Merton Thornless blackberry variety
Commercial thornless trailing variety with uniformed fruit and excellent aroma
Rubus subgenus Rubus Watson 'Merton Thornless'
Variety denomination - 'Merton Thornless'
Merton Thornless is the parent for Smoothstem, Fantasia
Plants are thornless
Bushes have trailing canes
Fruit weight is 4 g
Berries have a rounded shape
Fruiting habit - floricane fruiting (summer-bearing)
Flowering on floricanes starts in the second week of June
Ripening date (regular) - second week of August
Productivity is 3 kg per plant
Cold hardiness is excellent
Heat tolerance is low
Country of origin - United Kingdom
Current status - obsolete or rarely used
Fruits are produced on the previous year’s stems. The main distinctive feature of this variety were medium to large sized fruit and excellent blackberry flavor. Due to its compact growth (max. height is 2,5 m, but stem's length without cropping can achieve up to 7 m in length), this variety was an ideal for planting in small gardens and trials. Plants also demonstrate great yield in half shade or full sun. Merton Thornless has very high resistance to low temperatures (up to minus 26 C), but can be vulnerable to hard frosts on exposed sites.
Cropping season continues from mid August to mid September. Berries are 3-6 g in weight, have rounded or slightly elongated form and glossy black color. Yield is about 2-4 kg per plant, but can grow up to 6-8 kg, when using right cropping and fertilizer. A few strains of this variety exist with different flower colors, either white to pink.
Merton Thornless is still commercially grown in Iran and around the Caspian Sea region as it is highly adaptable, despite being a mid to late variety in colder Western climes. These warmer regions barely get 200 to 600 chill hours where winters are usually very warm. Merton Thornless is very popular in the UK, even though this variety is obsolete, also primarily used for its source of thornlessness in blackberry breeding.
What diseases is blackberry Merton Thornless resistant to?
What diseases is blackberry variety Merton Thornless vulnerable to?
Useful Growing Guides:
Berry Soil and Nutrient Management – A Guide for Educators and Growers. M. Pritts, C. Heidenreich, L. McDermott, and J. Miller; Cornell University, Ithaca, NY
High Tunnel Raspberries and Blackberries. AJ Both, Kathy Demchak, Eric Hanson, Cathy Heidenreich, Greg Loeb, Laura McDermott, Marvin Pritts, and Courtney Weber; Cornell Cooperative Extension
Raspberry and Blackberry Production Guide. L. Bushway, M. Pritts, D. Handley; Natural Resource, Agriculture, and Engineering Service Cooperative Extension, Ithaca