Mark McQuilken

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Bacteria, yeasts and filamentous fungi colonizing immature, mature and senescing primary leaves of field grown Beta vulgaris (sugar beet) were analysed over a complete growing season. Greatest microbial numbers were detected on senescing primary leaves and these numbers increased over most of the season. The number of colonizers detected on mature leaves(More)
Coniothyrium minitans, a mycoparasite of sclerotia of Sclerotinia sclerotiorum and Sclerotium cepivorum, produced four closely related metabolites inhibitory to fungal growth. The major metabolite, identified as macrosphelide A, had IG(50) values (the concentration of metabolite to inhibit growth by 50%) of 46.6 and 2.9 microgram ml(-1) against S.(More)
Manure-straw mixtures were composted and water extracts, made by incubating compost in water for 3 to 18 days, were assessed for antagonistic activity against Botrytis cinerea, using a range of tests. Extracts of all ages inhibited conidial germination on glass slides and reduced mycelial growth on agar. Mixing extracts of all ages with droplets of(More)
The effects of osmotic and matric potential on mycelial growth, sclerotial production and germination of isolates of Rhizoctonia solani [anastomosis groups (AGs) 2-1 and 3] from potato were studied on potato dextrose agar (PDA) adjusted osmotically with sodium chloride, potassium chloride, glycerol, and matrically with polyethylene glycol (PEG) 6000. All(More)
Pestalotiopsis isolates obtained from the foliage, stem-base and roots of hardy ornamentals grown on commercial nurseries in the UK were identified and characterised according to pathogenicity and colony morphology. All 18 isolates were identified as Pestalotiopsis sydowiana on the basis of conidia morphology, and confirmation of identification was made by(More)
Pestalotiopsis isolates obtained from the foliage, stem-base and roots of diseased container-grown ericaceous crops (Calluna, Erica, Pieris and Rhododendron) collected from UK nurseries were identified as Pestalotiopsis sydowiana (Bresad) B Sutton on the basis of conidia morphology. Inoculum sources of the pathogen included diseased stock plants, crop(More)
When disease levels are low,Coniothyrium minitans gives biological control of Sclerotinia disease in lettuce andPythium oligandrum control of damping-off in cress and sugar beet equivalent to standard fungicide treatments, but both fail as the inoculum potential of the pathogens increases. Possible approaches for improving the use and efficacy of these(More)
AIMS Assessment of antimicrobial activity of the mycoparasite Coniothyrium minitans and its macrolide antibiotic macrosphelide A. METHODS AND RESULTS Thirteen isolates of C. minitans were tested for ability to inhibit a number of filamentous fungi, yeasts, oomycetes and bacteria in agar based tests. Activity was found against some ascomycetes,(More)
Verticillium biguttatum, a mycoparasite of the ubiquitous soil-borne plant pathogen Rhizoctonia solani, excreted chitinase and β-1,3-glucanase into liquid medium when grown on laminarin and chitin, respectively. Neither chitinase nor β-1,3-glucanase was produced by the mycoparasite when grown on cell walls of two isolates of R. solani representing(More)