Berry Crops - Horticulture: Plants for People and Places - page 304

Table 9.1 Important histori-
cal and leading blackberry
cultivars

Cultivar Type

Natchez Erect to semi-erect

Navaho Erect

Ouachita Erect

Prime-Ark® 45 Erect

Tupy Erect

Čačanska Bestrna Semi-erect

Chester Thornless Semi-erect

Loch Ness Semi-erect

Triple Crown Semi-erect

Black Diamond Trailing

Kotata Trailing

Marion Trailing

Obsidian Trailing

Olallie Trailing

Genetic Resources and Breeding Advances

Several excellent in-depth reviews have been written on the breeding of blackber-
ries, from which much of the following information was drawn (Clark et al. 2007 ;
Clark and Finn 2011 ; Finn 2008 ; Jennings et al. 1992 ). Blackberries are classified
into three types based on their growth habit—trailing, erect and semi-erect. Plants
produce vegetative primocanes their first year and these usually become reproduc-
tive in the second year when they are called floricanes. Primocanes of the trailing
blackberry run for 3-6 m along the ground as they grow, and growers lift the canes
and tie them to a trellis. Trailing blackberries have historically been more com-
monly machine harvested for the processing market (whole frozen, puree, juice, and
dried). These types of blackberry were predominantly developed from the western
dewberry ( R. ursinus Cham. et Schltl.) native to western North America, but also
have an ancestry that includes red raspberry ( Rubus idaeus L.), Himalaya black-
berry ( R. armeniacus Focke) and the dewberry native to the central and eastern
U.S. ( R. flagellaris Willd.). The erect blackberries have an upright habit with the
primocanes emerging from crowns and root buds and growing to 2-3 m tall. While
growers typically use a trellis for this type it can be a much less substantial trellis
than for the other types. The primocanes from the semi-erect blackberries emerge
from a crown and grow vigorously upright until they arch over when they reach
3-4 m tall. A sturdy trellis is required for their production. The erect and semi-erect
blackberries are most commonly hand harvested for the fresh market and have a
similar genetic background with the predominant species in their ancestry being R.
allegheniensis Porter and R. argutus Link native to the eastern U.S.
These three types of blackberries were only developed and domesticated from wild
species in the past 100 years. The first cultivars of trailing blackberry were released in
the late 1930s by the U.S. Department of Agriculture-Agricultural Research Service
(USDA-ARS) in Oregon, the first semi-erect cultivars in the 1960s by the USDA-
ARS in Maryland, and the first improved erect cultivars by the University of Arkansas
in the 1970s. The goals of breeding programs for each of these types include develop-