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Not long after Scott Johnson joined the UC Kearney Agricultural Research and Extension Center academic staff in the early 1980s, he began working with a brand new giant underground weighing lysimeter, an instrument that would become the signature tool of his career. Johnson retired June 30.
For more than a quarter century, Johnson conducted experiments with peach trees growing in the lysimeter, which allowed him to calculate precisely how much water evaporates from the soil and transpires from the tree on an hour-by-hour basis. Results of this research helped growers properly manage their irrigation strategies to improve fruit quality and yield.
A native of Utah, Johnson earned a bachelor’s degree in biology at the University of Utah. He earned a Ph.D. at Cornell in 1982 and that year moved his family to the San Joaquin Valley to begin a 31-year stint as UC Cooperative Extension specialist in the Department of Pomology at UC Davis, based at the Kearney facility in Parlier, Calif.
Using the lysimeter, Johnson discovered that some common fruit tree irrigation strategies being used in the San Joaquin Valley were significantly impacting fruit quality and yield.
“We found that growers should not cut back on water after harvest, if they can help it,” Johnson said. “Anytime we cut back on water applications, we developed some sort of problem – diseases, sunburn, mites and fruit disorders in the subsequent crops, like doubling and deep sutures.”
Despite the importance of the irrigation research, Johnson had perhaps his greatest impact on growers’ practices from his research on nitrogen fertilization. Many growers, he said, were over fertilizing their stone fruit orchards.
“We did a survey and found the average rate of nitrogen fertilization was 150 pounds per acre,” Johnson said.
However, much of that fertilizer stimulated vegetative growth, which shaded the fruit and prevented the desired reddening; and required more pruning in the winter, labor that added to the expense of growing fruit. In addition, the high fertilizer rates caused more problems with fruit quality, insect pests and diseases.
“I started working on this right at the beginning and harped on this same thing my whole career,” Johnson said. “Today, farmers are using about a half or a third of the fertilizer they did decades ago.”
Johnson also worked on understanding fruit trees’ need for other nutrients, such as zinc and calcium.
“It was pretty common for growers to apply zinc every year,” Johnson said. “From research we conducted at Kearney, we learned that orchards don’t need zinc every year. We also compared materials and found the cheapest zinc products work just as well as expensive ones. We’ve saved growers a lot of money with these results.”
Calcium research also helped farmers’ bottom line.
“Save your money,” Johnson said. “Peach trees don’t need calcium. It doesn’t help anything.”
Over the years, Johnson contributed to 70 peer-reviewed journal articles. He was an active contributor to the International Horticulture Society’s meeting proceedings, titled Acta Horticulturae, having authored or co-authored 30 articles.
Johnson worked closely with his colleagues Ted DeJong, UC Cooperative Extension specialist in the Department of Plant Sciences at UC Davis, and Kevin Day, UCCE farm advisor in Tulare County, on these and many other orchard research topics, including rootstocks, pruning, training systems, thinning, girdling, irrigation and fertilization. In 2011, Johnson took a sabbatical leave to organize and aggregate all the research findings on a comprehensive website called The Fruit Report.
“Everything is there on the website for growers establishing and managing fresh market peach, plum and nectarine orchards,” Johnson said.
Johnson has already sold his home in California and has moved back to Utah, where two of his children have settled with their families. The Johnsons will volunteer, travel, garden and, in a year, embark on a humanitarian mission with their church. Johnson has been honored with emeritus status and, though will be living out of the area, has plans to continue work on orchard fertilization management.
“There’s a great deal of interest today in reducing the potential for nitrogen to percolate down to the groundwater,” Johnson said. “You can get some nitrogen into a peach tree by spraying it on the leaves. It doesn’t get to the soil so there is less of a possibility of groundwater contamination. There may be some interest in this idea in the future, particularly in areas where the soil is very sandy or the orchard is near a stream.”
Though Johnson said he had some misgivings about working off campus when he first took the job with the University of California, he leaves with no regrets.
“I loved working at Kearney,” Johnson said. “To me, it turned out to be the ideal job.”
When the University of California decided to provide geospatial support to its scientists at the UC Kearney Agricultural Research and Extension Center in 2000, they tapped Kris Lynn-Patterson, an experienced teacher and information systems technologist, to lay the groundwork. Geographic information systems academic coordinator Lynn-Patterson retired in June.
Lynn-Patterson earned bachelor’s and master’s degrees in geography/climatology at Fresno State University and taught weather, climate landforms and global information systems classes there as a full-time lecturer for five years and part-time at State Center Community College for 10 years.
In 1990, while still teaching part time, she took a new position as a climatologist with a crop insurance firm.
“We were embarking on a brand-new initiative in the crop insurance business using remote sensing and spatial imagery to appraise losses from weather events,” Lynn-Patterson said.
In 2000, she again broke ground by introducing geospatial technologies to agricultural research at Kearney. Geospatial technologies now allow scientists to take a broader view of landscapes than is possible from the field level.
For example, Lynn-Patterson worked with Pete Goodell, UC Cooperative Extension advisor with the Statewide Integrated Pest Management Program, to understand the migration of lygus bugs through the San Joaquin Valley’s mosaic of diverse crops. In the spring, lygus can reproduce in lush vegetation on foothills surrounding the San Joaquin Valley. As the plants dry when the weather warms and rain stops, the lygus begin looking for a new home in valley agriculture, including cotton, which suffers severe economic losses from lygus.
By combining observations made on the ground with GIS mapping technology, Goodell was able to determine the areas in the San Joaquin Valley where cotton is most likely to have lygus problems in mid-summer. Where alfalfa is scarce, cotton fields absorb the migrating bugs. But where alfalfa is close to cotton fields, the alfalfa acts as a lygus sponge and spares cotton most of the damage.
Recently, Lynn-Patterson and her staff, in collaboration with the Citrus Pest and Disease Prevention Program, have been engaged in mapping cropping patterns in the Central Valley citrus belt. This geographic database will provide information needed to ensure quick action when Asian citrus psyllids or huanglongbing disease is found.
Last year, the Kearney GIS program became part of a larger UC Agriculture and Natural Resources statewide program called Informatics and Geographic Information Systems. IGIS is organizing and preparing data pertaining to agriculture and natural ecosystems statewide and making the information accessible on the web.
Lynn-Patterson has a full retirement planned. She is establishing a non-profit animal rescue organization, “Four Feet Inn,” that will connect homeless dogs, horses and other animals with foster families.
“My goal is to find a path to get animals off the street and into no-kill shelters,” Lynn-Patterson said. “I love animals and I love people who want to help animals, so facilitating this connection is what my spirit wants to do.”
Lynn-Patterson is also pursuing a writing career. She has already completed the first novel in a trilogy and begun work on the second. Both of these hobbies she plans to combine via the Internet with travels around the United States and Canada in a motor home.
After a successful tenure as an entomology professor and researcher at the University of Hawaii, Manoa, Marshall W. Johnson added a 10-year capstone to his career as UC Cooperative Extension specialist and research entomologist in the Department of Entomology at UC Riverside, based at the UC Kearney Agricultural Research and Extension Center. He retired at the end of June.
Johnson traces his interest in insects to a visit with a family friend on the outskirts of his hometown, Roanake, Va., when he was 10 years old. He was intrigued by a copy of “A Golden Guide to Familiar American Insects,” and the friend gave it to him. “That’s how I got started,” Johnson said. He never looked back.
Johnson earned bachelor’s and master’s degrees in entomology at North Carolina State University and in 1974 completed a Ph.D. in entomology at UC Riverside. After conducting short stints of entomological research at two locations on the mainland, he moved to Hawaii in 1983 to serve as a professor and focus his research on biological control.
In Hawaii watermelon production, Johnson was able to help farmers reduce pesticide use by 90 percent by showing that pesticide applications were killing natural enemies of a Liriomyza leafminer pest they were trying to control. He also worked on biological control of pests on cucumbers, tomatoes, green onions, pineapple, papaya and coffee.
In 1995, Johnson took a six-month sabbatical leave to UC Davis and realized how much he missed living on the mainland. He started looking for a new job and eventually was offered the combined extension and research position at his alma mater, UC Riverside, based at the off-campus research center in Parlier, Calif.
Johnson’s arrival coincided with the introduction of olive fruit fly in California, a serious pest that has devastated olive production in the Mediterranean region for more than 2,000 years. Olive fruit fly was detected in Los Angeles in 1998, and by 1999 had made its way into the San Joaquin Valley, the leading producer of the state’s olives.
To the great relief of valley olive growers, Johnson and his biological control colleague Kent Daane, UCCE specialist in the Department of Environmental Science, Policy and Management at UC Berkeley, found that hot summertime temperatures in the valley depress olive fly populations. But that didn’t provide a statewide solution.
Johnson and Daane worked together to introduce exotic natural enemies of the pest from Africa. The beneficial insects have been released from quarantine and introduced at several locations in California, with recovery of one species in the San Luis Obispo and Redwood City areas.
“We think it’s on the way to establishment. That’s a good sign,” Johnson said. “Now we're waiting to see if the parasite’s presence will have an impact on olive fly populations.”
Johnson was also involved in research that showed the Central Valley isn’t as hospitable to glassy-winged sharpshooters as other parts of the state. When it gets very cold, GWSS cannot move or feed. They either starve or get dehydrated.
“About every 2 out of 10 years, it gets cold enough in the valley that glassy-winged sharpshooter populations are reduced 90 to 95 percent,” Johnson said. “It is unlikely glassy-winged sharpshooters would ever become well established in the Sacramento Valley or the northern San Joaquin Valley. But it is well established in the Bakersfield area.”
Johnson ended his career with a video production project designed to raise awareness about integrated pest management. Posted on the website Extending Orchard IPM Knowledge in California, the videos include interviews with IPM practitioners, researchers and farmers plus overviews of specific pest control techniques, such as biological control, cultural practices and pheromones.
For his research and extension efforts, Johnson received numerous awards and honors over the years. Most recently, he was named “Distinguished Scientist of the Year,” by the International Organization for Biological Control. He is an elected fellow of both the Entomological Society of America and the American Association for the Advancement of Science. He was author or co-author of more than 200 peer-reviewed articles, book chapters, and extension publications.
During retirement, Johnson plans to spend more time pursuing the art of photography, mainly landscapes and seascapes, which he captures during travels around the United States. Johnson also plans to continue cataloging the history of the family of his mother, whose maiden name was “Marshall.” He has already traced his lineage back to a 1729 immigrant from Ireland. An earlier ancestor, a member of the provincial council in Pennsylvania, was governor for one day when William Penn was absent from the colony, Johnson said.
Take one nationally celebrated artist and one nationally renowned entomologist. Blend together. Add...