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 plans to move immediately 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, particular 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."


More from Western Farm Press

Farmer’s death puts national focus on killer bees

Got wine grapes?

Honey bees a landmine solution?

15 must-ask questions before buying farmland

8 keys to a better wine grape grower contract

Cliff Young — the farmer who outran the field

Almond growers groom $3 billion crop

Sustainability matters to wine consumers

Honey bees: About those neonics