Farm advisor and director of University of California Cooperative Extension in Butte County Bill Olson retires June 14, but that doesn't mean he will close the door on agricultural research.

“I've always considered it a privilege to work with growers and for them to consider my research when they made their business decisions,” Olson said, adding that he will continue some of his research projects during his retirement.

“I'm still interested in them,” he said. “There are things I got started that I want to see through.”

Olson was named a Butte County farm advisor in 1973, after serving for five years as a staff research associate in the UC Berkeley Department of Entomology. He earned a bachelor's degree in entomology from California State University, San Jose, in 1965. He completed a master's degree in entomology at UC Berkeley in 1973.

“I didn't grow up on a farm, and I never was interested in collecting bugs,” Olson said. “I was more interested in studying insect economic injury levels, thresholds, pest monitoring and control techniques.”

Though his position in Butte County did not focus strictly on insects, his education and interest made entomology a good place to start. Olson began studying pests of walnuts, including codling moth and walnut husk fly. Among his first projects as an advisor was to educate growers on the use of pheromone traps for monitoring codling moth, which was a new technique at that time.

Olson joined a team of advisors and UC faculty to study walnut harvest timing. This work showed that delays in harvest were detrimental to walnut quality. He participated in evaluations of new walnut varieties being developed at UC Davis, including the now very popular Chandler variety. Research Olson conducted in walnut training, pruning and mechanical hedging has been widely implemented to cut production costs. His work on control of walnut husk fly led to practices that have been adopted statewide.

In dried plums (formerly called prunes), Olson was part of a team that worked on mechanical thinning and potassium nutrient supplementation. Olson led the team that developed the “Integrated Prune Farming Practices Decision Guide,” with more than 100 pages covering dried plum irrigation, nutrition, pest and disease management guidelines.

Less pesticide use

Olson credits the research and extension work of UC Cooperative Extension farm advisors with dramatically reducing use of synthetic pesticides over the course of his career.

“Decisions about pesticide treatment should not be based on the calendar or what the neighbors are doing,” Olson said. “We've been getting the word out and it is having an impact. Farmers and pest control advisers are doing a great job of putting on treatments based on need.”

Olson speaks warmly of Butte County farmers who generously served as his research cooperators.

“One grower has allowed me to come in his orchard 12 years in a row. He turned over 24 acres for research,” Olson said. “Another farmer allowed me to put overhead sprinklers in two acres of his orchard to create rain. The rain would ensure there was plenty of walnut blight disease in his orchard for me to get a good evaluation of the different treatments.

“Their assistance advanced my career, and advanced their industries, too.”

Over the years, Olson wrote 85 peer-reviewed articles, 678 trade journal articles and 577 walnut, dried plum and cling peach newsletters. In 1988 he received the UCCE Distinguished Service Award for outstanding research and, in 1997, the UCCE Distinguished Service Award for teaching. In 1998 Olson and UC integrated pest management advisor Carolyn Pickel produced an award-winning video on walnut husk fly control.

Olson was appointed director of UCCE in Butte County in 1993 and has served that role as well as maintaining farm advisor responsibilities since that time. UC vice president for Agriculture and Natural Resources W.R. “Reg” Gomes has granted Olson the honor of emeritus status effective June 14.

Along with his research, Olson will continue his participation in professional meetings during retirement. In August, Olson will present a paper on walnut husk fly in Australia and in November he will speak about his walnut hedging research at a walnut symposium in Italy. Traditional retirement activities will also have a place in Olson's future. He said he looks forward to more time for travel in the United States, fishing, playing golf and staying in touch with his grower friends.