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1.
Kate L. Constantine Fernadis Makale Idah Mugambi Duncan Chacha Harrison Rware Alexander Muvea Vincent K. Kipngetich Justice Tambo Adewale Ogunmodede Djami Djeddour Corin F. Pratt Ivan Rwomushana Frances Williams 《Pest management science》2023,79(11):4343-4356
Background
In Kenya, rice (Oryza sativa L.) is mainly produced under irrigation by small-scale farmers. Mwea irrigation scheme (MIS) in Kirinyaga County accounts for 80–88% of rice production. Here, rice is the main source of livelihood and a source of revenue generation for the county. However, a recently established invasive freshwater snail, Pomacea canaliculata (Lamarck) (family: Ampullariidae), a species of apple snail, presents a serious threat to rice production.Results
Household surveys, focus group discussions and key informant interviews highlight apple snail as a serious problem in MIS. Households that observed at least a moderate level of infestation (>20% of cultivated area) experienced significant reductions in rice yield (~14%) and net rice income (~60%). Farmers reported increased use of chemical pesticides for management of apple snail. In addition, the cost of hired labor for physical removal of egg masses and snails is resulting in substantial negative effects on net income. Farmer age, area of land owned, responsibility for decision-making, receipt of extension advice, training, and membership of a farmer organization, were all statistically significant variables to explain farmers awareness of the need for area-wide apple snail management.Conclusion
Strategies to limit the spread of apple snail are urgently needed. A Multi-Institutional Technical Team (MITT) has been established to spearhead management efforts and consolidate advice to farmers on how to manage apple snail. However, without action to mitigate spread, the consequences could be disastrous for rice production and food security in Kenya, and for other rice growing regions across Africa. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献2.
Nadeau JH Balling R Barsh G Beier D Brown SD Bucan M Camper S Carlson G Copeland N Eppig J Fletcher C Frankel WN Ganten D Goldowitz D Goodnow C Guenet JL Hicks G Hrabe de Angelis M Jackson I Jacob HJ Jenkins N Johnson D Justice M Kay S Kingsley D Lehrach H Magnuson T Meisler M Poustka A Rinchik EM Rossant J Russell LB Schimenti J Shiroishi T Skarnes WC Soriano P Stanford W Takahashi JS Wurst W Zimmer A;International Mouse Mutagenesis Consortium 《Science (New York, N.Y.)》2001,291(5507):1251-1255
3.
Regression analysis (analysis of covariance) is contrasted with the conventional "mean period length" for estimating the length of period of the spontaneous activity frequency (free-running period) in population samples of Gila monsters (Heloderma suspectum) and kangaroo rats (Dipodomys merriami) in the Sonoran Desert. The mean period length in each population does not differ significantly from 24:00 hours (P > .05) and it does not differ significantly (P > .05) between the species studied; the probability that the free-running period a(in constant dark) in natural populations of Gila monsters and kangaroo rats is different from 24:00.0 is less than 1 in 1000 (P < .001). The so-called "mean period length" is of little or no use for precise determination of the period and phase relationships in circadian rhythms; moreover, it is entirely without value for statistical testing of differences either within or between populations. 相似文献
4.
Zira Mavunganidze Ignacio Casper Madakadze Justice Nyamangara Paramu Mafongoya Nester Mashingaidze 《Weed Research》2020,60(5):334-342
Understanding drivers of weed density and diversity is essential for the development of weed management strategies. Here, we compared temporal changes in weed density and diversity under no-till (NT) and conventional (CONV) tillage systems in cotton–maize rotations on loam, clay loam and sandy loam soils immediately after transition to NT in Kadoma, Zimbabwe. The effect of tillage system on weed density varied through the growth season and was dependent upon soil type and species composition of the weed community. Although weed responses to tillage system varied amongst species, we identified general trend effects on weed density on specific soils. At 3 weeks after crop emergence (WACE), weed density on loam soils was 76% and 96% higher in NT than in CONV during the 2009/2010 and 2010/2011 seasons, respectively, and on clay loam soils it was 37% and 33% higher in NT than CONV, respectively. Weed densities in NT and CONV were similar across all soil types at 6 WACE during the 2009/2010 and 2010/2011 seasons and at 9 WACE in 2009/2010. Tillage system did not affect weed density during the growth season on sandy loam soils. Weed diversity (Shannon index) was at least 75% higher in NT than CONV on loam and clay loam soils at 3 WACE during both seasons. It is likely these increases in weed densities following conversion to NT will exacerbate already prevalent weed management problems in the smallholder sector. Earlier weeding is recommended to suppress weed emergence and reduce likely associated crop yield losses. 相似文献
5.
为了解福州菌草基地巨菌草和绿洲一号2种菌草的根际土壤真菌群落多样性,采用Illumina Miseq高通量测序技术和生物信息学方法,对菌草根际土真菌的多样性及群落结构进行分析。结果表明：从3份土壤样本中获得525 292条ITS序列,在97%序列相似性基础上可划分为7267个可操作分类单元（OTU）。真菌群落的丰富度指数（ACE）以菌草非根际土最低,绿洲一号根际土略高于巨菌草根际土;而多样性指数（Shannon-Wiener和Simpson）菌草根际土高于非根际土,绿洲一号根际土略高于巨菌草根际土。3份样品的优势菌门为子囊菌门（Ascomycota）、担子菌门（Basidiomycota）、接合菌门（Zygomycota）、壶菌门（Chytridiomycota）、球囊菌门（Glomeromycota）;优势菌纲为散囊菌纲（Eurotiomycetes）、粪壳菌纲（ Sordariomycetes）、座囊菌纲（Dothideomycetes）、伞菌纲（Agaricomycetes）、锤舌菌纲（Leotiomycetes）、圆盘菌纲（Orbiliomycetes）、银耳纲（Tremellomycetes）、粘膜菌纲（Wallemiomycetes）;优势菌属为篮状菌属（Talaromyces）、深黄伞形霉属（Umbelopsis）、枝孢菌属（Cladosporium）、暗双孢菌属（Cordana）、镰刀菌属（Fusarium）、隐球菌属（Cryptococcus）、淡紫紫霉属（Purpureocillium）、赤霉菌属 （Gibberella）、灵芝属（Ganoderma）。研究结果表明,菌草根际土真菌群落多样性高于非根际土,为进一步更好地利用菌草提供理论参考依据。 相似文献
6.
Justice A. Tambo Roger K. Day Julien Lamontagne-Godwin Silvia Silvestri Patrick K. Beseh Birgitta Oppong-Mensah 《国际虫害防治杂志》2020,66(4):298-310
AbstractSince its emergence in Africa in 2016, fall armyworm (FAW) has spread rapidly and poses a severe threat to the food security and livelihood of millions of smallholder farmers in the continent. Using survey data from Ghana and Zambia, we examined FAW prevention and control methods implemented by farm households and their impacts on maize output and household consumption of self-produced maize. The main control methods used included pesticide application and handpicking of larvae, while access to information on FAW was a key driver behind the implementation of the control methods. Results from an endogenous switching regression showed that the implementation of a FAW management strategy significantly enhanced maize yield and households’ own maize consumption. When disentangling the impacts of the main control methods, we found that the combination of pesticide application and handpicking of larvae produced the highest yield gain of 125%. We concluded that the current interventions put in place by farmers to tackle FAW infestations are providing positive outcomes, but successful management of the pest will require more actions, including raising awareness to enhance the adoption of control interventions and exploring other control options. 相似文献
7.
Ted R. Turner Steven D. Duke Brian R. Fransen Maryanne L. Reiter Andrew J. Kroll Jim W. Ward Janette L. Bach Tiffany E. Justice Robert E. Bilby 《Forest Ecology and Management》2010
Elevated landslide rates in forested landscapes can adversely impact aquatic habitat and water quality and remove and/or degrade soil resources required for forest regeneration. As a result, understanding the associations between management actions, natural factors, and landslide rates is important information needed for land managers. An unusual and powerful storm in early December, 2007, caused record flooding and thousands of landslides across southwest Washington and northwest Oregon, USA, and provided a rare opportunity to examine the effects of both natural factors and forest management practices on landslide density. Landslide inventory data were collected from both aerial photos and systematic field surveys to provide a broad survey database that was used to develop estimates of landslide density and to examine associations between landslide density, precipitation, topography, and forest stand age across a 152,000 ha forested landscape in the Willapa Hills, Washington. We estimated the probability of detecting landslides on aerial photos for six strata defined by forest stand age and a broad range of rainfall intensity, expressed as percent of the 100-year, 24-h, maximum rainfall. Key findings are that landslide detection probability decreased with increasing stand age, but was similar across rainfall intensities. The overall fraction of field-detected landslides that were not detected on 1:12,000-scale aerial photos was 39%. Very few landslides occurred in the 0–100% of 100-year rainfall category, regardless of stand age or slope gradient class. At higher rainfall intensities, significantly higher landslide densities occurred on steep slopes (>70% gradient) compared to lower gradient slopes, as expected. Above ∼150% of 100-year rainfall, the density of landslides was ∼2–3 times larger in the 0–5 and 6–10 year stand age categories than in the 11–20, 21–30, 31–40, and 41+ categories. The effect of stand age was strongest at the highest rainfall intensities. Our results demonstrate that ground-based landslide inventory data are required in order to correct for detection bias from aerial photos, develop reasonable estimates of landslide density across environmental gradients such as rainfall magnitude and topography, and make unbiased interpretations of relationships between forest management associations and landslide occurrence. 相似文献
8.
Machawe?M.?Motsa Justice?M.?Thwala Titus?A.?M.?Msagati Bhekie?B.?MambaEmail author 《Water, air, and soil pollution》2012,223(4):1555-1569
Natural clinoptilolite was modified with hexadecyltrimethylammonium chloride, a cationic surfactant, and then melt-mixed with polypropylene hollow fibres to produce polymer composites with adsorptive properties. The performance of the fabricated composites was evaluated by optimizing experimental parameters such as surfactant loading, contact time, pH and initial concentration for the adsorptive removal of 2,4,6-trichlorophenol (TCP) and ortho-nitrophenol (o-NP). Based on the fourier transmission infrared spectra and scanning electron microscopy micrographs of as-received and surfactant-modified clinoptilolite, the modification of natural clinoptilolite was attained. The composites showed enhanced adsorption capability for TCP over o-NP with removal efficiencies of 84% and 46%. Loading the clinoptilolite with surfactant concentrations beyond 8 mM reduced the adsorption capacity. The removal of TCP and o-NP was found to depend critically on the pH of the solution, and the optimum ranges were 4–6 and 2–6 for compounds, respectively. The adsorption dynamics were determined with first- and second-order kinetics models, and the adsorption system for TCP and o-NP followed the first-order kinetics. Adsorption isotherm analysis revealed that the adsorption equilibrium data obeyed/fit the Freundlich isotherm. 相似文献
9.
Singer JB Hill AE Burrage LC Olszens KR Song J Justice M O'Brien WE Conti DV Witte JS Lander ES Nadeau JH 《Science (New York, N.Y.)》2004,304(5669):445-448
Chromosome substitution strains (CSSs) have been proposed as a simple and powerful way to identify quantitative trait loci (QTLs) affecting developmental, physiological, and behavioral processes. Here, we report the construction of a complete CSS panel for a vertebrate species. The CSS panel consists of 22 mouse strains, each of which carries a single chromosome substituted from a donor strain (A/J) onto a common host background (C57BL/6J). A survey of 53 traits revealed evidence for 150 QTLs affecting serum levels of sterols and amino acids, diet-induced obesity, and anxiety. These results demonstrate that CSSs greatly facilitate the detection and identification of genes that control the wide diversity of naturally occurring phenotypic variation in the A/J and C57BL/6J inbred strains. 相似文献
10.
Alternative hypotheses on post-fire successions of monospecific European beech (Fagus sylvatica L.) and black pine (Pinus nigra Arnold) forests are investigated. The research area is located in the centre of the Apennine montane belt, Italy and covers portions of the Roccamorice and Lettomanoppello municipalities within the Majella National Park. Temporal moderate-resolution (MODIS) and spatial mid-resolution (ASTER) imagery are combined for the assessment of the 2007-fire features. Tree seedlings were surveyed on the ground in post-fire forests and their unburnt equivalents during September 2008. The satellite imagery analysis provides records on spread, intensity, location and extent of the forest fires. The evidence suggests an abandoned farmland fire spreading secondarily uphill into the forests. 相似文献