The effect of the intensity and method of pruning on the growth and yield of the apple variety ’Idared’ under conditions of ecological and integrated growing systems

The ecological growing system of apple produces inferior results as the admitted methods of nutrition and plant protection cannot provide for those conditions as usually secured by the integrated growing system (Gonda, 2005; Holb et al., 2005ab). The nutrients delivered by the soil and the photosynthetic activity of the canopy are temporarily or permanently limited, therefore the growth and performance of apple trees in the ecological growing system diminishes remarkably. Among the phytotechnical elements of the growing system, pruning is the most decisive regarding its influence on shoot growth as well as on the formation of fruiting bodies, flowers and fruits (Gonda, 2005). The fundamental objective of our experiment was definitely to strengthen the weak conditions securing reduced potential of the plant by relatively intense pruning, which may stimulate lively growing within certain limits. Pruning is able to overcome the apparent lack of vitality and restore optimal conditions (Zatykó, 1979). According to Zatykó, optimal conditions depend on the healthy balance between vegetative activity and provision of assimilates. Our experimental object, ‘Idared’, is known to need, now and then, strong pruning in the traditional as well as integrated practice of growers. At the same time, more or less shortening of the shoots is also recommended. Interventions of this type are necessary to stimulate shoot growth, which is essential for building up conditions for the development of fruits in the current and the next year. Based on those considerations, the pruning experiment has been planned and started in the spring of 2008.