Rothamsted Experimental Station Research Articles

Carbon and nitrogen dynamics in a grassland soil with varying pH: effect of pH on the denitrification potential and dynamics of the reduction enzymes

Abstract Soil pH is known to affect most soil biological processes, including denitrification. There are conflicting results as to the effect of pH on the denitrification process and the ability of denitrifiers to adapt to acid soil conditions. The denitrification potential and dynamics of the reduction enzymes involved were investigated for four soils of different pH values from the Park Grass Experiment at Rothamsted Experimental Station. Soils were incubated aerobically or anaerobically after being amended with 500 mg NO3--N kg-1. Anaerobic treatments were with or without C2H2 or with or without chloramphenicol (known to inhibit protein synthesis). All samples were incubated for 48 h, while CO2 and N2O production and NO3-, NO2- and NH4+ concentrations were monitored. CO2 and N2O production decreased with decreasing pH under both aerobic and anaerobic conditions. The addition of chloramphenicol under anaerobic conditions appeared to have no effect on CO2 production, but decreased N2O production in soils of pHCaCl2 greater than or equal to 5, but not in soils of pHCaCl2 less than or equal to 4, where N2O production was generally slow. Investigations of the enzyme dynamics involved in denitrification using the DETRAN model, suggested that the initial concentrations of N reductase enzymes were small in all soils and the biomass of Park Grass was not adapted to anaerobiosis. Data also suggested that soils of pHCaCl2 greater than or equal to 4.9, NO2- could accumulate to high concentrations (15-30 mg N kg-1) during anaerobic periods of 6-36 h. In the aerobic incubations nitrification was observed in all soils even at pHCaCl2 less than or equal to 3.9. Antecedent water regime of the soil appeared to be important in controlling denitrification activity and the dynamics of the reduction enzymes involved in the process. There were significant effects of pH on the number of microorganisms, the time to de novo enzyme synthesis and on the kinetics of the reduction enzymes involved in denitrification.

Organic geochemical studies of soils from the Rothamsted Classical Experiments—II, Soils from the Hoosfield Spring Barley Experiment treated with different quantities of manure

Total lipid extracts (TLEs) were obtained from soil samples taken in the years 1882, 1913, 1946, 1965 and 1995 from three treatments of the Hoosfield Spring Barley Experiment at Rothamsted Experimental Station, Harpenden, Hertfordshire, U.K. The extracts were fractionated and molecular analyses performed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). In addition to the soil samples (contemporary and archived), the two primary organic inputs, barley and farmyard manure (FYM), were studied so that the composition and diagenetic behaviour of extractable lipids from the two inputs could be assessed. The major aliphatic soil lipids exhibited variable dominance with respect to the expression of barley and FYM derived lipids. Wax esters were of low abundance and too strongly affected by degradation and transesterification processes to identify a dominant input whilst the composition of soil n-alkanols was largely determined by FYM with a minor pedogenic input. n-Alkanoic acids increased in overall abundance in soils with a continual FYM input and showed appreciable degradation in soils receiving no manure. C 32 ββ hopanoic acid was detected in two plots and appeared to degrade at a rate similar to 5 β-stanols with the most likely source of this compound being the FYM. Measurements of absolute concentrations of 5 β-stanols, biomarkers characteristic of manuring, revealed that a manuring signal persisted for >120 years within the soil which had been intensively cultivated annually and had received no manure since 1871. The persistence of a manure signal in soils has important implications for archaeological studies of agricultural practices based on 5 β-stanols.

Discussion

European Journal of Soil ScienceVolume 48, Issue 1 p. 12-17 Discussion M.A. OLIVER, M.A. OLIVER Department of Soil Science, University of Reading, RG6 6DWSearch for more papers by this authorR. WEBSTER, R. WEBSTER Rothamsted Experimental Station, Harpenden, Hertfordshire AL5 2JQ, UKSearch for more papers by this authorP. BULLOCK, P. BULLOCK Soil Survey and Land Research Centre, Cranfield University, Silsoe, Bedford, MK45 4DT, UKSearch for more papers by this authorP. RAINEY, P. RAINEY 6 Fresham House, 12 Durham Road, Bromley, Kent, BR2 0SG, UKSearch for more papers by this authorD. BARLTROP, D. BARLTROP Charing Cross and Westminster Medical School, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UKSearch for more papers by this authorA. COLEMAN, A. COLEMAN Geography Department, King's College, Strand, London WCZR 2LS, UKSearch for more papers by this authorJ.F. BITHELL, J.F. BITHELL Department of Statistics, 1 South Parks Road, Oxford OX1 3TG, UKSearch for more papers by this author M.A. OLIVER, M.A. OLIVER Department of Soil Science, University of Reading, RG6 6DWSearch for more papers by this authorR. WEBSTER, R. WEBSTER Rothamsted Experimental Station, Harpenden, Hertfordshire AL5 2JQ, UKSearch for more papers by this authorP. BULLOCK, P. BULLOCK Soil Survey and Land Research Centre, Cranfield University, Silsoe, Bedford, MK45 4DT, UKSearch for more papers by this authorP. RAINEY, P. RAINEY 6 Fresham House, 12 Durham Road, Bromley, Kent, BR2 0SG, UKSearch for more papers by this authorD. BARLTROP, D. BARLTROP Charing Cross and Westminster Medical School, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UKSearch for more papers by this authorA. COLEMAN, A. COLEMAN Geography Department, King's College, Strand, London WCZR 2LS, UKSearch for more papers by this authorJ.F. BITHELL, J.F. BITHELL Department of Statistics, 1 South Parks Road, Oxford OX1 3TG, UKSearch for more papers by this author First published: 10 August 2005 https://doi.org/10.1111/j.1365-2389.1997.tb00180.xCitations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume48, Issue1March 1997Pages 12-17 RelatedInformation

Organic geochemical studies of soils from the Rothamsted Classical Experiments—I. Total lipid extracts, solvent insoluble residues and humic acids from Broadbalk Wilderness

Total lipid extracts and insoluble organic matter, i.e. solvent insoluble matter and humic acids, were studied from soil samples taken from the three adjacent plots comprising the Broadbalk Wilderness at Rothamsted Experimental Station, Harpenden, Hertfordshire, U.K. Analyses involved high-temperature gas chromatography (HT-GC) and HT-GC-mass spectrometry (HT-GC-MS) to investigate trimethylsilylated total lipid extracts and Curie-point pyrolysis-GC (Py-GC) and Py-GC-MS to investigate solvent insoluble fractions. The plots were chosen specifically for their different types of vegetation cover. Samples of the vegetation were examined in parallel with the underlying soils in an effort to follow the fate of the major plant components in soil. The application of HT-GC and HT-GC-MS allowed changes in high molecular weight lipids, particularly intact acyl lipids, such as triacylglycerols, wax esters, steryl and triterpenyl esters, to be studied in leaf and soil extracts. The total lipid extracts of the soil samples from the wooded area were dominated by the input from leaf-derived lipids. The lipid extracts of soils from the grazed and stubbed areas were markedly different from those from the wooded area, and reflected the mixed vegetation cover dominated by grass species. In marked contrast, the pyrolysis data from the insoluble organic matter and humic fractions of the soils did not reflect the composition of the lignin comprising the overlying vegetation, but rather showed evidence of amino acid moieties probably present as polypeptides. The absence of the lignin signal is possibly due to rapid diagenetic changes presumed to be influenced by the slightly alkaline pH of the soil. The ability to recover recognizable chemical signals from soil lipids has important implications for archaeological investigations aimed at revealing temporal changes in vegetation cover and/or differences in land use at specific site locations.

Changes in the heavy metal contents of soil from the Park Grass Experiment at Rothamsted Experimental Station.

The classical Rothamsted Experiments allow to contribute to current research. The heavy metal content of soil and hay samples have been measured with ICP-AES from a control and a fertilized plot of the Park Grass Experiment. Today a difference of 1.2 can be observed in the pH levels of the control and fertilized plots; the pH level of the control plot has decreased about 1.0, that of the fertilized plot about 2.2 as a result of 150 years of acid deposition and fertilization. The changes in the pH levels has caused many changes in the heavy metal content of the top layer of the soil. Using different extraction methods (e.g., ammonium acetate, EDTA, and sequential analysis), the heavy metal content of different fractions have been estimated. In the control plot, the Zn, Cd and Pb content increased. In the fertilized plot, the Pb and Cd contents have also increased because of atmospheric deposition and small amounts of lead in the fertilizer. The available form of Cd and Pb increased in both the control and the fertilized plots.

A Conversation with Oscar Kempthorne

Oscar Kempthorne was born on January 13, 1919, in St. Tudy, Cornwall, England. His schooling was in Cornwall. He received a B.A. with Honors from Cambridge University in 1940, an M.A. from Cambridge in 1943, and was awarded an Sc.D. degree from Cambridge in 1960. He worked at Rothamsted Experiment Station from 1941 to 1946 and joined the Department at Iowa State College as Associate Professor in 1947. He was promoted to Professor in 1951, and was named Distinguished Professor of Science and Humanities in 1964. He was President of the Biometric Society, ENAR, in 1961 and President of the Institute of Mathematical from 1984 to 1985. He is a Fellow of the American Statistical Association, the Institute of Mathematical Statistics, the American Association for the Advancement of Science and an Honorary Fellow of the Royal Statistical Society. He was awarded an honorary Ph.D. degree from the University of Ioannina in Greece. This conversation took place at Dr. Kempthorne's home in Ames, Iowa on March 7, 1994. Folks: Kemp, I have enjoyed watching your ASA videotape From Observation to Inference (ASA archives) and I know about the videotape of your lecture The Adventures of a Cornish Farm Boy in Search of Statistics (Kempthorne personal copy). I am very interested in your university days.

The significance of the retention of atmospherically deposited cadmium on plant surfaces to the cadmium content of herbage

Samples of mixed herbage were collected in 1993 and 1994 from the Park Grass Experiment at Rothamsted Experimental Station in the UK. The samples were separated into grasses and other species and the material in each group was then halved; one half was washed and the other was left unwashed. Analysis of Cd was by Zeeman correction GFAAS following a nitric acid digestion. The results showed that washing the samples prior to analysis made no difference to their Cd concentrations and that there was almost the same concentration of Cd in grasses and in other species. This implies that Cd remaining on leaf surfaces and changes in sward composition have not made a significant contribution to the previously reported underlying changes in herbage Cd over the last 130 years. Herbage Cd content has changed in response to either an underlying increase in soil Cd, increases in absorbed atmospherically derived Cd and/or changes in soil chemistry.

Modelling recent and historic soil data from the Rothamsted Experimental Station, UK using SAFE

Historic soil data from 1883, 1906, 1964 and new data from 1991 from the Geesecroft Wilderness Experiment at Rothamsted Experimental Station, UK, was used as a test of the dynamic biogeochemical model SAFE in a situation where the available data can be used to confine the model completely. The test indicated that the model is capable of predicting the observed changes over time in soil chemistry, without calibration. This suggests that the model formulation and choice of significant processes are quantitatively correct. The model application at Rothamsted shows that deposition of acidity because of sulphur and nitrogen emissions during the last 110 years, is the major cause of soil acidification in Geesecroft Wilderness. Natural afforestation of the site has also contributed with a significant but smaller amount of acidity input to the soil. Acidification has caused a possibly irreversible decrease in the cation exchange capacity of the soil because of weathering of clay minerals.

Methane oxidation in temperate soils: Effects of land use and the chemical form of nitrogen fertilizer

Results are presented from long-term experimental sites showing that land use and agricultural management practices play an important role in mediating the sink strength of aerobic soils for methane. At sites located within 1 km 2 at Rothamsted Experimental Station, U.K. the methane sink strength of soil follows the order woodland > grassland > arable. Comparison of grassland plots receiving nitrate-N fertilizer compared to ammonium-N fertilizer shows that the long-term (138 years) application of ammonium-N fertilizer caused a significant decrease in the soil sink strength for methane but that the application of nitrate-N for the same length of time did not.These results are discussed in relation to land use and microbial ecology.

Effect of Phosphate Fertilizers and Atmospheric Deposition on Long-Term Changes in the Cadmium Content of Soils and Crops

Trends are reported in the Cd content of herbage collected and stored from the Park Grass Experiment at Rothamsted Experimental Station, a semirural location in the U.K. Samples from 1861 to 1992 were bulked for 5-year periods from two phosphate fertilizer-treated plots, now with soil pH 4.9 (unlimed) and 6.5 (limed), respectively. Analysis of Cd was by Zeeman correction GFAAS following a nitric acid digestion. The data are compared with those from control plots which have not received superphosphate. On the unlimed plots, levels of Cd in the herbage from the phosphate-treated plot were very similar to those on the control for the years to 1930; whereas from 1940 to the present, the Cd concentrations in herbage were considerably greater on the phosphate-treated plot. On the limed plots, Cd concentrations in the herbage from both the phosphate-treated and control plots have remained similar to each other, although both plots exhibit a small increase of about 1 Mg of Cd kg-1 year-1 since the beginning of the liming treatment in 1903

TOM GOODEY: The Father of Nematology in Britain

Tom Goodey O.B.E., D.Sc., F.R.S. is generally recognized as the Father of Nematology in Britain. Although his early postgraduate work was on soil protozoa, from 1920 he worked exclusively on nematodes. His first text book, Plant Parasitic Nematodes and the Diseases They Cause, published in 1933, was a notable landmark in the development of nematology (48). His second book Soil and Freshwater Nematodes (80) indicated his breadth of understanding of this vast group of animals. From 1921 until 1946 he was a member of the team working under Professor R.T. Leiper based for most of that time at the Institute of Agricultural Parasitology, Winches Farm, St. Albans, England. He was author, or coauthor, of 125 publications, which included the proposal of 9 new genera, 37 new species and 49 detailed redescriptions of nematodes. In 1947 he was made head of the newly formed Nematology Department at Rothamsted Experimental Station, where he stayed until his retirement in 1952. In his later years he struck up a very close friendship with Gerald Thorne, the American nematologist, with whom he exchanged ideas on techniques in hematology. In 1951, he was responsible for the very successful nematology symposium held in Harpenden, which marked the beginning of the biennial nematology symposia in Europe. As well as a very full and successful scientific career, he was also a professional singer with a fine tenor voice and he frequently performed for the theater, concert hall, and radio broadcasts under his stage name of Roger Clayson.

Proceedings of the Twenty-Fifth Meeting of the Agricultural Research Modellers' Group

This group, which is concerned with the applications of mathematics to agricultural science, is sponsored by the Biotechnology and Biological Sciences Research Council. It was formed in 1970, and has since met at approximately yearly intervals in London for one-day meetings. The twenty-fifth meeting of the group, chaired by Dr T. M. Addiscott of the Institute of Arable Crops Research, Rothamsted Experimental Station, was held in the Wellcome Meeting Room at the Royal Society, 6 Carlton House Terrace, London on Friday, 15 April 1994, when the following papers were read.

Yield response to insecticide treatment of a perennial ryegrass sward following sheep grazing or cutting by machine

Grass and Forage ScienceVolume 49, Issue 1 p. 105-106 Yield response to insecticide treatment of a perennial ryegrass sward following sheep grazing or cutting by machine R.O. CLEMENTS, Corresponding Author R.O. CLEMENTS AFRC Institute of Grassland and Environmental Research, North Wyke Research Station, UKR. O. Clements, AFRC Institute of Grassland and Environmental Research, North Wyke Research Station, Okehampton, Devon EX20 2SB, UKSearch for more papers by this authorL.F. HENDERSON, L.F. HENDERSON Rothamsted Experimental Station, Harpenden, UKSearch for more papers by this author R.O. CLEMENTS, Corresponding Author R.O. CLEMENTS AFRC Institute of Grassland and Environmental Research, North Wyke Research Station, UKR. O. Clements, AFRC Institute of Grassland and Environmental Research, North Wyke Research Station, Okehampton, Devon EX20 2SB, UKSearch for more papers by this authorL.F. HENDERSON, L.F. HENDERSON Rothamsted Experimental Station, Harpenden, UKSearch for more papers by this author First published: March 1994 https://doi.org/10.1111/j.1365-2494.1994.tb01981.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume49, Issue1March 1994Pages 105-106 RelatedInformation

New approaches to plant‐parasitic nematode control

Journal of ZoologyVolume 232, Issue 2 p. 341-346 New approaches to plant-parasitic nematode control P. R. Burrows, P. R. Burrows Department of Entomology & Nematology, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQSearch for more papers by this authorB. R. Kerry, B. R. Kerry Department of Entomology & Nematology, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQSearch for more papers by this authorR. N. Perry, R. N. Perry Department of Entomology & Nematology, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQSearch for more papers by this author P. R. Burrows, P. R. Burrows Department of Entomology & Nematology, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQSearch for more papers by this authorB. R. Kerry, B. R. Kerry Department of Entomology & Nematology, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQSearch for more papers by this authorR. N. Perry, R. N. Perry Department of Entomology & Nematology, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQSearch for more papers by this author First published: February 1994 https://doi.org/10.1111/j.1469-7998.1994.tb01577.xCitations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume232, Issue2February 1994Pages 341-346 RelatedInformation

A Conversation with David J. Finney

David John Finney was born in 1917 in Cheshire, England. He received his secondary schooling at the Lymm Grammar School and the Manchester Grammar School. At school he developed an interest in and showed an aptitude for mathematics. From 1934 to 1938, he pursued this interest by reading mathematics and statistics at Cambridge University. He then accepted a post-graduate scholarship to work with R. A. Fisher at the Galton Laboratory in the University of London. In 1939 he took a position as assistant to Dr. Frank Yates at Rothamsted Experimental Station, where he became involved in many problems concerning the design of field experiments and the interpretation of their results. In 1945, he began his university teaching career at Oxford University as first holder of the post of lecturer in the design and analysis of scientific experiments. In 1954, he left Oxford to establish a Department of Statistics in the University of Aberdeen and also to set up a unit of statistics funded by the British Agricultural Research Council that could provide a service for Scotland patterned along the lines of the Rothamsted statistics department's work in England. In 1966, David was invited to move this unit to Edinburgh, where he was to continue as its director and also to become the first Professor of Statistics in the University of Edinburgh, thereby inaugurating his third statistics department. He retired from his position at Edinburgh in 1984, but he has remained active, especially in the study of problems relating to the safety of drugs. David Finney is author or joint author of nine books, including those on probit analysis and on biological assay for which he is widely known among the international statistical community. He has over 250 other publications to his credit. In 1955 he was elected to fellowship of the Royal Society and of the Royal Society of Edinburgh. In 1978 he was honoured by appointment as a Commander of the Order of the British Empire. Other honours include Oxford University's Weldon Memorial Prize and honorary doctorates from the University of Waterloo, the National Faculty of Agriculture, Gembloux, Belgium, City University, London and Heriot-Watt University, Edinburgh. The main strands running through his career are experimental design, bioassay and (later) radioimmunoassay and other biometric techniques, statistical computing and drug safety. Pursuit of these interests has led to extensive travel and to many interesting assignments. He has spent substantial periods in India, in the Philippines and in the USA. He has been Chairman of the British Computer Board for the Universities (1970-1974), President of the Biometric Society (1964) and President of the Royal Statistical Society (1973). During 1987-1988, he was Director of the research centre operated by the International Statistical Institute. Ian MacNeill is Professor, Department of Statistical and Actuarial Sciences, University of Wes tern Ontario, London, Ontario, Canada N6A 5B9. The following conversation took place in Toronto during the Statistical Society of Canada's 1991 meeting, which immediately followed the symposium held in Hamilton, Ontario, in honour of Charles Dunnett

Molecular cloning of a novel barley seed protein gene that is repressed by abscisic acid.

Ru Liu 1, Odd-Arne Olsen 2, Martin Kreis 3 and Nigel G. H alford 4 , 1Biochemistry and Physiology Department, AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Hertfordshire AL5 2JQ, UK," 2plant Molecular Biology Laboratory NLVH, P.O.B. 51, N-1432,4S-NLH, Norway," 3 Universitd de Paris-Sud, Biologie du DOveloppement des Plantes, Bdtiment 430, F-91400 Orsay Cedex, France; 4Department of Agricultural Sciences, University of Bristol, AFRC Institute of Arable Crops Research, Long Ashton Research Station, Bristol BS18 9AF, UK (* author for correspondence)

Synthetic aphid sex pheromone lures female parasitoids

Entomologia Experimentalis et ApplicataVolume 61, Issue 1 p. 97-99 Synthetic aphid sex pheromone lures female parasitoids J. Hardie, J. Hardie Agricultural and Food Research Council Linked Research Group in Aphid Biology, Department of Biology, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK AFRC Linked Research Group in Aphid Biology, Imperial College at Silwood Park, Ascot, Berks. SL5 7 PY, UKSearch for more papers by this authorS. F. Nottingham, S. F. Nottingham Agricultural and Food Research Council Linked Research Group in Aphid Biology, Department of Biology, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UKSearch for more papers by this authorW. Powell, W. Powell AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UKSearch for more papers by this authorL. J. Wadhams, L. J. Wadhams AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UKSearch for more papers by this author J. Hardie, J. Hardie Agricultural and Food Research Council Linked Research Group in Aphid Biology, Department of Biology, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK AFRC Linked Research Group in Aphid Biology, Imperial College at Silwood Park, Ascot, Berks. SL5 7 PY, UKSearch for more papers by this authorS. F. Nottingham, S. F. Nottingham Agricultural and Food Research Council Linked Research Group in Aphid Biology, Department of Biology, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UKSearch for more papers by this authorW. Powell, W. Powell AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UKSearch for more papers by this authorL. J. Wadhams, L. J. Wadhams AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UKSearch for more papers by this author First published: October 1991 https://doi.org/10.1111/j.1570-7458.1991.tb02401.xCitations: 48 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume61, Issue1October 1991Pages 97-99 RelatedInformation

Role of esterases in resistance of insects to insecticides

Conference Article| August 01 1991 Role of esterases in resistance of insects to insecticides Alan L. Devonshire Alan L. Devonshire 1A.F.R.C. Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts. AL5 2JQ, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1991) 19 (3): 755–759. https://doi.org/10.1042/bst0190755 Article history Received: April 12 1991 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation Alan L. Devonshire; Role of esterases in resistance of insects to insecticides. Biochem Soc Trans 1 August 1991; 19 (3): 755–759. doi: https://doi.org/10.1042/bst0190755 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search Keywords: OP, organophosphorus, AChE, acetylcholinesterase, CCA, catalytic centre activity This content is only available as a PDF. © 1991 Biochemical Society1991 Article PDF first page preview Close Modal You do not currently have access to this content.

A review of tolerance by potato plants of cyst nematode attack, with consideration of what factors may confer tolerance and methods of assaying and improving it in crops

Annals of Applied BiologyVolume 117, Issue 3 p. 703-740 A review of tolerance by potato plants of cyst nematode attack, with consideration of what factors may confer tolerance and methods of assaying and improving it in crops K. EVANS, K. EVANS Entomology and Hematology Department, Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UKSearch for more papers by this authorP. P. J. HAYDOCK, P. P. J. HAYDOCK Entomology and Hematology Department, Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UK *Harper Adams Agriculture College, Newport, Shropshire TF10 8NB, UKSearch for more papers by this author K. EVANS, K. EVANS Entomology and Hematology Department, Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UKSearch for more papers by this authorP. P. J. HAYDOCK, P. P. J. HAYDOCK Entomology and Hematology Department, Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts AL5 2JQ, UK *Harper Adams Agriculture College, Newport, Shropshire TF10 8NB, UKSearch for more papers by this author First published: December 1990 https://doi.org/10.1111/j.1744-7348.1990.tb04836.xCitations: 32 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume117, Issue3December 1990Pages 703-740 RelatedInformation

Heterogeneity of variance in field experiments: some causes and practical implications

SUMMARYData from 62 field experiments on various crops in 1973–85 at Rothamsted Experimental Station were used to obtain knowledge about the heterogeneity of variance of yield. The results suggest that explaining heterogeneity of variance in terms of a mean–variance relationship is inadequate; better understanding of the patterns of changing variance can be gained by investigating the influence of the experimental factors on the variance. The effects of the factor ‘amount of nitrogen’ on mean yield and on the variance were positively correlated; factors which tend to affect variability but not the mean were identified. Suggestions are given for controlling variance but the need for further experimental evidence is emphasized.