The Floral Phenology, Growth and Productivity Of
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COPYRIGHT AND USE OF THIS THESIS This thesis must be used in accordance with the provisions of the Copyright Act 1968. Reproduction of material protected by copyright may be an infringement of copyright and copyright owners may be entitled to take legal action against persons who infringe their copyright. Section 51 (2) of the Copyright Act permits an authorized officer of a university library or archives to provide a copy (by communication or otherwise) of an unpublished thesis kept in the library or archives, to a person who satisfies the authorized officer that he or she requires the reproduction for the purposes of research or study. The Copyright Act grants the creator of a work a number of moral rights, specifically the right of attribution, the right against false attribution and the right of integrity. You may infringe the author’s moral rights if you: - fail to acknowledge the author of this thesis if you quote sections from the work - attribute this thesis to another author - subject this thesis to derogatory treatment which may prejudice the author’s reputation For further information contact the University’s Director of Copyright Services sydney.edu.au/copyright THE GROWTH AND PRODUCTIVITY OF HAZELNUT CULTIVARS (Corylus avellana L.) IN AUSTRALIA Basil Baldwin A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Faculty of Rural Management University of Sydney July 2015 i ABSTRACT During the 1990s, a question posed by new and intending growers of hazelnuts was “What is the best variety to plant when establishing a commercial orchard?” Although existing growers had a range of views on this matter, there had not been any scientific studies to evaluate the range of cultivars available in Australia. Although hazelnut cultivars were introduced to Australia in the mid-Nineteenth Century, there had been very limited industry development compared to other cool climate deciduous tree crops such as pome and stone fruits. In the 1970s many cultivars were imported from overseas, but there was no systematic evaluation of this material. In 1994, the author of this thesis obtained a grant from the Rural Industries Research and Development Corporation (RIRDC) to undertake an assessment of hazelnut cultivars and their potential for Australian conditions. The evaluation involved planting a range of cultivars at 5 field sites. Two were in New South Wales, 2 in Victoria, and 1 in Tasmania. There was variation between the sites in soil types and climate. A randomised block design was used with cultivars as treatments within blocks. Observations and measurements were recorded for tree growth, floral phenology, nut yields and the characteristics of both nuts and kernels. All sites had supplementary irrigation and common management practices. 1-year old hazelnut whips were planted at a spacing of 3 m x 5 m. Automatic weather stations were located at each site. There were major differences between cultivars, in terms of their vigour of growth, floral phenology, nut yields and kernel characteristics. In addition to the cultivar effects, soil type was a major factor influencing tree growth, as was rainfall. Cultivars with high vigour included ‘Barcelona’ and the Australian selection ‘Tokolyi/Brownfield Cosford’ (‘TBC’). Those of low vigour were ‘Tonda Gentile delle Langhe’ (‘TGDL’), ‘Negret’ and ‘Wanliss Pride’. There were significant interactions between cultivars and the sites in tree growth and nut yields. Timing of male and female anthesis was strongly influenced by cultivar and seasonal conditions. All cultivars were protandrous. The commencement of pollen shed ranged from late-May, for the cultivars ‘TGDL’ and ‘Barcelona’, to early August for ‘Hall’s Giant’. Chill hour requirements appeared to be the main factor influencing timing of pollen shed. Female ii anthesis was also spread over a period of several weeks with early cultivars being ‘Atlas’ and ‘Tonda di Giffoni’, late cultivars were ‘Ennis’, ‘Casina’ and ‘Hall’s Giant’. Studies with cut branches in controlled temperature environments indicated that catkins had a relatively high post-chill heat requirement compared to female inflorescences. The differences between cultivars in post-chill heat requirements for catkins were small. The relative dates of flowering across cultivars were found to be highly predictable. This, coupled with published data on genetic incompatibility, made it possible to recommend cultivars as pollinisers for the main nut-yielding cultivars. There were significant differences between cultivars in the date of bud break; ‘TGDL’ and ‘Tonda di Giffoni’ were early (late August) whereas ‘Hall’s Giant’ was late (late September). Nut yields were highly influenced by cultivar, vigour of growth, site and seasonal rainfall. Low rainfall in one season greatly reduced nut yields. High growth rates at one site lead to a closed canopy 7 years from planting with peak yields. Soil characteristics were a main factor influencing tree growth and nut yields. The best tree growth and highest levels of production were achieved on a deep, well drained, fertile loam soil. The characteristics of nuts and kernels were strongly influenced by cultivar, although seasonal conditions influenced nut and kernel size and the degree of kernel fill. An overall evaluation of cultivars was based on nut and kernel yields as well as kernel characteristics to meet market requirements. On average, ‘Ennis’ gave the highest yields of the in-shell cultivars. The cultivars ‘Barcelona’ and ‘TBC’ produced the highest average yields, although their relative performance varied between sites. These cultivars were considered best suited for snack foods and catering with 15-17 mm kernels. ‘Tonda di Giffoni’ produced moderately high yields, varying across sites, with kernels suitable for the confectionery market. Under favourable conditions ‘Barcelona’ achieved nut yields of 3 tonnes/ha within 6 years from planting. Potential areas in Australia for hazelnut production were identified, based on a set of recommended climatic parameters and soil characteristics. iii ACKNOWLEDGEMENTS I wish to acknowledge the help of many people with the research studies described in this thesis. The research would not have been possible without the financial support of the Rural Industries Research and Development Corporation (RIRDC), which provided funding for a total of 12 years. Thanks are extended to the program leaders, David Evans, Max Bourke and Alan Davey for their confidence in the value of the research and support for its on-going funding. At the time that the study commenced, I was an employee of the University of Sydney, Orange Agricultural College. The principal Professor John Chudleigh gave his strong support to the work. The university provided administrative services through its Research Office and travel funding, as a post-graduate student. Karilyn Gilchrist was employed as a part-time research assistant at the university. She and her husband, Richard, were of great help in the field, particullarly at harvest. Karilyn was of enormous help in maintaining the automatic weather stations, downloading data at Orange and managing the huge volume of data that was generated from all sites as well cracking numerous nuts for kernel assessments. Lester Snare of NSW Department of Primary Industries was also a great assistance and support. Not only did Lester manage the Orange site but he accompanied me on many field trips to plant trees and harvest nuts. NSW DPI purchased a Tonutti harvester which proved invaluable when Lester took it to Myrtleford for several harvests. NSW DPI also provided facilities for nut drying. Helen Nicol provided expert advice on experimental design and conducted statistical analyses of some data. My appreciation is extended to her for the advice and analyses conducted. I wish to express my appreciation for professional advice and support provided by Professor Shawn Mehlenbacher of the Oregon State University (OSU). I also thank Rebecca (Becky) McCluskey of OSU who spent sabbatical leave at the University of Sydney, Orange in 2001 and helped us in many aspects of the field studies, including training in the techniques used by the OSU team for kernel evaluation. The conduct of this research relied heavily on support provided by collaborating parties at all sites. At Orange it was NSW DPI. Jim and Lauren Gleeson provided the trial site on their iv property at Moss Vale and spent many hours tending the trees, recording data and harvesting nuts. Thanks are extended to Agriculture Victoria for the provision of trial sites and support from staff at the Ovens Research Station and the Horticultural Research Institute, Toolangi. Myrtleford. At first, it was not possible to obtain support for a site in Tasmania until John Zito offered to provide a site on his property at Kettering. John, his wife Connie and daughters Adele and Stephanie were always most welcoming and very supportive with the research. My thanks are also extended to Milan Paskas, Richard Salt, Janet Brown, Jim Beattie, Lyn and Colin McRae, Bruce West and Simon Hammond for the provision of planting material. Milan Paskas had a collection of cultivars and was most helpful in propagating material from his collection. He was also a valuable source of knowledge on hazelnut growing in Australia. The support provided by the hazelnut growers of Australia is acknowledged. Funding for travel was provided by RIRDC and the University of Sydney enabling me to present papers on the research at International Congresses on Hazelnut in Turkey, Oregon, Spain and Italy. Attendance at these Congresses was invaluable, networking with world leaders in hazelnut research and production. I particularly appreciated valuable discussions with Professor Shawn Mehlenbacher of Oregon State University (OSU) who also gave advice on cultivar identification. Thanks also to my supervisor, Emeritus Professor David Kemp, and Dr Yann Guisard, who have given much valuable feedback on the thesis. Finally I acknowledge the assistance of my wife Jean who accompanied me on many field trips, assisted with harvest and data collection.