Recently the interest in borage as a vegetable and medicinal plant has increased, yet the knowledge about a content of biologically active compounds in borage grown in Poland remains very scanty. In the experiment carried out in the south-eastern part of the country, fresh borage flowers and leaves contained 0.02% and 0.12% of lipids with the highest level of palmitic acid, i.e. 44.5% and 33.4%, respectively. Flower lipids contained stearic, oleic, elaidic, linoleic, linolelaidic, arachidonic, myristic and lauric acid as well. Besides, leaf lipids were rich in α-linolenic acid (17.7%), less in palmitoleic acid with absence of arachidonic acid. Leaves were found to have 0.16% of essential oil, 1.0% of flavonoids, 9.2 mg vitamin C·100 g f.w.-1 , 1.9 mg carotenoids·100 g f.w.-1 , 0.77 mg chlorophyll a·1 g f.w.-1 and 0.22 mg chlorophyll b·1 g f.w. -1 . Flowers contained more essential oil and vitamin C while less carotenoids, chlorophyll a and b and flavonoids. 45 components were found in the flower essential oil and among them 16 were identified with cumene (62.9%) as a major one. The content of other components was below 3%. As for the leaf essential oil, 18 compounds were detected, and 5 were identified with the highest level of cumene (58.5%) and hexenyl (13.3%). Generally, flowers had more polyphenols and their ferric reducing ability was higher than that of leaves. Besides, a content of remaining unreduced DPPH radical was higher in the flowers. Notably, the time necessary for 50% reduction of the initial concentration of DPPH radical was 2.5 times longer in flowers, whereas their antiradical efficiency 3 fold lower compared to leaves.

Recently the interest in borage seeds (mericarps) as an important source of γ-linolenic acid and a good natural antioxidant has increased, yet the knowledge about these properties of seeds developed by borage grown in Poland remains very scanty. Seeds collected from borage plants cultivated in the south-eastern region of Poland in the years 2017 and 2018 were characterized by following parameters: length – 5.0 mm, width – 2.7–2.8 mm, thickness 2.2 mm, weight of 1000 seeds – 17.2-19.4 g. The seeds contained 93.7% of dry matter, and in this 32.0% of lipids, 23.7% of protein and 1.1–1.8% of total sugars on average. Seventeen compounds were identified in the lipids with linoleic acid (35.1%), oleic + elaidic acids (20.8%), γ-linolenic acid (17.9%), palmitic acid (11.4%), stearic acid (5.3%), cis 11-eicosenoic acid (4.1%), and erucic acid (2.6%) as major ones. Other fatty acids constituted less than 2%. Saturated fatty acids constituted 17.5% of the total fatty acids. Flavonoids and phenolic acids accounted for 0.012% and 1.60–1.73% of seeds dry weight respectively. Antioxidant activity measured by FRAP assay and Folin – Ciocalteau method accounted for 1225 µmol of ferrous equivalent Fe (II) and 29.7 mg of polyphenols per gram of seeds dry weight respectively. Using antiradical activity against DPPH radical following average parameters were obtained: T 50% – 49 sec., DPPH rem % – 73.7, AE – 0.024 dm3∙(µmol∙s)–1. 100 g of seeds d.w. contained 0.27–0.34 ml of essential oil. Content of four macroelements expressed as % of seeds d. w. was following: P – 0.70, K – 0.48, Ca – 1.37 and Mg – 0.41.

Gibberellic acid (GA 3) is a plant growth regulator widely used in the cultivation of seedless grape varieties to increase their yield. Hormonisation treatment has beneficial effects on yield size and quality, yet its influence on the level of biologically active compounds and grape antioxidant activity has not yet been studied extensively yet. Clusters of 11-year-old 'Einset Seedless' grapevines trained according to the single Guyot pruning style were sprayed with GA 3 at 100, 200 or 300 mg/L dose once, twice or three times. Fruit harvested on 25 September were immediately examined for acidity, extract content, biologically active substances and antioxidant capacity using the DPPH test. In addition, correlations occurring between some parameters measured were calculated. Hormonisation had a negative effect on the content of extract, flavonoids and ascorbic acid, while it had no effect on the anthocyanin level. The antioxidant activity determined by the DPPH assay depended on dose and the number of treatments, and the analysed parameters were shown to decrease significantly with increasing application number. Gibberellic acid at 100 and 300 mg/L application rates had a significantly increased DPPH level compared to the control and 200 mg/L dose. The single GA 3 treatment, and when applied three times, and application rates at 100 and 200 mg/L were shown to have a significant influence on phenolic acid content. The level of tannins after a single GA 3 treatment and a 300 mg/L dose increased significantly.

Globally, the application of rootstocks for grapevine cultivation has been a standard, while in the northern regions, like in Poland where the viticulture tradition is relatively short, the selection of the most suitable rootstock types requires multi-year observation and research. The objective of the present study was to assess the effect of six following rootstock types: '101-14 Mgt', '161-49C', '125AA', '5BB', 'SO4', 'SORI', and own-rooted vines on yield quantity and quality of 'Regent' grapevine in southeastern Poland. The three-year research period indicates that the vines on '125AA' tended to produce not only the highest yields but had positive influence on the number and weight of clusters and berry weight as well. Whereas the vines grafted onto '161-49C' gave the lowest yields and had the smallest number of clusters per vine. The fruit extract content in 'Regent' grapes on '101-14 Mgt' rootstock was found to be significantly lowest among those under study. The extract content and yield of grapevines evaluated in the own-rooted vines and those grafted to the rootstocks which formed one group, did not differ.

Sour cherry is one of the most important fruit crops in Poland and cultivar is an important factor in its cultivation. The experiment was conducted in a commercial family orchard in a year characterized by a warm and wet spring and also by a very hot and dry summer. Fruit yields harvested from well fertilized 19-years old 'Kelleris 16', 'Nefris' and 'Łutówka' trees grafted on Mahaleb cherry and protected against pests using integrated plant protection system were medium high and of good quality, however productivity index of a tree was low. The fruits attained high weight and diameter and contained big amounts of sugars, vit. C, anthocyanins and flavonoids and medium amount of phenolic acids. Among anthocyanins the most important were cyanidin 3-glucosyl-rutinoside and cyanidin 3-rutinoside. Antioxidant activity of fruits measured as percent of DPPH inhibition was high and similar among compared cultivars. Łutówka was the most productive cultivar of medium leaf and fruit size and with fruits of highest vit. C and flavonoids content and lowest total sugars and monosaccharides content. The least productive cultivar was Nefris, though its fruits were the biggest and contained dry matter, soluble solids, anthocyanins and phenolic acids in the highest amounts of all and vit. C at the lowest level of all. Kelleris 16 was the medium productive cultivar characterized by widest leaf blades and smallest fruits. Content of total sugars and monosaccharides in its fruits was the highest and content of anthocyanins and phenolic acids was the lowest. Residues of dodine and thiacloprid determined in the fruits immediately after harvest were much lower than the permissible residue maximum level.