Inheritance of flowering time in six pea cultivars (Pisum sativum L.)     

L. E. Watts  E. Stevenson  M. J. Crampton 《Euphytica》1970,19(3):405-410

Summary The dates of flowering of six pea cultivars and their F₁ and F₂ generations grown under a moderate level of top-yellows virus infection were analysed by both Griffing's and Jinks' methods to assess the stability of the polygenic control of flowering period. Flowering period was shown to be under the control of an additive system with dominance for the late flowering characteristic. Some gene interaction was indicated in both analyses, mainly between the later-flowering cultivars, although tests for apparent over-dominance were insignificant. It was considered that the degree of virus infection within the experiment had little, if any, effect upon flowering times and that selections for flowering date in these circumstances should be almost as reliable as those made in a disease-free environment.Slightly increased earliness over the early parent was evident in five F₂ progenies and it appears possible to make further slight gains in earliness by selection in the present material.  相似文献   

Productivity of F hybrids of botanical varieties ofBrassica oleracea L.     

L. E. Watts 《Euphytica》1970,19(3):398-404

Summary F₁ hybrids were obtained by making pair-crosses between nine botanical varieties ofBrassica oleracea. Although non-inbred parents were used, their yield was surpassed by all F₁ hybrids. The highest yields were shown by the crosses marrow-stem kale × sprouting broccoli and marrow-stem kale × cauliflower while the highest consumable yield (assessed by feeding plants to sheep) was that of F₁ hybrids marrow-stem kale × cauliflower and wild cabbage × cauliflower. A scheme for the production of F₁ hybrid seed is suggested, based upon an adaptation ofThompson's (1964) Triple-cross technique.  相似文献   

Growth‐Oriented Small Firms and the Nature and Extent of Local Embeddedness: The Case of a Traditional Metalworking Cluster     

Andrew M. Wood  H. Doug Watts  Perry Wardle 《Growth and change》2004,35(4):419-433

ABSTRACT Clusters now form a central element in many regional economic development policies. Location within a cluster of related industries is thought to increase a firm's competitive advantage resulting in higher output and productivity growth rates than in similar firms located beyond the cluster. This study focuses on owner‐managers operating small firms within a traditional cluster of metalworking industries and empirically examines the relationship between growth‐orientation and the extent and nature of cluster embeddedness. The results indicate only a limited number of differences in growth‐orientation given variations in levels of cluster embeddedness. Contrary to conventional wisdom, many of the most growth‐oriented entrepreneurs focus their activities outside the cluster, especially in terms of market‐based linkages. However, those firms with more advanced process technologies do tend to show above average within cluster linkages.  相似文献   

Crop management based on field observations: Case studies in sugarcane and coffee     

James Cock  Thomas OberthürCamilo Isaacs  Peter Roman Läderach  Alberto PalmaJavier Carbonell  Jorge VictoriaGeoff Watts  Alvaro AmayaLaure Collet  Germán LemaEinar Anderson 《Agricultural Systems》2011,104(9):755-769

For millennia farmers have continually improved their crop management and production practices through their observations and experience. More recently modern science and research methods based on controlled experiments became the most visible instrument of technological change in agriculture, nevertheless farmers continued to develop and implement new technologies based on their own observations made under commercial conditions. Modern information technology and social organization of producers make it possible to use operational research, which is based on the observation and analysis of operations so as to improve them, to manage crops better. The article describes two cases, coffee and sugarcane, in which observation of the results obtained by farmers, with the natural variation in the environment and the distinct management practices they apply can be used to determine site specific crop management practices. The basis of the methodology is to (a) obtain data from a series of cropping events that characterizes the conditions under which each crop is grown, how it is managed and how it performs under commercial conditions (data capture), (b) to manage and analyze the data in centralized databases (data management and analysis) and (c) make the information derived from the data analysis available to growers so that they can use it to make better informed decisions (interpretation). All aspects of the methodology depend on the social organization of the growers and the supply chain of which they form a part, and hence social organization is an integral part of the methodology.The processes of characterization of the growing conditions, including both environmental and management parameters, the establishment of databases, the data analysis and interpretation, and mechanisms of interacting with producers are described with emphasis on the importance of social organization and farmers’ groups. Examples are given of how this approach can be used to better understand the crop response to variation in the environment and management, and how this can be used by farmers to improve productivity and quality in two contrasting crops. The paper demonstrates that operational research can be used to evaluate farmers’ experiences and to share that knowledge amongst them so as to improve their production practices in the context of their particular environment. It is suggested that the operation research approach is particularly effective in heterogeneous landscapes with perennial crops that have not been the subject of intense research. Furthermore operational research is effective in determining the crop response to variables that are not readily studied in small plots and in determining optimal combinations of multiple variables. Producers believe in the results obtained as there are none of the problems of scaling up from experimental plots to commercial conditions. It is proposed that the approaches described can readily be applied to other crop species.  相似文献   

Activities of Metabolic Enzymes in the Hepatopancreas and Tail Muscle of the Crayfish, Procambarus clarkii and Procambarus zonangulus     

Mickie L.  Powell Stephen A.  Watts 《Journal of the World Aquaculture Society》2005,36(4):554-559

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Radio Tracer Studies on P Use Efficiency in a Rice Based Cropping System     

Lekha  Sreekantan SP. Palaniappan 《Journal of Agronomy and Crop Science》1990,165(1):14-18

Tracer studies using ³²P labelled superphosphate and rock phosphate were conducted in microplots in a field experiment on rice-rice-greengram cropping system. The trial revealed that in all the rice crops studied, P uptake and P use efficiency were higher in superphosphate treated plots than in rock phosphate applied ones. P uptake was improved with organic manuring through application of green manure or crop residues like long rice stubbles. While superphosphate performed well either with or without organic manuring, rock phosphate performed fairly well only with organic manuring. Fairly good P use efficiency could be obtained in the system when green manuring and rock phosphate application in the first crop was followed by superphosphate and long stubble incorporation in the second crop. Apparent recovery values also showed nearly the same results. But tracer studies were found to be definitely superior in the evaluation of fertilizers.  相似文献   

Cattle tick in New South Wales     

R M Watts 《Australian veterinary journal》1969,45(10):437-444

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What can studies of woodland fragmentation and creation tell us about ecological networks? A literature review and synthesis     

Jonathan W. Humphrey  Kevin Watts  Elisa Fuentes-Montemayor  Nicholas A. Macgregor  Andrew J. Peace  Kirsty J. Park 《Landscape Ecology》2015,30(1):21-50

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Soil Degradation ‐ edited by Krümmelbein,J., Horn,R. & Pagliai,M.     

C. Watts 《European Journal of Soil Science》2014,65(4):625-626

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In vivo uncoating and efficient expression of foreign mRNAs packaged in TMV-like particles   总被引：9，自引：0，他引：9  

D R Gallie  D E Sleat  J W Watts  P C Turner  T M Wilson 《Science (New York, N.Y.)》1987,236(4805):1122-1124

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