Thinning techniques in relation to different rootstock type

26 Sep 2023
1838

The practise of thinning sweet cherries is primarily motivated by market forces, as larger fruit commands a higher price on the market. Fruit size is largely determined by the cultivar, but is also substantially influenced by the number of fruits on the tree.

This quantity is contingent on a number of variables, including the amount of pollination, which is affected by springtime weather conditions. It has been demonstrated that thinning improves crop quality by reducing fruit set in self-pollinating cherry cultivars, which have a 10-15% higher fruit set than cross-pollinating cultivars.

Therefore, in instances where there is a large fruit or flower bud set, early pruning may significantly increase the overall value of the crop. However, the practise of thinning flowers or fruit in cherries, apricots, European plums and Japanese plums for the purpose of size regulation and enhanced crop value is only applicable during years of abundant crop load, i.e. when there are a substantial number of blooms or fruit set.

In addition, bud thinning is recommended in later phases for stone fruit species in order to reduce the risk of branch breakage due to heavy fruit load. Due to the substantial time and labour investments required, the economic justification for hand/manual thinning may be brought into question.

Despite the need for many skilled personnel in a short amount of time, this strategy remains the most precise method for thinning. The use of a portable thinning machine can facilitate the manual thinning process. This device acts as a bridge between mechanical and manual thinning techniques, resulting in increased efficacy and a substantial cost savings.

Chemical thinning offers cost and time advantages over manual thinning because of reduced labour and the use of conventional plant protection equipment. For chemical thinning, bloom desiccants, growth regulators, and photosynthesis inhibitors are utilised. In comparison to pears and apples, cherry trees produce significantly more fruit per shoot.

Due to the comparatively low weight of the fruit per centimetre square of the trunk's cross-sectional area, thinning is not considered strictly necessary. Rootstock vigour affects the number of flowers in the plant, and it has been observed a higher production in those grafted onto dwarfing and semi-dwarfing rootstocks.

Regardless of vigour, the impact of rootstock on fruit production remains significant. However, the correlation between increased yield and smaller fruit size remains constant across all rootstock types. Using a suitable rootstock that enables the achievement of satisfactory harvests of high-quality cherry is a logical solution for cultivars that are self-fertile when chemical thinning produces inconsistent results in different years.

The results of comparative experiments conducted on self-fertile 'Lapins' sweet cherry trees reveal that the rootstocks Gi 154/7 and Gisela 4 resulted in the highest yield per tree and yield efficiency, especially in terms of producing fruit weighing approximately 7 grammes. Trees grown on P-HL-A and Gi 523/02 rootstocks produced cherries of substantial size, weighing 7.7 and 7.7 g, respectively. However, it is important to note that the aggregate production throughout the study period decreased significantly

The trees cultivated on the widely used Gisela 5 dwarf rootstock had a modest fruit size of 6.1 grammes and yielded a rather low quantity. Looking towards a greater sustainability (both environmental and economic) in the management of the production load, it is necessary to continue studies in this direction in order to adapt the thinning techniques to the cultivar-rootstock combination adopted.

Fonte: Rutkowski, K.; Łysiak, G.P. Thinning Methods to Regulate Sweet Cherry Crops—A Review. Appl. Sci. 2022, 12, 1280. https://doi.org/10.3390/app12031280.

Melissa Venturi
University of Bologna (IT)


Cherry Times - All rights reserved

What to read next

From field to shelf: how best to store sour cherries?

Post-harvest​

29 Nov 2024

The study carried out in collaboration between research institutions from Italy, Hungary and the Czech Republic wanted to evaluate the shelf-life of sour cherries that were freshly picked and cold stored under standard and MAP atmospheric conditions.

Engineering of cherry rootstocks to increase virus resistance

Rootstocks

05 Feb 2024

Regarding rootstocks, one of the most promising approaches to increase plant resistance to viruses is post-transcriptional gene silencing, which employs RNA interference (RNAi) to prevent pathogenicity and virus replication.

In evidenza

Cherry pruning: a winning strategy for Chilean quality and competitiveness

Tech management

24 Jun 2025

At Cherry Tech 2025, agronomist Carlos Tapia explained how strategic cherry pruning—supported by NDVI mapping and spatial analysis—can reduce labor, improve fruit size, and enhance profitability. A cost-effective, high-impact tool to maintain Chile’s global cherry leadership.

Blossoming Japan: the Sano family's mission to protect the Sakura

Specialties

24 Jun 2025

In Kyoto, Japan, the Sano family has protected a rare cherry blossom garden for generations. Tōemon Sano, 97, Japan’s most revered sakuramori, continues his mission to shield sakura trees from climate change and preserve their fleeting beauty and deep cultural significance.

Tag Popolari