ADDRESS

A truthful acknowledgement is addressed by myself to Dr. J. van Kampen, who offered the opportunity of organizing this Symposium, giving me the necessary courage to make such a difficult step.

I also would like to welcome Prof. Hartmann, who was the former chairman of the Working Group and who coordinated 4 important and successful meetings: the first was held at Geisenheim in 1972, the second at Bet Dagan in 1978, the third at Wageningen in 1981, and the fourth at Padova in 1985.

The positive trend of a world wide participation of experts is being also maintained in the 5th Symposium: 200 scientists, 50 of them are foreign researchers, will present 92 oral communications and posters, and 11 general reports, more than twice as many papers as were presented in the previous meeting. Since a wide range of aspects relating to irrigation scheduling will be presented, the Symposium was arranged in three sections:

WATER RELATIONSHIPS IN THE SOIL-ATMOSPHERE CONTINUUM

The improved understanding of plant water relations and the control of plant growth by drought, given by plant physiological studies, provide the essential basis for the development of optimal methods for irrigation scheduling.

Without this understanding, only approximate and inefficient techniques, formalized in terms of appropriate quantitative models, can be achieved, if at all, by long and expensive series of trial-and-error studies, which have to be repeated for each new crop or each new climatic situation. Many steps have to be done before a good description of many physiological aspects will be accomplished. For instance, there is currently much debate on the role of different sites in sensing water stress: is it the root or the shoot? Various authors have different opinions on the use of water potential as a valid indicator of the plant water stress, as well as on its “sound thermodynamic basis, which would turn out to have a great explanatory and unifying power”.

MEASUREMENTS AND INSTRUMENTATION FOR IRRIGATION SCHEDULING

Standardization of techniques is essential in agricultural practice for the worldwide adoption of the best research techniques from different countries for the good of mankind.

METHODS OF SCHEDULING

The third topic will give a survey of the various necessities that we will face at plot, farm and district level.

Since the World is in a time of transition in which contrasting climatic, economic and social aspects oblige irrigation experts to face new and often incompatible needs, the collaboration among scientists from various fields is a must. This Symposium wants to prove that the first steps have already been made, extending the invitation to collaborate not only to agronomists but also to physiologists, physicists, chemists, geologists.

I wish to thank again all of you for being present at this Symposium. I also thank the Scientific Committee and the Organizing Committee for the support given in the organization. Special gratitude should be expressed to the chairmen of the sessions for their qualified cooperation: prof. H.D. Hartmann(Federal Research Institute, GFR), prof. C. Giulivo (University of Padova, Italy), Dr. E. Fereres (INIA, Cordoba, Spain), Dr. S. Moreshet (A.R.O., Israel), Dr. F. Calame (Federal Station of Agronomical Research, Switzerland), Dr. D. Reikosly (USDA-ARS, MN, U.S.A), Dr. Riou (INRA, Bordeaux, France), prof. P. Rossi Pisa (University of Bologna, Italy), prof. L. Postiglione (University of Naples, Italy), Dr. R. Snyder (University of California, U.S.A.) and prof. F. Moore (Colorado State University, U.S.A.).

Special thanks I also express to Ms. Elisabeth Hellbach for her formal and linguistic revision of the scientific papers published in these proceedings.

We are all hopeful that the scientific contributions presented during this Symposium will meet the needs of clarity, facility and precision in every field of water supply and irrigation, and also assure the important task of the process of the knowledge transmission.

Sure about the possibility of achieving this goal thanks to the presence of many qualified scientists, it is with strong emotion but also with great expectation that I declare the Symposium to be in session.

A. Alvino
Chairman of the Working Group Water Supply and Irrigation