Emasculated flowers of ‘Draper’ were pollinated in 2002 with pollen from ‘Legacy’. The seeds were germinated, grown in a greenhouse for 1 year and then field planted at the Southwest Michigan Research and Extension Center (SWMREC) in Benton Harbor, Michigan. MSU 67 was first selected from a group of 103 siblings in 2006 by Jim Hancock (MSU).
The original selection of MSU 67 was evaluated at the Southwest Michigan Research and Extension Center at Benton Harbor, Michigan from 2003 – 2007. Softwood cuttings were also set in advanced trials at Grand Junction, MI (MBG Marketing), South Haven, MI (DeGrandchamp Nursery), Silverton, OR (Oregon Blueberry Company), Lowell, OR (Fall Creek Nursery) and Osorno, Chile (Hortifrut). Two year old plants were set at 4 x 10’ spacing in 2008 in MI, and 2009 in OR and Chile. The plantings in Michigan were evaluated for three years, and those in OR and Chile for two years. The plants were evaluated by Jim Hancock and Ed Wheeler (MBG Marketing) in Michigan, Peter Bouches (Fall Creek Nursery), Bob Gabriel (Oregon Blueberry) and Jim Hancock in Oregon, and Pilar Bañados (Pontificia Universidad Católica), Mike Remmick (Hortifrut) and Jim Hancock in Chile.
Description of Technology
‘Osorno’ is primarily Vaccinium corymbosum, with 13.3 % of its genes coming from V. darrowii, 3.8 % from V. angustifolium and < 1% from V. tenellum and V. ashei. It is a highly productive cultivar with exceptional fresh fruit quality. It is likely best adapted to the northern highbush production areas where winters are not severe, such as central Chile and the Pacific Northwest, but it is recommended for further trial in colder production regions such as Michigan. Plants of ‘Osorno’ are vigorous and upright, although the canes can be lax when loaded with fruit. Canes are numerous, moderately branched and the fruit are well exposed. Its berries are large, have small, dry picking scars, light blue color, excellent firmness and superior flavor. Its fruit held up extremely well in the unseasonably hot summer of 2012, when temperatures routinely exceeded 30 C.
The fruiting season of ‘Osorno’ significantly overlaps that of the widely planted, mid-season cultivars ‘Draper’, and ‘Bluecrop’. ‘Osorno has larger fruit than ‘Bluecrop’, as well as much better overall fruit quality. It is a little larger than ‘Draper’ with comparable fruit quality, but a sweeter taste. It is a much more vigorous than ‘Draper’ and likely more productive. ‘Osorno’ is meant as a very heat tolerant alternative to ‘Draper’, where the vigor of ‘Draper’ is an issue.
Performance and Quality Data
‘Osorno’ is likely not as winter hardy as ‘Bluecrop’ and ‘Draper’. It displayed consistent high yields in Michigan until 2011, when a sharp temperature reduction in early winter destroyed a high proportion of its flower buds. At Grand Junction MI, ‘Osorno’ lost about 70% of its flower buds, while ‘Bluecrop’ and ‘Draper’ lost about 40%. ‘Osorno’ flower buds were little damaged in the winter of 2011/2012, but this winter was unseasonably mild. No winter damage has been noted on ‘Osorno’ in Oregon or Chile.
In multi-location trials, ‘Osorno’ has been a semi-spreading bush that ripens fruit in the early mid-season (Table 1). Its fruit have had excellent size, color, firmness and flavor. It also has had high vigor and excellent yields, except in Michigan in 2011 (after the severe winter).
In comparative Michigan trials, ‘Osorno’ has ripened at about the same time as ‘Draper’ and ‘Bluecrop’ (Table 2). ‘Osorno’ has been superior to ‘Bluecrop’ in all measured characteristics. The fruit of ‘Osorno’ have been larger and better flavored than ‘Draper’ with a comparable scar, although the fruit of ‘Osorno’ have been a little darker.
The fruit weight of ‘Osorno’ has been larger than the standard cultivars in most comparisons in Michigan, except it was smaller than ‘Legacy’ in Chile. Soluble solids in the fruit of ‘Osorno’ have been comparable to all the standard cultivars except ‘Liberty’ and its titratable acidity has been among the lowest of any cultivar. Its fruit have also been very firm, comparable to ‘Draper’ and ‘Liberty’ in Michigan and superior to ‘Liberty’ in Chile.
Probable areas of adaptation and markets: Osorno is intended for northern highbush production areas where winters are not severe, such as central Chile, Western Europe and the Pacific Northwest. Further trial is recommended in the colder production regions of Michigan, Korea and Eastern Europe.
It has high yields and vigor, as well as exceptional fruit quality [very large, light blue, tiny scar, extremely firm & crisp, excellent flavor (balanced sweet)].
It may have only modest winter hardiness and a bush habit that will be difficult to mechanically harvest.
Inventors: James Hancock
Tech ID: 2007-0117