Sweet cherry cultivation represents a significant component of fruit production in the Balkan countries, with Serbia, Greece, and Bulgaria among the leading producers in the region (ranking 9th, 12th, and 17th worldwide, respectively).
The pedoclimatic conditions of the area—characterized by sufficiently cold winters to meet the chilling requirements of cultivars and relatively mild springs—are generally favorable for sweet cherry development, particularly in hilly zones and in the plains of southern and central Bulgaria.
Across the Balkans, including Romania, Serbia, and northern Greece, production systems rely on both traditional local cultivars and high-quality international varieties, frequently grafted onto semi-dwarfing or vigorous rootstocks (such as Maxma 14 or Gisela) to optimize productivity, adaptability, and orchard management.
Production is primarily oriented toward the fresh market and export to the European Union.
A study conducted at the Agricultural Academy in Sofia (Bulgaria) evaluated the phenological expression of six sweet cherry cultivars (‘Ferrovia’, ‘Regina’, ‘Kordia’, ‘Skeena’, ‘Lapins’, and ‘Canada Giant’) grafted onto the Maxma 14 rootstock and grown in southern Bulgaria.
The objective was to precisely describe the phenological stages of each cultivar and assess their temporal variability over two consecutive years of observation.
Monitoring was carried out according to the international BBCH scale, focusing on three critical developmental stages: bud swelling (BBCH 51), full bloom (BBCH 65), and fruit maturity (BBCH 87).
Data analysis revealed that phenological stages were significantly influenced by seasonal climatic conditions, particularly temperature fluctuations during dormancy release and flowering.
For most cultivars, the onset of the vegetative season in the second year of monitoring occurred 2–8 days earlier than in the previous year, indicating a phenological shift associated with more favorable thermal conditions prior to bud break.
Similarly, the full bloom stage (BBCH 65) was advanced by 4–8 days in the second year and showed a reduction in anthesis duration of 2–5 days.
These findings demonstrate not only variation in the timing of phenological onset and completion but also a compression of stage duration in response to annual climatic differences.
Further implications concern pollination dynamics and the potential exposure of flowers to adverse events, such as late spring frosts or thermal stress.
Analysis of phase duration highlighted cultivar-specific differences in the transitions from BBCH 51 to BBCH 65 and from BBCH 65 to BBCH 87; however, all cultivars exhibited phenological trends consistent with annual thermal conditions.
Overall, the total length of the vegetative season and flowering period varied among cultivars but remained highly sensitive to environmental factors.
These results indicate that, under controlled experimental conditions on Maxma 14 rootstock, cultivar phenological response is flexible rather than fixed.
While the rootstock allows the expression of varietal differences, the timing of key developmental stages remains closely linked to seasonal climatic patterns.
This has important agronomic implications, as understanding mean phenological values and their variability can support orchard management strategies, including frost protection, irrigation scheduling, and harvest planning.
Source: www.researchgate.net
Image souce: Stefano Lugli
Melissa Venturi
University of Bologna (IT)
12 Jun 2025
Washington State University may soon release R3 and R19, two early-season cherry varieties that outperform Chelan in sweetness, firmness and size. Developed through years of trials in Zillah and Mattawa, they could reshape early-season cherry production in the U.S. fruit market.
13 Aug 2024
In the study conducted at the Isparta University of Applied Sciences (Turkey), ensemble learning methods were used to obtain the classification of the 7 cherry cultivars used. During this study, a new dataset comprising 3570 images was generated.
10 Apr 2026
The first Spanish greenhouse cherries reach the European market with very limited volumes and prices up to €80/kg. Strong demand from the Netherlands, Scandinavia and the UK, while the open-field season may start later than usual, impacting exports.
10 Apr 2026
A study on 22 sweet cherry cultivars in Zaragoza examines how warmer winters affect dormancy and flowering. Declining winter chill alters phenology and threatens yield, varietal adaptation and long-term sustainability in Mediterranean growing regions.
