FOREWORD

We are very pleased that so many guests, more than 130 scientists from 24 countries, attended the conferences in the city of Veria, in the center of our pomological region and the historic land of Makedonia. The participating countries were: Australia, Bulgaria, Croatia, Czech Republic, Egypt, France, Greece, Helvetia, Hungary, Iran, Israel, Italy, Moldavia, New Zealand, Poland, Portugal, Romania, Russia, Slovakia, South Africa, Spain, Turkey, United States of America and Yugoslavia. I would like to thank you all for responding to our invitation and for your scientific contribution through the presentation of 49 oral and 83 written communications.

I would like to thank the ISHS Executive Committee, for the decision to lay the organization of this Symposium to our hands, the Chairwoman of the ISHS Apricot Working Group Professor Ruhinaz Gulcan, the Chairman of the ISHS Fruit Section Dr. Norman Looney and the Executive Director of ISHS Ir J. Van Assche, for the necessary technical assistance.

I would also like to express my respect, on the occasion of the W.G's 35^th Anniversary (1962–1997), to one of its founding members Professor Stanisa Paunovic who assisted in the preparation of this and past Symposia and thus offered a lot in the promotion of International Scientific Cooperation.

Thanks and honor are due to the memory of the unforgettable scientist Dr. Francesco Monastra, who passed away in October 1997 and who supported the activities of the Apricot Working Group by his «guiding spirit», enthusiasm and encouragement.

The Symposium included one opening, eight oral, three poster sessions and four round table discussions. The great number of scientific works on Variety and Breeding underlines the importance given to the future of this crop. The research on Breeding aimed to enhance apricot genetic variability, to improve resistance to diseases, mainly Sharka, or to improve fruit quality. A number of papers was devoted to the evaluation of apricot germplasm in various countries. Besides morphological characteristics, results of studies on isoenzymes, RAPD and RFLP markers were elaborated for distinguishing varieties and clones. The research carried out on apricot's floral self-incompatibility revealed that very considerable progress is being made in understanding the biology of this fruit species. It is hoped that a marker will be available in the near future that will allow early selection of self-incompatible progenies before planting. New information on propagation and rootstocks and new ideas on orchard management were presented. Ways of maintaining fruits after harvest, modified atmosphere in storage and conditions in package during transportation were investigated to prolong the marketability of fresh fruits. A high number of works was devoted to the protection by fungal, bacterial, phytoplasma and virus diseases. New molecular techniques, like PCR, have been used for the identification of the associated pathogens. Research was carried out for the evaluation of available germplasm to the infection by ‘Plum Pox Virus’. PPV is still the most serious disease threatening the apricot industry in European and Mediterranean countries today. The many and different aspects and the combined actions to be taken for its control were discussed.

The XI^th International Symposium on Apricot was an enjoyable meeting where so many researches had the opportunity to present the conclusions of their scientific work, to exchange information, to renew old friendship and to develop new contacts during four fruitful days. The dissemination of the results by the publication of the Proceedings will bring the acquired knowledge to interested persons for the benefit of the crop and the consumers. It is expected that apricot consumption will increase in the future. It is worth noting that apricots have a high nutritional value due to their high content in beta-carotene (provitamin A) associated with maintenance of a good health.

The Organizing Committee expresses its gratitude to the sponsors who financially supported the better preparation of this scientific event and among others the Ministry of Agriculture, NAGREF, General Secretariat of Research and Technology, Ministry of Makedonia -Thraki, Prefecture of Imathia, Municipality of Veria and Community of Portaria in Halkidiki.

I thank the members of the Scientific Committee, the members of the local Organizing Committee and all those who contributed to the success of this gathering, hoping to meet again at the next Symposium, which will be held in France, summer 2001.

Irene Karayiannis,

Convener, XIth International Symposium on Apricot Culture


WELCOME ADDRESS
Dear guests, ladies and gentlemen,

First of all I would like to express my gratitude to the organizers who have given me the chance to address you on behalf of the Apricot Working Group in Greece, a country where apricot production has been expanding during the last three decades like in Turkey, Spain, Italy and Syria.

I have the pleasure to greet and specially thank the local organizers in Greece of XI^th International Symposium on Apricot Culture in Veria, chaired by Mrs. Irene Karayiannis and those who have sponsored this conventional meeting of ISHS and those who have activated its organization.

Similarly, I would like to greet Professor S.A. Paunovic who has made great efforts as the founder and currently honorary chairman of the working group.

Probably, all of us know that the first decision of setting up a working group on apricot under the auspices of ISHS was during the meeting held in early October, 1961 in Perpignan, France.

After the colloquium on September 1, 1962 Brussels, Belgium, the International Committee for Apricot, the Fruit Section Commission of ISHS set up a new frame work under the name «Working Group on Apricot and Apricot Culture».

The first activities of the Working Group were to form a correspondent responsible member for each country where apricot crop is important, to prepare a bibliography of papers with the information on cultivation, practice and economic situations, a list of symptoms of different types of apoplexy, available apricot cultivars in each country and research projects on apricot. In short, the first attempt was to determine the current situation of apricot.

Up to now, the following ten International Symposia were held : Perpignan-France, 1961; Brussels-Belgium, 1962; Lednice-Chechoslavakia, 1966; Subatica-Yugoslavia, 1968; Madrid-Spain, 1973; Erevan-USSR, 1977; Bucarest-Rumania, 1981; Kecskemet-Hungary, 1985; Caserta-Italy, 1989 and the last one was in Izmir, 1993. Today we are here in Veria-Greece.

To bring solutions to the problems present in apricot culture, different activities were simultaneously elaborated involving many pomologists, breeders, agrotechnicians, physiologists, virologists, phytopathologists, entomologists, economists and others. If we evaluate the situation as a whole before the Working Group was established, many difficulties and problems with apricot were not explicit it was not even possible to explain things clearly. But today, there are many eminent scientists in each discipline of the Sub-working groups who create valuable scientific approach to the complaints raised by growers and consumers.

The evaluation of publications that could be gathered released during the last 35 years between 1961 and 1996 display the following situation. The highest number being in plant protection with 286 followed by rootstocks with 218. The main sources were CAB Abstracts and special issues of Acta on apricot.

This time span is divided in 3 distinct periods: 1961–1971, 1971–82 and 1982–96. During the first ten years a total of 87 publications was found available. The topics of these publications were classified under 7 fields. The number of the publications in each field, ranging between 8–20 (except on biology), was distributed rather evenly.

• Ecology, Physiology and Biochemistry
• Rootstocks, Propagation and Planting
• Selection, Varieties and Breeding
• Economics and Commercialization
• Plant Protection
• Soil, Biology and Nutrition

During the second ten years, the total number of publications increased 9 fold, from 87 to 786. This can be attributed to the establishment of the Working Group and great interest devoted to problems of apoplexy and decline. The highest percentage belonged to Pant Protection followed by:

• Rootstocks, Propagation and Planting
• Ecology, Physiology and Biochemistry
• Selection, Varieties and Breeding
• Harvesting and Handling
• Orchard Management
• Soils and Nutrition
• Quality

During the last 15 years, there was a gradual increase in the number of publications by nearly 50%. The first place is occupied by selection, varieties and breeding, and plant protection is in the second position. the other topics are as follows :

• Biology
• Ecology, Physiology, Biochemistry
• Harvesting and Handling
• Rootstocks, propagation and Planting
• New Technologies in apricot Growing
• Orchard Management
• Economics and Commercialization
• Quality

Biology which was in the last position during 1961–1971 raised to the third place probably due to increased awareness of the incompatibility issue and other problems in fertilization. The main reason for the reduction in the number of publications can be related to the limitations in terms of research funds and shifting of the research priorities for financial support towards environmental issues. However, the figures obtained for apricot production and consumption put forth that there is still a need to develop apricot culture or as Prof. Paunovic said «The people need more apricots, the apricots need more fundamental applied and developmental researches».

1. For a long time, most of the apricot trees were obtained by generative propagation in the apricot growing districts that are of primary and secondary origin countries. Eventually, the existing trees differ widely from each other in many characters, such as vigour, yield, quality of fruit, resistance to spring frost and susceptibility to pest and diseases.
   • From the Genetic Resources point of view, an organized attempt of conserving and evaluating this invaluable material should be carried out by establishing a coordinated policy at an international level.
   • In many countries existing apricot collections are established from important commercial varieties. Less emphasis is given to land races and related species. For this reason, much more attention should be given to collect and conserve these kinds of accession in order to provide useful gene sources to the breeders.
   • In order to provide information readily from the accessions in collections to users, characterization at least for important characteristics should be evaluated by using a unique Descriptor for Apricot.
   • During my activities as the apricot crop coordinator in IBPGR, I noticed that there are some name confusions of the cultivars within the existing collections. This is probably at a much more important level in the countries where the collections are improperly maintained. This problem can be solved by describing varieties according to their morphological and physiological characteristics. Besides, any attempt for identifying isoenzymes by using the electrophoresis technique will be of great importance in this field.
2. Resistance to pests and diseases are important for a profitable production, fruits of higher quality and overcoming the problem of residues of agrochemicals. For this reason

   Satisfactory screening methods must be developed and applied to the existing accessions so that the sources of resistance genes could be identified.

   • Selection for disease resistance must have priority in the apricot growing areas by field infection or artificial inoculation. This can be realized in collaboration with the phytopatologists.
   • To grow apricot trees in suitable areas and to improve the cultural methods could help to provide a reduction in the use of chemicals. This is a very important concept especially for the countries where pesticide usage is increasing from year to year.
   • Investigations aiming to find out the residual effects of pesticides applied for the production of apricot trees are of great importance. Thus, hygienic regulations for the use of related chemicals can be provided. Limits accepted and applied since January 1989 by EC countries can be taken into account at present.
   • Studies should be continued on the causes and controls of dieback diseases of apricots. The same importance should be placed on determining the limits of the areas in which virus and mycoplasma diseases are spread and on looking for tolerant or resistant apricot cultivars.
3. In recent years, more intensive orcharding systems have been established by using advanced training and pruning techniques and various rootstocks and thus early and high yield can be provided and labor and other expenses are saved.
   • Experiments carried out on training for pruning techniques which are convenient to different varieties, areas and purposes, such as mechanical harvesting, can be of great importance.
   • Taking into consideration that most of the advanced techniques can be applied only by using proper rootstocks. More attention should be paid to studies carried out on various problems of rootstocks.
4. The limited adaptation of apricot varieties is a challenge to apricot growers. Therefore, the breeders must continue the breeding programs to develop apricots adapted for each individual producing area or to obtain varieties with a wider range of adaptability.
5. In most cases, overemphasis has been placed on table apricot varieties in planning various related projects. Less emphasis is given to apricot varieties for drying and processing. However, it seems likely that much more can be done on this matter.
   • Selection or creation of apricots which are suitable for drying can provide a development in the quality of dried apricots.
   • In order to get dried apricots of desirable quality with less SO₂ residue, various techniques of apricot drying could be investigated.
   • Any research related with the quality of dried apricots such as colour, texture and elasticity of the flesh, nutritive value, mycotoxin will be of great help.
6. Since biotechnology is becoming more and more important, rapid and virus-free multiplication, somatic hybridization by protoplast fusion and somaclonal variations can be realized in apricot species by these methods.
7. Some useful induced mutants can be created by determining the best strategy.
8. As it is well known, working on breeding of fruit trees requires a long period of time, more attention must be given for developing screening techniques and working on pre-selection methods.

Agricultural crops are always produced as the result of an interaction of various factors. So, a problem can appear only under specific conditions, however it may then be a problem under similar conditions of another country. If some problems are seen as important, although they may be specific, collaboration will be very helpful.

For our future target, I would like to express, once more, the need for a closer collaboration within the working group on Apricot at international level and hope to move towards more research work on the subject.

Prof. Dr. Ruhinaz Gulcan
The Chairwoman of the ISHS
Apricot Working Group


OPENING ADDRESS BY THE PRESIDENT OF ISHS

Apricot is about to achieve another milestone at this ISHS Symposium in Greece, the heartland of the Hellenic-Macedonian agricultural civilisation. Our Society has always attached significant importance to this crop, which has in the countries of the Mediterranean Basin its most noble growing districts and a markedly long and date-varying ripening calendar that stretches from May in the Greek islands to August in Switzerland (Sion) and such other Alpine zones as Val Venosta in Italy.

Apricot can thus be a source of enhancement and promotion for difficult growing areas, if not even prohibitive ones to other important fruit crops more appropriate to hot-arid or Mediterranean climates, and be on a par with those crops that are adapted to continental climes of rather rigid winters. It is therefore a ‘malleable’ species, even with all its weak points-susceptibility to rot and canker, decline, sharka, early bloom, splitting and so forth-and offers favourable economic prospects to ‘suitable’ hillside growing districts, even in clay and nutrient-poor soils ill-adapted to fruit cultivation. Apricot is also much sought after by the processing industry for juice, jams, dried fruit and other derivatives.

The European Union, which has heavily invested in balancing the grape, apple, pear, peach, citrus and olive markets, has almost never had to intervene in the apricot market. The downside, however, is that funding for research in apricot is also a scarce commodity. For these and other reasons the ISHS decided to establish in the late 1950s-early 1960s its working group of experts. A great deal of the WG members' efforts and hard work has been expended since then in such fields as breeding, genetics, rootstocks, germplasm, growth habit biology, disease and pest control, especially in regard to bacteria and viruses. The ISHS Apricot WG can boast on very distinguished chairs. Let me mention only some of them : the honorary Chairman, Professor Paunovic, who was the founder of the WG, Professor R. Gulcan, who has drafted the most complete and up-to-date list of researchers in apricot (including eastern European and Asian colleagues) and started the WG's newsletter, and Irene Karayiannis, our host today, who has inherited the legacy of her predecessors and has done such an excellent job in organising this XI Symposium here in the very hospitable venue of Veria.

I harbour no doubts as to its complete success and full attendance, the originality and quality of the presentations and the chance to document the latest technology innovations in the growing, production and storage of apricot, as is the case in the other major fruit sectors. Yet apricot too is not without present and future challenges, including biennial cropping, susceptibility to many climatic and disease variables, its perishability and achieving a high and lasting standard of quality.

Thanks to the trade between the two hemispheres, the apricot in now able to extend its marketability in the northern, as well as the southern half, beyond the usual three-four months to at least four months in the summer and three in the winter. This means rising consumer demand. So it is our task, as researchers at the service of its cultivation, to assure that apricot, which has never been plagued by surplus yields, achieves proper yield stability and to educate and persuade potential new consumers to try this delicious fruit. Such an accomplishment would also be a gratifying reward for the tireless commitment of researchers in the field.

On behalf of the ISHS, let me express our thanks and gratitude to all participants, the Organizing and Scientific Committees, and our fine convener, Irene Karayiannis, and the very best wishes for a fruitful Symposium.

Silviero Sansavini
President, ISHS
Bologna, May 1997