Rubus subgenus Rubus Watson 'Prime-Ark 45'
Originated from a cross of APF-12 x APF-1
Variety denomination - 'APF-45'
Plants are thorny
Bushes have erect canes
Fruit weight is 5 g
Berries have a conical shape
Fruiting habit - primocane-fruiting (everbearing)
Flowering on floricanes starts in the fourth week of April
Ripening date (regular) - first week of June
Blooming on primocanes starts in the first week of July
Ripening date (remontant) - second week of August
Productivity is 5 kg per plant
Soluble solids - 9.7%
Acidity - 0.51%
Cold hardiness is moderate
Heat tolerance is moderate
Country of origin - United States
Patent US PP22,449 P3 dated January 09, 2012
Current status - cultivated (actual)
This two-season type of blackberry fruits on current-season canes (primocanes) and on second-season canes (floricanes), potentially providing for two cropping seasons, both traditional summer fruits in addition to late summer to fall production. Traditional blackberry cultivars fruit on floricanes, requiring canes to be overwintered toproduce a crop. This fruiting habit has the potential to expand blackberry production much like that which has occurred for primocane-fruiting red raspberries.
In addition to having thornless canes, this Prime-Ark 45 produces large berries with good flavor and is very early ripening on floricanes. Berries of Prime-Ark 45 does not exhibit exceptional postharvest storage potential, and it is not recommended for the shipping market.
The average primocanes length is about 2 m. Primocanes are strong and vigorous, but thornly. Plants like sun placement. Prime-Ark's 45 berries are medium-large size, average weight of berry is about 4-6 g. Color is black. Each plant produces groups of berries, like bunch of grapes. The first yield starts forming at primocanes in the middle of June and continues three to four weeks. During this first harvest season, Prime-Ark 45 intensively produces primocanes, which soon begin bloom. This is the second harvest season, it continues up to first frosts.
After the end of the second harvest season, Prime-Ark 45 requires winter shelter from frost, freezing and cold wind, because the cold-hardy of this blackberry variety is moderate, about minus 13..17 C.
|Cultivar||Yield, kg/ha||Berry weight, g|
|Floricane flowering date|
|10% bloom||April 28||April 28||May 3||April 30|
|50% bloom||May 4||May 5||May 8||May 4|
|Floricane harvest date|
|First||June 10||June 8||June 13||June 5|
|Peak||June 24||June 19||June 30||June 20|
|Last||July 13||July 17||July 19||July 13|
|Primocane flowering date|
|First||June 30||June 13||-||-|
|Primocane harvest date|
|First ripe fruit||August 8||July 15||-||-|
|Fruit (rating scale of 1 to 10 where 10 is the best)|
|Soluble solids, %||9.6||8.8||10.5||9.2|
|Plant (rating scale of 1 to 10 where 10 is the best)|
2. Annual spring nitrogen fertilization (56 kg/ha) using ammonium nitrate;
3. Additional fertilization (23 kg/ha) after the floricane crop production is completed in July;
4. Tipping primocanes at 42 inch height two times each season usually in mid-June and late July or early August;
5. Dormant pruning of primocane-fruiting plants must include removing dead floricanes and removing primocane tissue to a point below the fruiting (flowering) area on the primocanes;
6. Dormant pruning of floricane-fruiting plants must include removing dead floricanes and pruning lateral branches to ~ 0.4 m in length;
7. A single application of iron sulfate in late fall (October) and lime sulfur (94 L/ha) at budbreak in early spring;
8. Plant spacing at least 0.6 m;
9. Use sun shelters.
Download Prime-Ark 45 patent US00PP22449P3