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Home Journal of ASHS Research Reveals New Method for Developing Raspberry Varieties
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LYNDEN, WA—The Pacific northwestern region of the United States is recognized as a leader in the production of machine-harvested red raspberries. Here, where the 'Meeker' raspberry continues to reign as the region's most commonly produced commercial cultivar, scientists are looking to expand the range of successful fruit varieties available to breeders and growers.

M. Joseph Stephens, lead author of a study in the Journal of the American Society of Horticultural Science, said that one of the major difficulties with breeding new red raspberry cultivars is the time-consuming nature of data collection related to fruit yield and fruit quality in raspberry seedlings. "Typically, breeders might rely on visual scores for a number of key traits, including yield, which may not be accurate," he explained. "The lack of objective measurements on seedling populations may be a contributing factor to the low number of successful new commercial machine-harvest cultivars."

Stephens and colleagues from New Zealand and the United States tested strategies for developing new varieties of machine-harvested raspberries by conducting trials in Lynden, Washington, using raspberries planted in 2008. "We set out to see if we could bulk machine-harvest full-sib family plots for among-family selection and use yield component data on individuals within the plots for within-family selection," said Stephens.

The researchers estimated the direct costs for growing 1000 red raspberry seedlings by comparing hand-harvesting to machine harvesting for 1 year. The estimated costs showed that three times more seedlings could be machine-harvested than could be hand-harvested. "This research showed that it is possible to estimate individual seedling machine-harvest empirical breeding values by bulk harvesting full-sib families and using yield component data to derive indirect yield estimates for individual seedlings within families," Stephens noted. "In developing genotypes suited to machine harvest, this approach delivers greater genetic gain than hand-harvesting for the same cost. An additional benefit is the ability to identify individuals or families that do not release their fruit well and thus harvest poorly by machine, despite having high yield by hand-harvest."

The scientists said that their breeding approach could also work with other machine-harvested crops, especially perennial small fruit crops such as blueberry and black currant.



The complete study and abstract are available on the ASHS J. Amer. Soc. Hort. Sci. electronic journal web site:

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at


Original Article:

A Method for Breeding New Cultivars of Machine-harvested Raspberries with High Yield
M. Joseph Stephens, Peter A. Alspach, Ron A. Beatson, Chris Winefield, and Emily J. Buck
J. Amer. Soc. Hort. Sci. 137:458–464. [Abstract][Full Text][PDF]

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