Fruit thinning

Chair Name: Guglielmo Costa (address: University of Bologna, Via G. Fanin 46, 40127 Bologna, Italy; private address; Via Galliera 60, 40121 Bologna, Italy)

Secretary Name: Dr. Matej Stopar (Fruit and Vine Growing Dept., Agricultural Institute of Slovenia, Hacquetova ulica 17, SI-1000 Ljubljana, Slovenia, Tel: 38 61 28 05 237)  


Focus of Working Group

Fruit thinning WG deals with an applied and basic research related to fruit abscission, fruit quality and regular flowering of fruit trees. Most of the researches presented in the Fruit Thinning WG are related to efficacy of different chemical thinners, on chemical and mechanical thinning methods allowed in standard and organic fruit production, and on study of the environmental factors important for fruitlet abscission. These data are also use for the preparation of algorithms to be used to tune-up the efficacy of the recent chemical thinners released by different Chemical companies, to address the best use of the thinners and to avoid the risk of overthinning. More recently some WG members took in consideration Computer Vision models to collect data to be used for Precision thinning.

Technology and precision focus on the Study of other plant bioregulators beside thinners is also the focus of this group.


Planned activities


Meeting: Programmed to be held “in presence” in Kfar-Giladi, Israel from 21-23 February, 2023 - organized Michal Ackerman-Lavert, Omer Crane and Alon Samach

Documents: all the research data presented at the Meeting will be collected and published in the Acta Horticulturae

Outputs: the Meeting will concentrate the Precision thinning method as related to bloom density and climate change, on the prediction of the thinning efficacy of the most recent molecules released as thinning agents. The species considered are pomefruit (apple and pear) and stonefruit (peach, apricot, plum and cherry).



Meeting: Meeting organized “online” in Padova, Italy, Convener A. Botton

Documents: some of the research data presented have been published on the Proceedings of the Eufrin Working Group Symposium G Acta Horticulturae n1341.

Outputs: Trials did concentrate on the Physiological aspects and different thinning strategies, Technology and precision thinning. The considered specie were apple and pear. The meeting end with the presentation 4 Chemical companies that did present and update the activity ongoing



Meeting: Meeting organized “online” in Sint Truiden, Belgium, Convener:

Documents: Trials report distributed by the WG members

Outputs: Invited speaker: Paul O Connor that present Using Computer Vision to Improve Data Import for Precision Thinning Models in Apples. Trials presented by the WG members addressed the relationship between the efficacy of some recent molecules in relation to flowering intensity, the corymb hierarchy to predict thinning efficacy. Technology and precision thinning. The considered specie were apple and pear. The meeting end with the Company corner where the Chemical companies present the recent activity ongoing