During the summer, water is taken up by the roots and moves to the leaves. Holes in the undersides of leaves, called stomates, allow water vapor to exit the leaf and carbon dioxide to enter the leaf. With energy from the sun, chlorophyll molecules within the leaf use water and carbon dioxide to produce carbohydrates in the process of photosynthesis. When water is limiting, the leaves conserve water by closing the stomates. Not only does this stop transpiration, but it also stops photosynthesis. During periods of drought stress water is not available for cell expansion or the production of carbohydrates that are used for plant growth. The amount of water an orchard uses depends on the availability of water, the environmental conditions, and the amount of foliage per acre. Small trees or trees with few leaves use less water than trees that have filled their space and have a full compliment of leaves. Using a lysimeters (a very large pot on a scale) Worthington et al. (1989) determined that mature ‘Redglobe’ trees used about 37 gallons of water per day.