The aim of this study was to evaluate flowering, yielding, fruit quality, and growth of several less known pear cultivars growing in the climatic conditions of Lower Silesia. The experiment was conducted in the years 2006–2010 in the Fruit Experimental Station located in Samotwór near Wrocław. In spring 2006, trees of several less known pear cultivars were planted: 'Isolda', 'Hortensia', 'Fertilia Delbard Delwilmor', 'Wyżnica', 'Nojabrskaja' ('Xenia®'), 'Uta', 'David' on Caucasian pear (Pyrus caucasica Fed.), 'Bohemica' on quince S1 (Cydonia oblonga Mill.) as well as 'Morava' and 'Blanka' on both these rootstocks. The highest total yield in the years 2007–2010 was recorded for the 'Nojabrskaja' and 'Wyżnica' cultivars. The 'Blanka' cultivar produced the largest fruit, while fruits of the 'Isolda' cultivar were significantly the smallest. The largest growth and cross-sectional area of the trunk were recorded for the trees of the 'Wyżnica' cultivar, while the smallest were observed in the case of 'Morava', in which the thickness of the trunk was similar on both rootstocks. The 'Morava' cultivar grafted on quince S1 formed the smallest crowns. On the other hand, 'Isolda' and 'Hortensia' were among the cultivars that produced the largest crowns

In order to increase the profitability of pear production, a greater density of weak growing trees per area unit should be planted. In Poland, the most frequently used pear dwarfing rootstocks are quince clones. The main disadvantage of them is a physiological incompatibility with some cultivars. The aim of this study was to evaluate the effect of the rootstock, interstock, and intermediate stock on growth and productivity of two summer pear cultivars, which are not compatible with the quince rootstock. Twoyear- old pear trees of ‘Radana’ and ‘Clapp’s Favourite’ cvs of different compositions were planted in the spring 2006. The following combinations were evaluated: ‘Radana’ and ‘Clapp’s Favourite’ on Caucasian pear seedlings, ‘Radana’ and ‘Clapp’s Favourite’ on quince SI with an intermediate stem piece of ’Doyenne du Comice’ and ‘Radana’ on Caucasian pear with ‘Pyrodwarf’ interstock. Up to the 6th year after planting, trees of ‘Radana’ grafted on Caucasian pear seedlings and on quince with intermediate stock yielded better than ‘Radana’ trees composed of Caucasian pear seedling and ‘Pyrodwarf’ interstock. ‘Clapp’s Favourite’ in all combinations had significantly heavier fruits. The highest crop efficiency index had ‘Radana’ on quince with ’Doyenne du Comice’ intermediate stock.

Apple cultivars resistant to scab are suitable for the conventional and organic cultivation. Rootstocks impact on the growth of trees, yield and fruit quality of scab-resistant cultivars were examined in the experiment conducted at Fruit Experimental Station - Samotwór near Wrocław, during the years 1998-2008. In the spring of 1998, the trees of five Czech origin scab-resistant apple cultivars ‘Rosana’, ‘Rubinola’, ‘Rajka’, ‘Goldstar’ and ‘Topaz’ each on M.9, P2, P60, P16 and P22 rootstocks were planted at a spacing of 3.5 × 1.2 m (2380 trees per hectare). The results of 11-year-long studies showed that ‘Rubinola’ and ‘Rajka’ were characterised by the strongest vigour, while ‘Rosana’ grew much weaker. Significant differences in the cumulative yield were not observed between cultivars, but rootstocks influenced cropping instantly. Trees on rootstock P60 had biggest cross-section area and canopy volume, and the highest cumulative yield. Fruit weight was highest from trees on M9 and P60. ‘Topaz’ and ‘Rosana’ formed significantly lightest fruits and ‘Goldstar’ the heaviest. Trees on the super-dwarfing P22 rootstock grew and yielded very weakly and produced very small fruits. The greatest susceptibility to powdery mildew (Podosphaera leucotricha) was observed in ‘Topaz’ and ‘Rajka’. ‘Rubinola’ has the best potential for organic cultivation, especially on dwarfing rootstocks.

Choice of orchard system is one of the major factors, on which pear crop size and quality depend. The purpose of this research was to assess the influence of two training systems involving trees trained to different number of leaders on growth, yield, and fruit quality of three pear cultivars. The study was conducted in 2001–2012 near Wrocław (south-western Poland). One-year-old trees of ‘Carola’, ‘Dicolor’ and ‘Erika’ cultivars on the Quince S1 rootstock were planted in the spring 2001 using 3.5 m between rows and a variable in-row spacing: 1.7 m (Drilling form with 3 leaders) and 1.2 m (Güttingen – V system with 1 leader). More vigorous growth was observed from more sparsely planted trees under the Drilling form. The total per-tree yield during 2002–2012 was decreasing as the planting density increased. No differences were observed on yield per hectare between the tested systems. The Drilling trees produced significantly heavier and larger fruit than the trees trained to the V-Güttingen system.

The study was conducted in 2001-2012. The purpose of this research was to assess the influence of type of nursery trees of pear cvs 'Carola' and 'Dicolor' budded on quince S1 rootstock on growth and cropping, as well as fruit quality of two pear cultivars. The trees were planted in the spring of 2001 in 4 replications with 5 trees per plot. Trees were planted in rows with spacing 1.2 × 3.5 m (2381 trees per hectare). Three types of nursery trees, all without feathers, were planted: twoyear-old (3 years in a nursery), one-year-old maidens (2 years in a nursery) and annual grafts (only 1 year in a nursery). Tree canopies were formed as a spindle and were trained in the Güttingen-V system. Until the twelfth year after planting, growth and yield were significantly affected by the type of nursery trees. One-year-old maidens were characterized by the strongest vigor in orchard, while pears planted as twoyear-old trees grew rather weak (especially with 'Dicolor' cv.). Planting two-year-old trees didn't have any clear positive influence on tree cropping in the orchard. The final results of the study proved that trees planted as annual grafts, irrespective of cultivar, yielded significantly worse. The type of nursery trees had no clear influence on mean fruit weight.