Oxytetracycline: source and mechanisms of resistance. Oxytetracycline (Terramycin) is a naturally produced tetracycline antibiotic of Streptomyces rimosus, with a spectrum of activity similar to chlortetracycline and tetracycline and remarkable thermostability (16). In plant agriculture, oxytetracycline is used in the USA primarily on pear and apple for fire blight management. Oxytetracycline i...

Medicinal and Aromatic Plants • Lilium • Fire Blight • Tomato Diseases • Grapevine Breeding and Genetics • Urban and Peri-Urban Horticulture • What Do We Mean by Quality? Food Fights • Intellectual Property: Defining Horticultural Assets and Implications for Horticultural Research and Development • Southern African Society for Horticultural Sciences • Carrot: History and Iconography • The Biolo...

BACKGROUND Transgenic trees currently are being produced by Agrobacterium-mediated transformation and biolistics. The future use of transformed trees on a commercial basis depends upon thorough evaluation of the potential environmental and public health risk of the modified plants, transgene stability over a prolonged period of time and the effect of the gene on tree and fruit characteristics. ...

Pear trees on their own roots are tested in comparison to grafted trees in growth and yield characteristics and with special regard to the tolerance to diseases, above all fire blight (Erwinia amylovora). In spring 2004 15 randomized trees of the cultivar 'Williams' from three variants (self rooted in vitro, self rooted long cuttings, grafted on Quince A) were planted in a pear orchard, which w...

The efficacy of Pseudomonas fluorescens EPS62e in the biocontrol of Erwinia amylovora, the causal agent of fire blight of apple and pear, depends on the colonization of plant surfaces after spray application. A procedure to increase cell survival in the phyllosphere was developed consisting of saline stress and osmolyte amendment to the growth medium during inoculum preparation. Hyperosmotic st...

Fifty bacteriophage isolates of Erwinia amylovora, the causal agent of fire blight, were collected from sites in and around the Niagara region of southern Ontario and the Royal Botanical Gardens, Hamilton, Ontario. Forty-two phages survived the isolation, purification, and storage processes. The majority of the phages in the collection were isolated from the soil surrounding trees exhibiting fi...