The subjects of this study were 8-year-old sweet cherry trees of the cultivar 'Kordia' grafted on the 'Colt' rootstock. The trees had been trained as spindles for four years after planting. In the fifth year, four systems of pruning were introduced: 1) the spindle form - i.e. the pruning system remained unchanged, 2) Zahn's method of pruning, 3) one-year-old shoots were cut back leaving approximately 10 buds, 4) no pruning at all - control trees. An assessment of the effects of these training systems was carried out in the third and fourth year of the study. The best results were obtained with the trees formed in the shape of a spindle and the trees pruned according to Zahn's recommendations. Cutting back long one-year-old shoots caused a significant decrease in the total yield and a small increase in the average fruit weight. The smallest values of canopy volume were obtained in the combination where long shoots had been shortened, while the largest canopies were found in the control combination. Canopy volumes of the trees shaped as spindles and of those pruned using Zahn's method were similar.
Experiment with different training systems of apple trees 'Śampion' and 'Topaz' grafted on M.26 rootstock was established in the Experimental Orchard at the Agricultural and Pomicultural Experimental Farm in Przybroda near Poznań, belonging to Department of Pomology, University of Life Sciences in Poznań Maiden apple trees were planted in the spring 2002 at two densities: 3.5 x 2.0 m (1428 trees ha-1) and 3.5 x 1.0 m (2857 trees ha-1). Depending on the spacing of the trees, nine different tree trainings were applied. Trees of both cultivars planted most densely were trained in the following forms: V from Güttingen, Hytec, spindle, axis and spindle form from Bodensee Lake. Trees planted at the wider spacing had the following forms: double spindle, Drylling and Mikado. Each training system had 4 replications (five trees in each replication). Comparison of apple tree training system has shown that the growth and yield of trees depends more on the genetic traits whereas tree form changes the orchard architecture. Observations confirm the high values of the Drylling and Mikado crown forms, which require a moderate labour input for their formation and maintenance during fruiting time.