Mechanisation of pre-flowering leaf removal under temperate climate conditions

Abstract

Grapevine leaf removal (LR) in the cluster area is a common practice in temperate and cool climates, usually done between berry-set and cluster closure to create a less favourable microclimate for fungal diseases and to improve grape ripening. When applied before flowering, LR affects berry-set and is, therefore, an effective yield-control tool, reducing time-consuming manual cluster thinning; it also improves berry structure and composition (i.e., total soluble sugars [TSS], titratable acidity [TA] and polyphenols) (VanderWeide et al., 2021). The present five-year trial follows a previous study about pre-flowering LR under identical environmental conditions (Verdenal et al., 2019); it validates the sustainability of moderate pre-flowering LR and its possible mechanisation under Swiss climatic conditions, using low-pressure double airflow.