Effects of canopy management practices on grapevine bud fruitfulness

Background and aims: Bud fruitfulness is a key component of grapevine reproductive performance as it determines crop production for the following growing season. While canopy microclimate can impact bud fruitfulness, the effects of canopy management practices on bud fruitfulness are not well known. The objective of this study was to investigate the effects of common canopy management practices on bud fruitfulness and the relationships with shoot growth capacity, bud microclimate and bud carbohydrate level.Methods and results: Different canopy management practices, (shoot thinning, bunch thinning, leaf removal and lighter pruning) were applied to Semillon and Shiraz grapevines (Vitis vinifera L.). Light interception at the bud zone was measured after canopy management practices were applied. Bud fruitfulness at dormancy was assessed using bud dissection analysis. The number and size of inflorescence primordia, and the incidence of primary bud necrosis were recorded. The results were correlated with measurements of shoot growth capacity and carbohydrate content of buds and canes.Conclusions: Bud fruitfulness was mostly influenced by bud light interception, while the size of inflorescence primordia was positively correlated with shoot growth capacity and the carbohydrate level of buds. By altering canopy microclimate, canopy management practices can be used to manipulate bud fruitfulness and potentially bunch size.Significance and impact of the study: This study provides novel information on the impact of canopy management on grapevine bud fruitfulness and the size of inflorescence primordia. These findings can be used to make more informed vineyard management decisions for better yield control.