PREFACE AND PROSPECTS

In the present volume, papers and posters are published from the ISHS Workshop on "Improvement of Sweet and Sour Cherry Cultivars and Rootstocks", dealing with new developments and methods. Progress achieved during the last decade can be seen, and the workshop offered a unique chance for individual contacts of scientists from different fields and from a large number of countries. All are working on particular problems of cherries and have tried various way to solve such problems. A large amount of information about recent research and breeding activities was presented. In the informal atmosphere of the Horticultural Adult Education Center at Grünberg/Giessen, and during the excursions, participants freely discussed many of their special problems.

The approach to combine paper and poster sessions with travelling, and visits to places of commercial growing and marketing of cherries proved very useful. One afternoon was spent at the Fruit Field Station of Giessen University at Nidderau-Heldenbergen (interspecific cherry hybrids, 9 preliminary rootstock trials with sweet cherry cultivars grafted on a variety of hybrids).

On route to Munich we visited:

• Vereinigte Großmärkte für Obst und Gemüse Rheinhessen at Ingelheim/ Rhein (the largest cherry producers' market in Germany, two thousand tons of sweet cherries and eighteen thousand tons of sour cherries annually).
• Eichenberg Seed Company at Miltenberg/Main (Mazzard seed production from controlled pollination with Mazzard clones grafted on size controlling P.cerasus clones; propagation of P.cerasus clones by softwood cuttings).
• Two commercial trial orchards of sweet cherry cultivars grafted on P. cerasus clones in the traditional cherry growing area of Frankonia (3000 ha) with small farms on hilly sites.
• The workshop was concluded at Munich Technical University (Field plots with self rooted P.cerasus cultivars and those grafted on P.cerasus clones, a large selection plot with promising new P.cerasus rootstocks, which induce size control and precocity).
• In the Laboratories of Prof. Feucht new developments in the techniques of micropropagation were explained. Demonstrations and posters dealing with results from recent research on graft-incompatibility in Prunus species completed the workshop.

In the final session, summaries on sweet cherries (R. Theiler-Hedtrich), on sour cherries (S. Vestrheim), and on rootstocks (K.R. Tobutt) were given and future directions were outlined. Among others, R. Theiler suggested "that there is a tremendous amount of information available, which should be taken advantage of. The forthcoming proceedings will be one step towards this goal. To improve this information transfer in the future, we decided that a "Cherry News Letter" should be edited, in which the annual results from participants are published. The aim of such a "Cherry News Letter" should be to make available date of all places working on cherries, as well as to propose comparable experiments on rootstocks,cultivar trials and others,or outline specific evaluation programs. The "Cherry News Letter" should, therefore, contain annual information (as has to be presented in annual reports), and should contain in information from the west and the east. We are especially grateful to Prof. Kramer from Humboldt-University, Berlin, who has agreed to act as a coordinator for eastern countries, to ensure that such a "cherry News Letter" will contain informatio from all countries represented here."

S.J. Wertheim (Netherland) proposed joint field experiments in central european countries with recently introduced cherry rootstocks and those still in the course of development.

The members of the workshop agreed to continue their cooperation and to have another reunion in time, possibly in an european country with a more continental climate.

Werner Gruppe
Convener


ACKNOWLEDGEMENTS

It is a pleaure to acknoledge the help of all participants of the cherry workshop whose presentations and/or contribution to discussions ensure the sucess of the workshop.

Thanks are also due to the staff of the Horticultural Adult.Education Center, Grünberg/Giessen; Mr. H.Grundmann, General Manager,Vereinigte GroBmärkte für Obst und Gemüse Rheinhessen,Ingelheim;Mrs.Gisela Stenger and Mr. R. Schwinger, Eichenberg Seed Company,Miltenberg; Mr.H. Schimmellpfeng,Munich Technical University.

The workshop was financed by the participants themselves. Additional funding was supplied by DAAD (German Academic Exchange Service),Bonn.

Special thanks are due to the secretarial and technical staff of the Giessen team who were responsible for many tasks necessary for the successful and efficient organisation of the workshop and the excursions.

Werner Gruppe, Sabine Franken-Bembenek, Christel Zörb