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

Summary: On the Experimental Farm of the Debrecen University at Pallag, a factorial experiment has been started at springtime of 2008 on an orchard of 12 year old apple trees ’Idared’ grafts on M 26 understocks. The first factor was the growing system (integrated versus ecological), the second was the intensity of pruning (strong versus moderate thinning of the crown), whereas the third was the method of pruning (shortening versus thinning of individual shoots). Measurements have been concentrated on shoot growth, flower initiation, fruit set and accumulated yield of two successive seasons. The following conclusions are made.– In the ecological growing system, strong thinning proved to be beneficial for growth as well as for fruit bearing. – Strong thinning combined with shortening of shoots diminished yield in the first year, whereasmoderate thinning combined with shortening of shoots caused favourable growth and fruit bearing.– In the ecological growing system, the moderate shoot growth was associated with better flower initiation, which increases the chances of alternate yielding.– According to our results, the flower initiation of the ‘Idared’ was stimulated univocally by the thinning of shoots regardless of the intensity of pruning.The right choice of the intensity and method of pruning is a decisive moment of a successful yield in the ecological apple growing syste