The Measurement of Vascular Flow into Syrah Clusters

This project attempted to measure the vascular flow (xylem and phloem collectively) through the peduncle of ripening Syrah fruit clusters. Measurements were made on eight separate clusters beginning on July 31, 2006, and continuing until October 16, 2006; measurements were made at 30-minute intervals 24 hours a day. Companion measurements of fruit zone evaporation rates, reference evapotranspiration, irrigation system operation, and berry weights over time were also taken.

Due to unforeseen problems with the datalogging equipment, data was only collected from Sept. 7 onwards, and from only four of the eight clusters. This limited data did not appear to be of the same consistency that was attained the season prior with the same equipment at the same site. Analyses with this limited and possibly non-representative data indicated that the daily sap flow into the clusters was not correlated to daily fruit zone evaporation rates. The parameter ?grams of sap flow per berry, per mm of evaporation? was hypothesized to change over the berry ripening period, reflecting changes in berry physiology. However, the limited data did not show a trend in this parameter, but a proper evaluation was not possible due to the lack of data over the entire ripening period as had been proposed.