Effect of rootstock on nutrition, pollination and fertilisation in 'Shiraz' (Vitis vinifera L.)

Abstract

Rootstocks have previously been shown to alter reproductive performance in grapevines. The concentration of nutrients associated with pollination and fertilisation in grapevines such as boron, calcium, zinc and molybdenum were determined in petiole and pollen tissue from vines from a 'Shiraz' (Vitis vinifera L.) rootstock trial at flowering. 'Shiraz' on own roots had a higher calcium concentration in the petioles across the three seasons than the rootstock treatments. This coincided with higher seeded berry number, total number of berries per bunch and berry weight compared to rootstock treatments. '1103 Paulsen' had a significantly higher amount of boron and a lower number of seedless berries and a lower millerandage index (MI). Zinc deficiency was observed for '110 Richter' and '140 Ruggeri' across the three seasons and when zinc was found to be deficient, coulure index (CI) was increased. In the third and final year of the analysis pollen nutrition was incorporated into the analysis. Deficiency of molybdenum in both pollen and petiole analysis resulted in reduced berry weight due to stenospermocarpy or seed shrivel. Rootstocks with the highest number of pollen grains on the stigma also had the highest number of ovules fertilised. Calcium, zinc, boron and molybdenum are nutrients essential for pollination and fertilisation in grapevines and rootstocks were found to affect the sequestration of nutrients which affected reproductive performance.