Tree Fruit & Grape News, October 2000

4th International Symposium on Mineral Nutrition of Deciduous Fruit Crops

Report by Gerry Neilsen, Research Scientist, Pacific Agri-Food Research Centre, Summerland.

This International meeting was held August 13-18 in Penticton, British Columbia. Ninety scientific professionals from 24 countries and six continents made 57 oral and 20 poster presentations during the week long sessions. Orals were organized around themes including Nutrient Cycling in Fruit Trees, Fruit Quality: Its Relationship to Major and Minor Nutrients, The Relationship of Roots, Rhizosphere Characteristics and Soil Biology to Fruit Tree Nutrition, Diagnosing Nutrient Status, Field Response to N Fertilization, Effects of Production Systems and Rootstocks on Fruit Nutrition, and Foliar Nutrition. It is anticipated that an Acta Horticulturae summarizing written proceedings will be produced and available for purchase and to participants within the next year.

A special concluding session entitled "World overview of important fruit industry problems and how they are being addressed," designed with a commercial emphasis, was attended by an additional 100 technical, extension and grower representatives from the Pacific Northwest fruit industry. This session featured presentations on nutrition, soil and water management from several countries including South Africa, Belguim, United Kingdom, Switzerland, Italy, United States and Canada. A summary of the report from Switzerland follows this report as it provides insight into the requirements and procedures under integrated fruit production (85% of Swiss fruit is produced in this manner).

Two field tours of fruit production and research in southern British Columbia were organized as part of the scientific program associated with the 4th International Symposium on Mineral Nutrition of Deciduous Fruit Crops. The first tour on August 15th was organized by Dr. Eugene Hogue and involved an overview of the research programs at the Pacific Agri-Food Research Centre (Dr. Gordon Neish) including biotechnology (Dr. D’Ann Rochon), and food (Dr. Joe Mazza) for approximately 90 international scientific visitors. Horticulture and environment research was demonstrated in a tour of field plots which included research on sweet cherry and apple breeding (Drs. Cheryl Hampson and Frank Kappel), stone fruit disease control (Dr. Peter Sholberg), nitrogen and water management (Dr. Denise Neilsen), sweet cherry nutrition (Dr. Gerry Neilsen), and effects of mulch application (Dr. Eugene Hogue).

On Thursday, August 17, Dr. Bill Wolk of the Okanagan-Similkameen Co-op in Oliver organized a field tour of the south Okanagan Valley. Three commercial orchards (Dawson, Mennell/Edwards, Hayter) were visited where local orchardists discussed recent developments in high-density apricot and apple production, super spindle Fuji and Gala, nursery management and organic tree fruit production. The Sterile Insect Release (SIR) facility at Osoyoos and enology and viticultural operations at Inniskillin winery and vineyard in Oliver were also visited. International visitors were impressed by the enthusiasm and innovation of Canadian growers and the social and political skill required to organize and achieve area-wide insect control programs.

Tree nutrition, soil and water management of pip and stone fruit in Switzerland (as presented at the 4th International Symposium) Lukas Bertschinger 

Swiss Federal Research Station for Fruit-Growing, Viticulture and Horticulture, P.O. Box 185, SH-8820 Wadenswil, Switzerland

Switzerland’s fruit production covers within a small geographical area an impressive range of options, of how and for which purpose fruit is produced. Table fruit is mainly grown in intensively managed modern and densely planted orchards with small trees on about 7,000 ha (5,000 ha apples, 700 ha pears, 500 plums, 400 ha cherries). Apples, pears, cherries and plums are also grown on standard trees. The pip fruit produced on these trees is mostly used for cider production, while the stone fruit is used mainly for distillery. Particularly in stone fruit, an on-going move towards densely planted and intensively managed orchards with small trees and higher rates of return is notable, which is made possible by new varieties and new slow growth inducing rootstocks. The majority of professional fruit growers manage approx. 4 to 10 ha of orchards. Annual precipitation ranges in the main fruit producing areas between 600 to 1,000mm (up to 500mm during the growing cycle). Sandy loam soils with a varying proportion of clay are predominant. Over 85% of Swiss fruit is produced according to integrated production guidelines while at present 3 to 4% of Swiss apples are organic ("biological"). The guidelines of both production systems involve all aspects of production, including tree nutrition and soil management, but not water management: water has not been a major limiting factor for tree growth and nutrition so far in Switzerland, it has complicated the production of cherries and plums (fruit cracking).

The symposium presentation will address the actual practices in pip and stone fruit tree nutrition and soil management in Switzerland. It is based on an assessment of the respective actual situation by a working group of Swiss fruit production researchers and extensionists.

The presentation explains the prevalent Swiss guidelines and concepts for an integrated organic production regarding nutritional and soil management issues. Actual problems, causes and possible solutions of pip and stone fruit tree nutrition and soil management are commented.

While in the last two decades, ecology was among the highest priorities on the political agenda in agriculture and therefore also in research, extension and production, new key issues have come up with the sustainability debate and the interests of the World Trade Organization and an open European market economy. Economical and social aspects increase in significance for the development of the agricultural sector while achievements in the area of production ecology have to be maintained on the achieved level and constantly adapted to the present state of the art. What does this mean for tree fruit nutrition, soil and water management? Leakage of nutrients will continue to be a non-acceptable environmental hazard also in tree fruit production. This means, that fertilization rate settings and application techniques will continue to be demand driven on the quantitative and tree developmental scale. Fertilization will continue to focus on tree nutrition through the roots. However, guidelines should make possible a flexible and situational orchard management in response to prevalent particular orchard situations and problems (e.g. foliar fertilization to address acute nitrogen demand due to a cold and dry period in spring).

Efficiency and affectivity need to be a key issue behind nutrition, soil and water management issues in the next decade, be it at the nutrition, price or resource unit level. How many guidelines in the next decade will include also resource addressing issues (e.g. water and soil resource and support material management, e.g. also including water use and materials like plastic cover sheets, etc.) is difficult to say. Methods of measuring and regulating resource management are under study and will eventually become available. It will be the challenge of innovative growers, extensionists and researchers to develop nutrition, soil and water management systems that meet the demands of a sustainable development of the fruit sector and society. 

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