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Browsing by Author "Welham, S.J."
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A case study in measurement and analysis of disease gradients
Welham, S.J.; McCartney, H. A.; Fitt, Bruce D.L. (Association of Applied Biologists, 1995) -
Changes in populations of Pseudocercosporella herpotrichoides (eyespot) in unsprayed and fungicide-sprayed plots of winter wheat with different initial populations, 1984-1989
Fitt, Bruce D.L.; Bateman, Geoffrey L.; Welham, S.J. (1990) -
Changes in populations of the eyespot fungi Tapesia yallundae and T. acuformis under different fungicide regimes in successive crops of winter wheat, 1984-2000
Bierman, S.M.; Fitt, Bruce D.L.; Van Den Bosch, F.; Bateman, Geoffrey L.; Jenkyn, J.F.; Welham, S.J. (2002-04)Effects of regular treatments with the fungicides carbendazim and prochloraz applied to whole plots divided into subplots with different initial population mixtures of carbendazim-sensitive or carbendazim-resistant Tapesia ... -
A comparison of modelling methods for forecasting light leaf spot (Pyrenopeziza brassicae) on winter oilseed rape in the UK
Welham, S.J.; Papastamati, K.; Fitt, Bruce D.L.; Turner, J.A.; Gladders, P. (British Crop Protection Council, 2000-11) -
Development and control of light leaf spot (Pyrenopeziza brassicae) epidemics in winter oilseed rape in the UK
Sutherland, K.G.; Fitt, Bruce D.L.; Steed, J. M.; Welham, S.J.; Gladders, P.; Turner, J.A. (British Crop Protection Council, 1998) -
Development and uptake of a scheme for predicting risk of severe light leaf spot on oilseed rape
Evans, N.; Welham, S.J.; Antoniw, J.F.; Fitt, Bruce D.L. (2006-12)To reduce reliance on fungicides for disease control on oilseed rape, Decision Support Systems (DSS) are being developed to guide fungicide applications as part of an integrated pest and disease management strategy. This ... -
Development of a system for forecasting severe light leaf spot in winter oilseed rape
Sutherland, K.G.; Fitt, Bruce D.L.; Gladders, P.; Steed, J. M.; Turner, J.A.; Welham, S.J. (1998)In the UK, an estimated £3-9 M are spent each year on fungicides to control winter oilseed rape diseases, but losses in excess of £30 M still occur [1]. Light leaf spot (Pyrenopeziza brassicae) is one of the major diseases ... -
Development of the oilseed rape light leaf spot forecast : from model to mobile phone
Evans, Neal; Welham, S.J.; Baierl, Andreas; Antoniw, J.F.; Fitt, Bruce D.L. (Association of Applied Biologists, 2004) -
Early development of light leaf spot (Pyrenopeziza brassicae) on winter oilseed rape (Brassica napus) in relation to temperature and leaf wetness.
Figueroa, L.; Fitt, Bruce D.L.; Welham, S.J.; Shaw, M.W.; McCartney, H. A. (1995-08)In controlled environment experiments to study early development of light leaf spot, lesions developed with leaf wetness durations of 16 to 48 h after inoculation of oilseed rape with conidial suspensions of Pyrenopeziza ... -
Effects of light leaf spot (Pyrenopeziza brassicae) on yield of winter oilseed rape (Brassica napus)
Su, H.; Fitt, Bruce D.L.; Welham, S.J.; Sansford, C.E.; Sutherland, K.G. (1998-06)The relationship between development of light leaf spot and yield loss in winter oilseed rape was analysed, initially using data from three experiments at sites near Aberdeen in Scotland in the seasons 1991/92, 1992/93 and ... -
Effects of previous cropping and fungicide timing on the development of light leaf spot (Pyrenopeziza brassicae), seed yield and quality of winter oilseed rape (Brassica napus)
Figueroa, L.; Shaw, M.W.; Fitt, Bruce D.L.; McCartney, H. A.; Welham, S.J. (1994-04)Light leaf spot, caused by Pyrenopeziza brassicae, was assessed regularly on double-low cultivars of winter oilseed rape during field experiments at Rothamsted in 1990-91 and 1991-92. Previous cropping and fungicide ... -
Effects of severity and timing of stem canker (Leptosphaeria maculans) symptoms on yield of winter oilseed rape (Brassica napus) in the UK
Zhou, Y.; Fitt, Bruce D.L.; Welham, S.J.; Gladders, P.; Sansford, C.E.; West, Jon S. (1999-10)The relationships between yield loss and incidence (% plants with stems affected) or severity (mean stem score, 0-4 scale) of stem canker in winter oilseed rape were analysed using data from experiments at Rothamsted in ... -
Effects of stem canker (Leptosphaeria maculans) and light leaf spot (Pyrenopeziza brassicae) on yield of winter oilseed rape (Brassica napus) in southern England
Zhou, Y.; Fitt, Bruce D.L.; Welham, S.J.; Evans, N.; Gladders, P. (2000-08)The relationships between yield loss and incidence or severity of stem canker and light leaf spot in winter oilseed rape were analysed by correlation and regression analyses, using data from experiments at Rothamsted, ... -
Effects of temperature and wetness duration on conidial infection, latent period and asexual sporulation of Pyrenopeziza brassicae on leaves of oilseed rape
Gilles, T.; Fitt, Bruce D.L.; Kennedy, R.; Welham, S.J.; Jeger, M.J. (2000-08)Experiments in controlled environments were carried out to determine the effects of temperature and leaf wetness duration on infection of oilseed rape leaves by conidia of the light leaf spot pathogen, Pyrenopeziza brassicae. ... -
Effects of temperature and wetness duration on infection of oilseed rape by ascospores of A-group or B-group Leptosphaeria maculans (stem canker)
Biddulph, J. E.; Fitt, Bruce D.L.; Gladders, P.; Jedryczka, M.; West, Jon S.; Welham, S.J. (1999)Phoma lesions produced on oilseed rape leaves by B-group ascospores were smaller and less distinctive than lesions produced by A-group ascospores of Leptosphaeria maculans, when leaves were inoculated with ascospore ... -
Effects of temperature and wetness duration on infection of oilseed rape leaves by ascospores of Leptosphaeria maculans (stem canker)
Biddulph, J.E.; Fitt, Bruce D.L.; Leech, P.K.; Welham, S.J.; Gladders, P. (1999-11)In controlled environment experiments, ascospores of Leptosphaeria maculans (stem canker) infected oilseed rape (cv. Nickel) leaves and caused phoma leaf spots at temperatures from 8 degrees C to 24 degrees C and leaf ... -
Effects of temperature, cultivar and isolate on the incubation period of white leaf spot (Mycosphaerella capsellae) on oilseed rape (Brassica napus)
Inman, A.J.; Fitt, Bruce D.L.; Welham, S.J.; Evans, R. L.; Murray, D. (1997-04)When leaves of oilseed rape (cv. Cobra) were inoculated with conidial suspensions of Mycosphaerella capsellae (white leaf spot) and incubated in controlled environments, the lag period from inoculation to the appearance ... -
Effects of wetness period and temperature on development of dark pod spot (Alternaria brassicae) on oilseed rape (Brassica napus)
Hong, C.X.; Fitt, Bruce D.L.; Welham, S.J. (1996-12)In controlled environment experiments, when oilseed rape pods or leaves were inoculated with spore suspensions of Alternaria brassicae, the maximum disease incidence (proportion of pods or leaves diseased) increased as ... -
Empirical models for prediction of regional light leaf spot (Pyrenopeziza brassicae) incidence on winter oilseed rape in the UK
Welham, S.J.; Turner, J.A.; Fitt, Bruce D.L.; Gladders, P.; Sutherland, K.G. (1998)Empirical models have been used to forecast plant disease epidemics and guide spray decisions. Light leaf spot (Pyrenopeziza brassicae) is a serious disease of winter oilseed rape in the UK, showing seasonal and regional ... -
Epidemiology, forecasting and management of winter oilseed rape diseases in the UK
Fitt, Bruce D.L.; Gladders, P.; Sutherland, K.G.; Turner, J.A.; Welham, S.J. (1999)Survey results show that the most serious diseases on winter oilseed rape in the UK are light leaf spot (Pyrenopeziza brassicae) and stem canker (Leptosphaeria maculans), then stem rot (Sclerotinia sclerotiorum) and dark ...