Blackberry varieties /

Siskiyou blackberry variety

Rating [ 3 ]

Very productive thorny trailing blackberry variety for processing and fresh market

Rubus subgenus Rubus 'Siskiyou'

Originated from a cross of ORUS 2027 x ORUS 1826

Variety denomination - 'Siskiyou', tested as ORUS 830-4

Siskiyou is the parent for Black Butte

Plants are thornless

Bushes have trailing canes

Fruit weight is 7 g

Berries have a rounded shape

Fruiting habit - floricane fruiting (summer-bearing)

Flowering on floricanes starts in the fourth week of May

Ripening date (regular) - first week of July

Productivity is 11000 kg from ha

Soluble solids - 11.4%

Acidity - 1.5%

Cold hardiness is moderate

Heat tolerance is moderate

Current status - obsolete or rarely used

Country of origin - United States

Agawam Amanda Anastasia Wyeberry Apache Arapaho Babycakes Bailey Big Daddy Black Butte Black Diamond Black Gem Black Jack Black Magic Black Pearl Black Satin Blakely Boysenberry Brazos Caddo Chesapeake Chester Thornless Cheyenne Chickasaw Chief Joseph Choctaw Clark Gold Columbia Giant Columbia Star Columbia Sunrise COX's miracle berry Danna Douglass Doyle's Thornless Eclipse Evergreen Thornless Galaxy Hall’s Beauty Heaven Can Wait Hedrick HJ-6 HJ-7 Hull Thornless Illiny Hardy Kelly Kiowa Kotata Loganberry Lucretia Marion Mary Carmen Metolius MM01 Natchez Navaho Nettleton Creamy White Newberry Nightfall Obsidian Onyx Osage Ouachita Ponca Prime-Ark 45 Prime-Ark Freedom Prime-Ark Horizon Prime-Ark Traveler Prime-Jan Prime-Jim Reuben Schultz Shawnee Siskiyou Smoothstem Sweetie Pie Thornfree Triple Crown Twilight Von Waldo Wild Treasure Willamette Thornless Marion

The primary goal of the US Department of Agriculture–Agricultural Research Service breeding program, in cooperation with Oregon State University, was the development of blackberry cultivars that will complement or replace Marion blackberry. While Marion fruits are ideal for processing, the plants are thorny and trailing, susceptible to winter injury, and were too soft and tender skinned for the fresh market. Black Butte variety, released in 1996, has extremely large fruit, and is early ripening and firm enough for local fresh-market sales, but it was not suitable for processing.
Siskiyou (ORUS 830-4) is early, large-fruited, stress-tolerant, and is a dual purpose berry for the fresh and processed market. Generally, trailing blackberries, such as Marion, Olallie, Boysen and Waldo, are grown in mild climates where winter temperatures do not fall below minus 17 C and they usually have very poor fruit quality if the fruit ripen when daytime temperatures are higher than 32 C. Siskiyou was widely adapted by trailing blackberry standards.
The average fruit weight for a season is about 8 g. The fruit are cylindrical and blocky. Set of the drupelets at the tip of Siskiyou fruit is not consistent. The primary fruiting season of Siskiyou is similar to that of Black Butte, it ripens its first fruit at the beginning of July. The duration of harvest season is about 30 days. Siskiyou has excellent fresh flavor but is not as strongly aromatic as Marion. Siskiyou can be mechanically harvested.

Table 1. Yield and average berry weight of Siskiyou blackberry cultivar compared to some other varieties
Cultivar	Yield, t/ha			Berry weight, g
Cultivar	1995	1996	1997	Berry weight, g
Siskiyou	5.6	14.3	15.1	7.8
Black Butte	7.1	9.7	9.5	8.9
Kotata	13.0	16.8	12.9	5.0
Marion	5.9	15.0	21.2	5.0
Ranui	2.3	8.7	11.6	7.6
Waldo	7.9	20.3	24.1	6.0