The nutritional quality of food raised by organic farming in comparison to conventional farming is a currant topic that focuses interest and generate discussion. The data on nutritional quality of organic produce in comparison to conventional produce are often inconclusive. The study presents comparison of some nutritional values of juices made from organic and conventionally grown fruits (apple, pear, black currant). For the experiment 33 orchards located in the south and east of Poland were chosen. All organic farms were certified according to UE Council Regulation no. 2092/91 and obtained valid certificates. Unclarified juices were obtained with cold press juicer. After microwave mineralization in HNO₃ the following nutrient elements were measured: P, K, Mg, Ca, S, Fe, Zn, Mn, Cu, B as well as Na, Cd, Pb, and Ni. Moreover, ammonium N and nitrates content were evaluated using FIA method. Black currant juices contained the highest amounts of Ca, K, Mg, P, S, Fe, Mn and Na. In the case of Ca, Fe and Mn the measured levels were ten times higher than for other juices. The highest content of Cu was proved for pear, whereas apple juices revealed the highest B amount. The husbandry method also influenced the mineral content of the juices, however in different manner for each species. Organic apple juices were having lower content of S, Na, Cu, B i Ni than their conventional contra partners. Organic farming method favored higher accumulation of Ca, Mg, P, Na, Zn, Cu, B, Cd and Ni in organic currant juices. The only difference in pear juices was found analyzing Mg content. ‘Bio’ juices revealed lower amount of this element.

The total yield of mushrooms depends on the amount and quality of the applied substrate. The results given in this study concern the proportions of quality classes of mushrooms in the total yield. This study presents data on yield classes of mushrooms over the four years of the study in terms of months of the year. All the evaluated periods of culture, irrespective of the year and months, varied in terms of the volume and quality of produced explanation yield. The highest increase in yield in the successive cultures was recorded for mushrooms class Exthra. These results show that the direction of development for mushroom production was correct. The advantage of yield-forming property of phase III compost over the yield-forming efficiency of phase II. Its rate of development was not very intensive.

Fertilization is one of the most important factors which can significantly affect potato tuber quality. The effect of multi-nutrient complex fertilizers (HydroComplex, Nitrophoska Blue Special and Viking 13 representing the nitrophoska group, and Polimag S from the amophoska group), and single-nutrient fertilizers (ammonium nitrate, single superphosphate and potassium sulphate) on tuber quality of very early potato cultivars (‘Aster’, ‘Fresco’, ‘Gloria’) was compared in a three-year field experiment. It was found that the single-nutrient and multi-nutrient complex fertilizers did not affected the dry matter, starch and L-ascorbic acid content in tubers of very early potato cultivars, but they increased nitrate (V) content. Of the multi-nutrient complex fertilizers, only HydroComplex containing most of magnesium and sulphur of all with the nitrophoska group significantly increased nitrate (V) content in tubers, on average by 4.0 mg N-NO₃ kg^-1 of fresh weight and, as result, reduced the ascorbate-nitrate index, compared with the single-nutrient fertilizers. The fertilizers applied in the study had no effect on the content of mineral compounds in potato tubers, except of potassium. The potassium content increased as the result of HydroComplex applied, on average by 0.86 g kg^-1 of dry matter. The kind of fertilizer had a greater effect on the quality of ‘Aster’ and ‘Gloria’ than ‘Fresco’ tubers. Tubers of ‘Aster’ and ‘Gloria’ contained more dry matter and starch, and less nitrates (V) and calcium than ‘Fresco’. The content of L-ascorbic acid, phosphorus, potassium and magnesium in tubers of the examined potato cultivars was similar.

Biological control is a modern, comprehensive and non-polluting approach to the management of diseases. Control of plant pathogen by using biological preparations derived from plants like garlic, mint, thyme, grapefruit, has shown attractive and promising results. Present study aimed at laboratory evaluation the properties of ethanol extract of Silphium perfoliatum leaves towards fungi colonizing pepper plants grown in the field. The mycelium of Alternaria alternata, Botrytis cinerea, Colletotrichum coccodes, Fusarium oxysporum, Penicillium expansum, Trichoderma harzianum were used in experiment. The Silphium extract was applied in two concentrations: 5% and 10%. Leaves were obtained from the three-year S. perfoliatum plantation. Tested fungal isolates originated from pepper plants grown in the field. The studies made use of a Petri dishes method recommended for testing fungicides in laboratory conditions. The Silphium extracts in two tested concentrations significantly inhibited the growth of tested fungi species, with the exception of T. harzianum and B. cinerea in 5% concentration extract. Effects of 10% extract were longer than those of 5% one. A. alternata and C. coccodes were fungi, growth of which was the most strongly inhibited by tested concentrations of Silphium extracts.

Ligularia genus includes species cultivated in house gardens and urban parks as an attractive ornamental plants. During flowering period their flower heads may provide pollen food for pollinators. In the period 2004–2008, the present study investigated the abundance of flowering and pollen production of two Ligularia species as a source of pollen for insects. Under the conditions of Lublin, the onset of flowering of L. clivorum occurs in the second half of July, whereas L. przewalskii starts to bloom already in the last week of June. Depending on species and weather conditions, the period of flowering of L. clivorum lasted 48–67 days, while in the case of L. przewalskii from 29 to 38 days. In both taxa, female ray florets and bisexual disc florets are found in capitulum inflorescences. The weight of pollen produced by 10 L. clivorum flowers was almost twice higher than that in L. przewalskii. Pollen production per unit area for these taxa was 6.92 g·m^-2 and 1.53 g·m^-2, respectively.

Corylus avellana belongs to early spring pollen sources for Apis mellifera. The aim of the present study was to evaluate the dynamics of the Corylus pollen seasons over a 10-year study period (2001–2010). The study was carried out in Lublin by the volumetric method that is currently used in aerobiology. Years of abundant pollen production by this taxon were determined, as well as the period of maximum pollen release in each year, which is associated with the availability of large amounts of pollen to bees. Thermal conditions accompanying the beginning of pollen shed and the conditions prevailing during abundant pollen shed were presented. In particular years, the start of the Corylus pollen seasons was recorded between 9 January and 25 March, with an average temperature of 4.1°C. The duration of the pollen season varied between 19 and 78 days. Years of the highest hazel pollen production were as follows: 2006, 2010, 2007, and 2005. The period of pollen abundance, associated with the presence of high Corylus pollen content in the air, was recorded most frequently in the second half of March and at the beginning of April, with the average temperature between 2.4 and 14.4°C, with the 10-year mean value of 8.1°C. At the temperature of 8°C, the honey bee undertakes its first foraging trips, among others, to search for water and collect pollen. The present study showed that the nitrogen content in Corylus pollen grains was 4.82%, while the protein content 30.13%, which demonstrates the significant nutritional value of this pollen.

Studies were conducted with tomato of Admiro F₁ cultivar grown in glasshouse in the years 2008–2009. Four substrates were applied: 1) triticale straw, 2) triticale straw + high peat (3:1 v:v), 3) triticale straw + pine bark (3:1 v:v), 4) rockwool (100 × 20 × 7.5 cm = 15 dm³). Straw, cut into pieces, (2–3 cm) was put in plastic boxes (height of the box ca. twice its width) with the capacity of 15 liters. In each box/slab two plants grew. Experiments were conducted with the use of complete randomization method, in seven repetitions. Drop fertigation was applied in a closed system, without nutrient solution recirculation. In the period of high temperatures the daily nutrient solution consumption equaled 4.2 dm³ on a one-off basis in 10–12 doses with about 20% overflow. In the conducted studies full usefulness of triticale straw was demonstrated as the substrate for tomato grown in glasshouse. Higher yield was obtained from growing in the substrate of triticale straw+ pine bark, as well as triticale straw + peat compared to rockwool, and these differences were not statistically significant. The highest dry matter content was found in the fruit grown in straw substrates, the least – in those from rockwool substrates. No significant differences were demonstrated in the contents of N, P, K, Ca and Mg in fruit with reference to the examined substrates. After 33 weeks of vegetation (end of the studies) about 70% of the straw was mineralized.

In this study we hypothesized that the effect of nitrogen form well as light intensity on Ca content in the sweet pepper fruit may depend on stage of fruit maturity. Thus the effect of nitrogen form (100% N-NO₃ or 50% N-NO₃ + 13% N-NH₄ + 37% N-NH₂), type of polyethylene film covering the tunnel (two types of film, Ginegar or Gemme 4S, characterized by various PAR transmissions) and stage of fruit maturity on Ca and dry matter content in sweet pepper fruits were determined. Sweet pepper plants were cultivated in rockwool slabs. The chemical analyses were performed on sweet peppers harvested in five stages of growth and ripening, beginning with fruits of 2–4 cm diameter. Plants supplied with nutrient solution containing nitrate N form accumulated more Ca. The influence of film type covering the tunnel was unsystematic. Irrespective of N form and film type the contents of Ca and dry matter varied depending on fruit growth and ripening stages. Systematic increase in Ca accumulation occurred until reaching the stage of mature-green sweet peppers, while during further ripening the level of Ca decreased. The dynamics of dry matter accumulation were opposite to that of Ca. Additional determination of Ca was performed in mature green fruits, coming from nitrate N and Gemme 4S film (transmitted more light) treatment, both normal and with visible symptoms of blossom-end rot (BER). The analysis was conducted separately in the upper and lower part of fruits. Higher amount of Ca was found in the upper part in normal and BER fruits. Since BER was developed in fruits with Ca content in the lower part equaled to 0.60 mg∙g^-1 d.m., but in 2007 no symptoms of BER were noted in fruits contained only 0.38 mg∙g^-1 of Ca, other co-factors, not only low Ca level in fruit, should be considered in the prediction of BER.

With the uptake of organic farming the importance of green manures increases, and the cultivation of cover crops plays an ever important role both in agriculture and in horticulture. The fertilizer value of plants cultivated for green manures is largely dependent on the biomass produced, and also the nutrients that were accumulated within it. The aim of this work is to determine the influence of weather conditions in the second half of summer on the fertilizer value of catch crops intended for cultivation of vegetables. The research included: spring rye (Secale cereale), oats (Avena sativa), common vetch (Vicia sativa), white mustard (Sinapis alba), tancy phacelia (Phacelia tanacetifolia), buckwheat (Fagopyrum esculentum), fodder sunflower (Helianthus annuus). The catch crop plants, cultivated as a pre-crop for the cultivation of vegetables proved to be a rich source of organic matter and nutrients for the following crops. The course of weather had a major influence on the volume of biomass, and the chemical composition and fertilizer value of cover crops. Shortage of water and high temperatures after rainfalls, causing the formation of crust on the soil did mostly limit the growth of catch crops. The biggest biomass among the investigated catch crops was created by sunflowers, phacelia and rye, the lowest by common vetch. White mustard and sunflower provided the biggest amount of nitrogen in their role as catch crops. The sunflower proved to be a rich source of K, Ca and Mg. The most Ca was left in the field by tancy phacelia, which also proved to be a good source of K. The biomass of buckwheat provided large amounts of Mg, but it was poor in N, P and S. Rye and oats proved to be a rich sources of P, but they also contained small amount of Ca and Mg. The most sulphur was left over by the biomass of white mustard. The common vetch proved to be the most weather-sensitive of all plants. Its biomass left the least P, K, Mg and S in the field, the Ca content was also small, compared to other catch crops. Nitrogen content of dry matter of common vetch was high, but not the highest in the three year average.

Actinidia arguta and Actinidia purpurea and their hybrid cultivars are species which bear valuable fruits due to their content of valuable bioactive substances and good sensory qualities. This paper presents the yield results from the cultivars’ initial 10 years (2000–2009) as well as the morphology and chemical composition of the fruits of some Ukrainian hybrid cultivars of Actinidia arguta and Actinidia purpurea: ‘Figurnaja’, ‘Kijewskaja Gibrydnaja’, ‘Kijewskaja Krupnopłodnaja’, Actinidia purpurea: ‘Purpurowaja Sadowaja’ and Actinidia arguta: ‘Sientiabrskaja’. In 2007, the flowers of the tested cultivars were damaged by late spring frost. The lowest yield and the smallest weight, as well as the low stability of morphological features of fruits of the ‘Sientiabrskaja’ cultivar, indicate its low utility as a commercial crop in north-eastern Poland. However, chemical analyses found high levels of phenolic compounds and vitamin C in the fruit of the cultivar. An analysis of the yield and fruit quality of the other tested cultivars indicated their suitability for cultivation under the climatic conditions of the 6A USDA zone.

The Brassica rapa var. japonica is a valuable plant, commonly cultivated in the Far East. It is still unknown vegetable crop in Poland. It is necessary to assess plant response to field conditions in Polish climatic zone before introducing this species to the large-scale production. The aim of the study was to evaluate the effect of growing date (transplants were planted out to the field in the middle and at the end of August – 1^st and 2^nd production term, respectively) and cultivar (Mibuna, Mizuna) on morphological parameters, yielding and chemical composition of the plants. Before planting out, transplants of Mibuna have been found to be larger than Mizuna, the differences in the contents of chemical components in these cultivars were statistically insignificant at this time (with the exception of dry matter). The transplants from a later production term were characterized by greater fresh weight and height, longer leaves, and lower content of dry matter, soluble sugars and carotenoids. Based on collected data regression equations were developed to predict the course of growth and development of Brassica rapa var. japonica during field vegetation with a precision of more than 94%. There were no statistical differences in yields among cultivars, while significant effect of growing date was observed. The total and commercial yield was higher by 3.34 and 3.77 t·ha^-1, respectively, in the 2^nd production term than in an earlier one. During harvests the content of chlorophylls, carotenoids and L-ascorbic acid was higher in the rosettes of Mibuna cultivar, while Mizuna had more dry matter and soluble sugars. Production of the plants from later plantings resulted in significantly increased soluble sugars content in the rosettes, but the reduction in dry matter and L-ascorbic acid was observed.

Eremurus spectabilis is used as a vegetable in Turkey, especially in Eastern Anatolia region. In this study, eight E. spectabilis from different growing areas have been analyzed for its nutrition value and antioxidant properties. The results showed that there were significant differences among samples in terms of all above parameters. The mean values of the parameters investigated were 86.62–91.35% for water content, 4.78–5.15 for pH; 0.42–0.70% for acidity, and 0.61–1.11% for ash content. The antioxidant activity tests evaluated by using 2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging and β-carotene/linoleic acid assays indicated that the extracts of E. spectabilis samples had high antioxidant capacity. In the DPPH and β-carotene/linoleic acid systems, average values were 73.69 μg extract ^. ml^-1 and 94.56%, respectively. The average amount of total phenolics in samples was 223 mg GAE ^. 100 g^-1 FW. Protein, K, Ca, Mg, Fe and Cu contents of E. spectabilis species were found higher than in some other commonly used vegetables. The results suggest that E. spectabilis could be a valuable source of antioxidants, phenolics and minerals.

Cucumber cultivation in Poland is connected with a certain climatic risk, producing small yields of the plant. Selection of areas suitable for cucumber cultivation should be based not only on soil conditions and agrotechnical recommendations, but also on knowledge of the rate of growth and development of the plant. The aim of this work was to determine the effect of solar conditions and the thermal conditions of air on the variability of cucumber developmental stages in Poland from 1966–2005. To achieve the goals, data was collected from 28 experimental stations of the Research Centre for Cultivar Testing (RCCT) and 50 meteorological stations of the Institute of Meteorology and Water Management (IMWM) concerning respectively: the duration of cucumber development stages and sunshine duration and air temperature from 1966–2005. The relationship between the duration of developmental stages and the examined meteorological elements was determined by analysis of linear and second degree polynomial regression and thermal requirements of the cucumber in the period from sowing to the beginning of fruit setting, determined by means of the effective temperature sum method. Results obtained in this work may be used, for example, in the process of adjusting field production of cucumbers to changing climatic conditions in Poland.

The problem of soil fatigue occur in polish orchards more and more often. This problem can cause to lower profitability of the production. Studies were carried out in an experimental orchard in the years 2008–2010. The objective of the presented studies was the determination of the earlier applied method of soil utilization on the growth and yield of `Topaz` apple-tree cultivar. Apple-trees were planted in fivesoil localities: 1 – directly in grubbed up rows of an apple-tree orchard, 2 – in herbicide fallow belts of grubbed up apple-tree orchard, 3 – in turf belts of grabbed up apple-tree orchard, 4 – in a locality after a four-year break in apple-tree cultivation, without any preparatory treatments and 5 – in a soil after previous agricultural use – virgin soil. During the realization of our studies, an estimation was carried out of the trunk cross-section, of leaf blade area and of the yield, size and fruits quality. Our studies have shown an influence of the soil locality on the yielding of trees which ten years after replantation was very low amounting on the average to about 4 t·ha^-1 in case of apple trees planted directly in the place of the grubbed up trees, while in the virgin soil, the yield reached up to 40 t·ha^-1. The growth of trees planted in the locality after replantation was also significantly poorer, in comparison with the apple trees planted in the soil which was agriculturally utilized before.

Endive is a leaf vegetable, not commonly known in Poland, although popular in Western and Southern Europe. It deserves attention because of its high nutritive value and bitter taste caused by sesquiterpene lactones. In the experiments carried out in the years 2008–2009 the effect of mineral-organic fertilizers (Goëmar Goteo, Aminoplant) on the yield and quality of curly endive (‘Cigal’) and escarole (‘Excel’) was investigated. Seeds were sown in three periods. After four weeks plants were transplanted into the field. Mineral-organic fertilizers were applied in accordance to the producer’s recommendation: the Goëmar Goteo preparation was used twice for seedlings watering while the Aminoplant preparation was used for plants spraying in the second and third week after transplanting them into the field. Mineral-organic fertilizers did not affect the yield of the investigated cultivars. The highest commercial yield of endive and the highest mean weight of leaf rosette was obtained for the first term of cultivation. Plants in the third term of cultivation characterized with the highest dry matter content. The least amount of nitrates was cumulated in curly endive leaves. The highest content of calcium was observed in the first term of cultivation. The content of potassium and phosphorus was on similar level during the first and the second term of cultivation. The significant effect on the macroelement content due to applied preparations was not observed. The effect of mineral-organic fertilizers on the content of flavonoids was examined. Leaves of endive rosettes treated with mineral-organic fertilizers synthesized rutoside and higher amount of astragalin (3-O-kaempferol glucoside) in comparison with control combination.

The usable part of leaf celery consists of the intensely green leaves with strong aroma, used for seasoning when fresh, dried, or frozen. The plants form from several tens to one hundred leaves, which can be cut several times during vegetation. The studies conducted in the years 2006–2008 were aimed at assessing the response of leaf celery to additional irrigation in the periods of humidity deficiency in the soil. The celery seedlings production was started at the beginning of March, the plants were put into the field in the third decade of May, in the spacing of 25 × 25 cm. Leaves were collected twice: in mid August and mid October. A significant effect of watering upon the height of plants was demonstrated, as well as upon the total celery yield quantity, nitrate (V) and total chlorophyll contents. Irrigation contributed to the increase of petiole weight share and decrease of leaf blade share in the weight of whole leaves. No effect of irrigation was found upon the number of leaves, total sugar content in leaf blades, as well as upon the content of essential oil in the whole leaves. A factor that significantly modified the leaf composition was harvest term. It significantly influenced the total sugar content, as well as the contents of nitrates (V) and essential oils in celery leaves. During the first harvest, conducted in mid August, the leaves contained less total sugars, whereas there were more nitrates (V) and essential oil.

Fertilization of horticultural plants significantly contributes to increased yield but also affects yield quality. Nitrogen, potassium, and sulphur, which belong to the main macronutrients, can have a large effect on the chemical composition of edible parts of plants. The aim of the present study was to determine the effect of the rate of nitrogen as well as of the rate and form of potassium on the accumulation of dry matter, N-NH₄, N-NO₃, Fe, Zn, Mn, and Cu in the leaves of garden rocket grown in a greenhouse during the spring period. These macronutrients were applied at the following rates (in g ^. dm^-3 of medium): 0.3 and 0.6 N in the form of Ca(NO₃)₂; 0.3, 0.6, and 0.9 K in the form of K₂SO₄ and KCl; 0.4 P; 0.2 Mg; as well as the following micronutrients (in mg ∙ dm^-3 of medium): 8.0 Fe (EDTA); 5.1 Mn (MnSO₄ ∙ H₂O), 13.3 Cu (CuSO₄ ∙ 5H₂O), 0.74 Zn (ZnSO₄ ∙ 7H₂O), 1.6 B (H₃BO₃); 3.7 Mo (NH₄)₆Mo₇O₂₄ ∙ 4H₂O). The increased rates of nitrogen and potassium caused significant changes in dry weight (DW) of rocket plants; its higher proportion was found when the lower rate of N was applied, compared to the higher rate. The increased rate of N increased the content of N-NH₄ and N-NO₃, whereas the rising amount of K in the medium resulted in a decrease in the amount of N-NO₃ in the plant material studied. Plants fertilized with the lower rate of nitrogen accumulated more iron and zinc as well as less manganese than plants that received more of this nutrient. Plants fed with the highest rate of K accumulated the largest amount of iron, while the largest amount of manganese was found in plants that received the lowest amount of this nutrient. The application of K₂SO₄, as a source of potassium, contributed to an increased accumulation of iron, whereas the application of KCl resulted in an increased concentration of manganese in rocket leaves.

In this study, the antioxidant activities of Strawberry tree (Arbutus unedo L.) flowers at flowering period and fruits during ripening period were investigated, along with some ripening characteristics such as color, reducing sugar and acidity. Antioxidant activity characteristics were investigated using by the methods of DPPH (1,1-Diphenyl-2- -picryl-hydrazyl) scavenging activity, β-carotene bleaching, reducing power, metal chelating capacity, superoxide anion scavenging and hydrogen peroxide scavenging activity in water, ethanol and methanol extracts. The total phenolic content of flowers in water extracts was found to be 232.38 ± 7.19 mg GAE ^. g^-1 extract, and the DPPH activity was 81.3 ± 0.49% at 50 µg·ml^-1 concentration. In the ripening stages, the fully red fruits were determined higher antioxidant capacity than green and yellow fruits, except H₂O₂ scavenging activity which was highest in green fruit. In correlation study, the highest relationship was found between total phenolic content with reducing power (r² = 0.987**, P < 0.01), while the lowest with H₂O₂ scavenging activity (r² = 0.519*, P < 0.05).

Nitrogen and calcium are the two elements, among other main nutrients, responsible for proper nutrition of plants. The experiments conducted with lettuce of the Omega F₁ variety aimed at an analysis of differentiated methods of nitrogen and calcium carbonate fertilization on the general crop yield and its biological value. After the plants were collected, the fresh weight of the plants, the dry mass, the vitamin C content, extract and protein contents were measured. After the vegetation period of plants samples of medium were collected and, with use of 0.03 M extract of acetic acid, the contents of mineral nitrogen, phosphorus, calcium and magnesium were determined, as well as the pH and EC values of the medium measured. The crop yield of fresh leaves mass was significantly dependent on the used dose of nitrogen and calcium carbonate. The largest lettuce crop yield was recorded in objects fertilized with 0.4 g ∙ dm^-3 of nitrogen and the higher dose of calcium carbonate (283 g∙plant^-1). The vitamin C, extract and protein contents were dependent on the dose of nitrogen. The largest quantity of vitamin C characterized the lettuce plants fertilized with the largest dose of nitrogen and the higher dose of calcium carbonate (33.7 mg∙100 g^-1 fr. m.). The application of calcium carbonate in 14 g ∙ dm^-3 causes the calcium content of the medium to rise. The EC value of the medium was largely arisen under the influence of the mineral nitrogen and varied between 1.33 and 1.96 mS∙cm^-1.

Lettuce needs a properly balanced nutrition base for its proper development. During the greenhouse experiment of 2009 and 2010, the influence of the dose of nitrogen and calcium carbonate on the content of nutrients in edible parts of lettuce was examined. The sowing of the seeds of the Omega variety of lettuce took place on February 24^th, on March 7^th the plants were bedded out into pallets, and finally planted into pots on March 19^th. The vegetables were collected on April 24^th, together with leaf samples for micro- and macro-elements analysis. The results of the experiment suggest that the increase in the dose of nitrogen had a significantly positive influence on the accumulation of total N and N-NO₃ in the plant and a significantly negative effect on the content of phosphorus and potassium in lettuce leaves. The microelements uptake of the plant was largely dependent on the dose of nitrogen and calcium carbonate. The largest amount of iron and manganese was found in plants nourished with the lowest dose of nitrogen, and the highest amount of zinc and copper was found in lettuce leaves from plants nourished with the quadruple, compared to the original value, dose of nitrogen, connected with the lower dose of calcium carbonate.

Experiments involving sweet pepper of ’Red Knight’ F₁ cultivar were carried out in 2008–2010 in a greenhouse. They aimed at evaluating the influence of foliar feeding using diverse preparations and rates of calcium on yielding, dry matter, sugars, and vitamin C contents in sweet pepper fruits. Following forms of calcium were used in the experiment: Ca(NO₃)₂, Librel Ca, and Wapnowit. Calcium was applied in the amounts of 0.4 g Ca ∙ plant^-1 (10 treatments) and 0.2 g Ca ∙ plant^-1 (5 treatments). No significant influence of applied calcium feeding on the pepper fruit yield size was recorded, while it significantly reduced the number of fruits infected by apical blossom-end rot (BER) at calcium-fed of Librel Ca plants as compared to the control. No significant effect of studied factors on dry matter content was found, although its lower level in pepper fruits harvested at the initial stage of fruiting was prominent. The influence of calcium feeding on monosaccharides and total sugars concentrations was positive when 0.2 g Ca ∙ plant^-1 (5 treatments) in a form of Wapnowit was applied. Considerably higher vitamin C concentration in calcium foliar-fed pepper fruits as compared to the control was recorded.