Infestations of container nursery beds by Phytophthora spp. can be persistent and costly. One method of disinfestation that does not require the use of chemicals is soil solarization, which captures energy from the sun to heat soil and thermally inactivate target pathogens. In laboratory temperature gradient experiments, I investigated the...
Phytophthora lateralis Tucker and Milbrath, causal agent of a serious fungus root rot of Chamaecyparis lawsoniana, has seriously damaged natural stands in southwestern Oregon forests and affected ornamentals throughout the Pacific Northwest. Progress with an effective control program in the field has been limited by lack of critical knowledge of...
Phytophthora cactorum lacks sterol synthesis capability. Nevertheless,
it exhibits vegetative growth in the total absence of sterol.
Supplementation of the growth medium with sterol, however, resulted in
a three-fold increase in cell yield. This increase was shown by whole
cell and cell free experiments to be the consequence of altered...
Rhododendron species are host to many Phytophthora species and are an important crop in the nursery industry. The foliar epidemiology of twelve Phytophthora diseases on Rhododendron was studied in field and growth chamber experiments on two Rhododendron cultivars. The relative aggressiveness of Phytophthora spp. was assessed using disease incidence, severity,...
A newly described funguslike organism named Phytophthora ramorum was discovered in 1993 to cause leaf blight, stem canker, and tip dieback on nursery-grown rhododendrons and viburnums in Germany and the Netherlands. At about the same time, many tanoaks (Lithocarpus densiflorus) and oaks (Quercus sp.) in the San Francisco Bay Area...
Phytophthora pini Leonian, recently re-established from P. citricola
I, is a pathogen with a wide range of forest and nursery hosts. It causes foliar
infections in horticultural nurseries in Oregon, where recirculating irrigation
systems are common. Increased use of recirculating irrigation systems may
contribute to disease caused by waterborne plant...