Rubus subgenus Rubus Watson 'Columbia Star'
Originated from a cross of NZ 9629-1 x ORUS 1350-2
Variety denomination - 'Columbia Star', tested as ORUS 3447-1
Plants are thornless
Bushes have trailing canes
Fruit weight is 7 g
Berries have a conical shape
Fruiting habit - floricane fruiting (summer-bearing)
Begins to bloom in the second week of May
Harvest season starts in the fourth week of June
Productivity is 7 kg per plant
Soluble solids - 12.8%
Acidity - 1.6%
Cold hardiness is good
Heat tolerance is high
Country of origin - United States
Patent US PP 25,532 P2 dated May 11, 2015
Current status - cultivated (actual)
Columbia Star is the first thornless blackberry to be released with the Lincoln Logan source of thornlessness other than the original Lincoln Logan and Waimate that have Logan-type fruit and Marahau that has Boysen-type fruit. A main goal of the breeding program has been to develop a thornless blackberry with high yields and with fruit quality similar to Marion blackberry. Fresh fruit of Columbia Star are rated as having better firmness than either of the current industry standards. Although not yet evaluated in commerce, Columbia Star fruit have sufficient firmness for local fresh market sales, but it is not certain whether firmness would be sufficient for wholesale fresh shipping.
Fruit color was rated similarly to Black Diamond fruit and more black than those of Marion. Columbia Star and Marion are rated similarly for fruit texture and flavor as fresh fruit and both are considered better than Black Diamond. For flavor, Columbia Star has the highest rating, comparable to Marion and better than Black Diamond. Black Diamond has become the industry favorite for its yield, machine harvestability, and generally good fruit quality but many are of the opinion that its flavor could be better.
Average fruit weight is about 7 g. Average yield is about 7 kg per plant. Columbia Star ripens in the early midseason (at the beginning of July) for trailing blackberries and over 1 month earlier than Chester Thornless semi-erect blackberry. Within the trailing cultivars, Columbia Star harvest started as early as Black Diamond, a few days ahead of Marion, but reached the midpoint of harvest 5 days ahead of Black Diamond and 3 days ahead of Marion (from the beginning of July to the end of July). Columbia Star cultivar is vigorous, comparable to Marion, and the floricanes and primocanes are more vigorous than Black Diamond.
Columbia Star nuclear stock has tested negative for Tomato ringspot virus, Tobacco ringspot virus, Apple mosaic virus, Prunus necrotic ringspot virus, Cherry leaf roll virus, Raspberry ringspot virus, Arabis mosaic virus, Tomato black ring virus, Strawberry necrotic shock virus, Raspberry bushy dwarf virus, and Tobacco streak virus by enzymelinked immunosorbent assay and has tested negative for Raspberry leaf mottle virus, Raspberry latent virus, Rubus yellow net virus, Blackberry yellow vein associated virus, Blackberry virus Y, and Blackberry chlorotic ringspot virus in reverse transcription–polymerase chain reaction assays.
Winter hardiness is about minus 17 C.
|Cultivar||Berry weight, g||Yield, kg/plant|
|Cultivar||Columbia Star||Black Diamond||Marion|
|Cultivar||Soluble solids, %||Titratable acidity, %||pH|
|First (5%)||Peak (50%)||Last (95%)|
|Columbia Star||July 3||July 12||July 24|
|Black Diamond||July 3||July 17||July 26|
|Chester Thornless||August 5||August 28||Sept. 25|
|Marion||July 8||July 15||July 24|
2. Include annual spring nitrogen (N) fertilization (about 78 kg/ha) using ammonium nitrate (NH4NO3);
3. Postharvest removal of floricanes;
4. Sprinkler irrigation apply weekly during the growing season;
5. Training of primocanes to a two-wire-trellis;
6. A single application of liquid lime sulfur (94 L/ha) each spring at budbreak for control of anthracnose;
7. Use sun shelters.
Download Columbia Star patent US00PP25532P2