IX International Symposium on Grapevine Physiology & Biotechnology

An abstract on the outcomes of Wine Australia project CSP 09/01 “Achieving water use efficiency and improved drought tolerance with rootstocks” was selected for an oral presentation in the “Rootstocks water use efficiency and mineral nutrition” session while a second abstract was presented in the poster sessions. The oral presentation outlined how low-moderate vigour rootstocks can be utilised to improve crop water use efficiency through decreasing canopy size and vine transpiration. The outcomes suggest that irrigation strategies for the different rootstocks can be tailored to reduce actual vineyard water use and that higher density plantings may be practical to overcome yield reductions often associated with low-moderate vigour rootstocks. The poster explored the mechanisms driving rootstock vigour control which has important implications for vine water use. Experimental results suggest that differences in root hydraulic conductivity and therefore possibly vine vigour are being affected by differences in root size / type or the graft union. The up-regulation of aquaporins in vines with low root hydraulic conductivity also suggests that PIP genes may be playing a role in regulating water flow through the root systems.