Stone fruit breeding began at Washington State University in 1949 with the arrival of Dr. Harold Fogle, who had just finished his doctorate at the University of Minnesota.

In 1952, by crossing the two red cherries Bing and Van, he developed the blushed Rainier cherry. The variety—WSU’s first—was released in 1960 but did not become popular until long after Fogle had left to join the U.S. Department of Agriculture in Beltsville, Maryland.

He was succeeded at WSU, Prosser, in 1963 by Dr. Tom Toyama.

In 1968, the cherry breeding program in Summerland, British Columbia, released Stella, its first self-fertile ­variety that had acceptable fruit quality.

Toyama soon recognized the importance of self-fertile cherry varieties, and in 1970 he used Stella in a number of crosses and evaluated the offspring for many years but never released any.

When Toyama retired in 1985, WSU ended the breeding program because of budget constraints, but WSU horticulturist Dr. Ed Proebsting continued to evaluate the Toyama material at Prosser in collaboration with a group of fruit tree nurseries that formed the Northwest Nursery Improvement Institute. The institute’s mission was to salvage, evaluate, and commercialize stone fruit material left over from Toyama’s program.

Ten cherry varieties were patented and released (see “WSU cherry varieties” on page 24). With the exception of Olympus, all the named varieties are descendents of Stella.

The early maturing Chelan cherry is now a significant variety in the Pacific Northwest, with production of 1.2 million cartons last season. Benton, Index, Selah, and Tieton are also being produced in commercial volumes.

Material that Toyama developed has also been used in recent years in the university’s quest to develop varieties that are resistant to powdery mildew.

In an interview with Good Fruit Grower in 1999, Toyama recalled that in the spring of 1977, all his crosses were wiped out by frost. The following spring, since he had nothing to work with, he went out and collected seeds from a large collection of European varieties that the station had in variety plots that were on high ground and had escaped the frost.

He planted a dozen seeds of each variety in the greenhouse. None produced much fruit, and he ended up discarding them. All succumbed to powdery mildew except one seedling that still had healthy foliage after everything else had been defoliated. He planted it in the field, then propagated a couple of trees, and put them out in a test planting.

Twenty years later, Jim Olmstead, who was studying the inheritance of the mildew-resistant trait as part of a research project for his master’s degree at WSU, became interested in the material and used it in crosses with Bing, Van, and Rainier. He then went to Michigan State University to work on his doctorate in plant breeding and genetics. Cherry horticulturist Dr. Greg Lang, who worked with him on the project, also left WSU to take a position at MSU.

Breeding program revived

In 2004, Dr. Matt Whiting, cherry horticulturist at WSU, and Dr. Amy Iezzoni, cherry breeder at MSU, began a pilot project to look at the feasibility of starting a new sweet cherry breeding program at WSU.

Cherry growers in Washington and Oregon had been relying to a large extent on the Summerland breeding program in British Columbia as a source of high-quality self-fertile varieties, but access to its new releases was becoming more restricted.

Meanwhile, the pool of ­material from Toyama’s crosses was drying up.

In 2005, the Washington Tree Fruit Research Commission and the Oregon Sweet Cherry Commission agreed to provide the first three years of funding for a program to develop new cultivars for the Washington and Oregon cherry industries. The project also involved developing molecular markers for fruit size, quality traits, and powdery mildew resistance to make the selection process more efficient and reduce the time it takes to develop a new variety.

The following year, Olmstead moved back to Prosser as a postdoctoral researcher and continued to evaluate the crosses he had made. Three selections turned out to have good fruit quality, and he arranged for small trials in commercial orchards.

Olmstead was named manager of the breeding program and made more crosses in an attempt to develop varieties with different harvest timings, larger fruit, better flavor, self-fertility, disease resistance, and better firmness than existing varieties.

Another objective was that they would be suited to mechanical harvesting.

In 2007, Olmstead left to become a WSU Extension educator in Yakima, and the following year WSU hired Dr. Nnadozie Oraguzie, formerly a scientist with Hort Research in New Zealand, as cherry breeder. Olmstead is now the blueberry breeder at the University of Florida.