 28 genera and 24 families were reported as traditional treatments against helminthosis. The frequently used plant parts were leaves(54.1%) and roots (29.7%). Cold aqueous extraction (pounding and adding water) (81.1%) was the main method of preparation of ethno-veterinary remedies with oral drenching as the main route of administration. About 65% of population used combination of traditional and conventional veterinary medicine, 22% used only conventional veterinary medicines, while 13% of the farmers used traditional medicine. Accuracy of ethno-diagnosis compared well with conventional veterinary medicine diagnosis although the causes of the diseases were not well understood by the respondents. Medicinal plants were found to be an important input in livestock production although their efficacy, active molecules and safety is not known thus there was urgent need of scientific studies into these research gaps
Potential of intercropping for management of some arthropod and nematode pests of leafy vegetables in Kenya
African leafy vegetables (ALVs) play an important role as income and food
security crops in many households in Kenya. However, their potential in
alleviating poverty and ensuring household food and nutrition security has
not been fully exploited. The objectives of this study were to identify some
arthropod and nematode pests that infest ALVs and to evaluate the
effectiveness of intercropping of susceptible and resistant plants for the
management purposes. Three vegetable types: African nightshade, sunn hemp and
spider plant were used in determining the efficacy of an intercrop of
susceptible and non-susceptible types in reducing arthropod and nematode pest
effect. The treatments in the field experiment consisted of different
intercrop designs and a sole crop design as control while data was taken
based on five different variables. Crops in the field were infested with
arthropod pests and eight different species were enumerated. The same row and
hill intercropping designs were the most effective in reducing the effect of
arthropod and nematode pests compared to the control plots. Spider plant and
African nightshade intercrops recorded the least arthropod pest damage,
higher fresh and dry shoot yields and differed significantly (Pâ€0.05) to
African nightshade planted as a sole crop. A similar trend was observed when
the experiment was repeated with a sunn hemp and African nightshade
intercrop. It is concluded from this study that intercropping of different
crops can be integrated with other methods to provide an easily adaptable
technology to apply for effective management of arthropod and nematode pests
with low external inputs