Grapevine reproductive development is a long and complex mechanism that extends over two growing seasons.
Induction and floral differentiation lead to the formation of reproductive structures that determine the potential number of clusters for the following season. Thus, the number of inflorescences primordia (IP) is directly related to bud fruitfulness, which can provide an estimate of potential yield for the following year. This information allows the bud load to be adjusted according to the fruitfulness and to the productive objectives for that vintage.
Nevertheless, bud fruitfulness is not only dependent on the induction and floral differentiation but also on a set of environmental and endogenous factors that directly or indirectly induce the number of IP.
During winter dormancy, bud fruitfulness is not visible to the eye. However, three distinct methodologies can be used: bud dissection, histological observations and forced bud growth under controlled environmental conditions. Furthermore, these methodologies are also useful to analyze the bud viability, assessing the existence of tissue damage, namely necrosis that can compromise bud development.
Therefore, we intend to overview these techniques of fruitfulness analysis, their advantages and limitations, and their contribution to predicting yield potential. In this context, three Portuguese white varieties (Alvarinho, Fernão-Pires and Loureiro) were used.
Acknowledgments: This study was funded by the “Grupo Operacional - VITISHIDRI-Estratégias para a gestão do stress hídrico da vinha no Douro Superior”, financially supported by the European Agricultural Fund for Rural Development and the Rural Development Programme 2020
Poster presented at Enoforum Italia (May 18-20, 2021)