In a study from the Barossa Valley, South Australia, sap flow was monitored on various Shiraz vines receiving either a full irrigation or a half irrigation treatment.
SFM1 Sap Flow Meter: Ideally suited to monitor both wine and table grapes.
In a study from the Barossa Valley, South Australia, sap flow was monitored on various Shiraz vines receiving either a full irrigation or a half irrigation treatment (Figure 1). The vines were about 5cm in diameter and monitoring took place shortly after bud burst to shortly before harvest.
Figure 1: SFM1 installed on Shiraz grapevines
Data presented in Figure 2 is an example of sap flow data (cm3 hr-1 ) over a seven day period in February, 2013 (during the Australian growing season). Sap flow in the full irrigation treatment (blue line) is approximately 15% higher than the half irrigation treatment (red line) from approximately 10am to 2pm, but values for other times of the day are similar.
When data in Figure 2 is presented as daily flows, or the total sap flow over a 24 hour period; the difference between full irrigation and half irrigation become less apparent. Sap flow under full irrigation is now ranges between -2% and 8% that of half irrigation (Figure 3).
These preliminary results suggest that irrigation can be halved in this plot with little effect on overall sap flow, or plant water use. Further research is needed to determine if this will affect grape yield and quality in the Shiraz vines.