EVALUATION OF POTENTIAL ALTERNATIVE EUROPEAN PEAR CULTIVARS FOR U.S. WEST COAST GROWERS

Autor: W. V. Biasi, Clark Seavert, E. J. Mitcham, A. Colonna, S. Castagnoli, R. B. Elkins, R. Bell, J. Turner
Rok vydání: 2008
Předmět:
Zdroj: Acta Horticulturae. :483-490
ISSN: 2406-6168
0567-7572
DOI: 10.17660/actahortic.2008.800.61
Popis: California, Oregon, and Washington produced 98% of the commercial U.S. pear crop from 2003–2005, consisting of ‘Williams’ (‘Bartlett’) (51%), ‘Beurre Anjou’ (36%), ‘Beurre Bosc’ (11%) and 2% others, mainly ‘Doyenne du Comice’, ‘Red Clapp’s Favorite’, ‘Seckel’ and ‘Concorde’. Declining processing demand has heightened interest and evaluation of new fresh market alternatives. Production, post-harvest quality, and consumer sensory evaluation data from 2001 to 2006 has allowed identification of several new potentially commercially valuable cultivars. Among the more favorably rated candidates are fire blight resistant selections developed at the USDA Appalachian Fruit Research Station in Kearneysville, West Virginia. These are ‘Blake’s Pride’ (OHUS 66131-021), US 71655-014 and ‘Sunrise’ (OHUS 66170-047), which both bloom and harvest before or with ‘Bartlett’. ‘Blake’s Pride’ trees yield consistently but dry weather is required for optimum fruit finish. ‘Sunrise’ trees are also productive and fruit maintains a clear finish. Also promising is Cinnamon (Fowler Nurseries, Inc., Newcastle, CA, USA), a fully russeted sport of ‘Bartlett’ which blooms before or with ‘Bartlett’ but harvests about two weeks later in California. ‘Abate Fetel’ and ‘Concorde’ have been difficult to ripen in California, and ‘Concorde’ has shown some internal browning after one month of storage. INTRODUCTION The U.S. West Coast pear industries of California, Oregon and Washington have traditionally relied upon a limited number of cultivars for commercial sales. Three cultivars accounted for 98% of the total production from 2003–2005: ‘Bartlett’ (hereafter referred to as ‘Williams’) (51%), ‘Beurre d’Anjou’ (36%), and ‘Beurre Bosc’ (11%) (Elkins et al., 2007). ‘Anjou’ is favored for its storability and ‘Williams’ for its versatility for both fresh market and processing. ‘Bosc’ (mainly the russeted strains) and ‘Doyenne du Comice’ are the two alternatives familiar to most consumers. Other lesser known and Proc. X IS on Pear Eds.: A.D. Webster and C.M. Oliveira Acta Hort. 800, ISHS 2008 484 less-planted cultivars are ‘Red Clapp’s Favorite’, ‘Red Anjou’, ‘Sensation Red Bartlett’, ‘Cascade’, ‘Concorde’, ‘Forelle’ and ‘Seckel’. The paucity of commercially-favored major pear cultivars contrasts with the large number of apple cultivars offered to consumers in recent years, e.g., ‘Braeburn’, ‘Gala’, ‘Honeycrisp’ and ‘Pink Lady’ to name a few. In recent years, there has been a tendency toward over-supply and stagnant returns for ‘Anjou’ and ‘Williams’. ‘Williams’ demand has declined due to reduced processing demand, while the winter pear ‘Anjou’ must now compete with summer pear shipments from Argentina, Chile and South Africa, as well as the wide spectrum of apple cultivars. Coincidently, consumers show more interest in diverse produce selections and the retail trend toward specialized and up-scale inventory is increasing. Varietals offer added value, at least in the initial marketing years. The evolving supply and demand scenario has thus fostered renewed interest in alternative European pear cultivars among West Coast growers. There are, however, only two major public European pear breeding programs in North America. Fire blight resistant cultivars have been developed at both the USDA Appalachian Fruit Research Station in Kearneysville, West Virginia, under the direction of Dr. Richard Bell, and at the Harrow and Vineland Research Centres in Ontario, Canada, under the direction of Dr. David Hunter (Ingels et al., 2007). A third, smaller breeding program exists at the Kentville Research Centre in Nova Scotia, Canada under the direction of Charles Embree. Due to the limited number of domestic breeding programs, potential new cultivars must be accessed worldwide, for example, from England, Italy and New Zealand. Increasing interest in new cultivars catalyzed initiation of two projects in California and Oregon to test the horticultural and sensory attributes of potential commercially-viable cultivars. Goals were to: 1) introduce growers to new possibilities for various types of markets, 2) gain localized production and post-harvest information, and 3) test consumer reaction. MATERIALS AND METHODS Two trials were established in commercial orchards near Kelseyville in Lake County, situated at 460 m above sea level (N39, W122) in the Mayacamas Mountains of northwestern California. The first trial, established in 1995, was planted in a randomized complete block design with five single-tree replicates per selection in a conventionallyfarmed orchard on Still loam soil. It was comprised of five selections from the USDA pear breeding program: OHUS 66131-021(‘Blake’s Pride’) (Bell and van der Zwet, 2002); OHUS 66170-047 (‘Sunrise’), US 67218-083, ‘Potomac’ (Bell et al., 1996); and US 76115-010. All were planted as grafted trees on Pyrus betulifolia rootstock. The second trial was planted in 1997 in an organically-farmed orchard. It was non-randomized and consisted of five trees each of 22 selections on two different rootstocks, P. betulifolia and Old Home × Farmington 97 (OHxF97), planted on Cole clay loam soil in 1997. Cultivars were chosen in consultation with Oregon State University (OSU), USDA and nursery personnel. The third trial site was established in 2000 at the OSU Mid-Columbia Agricultural Research and Extension Center in Hood River (167 m above sea level, N45, W121). It was also non-randomized and consisted of four trees each of 27 selections on OHxF97 rootstock. The first of three pear selection trials with ‘Sunrise’, ‘Blake’s Pride’ at the USDA-ARS Appalachian Fruit Research Station in Kearneysville, WV (178 m above sea level, N39 W78) consisted of four non-randomized trees of each cultivar on ‘Bartlett’ seedling rootstock planted in 1978 in a Hagerstown-Frederick cherty, silty clay loam soil. A similar selection trial that included US 71655-014 was planted in 1984. A third trial consisting of ten tree replicates of these cultivars, propagated on ‘Bartlett’ seedling rootstock, was planted in 1997 in a randomized complete block (RCB) design. A fourth trial, which included ‘Concorde’, ‘Abate Fetel’ and ‘Sunrise’ propagated on ‘Winter Nelis’ seedling rootstock, was planted in 1996, with three to five trees of each cultivar in a RCB design. ‘Bartlett’ was included as a reference cultivar in all AFRS trials. Fruit quality and production data were collected from 1983, 1988, 2001 and 2000
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