Flowering and fruitset of the grapevine

Abstract

This was a pilot project that investigated many aspects of the flowering and fruitset process. For this reason, it has been wide-ranging in its approach, from phenological and climatic studies in the field to studies of gene expression during flowering. The effect of site and season on reproductive performance was studied over four consecutive growing seasons on ten winegrape varieties across
a range of climatic regions—the differences between varieties and between sites were greater than the differences between seasons for most variety and site combinations. Flowering time may be accurately predicted by the use of a degree-day model or by the use of an indicator variety such as Ganzin Glory. Fruitset and yield per vine increased in response to both shoot topping and CCC foliar application. Cultural practices, e.g. Mo or CCC foliar sprays, can exert an effect on fruitset via an influence on pollen tube growth, ovule fertilisation or ovule cell morphology. This project has provided an insight into the role of polyamines and ethylene in the flowering and fruitset process.

Summary

See ASVO symposium proceedings