Two seedling rootstocks of Mahaleb cherry (Prunus mahaleb L.) from a German type cv. Alpruna marked as No. 2 and No. 6 were selected for their semi-dwarfing properties from biotypes growing at the Rural Experimental Station in Baranowo belonging to the University of Life Sciences in Poznan, Poland. In an orchard experiment in 2012-2013, growth and yield of eight-and nine-year old trees of the cvs Regina, Summit and Vanda were studied. These cultivars were grafted on Mahaleb cherry No. 2 and No. 6 and were compared to the control rootstock Mazzard (Prunus avium L.) cv. Alkavo. The Mahaleb cherry biotypes significantly decreased the trunk cross-sectional area and the crown volume of the trees. The cultivars grafted on Mahaleb cherry biotypes No. 2 and No. 6 had more flowers and they gave a higher yield. The yield efficiency for cultivars grafted on these rootstocks was higher than for rootstock Mazzard. Significant differences of the concentration of the elements were found for Fe, Cu, Zn in fruit and for Fe, Cu and Cr in leaves. Presence of Pb and Cr was not detected in sweet cherry fruit.

The aim of the research was to determine selected biochemical and physical characteristics and yielding of fruits in apple varieties (Malus domestica Borkh) such as Gala Schniga, Beni Shogun (Fuji) and Ligol, M.9 rootstock growing in the Wielkopolska region, Poland. high-performance liquid chromatography (HPLC) analysis revealed differences both in the profile and contents of soluble sugars and other metabolites detected in fruits of the tested apple varieties. The highest total saccharide content was found in fruits of cv. Gala Schniga, while leaves and shoots of this variety showed the lowest contents. Electron paramagnetic resonance (EPR) spectroscopy revealed the lowest contents of semiquinone radicals in apple fruits and the highest in leaves of apple trees. All organs of Schniga Gala apple trees were characterized by the highest levels of these radicals. Besides, gas chromatography-mass spectrometry (GC-MS) analysis of abscisic acid (ABA) revealed the highest levels of this molecule in shoots of apple trees, especially the Beni Shogun variety, while in fruits the levels were the lowest. Ligol fruits had the highest content of ABA. The percentage of injury observed after a low-temperature treatment and estimated on the basis of electrolyte leakage, was shown to be the lowest in fruits of the Beni Shogun variety. In turn, the lowest average yield of apple fruits was recorded for the Ligol and Fuji varieties, with the highest in the case of the Gala Schniga variety. At the same time, a significant variability in the average weight of fruits was observed; the highest average mass of fruits was recorded for the Ligol variety, while it was lowest for Gala Schniga. Additionally, firmness evaluation of the fruits revealed that the firmest fruits were harvested from Gala apple trees, before the Beni Shogun and Ligol varieties. A significant variability was recorded in the red blush on fruit surfaces of the tested varieties, with Ligol fruits having the weakest blush. Altogether, these results indicate that fruits of the analyzed apple varieties differed both in terms of their biochemical composition and physical characteristics.

Cultivation of sweet cherry trees is growing in popularity in Poland thus there is an increasing demand for good quality nursery material. The growth of maiden sweet cherry trees of ‘Vanda’ depending on three rootstocks was compared within three years of the nursery experiment. Also the nutritional status as well as photosynthetic activity of maiden trees after the use of four foliar preparations were in the scope of interest. On the basis of the size of the trunk diameter and weight of maiden sweet cherry tree fresh mass as well as on the basis of dry mass of leaves, the strongest vigor of growth was observed on Colt rootstock, contrary to the vigor on GiSeLa 5 rootstock, in which it was the weakest. Maidens produced on Colt rootstock formed more lateral shoots in comparison to other rootstocks. After foliar fertilization, maiden sweet cherry trees growing on Colt rootstock did not show better parameters of growth, except for Maxi Grow Excel preparation that caused better results of growth. The influence of preparations used on the content of macro and microelements was differentiated. A positive effect of all preparations was noted as far as gas exchange parameters were concerned, especially in the case of Maxi Grow Excel.

The article describes an experiment conducted on maiden apple trees of selected cultivars growing in a nursery. The aim of the study was to investigate how the foliar application of four biostimulants (Aminoplant 0.4%, Biamino Plant 0.2%, Bispeed 0.2% and Fylloton 0.4%) and two fertilisers (Basfoliar 6-12-6 and Basfoliar 12-4-6+S both at a concentration of 0.5%) affected the growth of the trees cultivated with the mineral fertilisation reduced by half. The plants were sprayed with the preparations and fertilisers four times at three-week intervals, between late May and late July. Selected parameters of the plants’ physiological processes were also assessed: net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (C) and intracellular CO2 (I). The foliar application of all the biostimulants and fertilisers significantly improved the growth of the maiden apple trees. The lowest values of the plant growth parameters were noted in the control combination, which was treated with a full dose of mineral fertiliser. The foliar spraying of the apple trees particularly improved the total length and number of side shoots and the fresh weight of maiden apple trees. The apple tree cultivars differed in their growth parameters, and the influence of individual foliar treatments was not conclusive. The foliar application of selected preparations intensified the leaf transpiration coefficient and the internal concentration of carbon dioxide, but it did not increase the net photosynthesis intensity or stomatal conductance.

The experimental studies were conducted from 2015–2017 years in two cycles. The aim of the research was to determine a better grafting time and a choice of an appropriate rootstock for the propagation of two cultivars of mountain pine (Pinus mugo Turra). The influence of the grafted cultivar and rootstock used on the level of chloroplast pigments in the needles was also checked. The studies concerned two cultivars of mountain pine (Pinus mugo) ‘Grześ’ and ‘Zundert’, which were grafted on four different rootstocks: Pinus contorta (Dougl. ex Loud.), Pinus nigra (Arn.), Pinus sylvestris (L.) and Pinus mugo subsp. uncinata (Ramond Domin) in two dates: 20 January and 15 March. The highest percentage of graft success was obtained for the two cultivars on Pinus uncinata and Pinus contorta rootstocks. A later term of grafting procedure affected bigger effectiveness of grafting of the two studied cultivars, except for the graft success on Pinus sylvestris rootstock. The highest increments of side shoots and lengths of main stems for ‘Grześ’ cultivar were obtained on Pinus nigra, and for ‘Zundert’ the influence of the rootstock on the above mentioned parameters was not evident. No significant differences in the number of increments in the first and second year of studies were observed. The highest level of chlorophyll A and B was found in the needles of ‘Grześ’ cultivar, independently from the rootstock used. Among tested rootstocks, only Pinus nigra had a significant impact on a higher content of chlorophyll B in the needles of the studied cultivars of mountain pine trees.