English: CSIRO researchers are studying how grapevines respond to high temperatures and low water availability – conditions which can reduce grape yields by up to 25 per cent. The researchers are hoping the work will aid in determining the best time to irrigate vineyards to enable Australian farmers to maximise harvest quantity and quality, while saving water. Scientists have been investigating stomatal conductance, both in the field and at the molecular level. Stomatal conductance is a measure of how much water a plant can potentially lose through its leaves.