Blueberry (Vaccinium corymbosum) CLARKSVILLE

Northern Highbush Blueberry - Variety 'Clarksville'

'Clarksville' is an innovative, ultra-early Northern Highbush blueberry variety developed with one main goal: to dominate the very beginning of the blueberry season. For commercial growers, it represents a massive strategic advantage, as it ripens nearly two weeks earlier than the current global early standard, the 'Duke' variety. Beyond its market primacy, it also brings a unique feature – its aromatic flavor is not lost during storage; on the contrary, it further develops and improves.

Northern Highbush Blueberry (Vaccinium corymbosum) 'Clarksville'

The variety originates from the USA, emerging from the prestigious breeding program at the University of Arkansas. It was developed with a specific goal – to obtain a high-quality variety for the fresh fruit market that would fill the "window" at the very beginning of the season when fruit purchase prices are highest. It is protected by Plant Breeders' Rights (PBR).

Main advantages of the variety:

• Ultra-early harvest: Ripens 10 to 14 days earlier than the 'Duke' variety.
• Unique flavor: Excellent, aromatic taste that actually improves with cold storage.
• Fruit quality: Good firmness of the berries, ideal for fresh market sales and transport.
• Flexibility: Lower winter chill requirement (400-500 hours) while maintaining high cold hardiness.
• Reliability: High and stable yield with excellent fruit set.
• Health: Good natural resistance to common diseases.

Detailed variety description: Plant

• Growth and habit: The bush has a semi-upright to spreading habit. This type of growth requires proper shaping pruning to prevent the branches from drooping to the ground under the weight of the crop.
• Chill requirement: For a Northern Highbush type blueberry, it has a surprisingly low to medium winter chill requirement – needing only 400 to 500 chill hours (temperatures below 7 °C). This makes it highly flexible and suitable for areas with milder winters, or for cultivation in high tunnels.

Fruits and flavor profile

• Appearance and size: The fruits are medium-sized. They have a very attractive, lighter blue color, covered with a high-quality waxy bloom.
• Firmness: The berries exhibit good firmness, allowing them to handle manipulation, sorting, and transport to the fresh market exceptionally well.
• Taste and aroma (Unique specific): The taste is very good and distinctly aromatic. The absolute uniqueness of the 'Clarksville' variety is the fact that its flavor profile continues to develop and improve during cold storage, significantly increasing its appeal to the end consumer.

Growing characteristics and agrotechnics

• Ripening and yield:
  • Harvest window (Ultra-early): The biggest asset of the variety. It ripens 10 to 14 days before 'Duke'. This allows growers to enter the market at a time of maximum demand and minimal competition.
  • Yield: The plants are highly productive and are characterized by very good and reliable fruit set.
• Resistance and requirements:
  • Cold hardiness: Despite the lower chill hour requirement, the variety maintains strong winter hardiness, typical of northern varieties.
  • Soil: Strictly requires acidic (pH 4.5 – 5.5), light, peaty, and well-drained soil with regular irrigation.
  • Diseases: Shows good natural resistance to common blueberry diseases.

Disadvantages of the variety:

• Fruit size: The fruits are medium-sized (do not reach the giant dimensions of later varieties).
• Pruning requirements: The spreading to semi-upright habit requires more precise pruning so that branches do not bend to the ground and complicate the harvest.