The pathogen attacks three species of oaks - tanoak, coast live oak and black oak. Marin, Sonoma and Santa Cruz counties have been hardest hit by sudden oak death, but it is also present in Monterey, Napa, San Mateo and now Santa Clara counties.

In the January-February issue of California Agriculture, UC scientists provide critical background on current efforts to thwart the disease, including molecular biology advances, historical details on the identification of the disease, and how geographic information systems are being used to map its spread.

Last summer UC scientists identified the disease agent as a yet unnamed species of Phytophthora.  In addition to spreading geographically, the SOD Phytophthora has been spreading across species.  UC authors report it was recently found in Santa Cruz County rhododendrons and that it may well infect other plants and be capable of moving large geographical distances.  For example, the UC scientists who identified the disease agent believe it is the same organism that was isolated in German rhododendrons in 1993, although that pathogen was not described at the time.

"Never before have we experienced such a rapid death of oaks," says Marin County horticulture advisor Pavel Svihra. "When symptoms start to manifest, it will last no more than 6 to 8 weeks, then the tree is gone."

Last summer, UC plant pathologists David Rizzo and Matteo Garbelotto determined that the disease is caused by a species of Phytophthora. Rizzo says the pathogen is technically a "killer brown algae," but is commonly referred to as a fungus.

Also in the January-February issue of California Agriculture:

First-grade gardeners more likely to taste vegetables. 

Children who worked in the school garden while learning about nutrition were more likely to try, and even like, spinach, carrots, peas and broccoli, say UC researchers reporting in the January February issue of California Agriculture.  To encourage kids to eat fruits and vegetables, a garden-enhanced nutrition education program was introduced to elementary-school students.  First-graders learned about nutrition in the classroom while growing vegetables outdoors in their own gardens.  Improving children's desire to taste vegetables is thought to be the first step in developing healthy eating habits.

Almond advertising yields net benefits to growers. 

A UC study of almond sales from 1962 through 1998 shows that industry advertising and promotion had a positive effect on demand. Under the almond marketing order, funds for advertising and promotion are collected through an assessment on almond handlers. The industry has also conducted a generic advertising program. The agricultural economists evaluating the program concluded that each dollar spent on almond advertising has yielded marginal benefits between $3 and $10. When the program was suspended, from 1994/95 through 1996/97, almond growers' profits dropped by as much as $231 million over those three seasons.

California Agriculture is the University of California's peer-reviewed journal of research in agricultural, human and natural resources. For a free subscription, call (510) 987-0044 or e-mail us at calag@ucop.edu. Visit California Agriculture on the Internet at our redesigned site http://danr.ucop.edu/calag.