Disturbance severity and canopy position control the radial growth response of maple trees (<Emphasis Type="Italic">Acer</Emphasis> spp.) in forests of northwest Ohio impacted by emerald ash borer (<Emphasis Type="Italic">Agrilus planipennis</Emphasis>)     

K.C. Costilow  K.S. Knight  C.E. Flower 《Annals of Forest Science》2017,74(1):10

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Stand dynamics and tree quality response to precommercial thinning in a northern hardwood forest of the Acadian forest region: 23 years of intermediate results     

D. Edwin Swift  William Knight  Martin Béland  Issifi Boureima  Charles P.-A. Bourque  Fan-Rui Meng 《Scandinavian Journal of Forest Research》2017,32(1):45-59

In the late 1980s, large forest companies began precommercial thinning (PCT) operations in young northern hardwood cutovers in New Brunswick, Canada. To provide supporting growth and yield information, an industrial experiment was established at residual stand densities of 1300, 1600, 1900, and 2200?stems?ha^?1. Stand responses were examined for measurements recorded at 0 (1987), 5 (1992), 10 (1997), 16 (2003), and 23 (2010) years after establishment. Average diameter at breast height, quadratic mean diameter, stand basal area, and stand total volume growth increased as stem density decreased from PCT. There were significant linear differences for many of these variables between treatments and time periods (year). No significant differences were detected in tree height between treatments. In 2010, the four PCT thinning treatments did not exhibit any differences in potential sawlogs at 2.4?m (8?ft) and 3.6?m (12?ft) lengths. Significant differences were observed for 4.9?m (16?ft) sawlogs that were produced at the least dense spacing (1300?stems?ha^?1). Results from this study and recommendations from the European literature suggest that value-added timber products may be produced from more intense PCT treatments than are currently being practiced on sites dominated by yellow birch (Betula alleghaniensis Britt.).  相似文献   

Cross‐resistance between azinphos‐methyl and acetamiprid in populations of codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae), from Washington State     

Alan L Knight 《Pest management science》2010,66(8):865-874

BACKGROUND: Codling moth, Cydia pomonella (L.), has been intensely managed with the organophosphate insecticide azinphos‐methyl for 50 years, and populations have developed resistance. New management programs have been developed and implemented that rely more heavily on other classes of insecticides. A prerequisite for developing effective resistance management strategies for these compounds is to establish their current levels of effectiveness. Adult and neonate larval assays were conducted to assess the response of field‐collected codling moth populations from apple in Washington State. RESULTS: Male codling moth populations exhibited a range of responses to a discriminating concentration of azinphos‐methyl in a survey of 20 populations. Populations from certified organic orchards were more susceptible than those from conventional orchards. Mean fecundity was inversely related to azinphos‐methyl tolerance. Male responses to azinphos‐methyl and acetamiprid varied significantly among populations and were correlated. The residual effectiveness of field applications of both insecticides varied significantly against neonate larvae. Neonate bioassays with insecticide‐dipped fruit found significant differences among populations with azinphos‐methyl, acetamiprid, methoxyfenozide and spinosad, but not with esfenvalerate. CONCLUSION: These results support a concern that alternation of insecticides with different modes of action may not be a sufficient strategy to avoid the evolution of broad‐spectrum insecticide resistance by codling moth. Published 2010 by John Wiley & Sons, Ltd.  相似文献   

Climate And Land Degradation,M.V.K. Sivakumar,N. Ndegwa (eds). Springer: Heidelberg,Germany, 2007. ISBN: 978‐3‐540‐72437‐7 (hardback), xxvi+624 pp     

Melanie Knight 《Land Degradation \u0026amp; Development》2009,20(3):349-350

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Fruit and vegetables are similarly categorised by 8-13-year-old children     

Sepulveda KK  Beltran A  Watson K  Baranowski T  Baranowski J  Islam N  Missaghian M 《Public health nutrition》2009,12(2):175-187

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Histopathological assessment of wheat seedling tissues infected by Fusarium pseudograminearum     

N. L. Knight  M. W. Sutherland 《Plant pathology》2013,62(3):679-687

Histopathological assessment of infection by the crown rot pathogen Fusarium pseudograminearum in wheat seedling tissues was performed using fluorescence microscopy. The coleoptiles and leaf sheaths of four host cultivars of differing susceptibility were examined. Leaf sheaths were most frequently penetrated via stomata, indicated by initial lesions forming at the guard cells. Internally, cell wall penetration was facilitated by penetration structures which appeared as hyphal swellings or septate foot‐shaped appressoria. Colonization of leaf sheaths resulted in the re‐emergence of hyphae from stomata on both surfaces of the sheath. These hyphae are hypothesized to have two major roles; first as exploratory hyphae for colonization of new tissues, and secondly as sites of profuse conidial production. The formation of conidia on the leaf sheath surface was only recorded on the most susceptible bread wheat genotype. No other major differences in host–pathogen interactions were observed among these cultivars. Almost all cell types in the leaf sheath tissues were extensively colonized, except for the vascular bundles and silica cells. This investigation provides the first comprehensive assessment of F. pseudograminearum infection structures and growth patterns during the infection of wheat seedlings.  相似文献   

Use of the salmonberry,Rubus spectabilis Pursh., in red raspberry breeding     

Victoria H. Knight 《The Journal of Horticultural Science and Biotechnology》2013,88(5):575-581

Rubus spectabilis Pursh. was introduced as a donor of earliness in summer fruiting raspberries. F, hybrids between R. ideaus and R. spectabilis were more or less sterile but flowered very early. Fertility was almost fully restored in the BC[ generation. Some BC, individuals were early summer fruiting while some were early primocane fruiting. Using these as parents, further generations were raised and individuals with cultivar potential have been selected in the BC2 generation. The F, showed resistance to cane diseases and this resistance was largely retained in BC, and BC3 summer fruiting progenies. The two F, individuals used as parents were highly resistant to Phytophthora root rot and ten 2nd or 3rd backcross derivatives of R. spectabilis were moderately resistant.  相似文献   

The Potato Association of America 75th Annual Meeting Spokane,Washington, U.S.A.     

David Curwen  Pete Weingartner  Ronald Knight  Therese M. Work  Hugh J. Murphy  Steven B. Johnson  Richard Zink  Leigh Morrow  A. R. Mosley  Rod Davidson  Thoms Owings  Don Halseth  John Bamberg  John C. Wallace  Stephen Love  Don Halseth  Elmer E. Ewing  LaMont Anderson  Neil Gudmestad  Oscar Malamud  Jane Seabrook  Robert E. Thornton  Ronald Voss  A. J. Mosley 《American Journal of Potato Research》1991,68(12):861-902

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Association Business     

David Curwen  Ronald Knight  Therese M. Work  Hugh J. Murphy  Pete Weingartner  John Ojala  Gary Franc  Roger Brook  Tom German  Sam Thorton  John Bamberg  John C. Wallace  Creighton Miller  Brian Rex  J. Laganiére  Susan M. Paradis 《American Journal of Potato Research》1993,70(2):147-179

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Age at first start and racing career of a cohort of Australian Standardbred horses     

Knight PK  Thomson PC 《Australian veterinary journal》2011,89(9):325-330

OBJECTIVE Compare the career profiles of a cohort of Standardbred horses that first raced as 2-year-olds with those that started their racing careers at a later age. METHOD Retrospective analysis of the racing records of all foals born in New South Wales in the 2000 foaling season. RESULTS The career records of 999 horses were analysed. Almost half (43.9%) first raced as 2-year-olds and one-third (33.9%) as 3-year-olds. The median career duration for horses that first raced as 2-year-olds was 2.93 years (interquartile range (IQR) 2.70-3.16), which was significantly greater than the median for horses that first raced at 3, 4 or ≥5 years old (P < 0.001). Males, and horses that first raced as 2-year-olds, earned significantly more prize money than females or horses that started racing aged ≥3 years (P < 0.001). The population median number of career starts was 28.0 (IQR 8-64). Males, and horses that first raced as 2-year-olds, had significantly more career starts than females or horses that started racing aged ≥3 years (P < 0.001). CONCLUSION This study found no evidence suggesting that racing as a 2-year-old had a deleterious effect on a horse's racing career.  相似文献