Abstract
Against a background of climate change, the experimental components of this project looked at the effects of increased soil temperature on grapevine performance and the combined effects of water stress and heat stress berry ripening. Climate change related increases in soil surface temperatures and these alterations in the root-zone environment will impact vegetative growth, final yield and fruit composition.
Summary
The effectiveness of ATR-FT-IR spectroscopy for the measurement of the free sugar component of grapevine non-structural carbohydrates (TNC) was assessed. Preliminary calibrations were successfully developed for sucrose, glucose, fructose, total free sugars and TNC using a sample set of 2245 samples which encompassed variability associated with 4 growing seasons, 9 growth stages, 7 varieties or rootstocks, 3 tissue types and 26 vineyards. Of these samples, scans from 520 new samples were added to a pre-existing database as part of the current project.
A rhizolysimeter facility with future capacity for soil temperature control and automated irrigation management was designed and constructed with joint support from GWRDC, NSW DPI, CSU and the NWGIC. The system consists of 12 x 780 L plastic bins suspended at ground level in two parallel concrete trenches in an outdoor bird-proof enclosure. At the time of reporting, all bins have had the water based heating / cooling system installed, instrumented with temperature sensors and TDR probes, filled with soil and planted with pre-prepared 3-year old cordon trained Shiraz grapevines. Installation of the data logging and control system, together with testing and validation will take place over the 2013/14 season.