
Click image for caption and other photo
information. Rose Research
Targets Mites, Powdery MildewBy Marcia Wood October 31, 2001Spider mites and a disease called
powdery mildew rank among the worst natural enemies of roses growing in
greenhouses. But the Agricultural Research
Service is helping these splendid plants fight back. ARS is among the
sponsors of investigations at the University
of California, Davis, that will yield effective, environmentally friendly
ways to control mites and mildew. The studies may help rose growers reduce the number of times they have to
spray chemicals. Sometimes that's as many as 25 to 45 times a year, according
to ARS plant pathologist Edwin L. Civerolo at Davis, Calif. He is ARS'
representative for the greenhouse roses research. The spider mite studies, conducted by Christine A. Casey and Michael P.
Parrella of the University of California, Davis, will give growers new,
science-based techniques for monitoring and sampling mites that infest rose
plants. About the size of the period at the end of this sentence, spider mites
use their mouthparts to suck out the contents of leaf cells. By removing cell
components called chloroplasts, for example, mites interfere with the plant's
ability to convert sunlight into food. Investigations of powdery mildew will determine whether an early-warning
system for forecasting outbreaks of this pathogen in vineyards can be
successfully adapted to greenhouse production of roses. The monitoring system
tracks environmental conditions that favor proliferation of grape powdery
mildew. But grape powdery mildew is not expected to behave exactly the same as
rose powdery mildew. So, researchers Linda L. Bolkan and James D. MacDonald at
the university are fine-tuning the computerized, mathematical model that drives
the grape mildew forecasting system so that it will be applicable to greenhouse
rose production. In addition to ARS, other sponsors of the research include the
State of California Department of
Pesticide Regulation; Roses, Inc.; the American Floral Endowment, and the
California Cut Flower Commission. ARS is the U.S. Department of
Agricultures chief scientific research agency. Civerolo is at the ARS
Crops Pathology and Genetics Research Unit. U.S. Department of Agriculture |