ORGANIC SYSTEMS OF APPLE PRODUCTION BRING NEW HORIZONS TO TRADITIONAL CROP PHYSIOLOGY

Traditional apple crop physiology has majored on the effects of environmental factors on tree and fruit growth and development, in orchards or controlled environments, with adequate nutrition, water and good control of pests and diseases. This has undoubtedly led to greater understanding in the traditional scientific reductionist pattern. The advent of organic systems of production, however, raises new challenges for crop physiology, not the least of which is to attract funding for systems of production that are still seen by some as on the outer fringes of scientific endeavour. The real scientific challenges relate to the effects on tree growth and fruit development of less than complete insect and disease control, spray materials such as sulphur that are more phytotoxic to some cultivars than conventional fungicides and less than ade¬quate nutrition. Fortunately, progress has already been made in computer modelling of crop growth of apples and peaches but this will need to be considerably expanded to include pest, disease and nutritional modules, including root growth, to adequately encompass the organic growing system - to do this we will need multi-disciplinary teams.
The wider issues raised by the organic farming community regarding sustainability are important for all of us to face with reasoned discussion based on sound experimental data if we are to be all-round environmental physiologists. The challenge for the physiologists of the future is to make all systems of production more sustainable. This can only be achieved by a detailed understanding of the total orchard environment and how we can then manipulate our system of fruit production to move more rapidly towards the ideal of a sustainable system.