 
Saving water to make wine.
In the 1990s basic research at the University of Adelaide, CSIRO
Plant Industry and South Australian Research and Development
Institute (SARDI) through the Cooperative Research Centre for Viticulture on
plant hormone responses in drought situations led to the development in the late 1990s of an innovative
irrigation technique known as "partial root zone drying" (PRD).
Researchers led by Associate Professor Peter Dry at the University and Dr Brian Loveys at CSIRO discovered
that when part of the root zone dries out levels of abcissic acid (a plant growth hormone) increases
in the plant. This then sends a signal to the leaves to close their stomata in response to water stress,
reducing shoot growth and evaporation from the leaf surface. However, because other roots still have
access to water, the plant continues to grow and fruit development is not significantly affected. By
then swapping the irrigated side regularly, the repeated surges of abcissic acid sent to the shoots produces
a reduced canopy and less transpiration. Better crops are produced with much less water.
PDR is now being used in vineyards across the world. Although originally developed for grapevines,
PDR is also being used for perennial tree crops in Australia, tomatoes in Europe, raspberries in Scotland
and citrus in the Mediterranean basin. In 2001, the Australian Academy of Technological Science and Engineering
named PRD as one of the 100 most important technological innovations of the 20th centure in Australia.
For more information contact Associate
Professor Peter Dry.
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