FOREWORD

This second Symposium volume reviews relevant research over the last four years and also progress towards intensification of commercial fruit production. Substantial advances are reported. The physical basis of orchard system productivity, in terms of interception of radiant energy and the use of water resources is now much better understood. The discovery of clones of M.9 of superior propagation characteristics and progress in the production of winter-hardy dwarfing rootstocks (the P series) should facilitate the spread of intensive apple systems. The current pattern of orchard economics, however, with high interest charges and low fruit prices, accentuates the need to reduce planting costs and obtain earlier returns. The potential value of eliminating staking is defined in this volume, and, although still at an early stage of development, the results reported with MAC 9 rootstock confirm that trees worked on it are not only dwarfed and precocious but also free-standing. Use of new chemical branching agents and a new growth retardant are also shown to offer the potential of early cropping and tree vigour control on existing semi-vigorous rootstocks which are normally unstaked. Work on compact, own-root apple scion varieties was touched on only in the discussions but substantial progress was reported on intensive systems based on own-root peach trees.

With regard to integrated systems the most rapid development has, perhaps, taken place with the peach with variants on the Meadow Orchard and with mechanically- harvested Tatura Trellises using own-root trees as well as more conventional double-row systems. Work reported on the development of mechanised canopy systems for vineyards links in with interesting studies on horizontal canopy systems for raspberries and apples. The latter appears to give good fruit exposure and therefore colour and size as well as virtually damage-free harvesting. This is in contrast with some of the results reported using bed-systems under too-vigorous growing conditions when, as predicted from earlier light studies, adverse effects on fruit quality are obvious.

In commercial practice it seems as if in many Countries the early plantings of apples in multlple-row systems have not met with success and single-row systems are preferred. Economic studies in the Netherlands do, however, indicate that under their conditions intensification beyond single rows is desirable and on-going work there on the mechanisation of these may do much to increase their acceptability. The use of M.27 rootstock, which minimises problems of vigour control may also be important in this respect. The visits to excellently managed and very productive orchards, which were a feature of the Symposium, also left a clear impression of the importance of site factors, including both vigour of tree growth and size and type of holding, in determining the choice between medium-high-density single-row systems and very-high-density multirows.

John E. Jackson


ACKNOWLEDGEMENTS

It is a pleasure to acknowledge the help of all participants at the Symposium whose presentations, contributions to discussions, and co-operation in keeping a very full programme to time ensured the success of the meetings.

Thanks are also due to Professor F. Scaramuzzi for his welcome on behalf of the Italian Society for Horticultural Science, to Professor G. Bünemann, Professor L.D. Tukey, Professor R.F. Carlson and professor F. Scaramuzzi for effective chairmanship of the sessions and to Professor G. Bargioni for the excellent arrangements be made for our visit to the Verona region.

We are grateful to the Landesrat of Agriculture of the Province of Bozen and the Burgomaster of Lana for their welcome, to the staff of the Kulturhaus, Lana for the excellent conference facilities provided and to the owner of the Hotel "Pöder" for his welcome and assistance throughout.

Much help and finacial support was provided by the Landesrat of Agriculture - Dr. L. Durnwalder, the VOG and ESO of Bozen, the Raiffeisenkasse Lana, the Verkehrsamt Lana, the Gemeinde Lana and the Provincia di Verona.

Especial thanks are also due to the secretarial and typing staff on whom so much of the efficient symposium organisation depended. The staff of the Südtiroler Beratungsring, Lana were responsible for much of the preconference work including the preparation of the special abstract issue of "Obstbau*Weinbau" and for the smooth running of all symposium arrangements while Mrs. A. Morrissey was responsible for the preparation of all the papers that had required substantial editing for publication.

J.E. Jackson, H. Oberhofer, S. Sansavini, S.J. Wertheim