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p r a c t i c a l w i n e r y & v i n e ya r d J U ly 2 0 1 4 61 g r a p e g r o w i n g tics of the fruits and the style of winemak- ing, different levels of water stress can be applied to adjust canopy size and alter the level of sun exposure of clusters. For exam- ple, too much sun exposure of Riesling should be avoided to decrease the potential production of 1,1,6-trimethyl-1,2-dihydro- naphthalene during bottle aging. 26 Summary Well-managed and goal-oriented irrigation strategies not only provide substantial sav- ings in agricultural water by increasing WUE, but also enhance berry quality by controlling canopy growth, modifying cluster microclimate and manipulating berry size. The process of designing and imple- menting the irrigation strategy requires good communication between the grow- ers and winemakers (to clarify the pro- duction goal) and accurate monitoring of soil/vine water status. Without proper management, over- or under-irrigation can cause various prob- lems depending on the phenological stage (Table III). Practical signs of vine growth indicating good or bad irrigation management are summarized in Table IV with suggested water stress levels throughout the season. PWV Acknowledgements: The author sincerely thanks Dr. Markus Keller for providing the data in Figure 2 and three photos in Table III. Bibliography 1. Allen, R.G., L.S. Pereira, D. Raes and M. Smith. 1998 Crop evapotrans- piration—Guidelines for computing crop water requirements. Food and Agriculture Organization of the United Nations, Rome. 2. Bellvert, J., P.J. Zarco-Tejada, J. Girona and E. Fereres. 2013 "Mapping crop water stress index in a Pinot-noir vineyard: comparing ground measure- ments with thermal remote sensing imagery from an unmanned aerial vehicle." Precision Agriculture 1–16. 3. Chaves, M.M., O. Zarrouk, R. Francisco, J.M. Costa, T. Santos, A.P. Regalado, M.L. Rodrigues and C.M. Lopes. 2010 "Grapevine under deficit irrigation: hints from physiological and molecular data." Annals of Botany 105, 661– 676. 4. Evans, R.G., S.E. Spayd, R.L. Wample, M.W. Kroeger and M.O. Mahan. 1993 "Water use of Vitis vinifera grapes in Washington." Agricultural Water Management 23, 109–124. 5. Fereres, E. and R. Evans. 2006 "Irrigation of fruit trees and vines: an introduction." Irrigation Science 24, 55–57. 6. Garnier, E. and A. Berger. 1985 "Testing water potential in peach trees as an indicator of water stress." J. of Horticulture Science 60, 47– 56. 7. Hardie, W.J. and S.R. Martin. 2000 "Shoot growth on de-fruited grape- vines: a physiological indicator for irrigation scheduling." Aus. J. Grape & Wine Research 6, 52–58. ScareWindmill To birds windmill looks like a flock of birds taking off in fright. New improved lock system to keep blades from coming loose 36" dia. blades that repel birds in one or more acre area. Effective for birds in vineyards, fruit trees, and blueberries. Effective on wild turkeys & geese too 30 day unconditional money back guaran- tee. $89 JWB Marketing (800) 555-9634 birddamage.com RDI PRD Similarity Control vigor, increase berry quality, increase water use-efficiency Decrease vine water status Maintain vine water status and berry size and berry size Difference Apply water stress over me Apply water stress over space Timing is cri cal Timing is flexible Less margin for error More forgiving table II. Similarities and differences of regulated deficit irrigation (rdI) and partial root- zone drying (Prd).