‘Pearl’ Southern Highbush Blueberry

Abstract

‘Pearl’ is a new southern highbush blueberry (Vaccinium spp. hybrid) developed and released by the United States Department of Agriculture Agricultural Research Service. The new cultivar has several advantages for growers in the Southeastern U.S. over rabbiteye blueberry cultivars, the most widely grown type of blueberry in the region. Among these are an earlier ripening period, high yield potential, and fruit quality. These attributes enable producers to participate in the lucrative early U.S. fresh market where opportunities for marketing rabbiteye blueberries have diminished due to expanding acreage in the region and other states.

Keywords:

• Vaccinium spp. hybrid
• fruit breeding
• cultivar

ORIGIN

‘Pearl’ (selection number MS 812) was selected in 1999 at the USDA-ARS Thad Cochran Southern Horticulture Laboratory in Poplarville, Mississippi by Arlen Draper. It originated from a crossing of ‘Bluecrisp’ x ‘Magnolia’ also made by Arlen Draper at the USDA-ARS, Beltsville, Maryland. The pedigree of ‘Bluecrisp’ is unknown but it was tested as Fla. 84-40, and ‘Magnolia’ was derived from the cross (‘Harrison’ x ‘Avonblue’) x Fla72-5. Florida 72-5 resulted from a cross of E66 x Florida 61-3. E66 was a selection from Arthrur Elliott in Michigan and Florida 61-3 resulted from a cross of [Earliblue x Florida 4A (V. darrowi)] x 37-9. It is likely that 37-9 resulted from selfing US 37. Florida 65-28 was derived from a cross of A x E22; A = (Florida 4B (V. darrowi) x V. asheii clone #3) x (Berkeley x Florida 4B). E22 is another selection from Arthur Elliott. Thus, ‘Pearl’ is a complex hybrid containing primarily Vaccinium corymbosum L. (4x) and V. darowii Camp (2x) with a small amount of V. virgatum Ait. (6x). Reade (6n) coming through ‘Avonblue’ (Sharpe and Sherman, 1976).

DESCRIPTION

Plants of ‘Pearl’ are vigorous and productive with dark green foliage and have a moderately spreading growth habit and narrow crowns. ‘Pearl’ produces large and attractive light blue and firm berries with excellent flavor and small picking scars. Through comparison of flowering dates to those of other blueberry cultivars with known chilling requirements, ‘Pearl’ is estimated to have a chilling requirement of 400 to 450 hr below 7°C. It is suggested that ‘Pearl’ will perform well not only in the Gulf-coast region, but also in other areas where other southern highbush blueberry cultivars having low to moderate chilling requirements are grown successfully.

PERFORMANCE

Plant and berry attributes of ‘Pearl’, two standard southern highbush cultivars, and two early ripening rabbiteye blueberry cultivars were evaluated over 6 years from 2005–2010 at Stone County, Mississippi near the DeSoto National Forest in south central Mississippi. Plants were established in 2001 and grown in an acidic (pH 5.2) soil amended with 200 cubic meters of pine bark per ha using recommended production practices. Table 1 lists berry and plant attributes of ‘Pearl’, ‘O'Neal’, and ‘Star’ southern highbush and the early ripening ‘Premier’ and ‘Climax’ rabbiteye blueberry cultivars. Some attributes of ‘Pearl’ have been early ripening, large berry size, and light blue color when compared to ‘Climax’ and ‘Premier’ rabbiteye blueberries. The blooming period of ‘Pearl’ was similar to that of ‘Climax’ and ‘Premier’ while ripening was >21 days earlier. In comparison to ‘O'Neal’ and ‘Star’, berries of ‘Pearl’ are larger, have lighter blue color, greater firmness, similarly sized picking scars, and comparable flavor. Additionally, ‘Pearl’ has shown greater productivity and comparable plant vigor to these southern highbush cultivars and blooming and ripening periods are 10–12 days later. ‘Pearl’ should be planted with other southern highbush blueberry cultivars having similar blooming periods to facilitate pollination and fruit set.

TABLE 1 Ratings of Fruit and Plant Characteristics of Pearl, Two Southern Highbush (O'Neal and Star), and Two Rabbiteye (Climax and Premier) Standard Cultivars over a 6-Year Period (2005 through 2010) at Wiggins, Mississippi ^z

	Cultivar
Berry and plant attributes ^z	Pearl	O'Neal	Star	Climax	Premier
Berry size	8.4 a ^y	7.2 b	7.1 b	7.4 b	7.2 b
Berry color	8.2 a	7.5 b	7.8 ab	8.0 a	7.8 ab
Berry firmness	8.1 a	7.4 b	7.6 ab	8.0 a	7.4 ab
Berry scar	8.2	8.2	7.9	7.9	7.9
Berry flavor	7.8	7.7	7.8	7.9	8.2
Productivity	7.3 ab	5.8 c	6.7 b	8.3 a	8.1 a
Plant vigor	7.4 ab	6.7 c	7.5 ab	8.4 a	8.0 a
Date of 50% bloom	March 23	March 14	March 11	March 16	March 21
Date of 50% ripe	May 29	May 22	May 19	June 14	June 22
^zRatings are based on subjective scores ranging from 1 to 10, with 1 being the least desirable and 10 being the most desirable. A value of 6 to 7 is considered to be the minimum acceptable rating for a commercial blueberry cultivar.
^yMeans within rows separated by Duncan's multiple range test, 5% significance level.

‘Pearl’ propagates readily from both softwood cuttings taken from new growth in late spring or flushes of new growth in late summer, as well as from hardwood cuttings taken in the winter, and grows vigorously in the nursery. ‘Pearl’ has shown excellent survival in fields in southern Mississippi, and no diseases have been observed.

AVAILABILITY

‘Pearl’ is a public domain blueberry cultivar, and a limited supply of rooted cuttings, cutting wood, and tissue cultured plants is available to certified nurserymen. Written requests for plant materials should be sent to Dr. Stephen Stringer, USDA-ARS Southern Horticulture Laboratory, P.O. Box 287, Poplarville, MS 39470. Genetic materials of this release are deposited in the National Plant Germplasm Repository at Corvallis, Oregon, where it is available for research purposes and commercial development.

Notes

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