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Genetic variability of agricultural traits of maize inbred lines is a valuable trait that is useful in breeding practice, especially for selecting parental lines to achieve the effect of heterosis. Twenty-four hybrids obtained from crossing 6 inbred lines with 4 dent lines were analyzed. The experiment was carried out in two localities (Kobierzyce and Smolice), using a randomized block design with two replications. Lodging at harvest, smut resistance, dry matter content and grain yield were evaluated. The of analysis variance showed significant differences between localities in all the traits as well as differences in two traits within Kobierzyce, and in three traits within Smolice localities. The analysis of combining ability reviled significant interaction of GCA and SCA with the environments affecting dry matter content and grain yield. A female line 1294-7 is noteworthy, as it influenced both a grain yield and dry matter content. Hybrid 1044-87 × S335 was characterized by a high yield and high content of dry matter.

The aim of the study was to evaluate combining abilities of inbred maize lines. The experimental material consisted of 6 female lines and 4 male lines (flint types). The experiment was carried out in two localities (Kobierzyce and Smolice) using a randomized block design with two replications. Lodging at harvest, smut resistance, dry matter content and grain yield were evaluated. The analysis  of variance showed significant differences between localities in all the traits as well as difference in three traits within Kobierzyce, and in two traits within Smolice localities. The analysis of combining ability showed significant interaction of GCA with the environments, affecting dry matter content, and of SCA with the environments, influencing dry matter content and grain yield. A female line 1294-7 and hybrids 1375-5 × S41324A-2, 1360-5-1 × Co255, and  1044-87 × K154 were distinguished as the most valuable forms.

A detailed analysis of genotype × environment interaction was carried out among yields of ten hybrids of maize grown at five localities in the years 1999–2000. Statistical analysis was performed using computer package Sergen 3. The hybrids were divided into 3 groups: depending on whether they yielded at the average level above or below a grand mean. The results allowed to identify five stable hybrids which can be recommended for cultivation across all environments in Poland.

In this paper the agronomic value of 110 maize hybrids included into preliminary grain trials carried out in 1999 and 2000 in 5 localities was studied. Out of these, 36 hybrids were tested in both years. The trials were preformed in a lattice design on 10 m2 two-row plots in three replications. The yield of grain in dt/ha at 15% moisture content and dry matter content in grain at harvest were evaluated. For 36 hybrids tested in both years the data are presented in three tables as mean values obtained in each year of testing and as a two-year average. Based on the results obtained, the best twelve hybrids were applied for the official trials in 2001.

The field trials were carried out at two sites: Plant Breeding and Acclimatization Institute experimental field in Poznań in the season 1998–1999 and the Experimental Station Institute of Plant Genetics Polish Academy of Science in Cerekwica in the season 1999–2000. Field experiments were conducted in randomized blocks, in three replications. Thirty-two lines of doubled haploid (DH) winter oilseed rape were obtained from F1 hybrid DH-O120 × DH- C-1041 using isolated microspore culture. Parental forms and F1 hybrids (in the first year) and F2 and F3 hybrids (in the second year) were studied. A content of the following fatty acids: palmitic acid (C16 : 0), stearic acid (C18 : 0), oleic acid (C18 : 1), linoleic acid (C18 : 2), linolenic acid (C18 : 3) was determined. Two-factor analysis of variance showed significant differences between the years of the study and genotypes. However the interaction genotypes × years was not significant with any of the acids. Based on DH lines and respective segregating generations, genetic parameters describing the effects of: additive genes (d), dominant genes (h) and non allelic interaction of homozygous (i) and, heterozygous (l) loci were estimated. The parameters were calculated for a content of fatty acids in each year (period) of the study and for two years in total. This work provides the example of how to determinate the means for genetic parameters in a two-year estimation period with the use of F1 and F2  hybrids in the first year and F2 and F3 hybrids in the second year.

Winter oilseed rape is an important crop as the demand for plant oils has successively been growing. The yield trials with rape cultivars were conducted at 4 sites (Głubczyce, Krościna Mała, TarnĂłw and TomaszĂłw Bolesławiecki) in the years 1999–2001. Standard and intensive variants of cultivation were applied. In the intensive variant, as compared with the standard one, a dose of nitrogen fertilization higher by 50 kg/ha, application of anti-lodging agents, foliar feeding of plants with microelements and complete control of fungal diseases and insects were used. Herbicides, potash and phosphate fertilizers were applied at the same level in both variants. Statistical analysis was performed according to computer program Sergen 3. The study of G × E interaction structure revealed a major contribution of the Krościna site to the significance of the interaction. At this site, the yields of winter rape were relatively high, but variable. In contrast, stable but lower yields were observed at TomaszĂłw Bolesławiecki. The results of three-year trials indicate that cultivars Lisek and Bristol can be recommended for standard cultivation in the Lower Silesia region. The yields of Buffalo are satisfactorily high at both variants of cultivation, but this cultivar exhibits higher sensitivity to changes in environmental conditions. A differential response of rape genotypes to environmental factors suggests that it is advisable to survey rape cultivars at various locations.

A content of aliphatic glucosinolates in seeds of winter oilseed rape is a very important trait determining the nutritional value of fodder. Further reduction of their content is one of the most important goals in breeding of improved cultivars. Better understanding of their inheritance should make selection more effective and speed up the breeding process. The knowledge of general combining ability (GCA) values in respect to individual glucosinolates is of great importance for breeding both population varieties and hybrids. Eleven inbred lines of winter oilseed rape characterized by a very low glucosinolate content were studied. These lines were crossed with five cultivars used as testers. The crosses were carried out in both directions. Hybrids were grown in field trials in two replications. Statistical analyses of GCA values were performed separately for particular glucosinolates as well as F1 and F2 generations. To estimate the heritabilities analyses of regression, correlation and determination coefficients between both generations were made. Most of the calculated coefficients were significant at the level a = 0,01 or a = 0,05, which proved that the method of GCA estimation used in our experiments was satisfactorily reproducible.

Nowadays breeding of oilseed rape in Poland and in the world develops in two directions: breeding of open pollinated varieties and breeding of hybrid varieties. The aim of this work was comparison of variability of yield-forming characters and yield and their phenotype and genotype relationship in experiments with open pollinated strains and F1 hybrids created by utilisation of CMS ogura system. In 2000/2001 in five locations two initial field experiments were conducted. Subject of the first experiment were 18 strains of winter oilseed rape and two standard varieties: Lisek and Kana. In the second experiment, 18 F1 hybrids of winter oilseed rape and two standard varieties: Lisek and hybrid variety F1 Buffalo were investigated. In both experiments yield and some determined yield plant characters: overwintering, earliness and duration of flowering, height of plants, height of canopy, and weight of 1000 seeds were estimated. Statistical analysis include a summary analysis of variance for locations, calculation of average, range, variation coefficient, index of heritability for the traits. Moreover, matrix of phenotype and genotype correlation between studied traits for both experiments was calculated. Also causual-consecutive relationship by the use of Wright method of path coefficients was estimated.

The basis of the study were three experiments with pea (Pisum sativum L. sensu lato).The arrangement of the experiments enabled detection and estimation of competition effects as the interference effects of the paths between the experimental strips and plots as well as of the intercrop that separated the pea plots. It was stated that pea plant competition depended on the experimental method, genotypes selection and environmental conditions. Plants grown in border parts of the plots yielded 2–6% higher than plants in central parts of the plots, and the effects of the border interference spread up to 0.5 m.

The objective of the study was to estimate the competition effects as the interference between plants in adjacent plots and inside the plot. The study was based on the four field experiments with morphologically and physiologically differentiated genotypes of pea (Pisum sativum L. sensu lato). The experiments were performed in plots of different size. Two traits, plant height and seed yield, were analyzed. More or less pronounced competition effects upon each of the two traits were noticed in each experiment. However the effects were statistically significant only for the 1-row plot experiments. It was shown that competition effects in pea breeding field experiments could affect the reliability of experimental results. Thus, in a phase of planning the experiment, it is essential to consider all potential competition effects and, if necessary, take into consideration available technical and statistical methods to reduce or eliminate a disadvantageous influence of plant competition on  the estimation of genotypes.

Seven pea genotypes (Ametyst, Agat, Agra, Kwestor, Rubin, Bohatyr, line 1167/96) and their F2 hybrids derived from diallel crosses consisted the experimental material. Analysis of variance showed significance of GCA for all tested traits. Lack of significance of SCA for lodging, plant height, nodes per plant and TSW indicates important role of additive gene action in expression of these traits. Significant variances of GCA and SCA for remaining traits indicate both additive and nonadditive gene action in their inheritance. The cultivars Kwestor and Agra were good combiners for seed yield; Rubin and Agra, opposite to Bohatyr, caused higher lodging in comparison to the average of progeny in the crossing scheme. The cultivars Rubin, Agat and Ametyst adversely influencing seed yield and its components should be discarded from crossing programmes.

The purpose of this study was to evaluate the changes in accumulation of oligosaccharides during seed development and their relation to seed germination and health. The experimental material consisted of seeds of four pea varieties harvested in 1998, 1999 and 2000. Seeds were collected every 5 days, beginning on the 25th day after flowering (daf) until full maturity. Seed moisture content, fresh and dry matter weight, germination, and seed health were determined. Moreover a content of saccharose, raffinose and stachiose was measured. Fresh weight of immature seeds (moisture content over 60%) was high, but when the seeds reached full maturity, it decreased almost two-fold. Dry matter accumulation proceeded slowly during the whole maturation time. Germination capacity on 25 daf ranged from 3 to 69%, and on 35 daf the moisture content declined sharply and germination percentage reached the maximum values for the majority of examined samples. At the end of the maturation stage, when no increase in germination ability was observed, a decrease of general seed health was noticed, with saprophytic fungi being more frequent than pathogenic ones. Ascochyta ssp. were more abundant on seeds harvested on 25 daf (7,9%) and 30 daf (10%) than on mature seeds (4%). Similarly, the occurrence of Botritis cinerea on seeds declined from 7% to 3% with seed maturing. No close relationship between seed health and seed stage of development was found. At the beginning of maturation a level of oligosaccharides was high (6,4–7,5%) followed by decreasing with maturation to 3,2–5,3%.The highest decrease in oligosaccharides content was noticed between 25 and 35 daf. In this period both the intensive accumulation of dry matter and increase in germination ability were observed. The content of saccharose decreased almost three-fold. The content of raffinose maintained rather at the same level, whereas that of stachiose was variable during the whole maturation time. Oligosaccharides played a significant role in creating seed value although their effect was changeable in the course of seed development.

The objective of this study was to investigate the changes in protein and starch accumulation during seed development and their relationships with seed vigour. Plants of four pea cultivars were grown from seeds harvested in 1998, 1999 and 2000. Seeds from these plants were collected every 5 days, beginning on the 25th day after flowering (daf) until seed maturation was completed. Seed moisture and vigour were evaluated. A content of protein and starch in the seeds was determined. In the following season, field emergence of plants was assessed. At the end of maturation, no increase in germination ability was noticed, whereas  seed vigour continued to enhance. Seedlings produced by mature seeds showed great vigour, irrespective of plant cultivar and the year of harvesting. A conductivity test was found to be rather useless in evaluation of vigour of immature seeds. The effects of maturation viability and seed germination ability upon the dynamics of field emergence were found to be of substantial significance. Pea seeds achieved a high value as potential seed material prior to accumulation of protein and starch to the maximum content.

Path coefficient analysis of some quantitative traits related to seed yield was performed for three leguminous species. The high similarities of interrelations among the tested traits were found for these species. Of the yield components, seeds number per plant had the highest direct effect upon yield. Lower direct effects of pods per plant and 1000 seed weight (TSW) on seed yield were recorded. The high phenotypic correlation of pods per plant with seed yield was due to the large indirect effect of seed number per plant. In developing higher yielding genotypes of pea, dry bean and soybean the number of seeds per plant, TSW and pods number per plant should be considered jointly.

The use of mutagenic agents for obtaining broader genetic variation of traits is particularly important for species characterized by a narrow pool of natural variability. Among lupine species it is essential for Andean lupine (Lupinus mutabilis). However, for widespread cultivation of this species, certain undesirable traits need to be corrected. The aim of this work was to estimate reaction of Andean lupine to chemomutagens and compare it with those of cultivated species, L. albus and L. angustifolius. In M1 progeny the variability of yield structure parameters was analysed after treatment of seeds with sodium azide (S.A.) and N-nitroso-methylurea (MNU). The means for M1 plants of the analysed species compared to a control variant in the field experiment showed that, in general, both mutagens could decrease the level of analysed traits and cause the delay of flowering. These effects enhanced when higher doses of chemomutagens were applied. Somatic harmfulness of MNU was larger than that of SA. The mean squares from analysis of variance for each trait and three lupine species showed that if a mutagen was the source of variance, the trait variability was significant, except a number of pods in lateral branches. The values of mean squares indicated that both lupine species and plant organs (main stem, lateral branches) did differ in their susceptibility to mutagens applied in the study. A range of statistically significant differences was wider in evaluating the yield structure of the main stem than the lateral branches. Moreover, it was wider with L. albus or L. angustifolius than L. mutabilis.

Lupinus mutabilis Sweet is a cultivated species in South America. Numerous attempts to adapt the species to the conditions of temperature climate have shown that yield stability and earliness are of paramount importance. Widening genetic variability would be especially desirable in order to obtain promising selections. A mutation program was used to increase genetic variance. Seeds of populations: XM.5, 15 and cv. Potosi were radiated with caesium 137 gamma rays. From the obtained material, 25 mutant lines were chosen and evaluated in an experiment conducted at Swojec Experimental Station (of Wrocław Agricultural University) using a randomized complete block design with three replications. The plot was 1 m2. Significant differences among the lines were found for height of the main stem, no. of lateral branches of first order and no. of seeds/pod. However, coefficients of variability were relatively low, ranging from 4% to 13%. No significant differences were observed for no. of pods/plant, no. of seeds/plant, seeds yield/plant and 1000 seeds weight.

Diallel crosses (Griffing's method 2) between five soybean genotypes were carried out. Field experiment (in three replications) was performed with F2 generation. Variability of five yield component traits: number of pods per plant, number of seeds per plant, number of seeds per pod, 1000 seeds weight, seed weight per plant were analyzed. The highest variability coefficient for parental genotypes was obtained for seed weight per plant (V = 57,8%) and in hybrids for number of seeds per plant (V = 77,2%). Variability of analyzed hybrid traits (expressed by variability coefficient and range) was much higher than variability of traits in parents. The highest increase of mean trait value and variability of trait was observed in progeny of crosses with line 2349. In F2 progenies of all crosses single plants appeared to be better than the better of the parents. The greatest numbers of these plants were obtained in progeny of crosses Progres × line 16 and line 2349 × line 16. General combining ability (GCA) significantly affected the number of seeds per plant (line 2349), number of seeds per pod (Progres and line 16) and 1000 seeds weight (lines 16, 2336 and 2349. Positive, significant effect of specific combining ability (SCA) was  found only in cross combination 2336 × 2349 for number of seeds per plant.

Resistance to drought of 13 inbred lines of field bean and 9 synthetic populations originated from these lines was evaluated. Our studies included two-year field trials and morphological descriptions of all plants from treatments designated ‘control’ (natural field conditions) and ‘drought’ (polyethylene tunnel in the period of plant flowering). When estimating the resistance of plants to drought, two criteria were taken into account: yielding under drought conditions and plant response to drought, expressed in the number of: fruiting nodes, pods per plant, seeds per plant and seed yield per plant. The response has been shown in the work as a tolerance by using percentage values illustrating the proportion of evaluated trait in the drought treatment (D) to that in the control treatment (C), taken as 100%. It was found that the response of synthetic populations was less pronounced than that of the lines, and showed higher heterosis effect under water deficiency than under  field conditions. Analysis of correlation (mean value for components — synthetics) showed that the yield obtained in drought conditions was a better criterion for selecting inbred lines to become the components of synthetic cultivars than the response to drought.

Ten cultivars and 30 natural populations of T. pratense and T. repens were surveyed in order to characterize the genetic changes which had appeared in these two species as a result of the breeding manipulations. Fifteen enzyme systems were applied. A total number of identified common alleles and genotypes in cultivars and natural populations, and the total number of alleles and genotypes different for T. pratense and T. repens cultivars and natural populations were calculated. The number of alleles and genotypes was each smaller in cultivars than in natural populations of both species. Relatively small reduction in the number of alleles led to greater differences in genotypic changes in cultivars. The breeding manipulations resulted in reorganization of variability at a genotypic level. Some alleles and genotypes had been eliminated, but new ones not occurring in natural populations, were found in cultivars. New foreign alleles, which were incorporated into cultivar gene pools led to changes in genotypic composition of cultivars. New genotypes identified among cultivars could be created by segregation of alleles which were already present in natural populations but were eliminated in the process of natural selections.

Two types of red clover breeding forms of different length and number of flower heads were developed by 1–3 backcrosses of cv. Nike with long-head clover. Progenies N were obtained by backcrossing F1 to Nike, and progenies D — to long-head genotypes. Index selection for seed yield among progenies included negatively correlated traits: flower head length and their number. Compared to cv. Nike all the progenies gave higher seed yield and on average showed longer heads, a greater number of seeds per head with a lower number of heads. Although the head length and seed number per head in progenies D were much higher than in progenies N, their seed yield was comparable due to much smaller number of heads. Their green and dry matter yield were lower that those of progenies N. One of the progenies N exhibited a higher level of seed and forage yield, as well as of other agronomic traits, as compared to cv. Nike. It is concluded that forage and seed yield of red clover can be improved by intercrossing forms of different flower head length and head number followed by appropriate selection.

The relationships between a type of cooking quality and both morphological features of potato tubers (size of tubers, flesh colour, tuber shape, regularity of tuber shape, depth of eyes, skin quality and general appearance of tubers) and starch content of tubers were analyzed for 120 potato cultivars from COBORU basic trials in 1995–2000. Regression analysis showed negative correlation between a type of cooking quality and morphological features of potato tubers. The relationship between starch content in tubers and a type of cooking quality was positive and very significant.

In the studies carried out in 1997–1999, the content of vitamin C, starch and the total protein as well as the exogenous amino acids sum were determined in tubers of two potato varieties: Irga table potato and Ekra industrial potato. The genotype-environment interaction for these characteristics was evaluated based on the main effects (genotypes and years) and specific effects (interaction), with the use of standard variance analysis for multiple experiments and Tukey’s test. The variance of the genotypes stability (s2i), which characterizes environmental variability of genotypes, was calculated in addition to the ecovalence coefficient (Wi), which describes the interaction of a genotype with the environment. Most of the analysed characteristics of potato quality (except the exogenous amino acids content) were influenced by the varieties (genotypes). As regards the two genotypes under study, a higher content of both vitamin C and starch was found in variety. Ekra, whereas a higher total protein content was typical of var. Irga. The tuber quality characteristics were modified by the environment. The genotype-environment interaction, relating to the different reaction of varieties on changeable environmental conditions, was also significant. The analysis of this interaction did not allow to select satisfactorily stable genotype (variety Irga is more stable for some characteristics, whereas variety Ekra is more stable for the others).

The aim of the factorial cross experiment conducted at Młochów Research Centre of Plant Breeding and Acclimatization Institute was the assessment of ability of eight parental forms to generate progenies representing salad (A) or multi-purpose culinary type (B) with high cooking quality and good tuber appearance. Each of 16 crosses was represented by 90 field grown seedlings in 2000, of which 14 clones were retained after initial selection to the first clonal trial (year). In 2001, the above mentioned clones were planted in 28-hill plots. A completely randomized block design in two replications was applied at the stage of first clonal year. After harvest of the progeny trial, a frequency of clones that exceeded the target values in all the four variates (set of traits characterizing tuber appearance) and all the three varieties (set of traits characterizing cooking quality) was estimated. Three outstanding combiners (clones M-191, M-493 and cv. Donella), which expressed the ability to increase in their progenies the frequency of valuable clones showing firm texture and good cooking quality, were identified. Estimation of the effects of specific combining ability (SCA) allowed to identify four crosses which were able to generate (with higher frequency) clones combining high level of cooking quality with good tuber appearance.

The objective of the studies carried out in 2000–2001 was to characterize 16 morphological characters of leaves and yields of the main roots and root cuttings of four Polish ecotypes of horseradish (Armoracia rusticana Gaertn.): Mazaniec, Lipnik, Tądle and OsjakĂłw, cultivated in two localities differing in both soil and climatic conditions. The experiments were performed simultaneously in the environs of Wieluń (the region where the ecotypes have been cultivated) and in the Experimental Field of the Department of Vegetable and Medicinal Plants of Warsaw University (SGGW) in WilanĂłw. Chemical analyses were done to determine the content of dry matter, vitamin C and total sugar as well as the activity of peroxidase. Volatile components were identified using gas chromatography. The altered soil and climatic conditions in the Experimental Field had no influence on 14 of the 16 (nearly 90%) morphological traits of leaves. However, they did strongly affect yield of the main roots produced by ecotypes OsjakĂłw (increase) and Tądle (decrease). Similar results were obtained with the crop of root cuttings, Tądle being the most fertile ecotype in both vegetation periods and both cultivation localities. The content of dry matter, total sugar and vitamin C markedly depended on plant ecotype as well as soil and climatic conditions. The plants cultivated in the Experimental Field generally contained a greater amount of allyl isothiocyanate and peroxidase than those grown in the environs of Wieluń. The oxidation of pyrogallol catalysed by horseradish peroxidase was most intensive during the initial 30 seconds.

Variability of measurable characteristics appearing in DUS (distinctness, uniformity and stability) trials on three species of grass was compared. The data have been derived from the assessments carried out on a number of varieties of Red fescue, Kentucky bluegrass and Perennial ryegrass species from 1998 to 2001. The characteristics concerned the stem, flag leaves and inflorescence of single plants. The variability was measured with the use of coefficient of variability. Nonparametric Friedman’s test was used for analysis of the differences. In general (independently of species), the characteristics concerning the stem were significantly less variable than those concerning the leaves. The characteristics concerning the inflorescence were of moderate variability. Significant differences caused by years were also noticed.

The field experiment was performed to evaluate the effect of the size of rhizomes used as the planting material on some selected morphogenetic traits of Miscanthus pp. The plant material consisted of four hybrids of Miscanthus sinensis × giganteus and one clone of M. sinensis. The effect of plant genotype on the growth rate and development of plants was evaluated. The studies were supplemented with the observations of frost resistance of different plant genotypes.. The significant influence of plant genotype on the growth rate and plant development was shown based on the analysis of variance. A number of both initial and productive sprouts per plant and the average plant height were the most important traits. There was a significant correlation between the genotypes and the size of rhizomes. The interaction genotype × rhizome considerably affected growth and development of the plants. The evaluation of frost resistance showed that propagation of Miscanthus spp. with the use of rhizomes could be an appropriate method of planting in the climatic conditions of Poland.

Possibilities of increasing fodder production from prataecos and agroecos ecosystems depend primarily on prolific, specialized grass varieties. This study presents results of the analysis of yields for varieties of the following grasses: meadow fescue, timothy, perennial ryegrass and italian ryegrass grown in several different environments (in Experimental Stations for Variety Testing) in the years 1995–1999. The hypothesis of the lack of significant differences among the effects of environments has been discarded on the basis of the results. Moreover, the hypothesis of the lack of variety-environment interaction has also been proven wrong. In addition, the assumed lack of deviation from regression of interaction with regard to environment has been verified. The varieties, which deviations from the overall average for the tested species were particularly significant, have received special attention. The interaction of species with their environments has been largely conditioned by the method of management. Significant coefficients of regression and determination have brought to light the intensive varieties, e.g. Limosa in three-year multi-cutting management and the extensive ones — Skra in two-year, three-cutting meadow management

The aim of the study carried out in 1999–2001 was to compare the share of Lolium perenne L. varieties in sward of legume-grass mixtures under pasture and meadow conditions. Mixtures consisted of 3 species: Lolium perenne L. (46%), Phleum pratense L. (30%) and Trifolium repenes L. (24%). Set of 18 varieties of Lolium perenne L. of various origin and polyploidity (Danish varieties — Fanda, Pimpernel, Husky, Canasta, Tivoli, Napoleon; Netherlander — Barezane, Baristra, Barylou, Bardonna, Barplus, Heraut, Hercules, Bravo; German — Kelibia and Polish — Arka and Solen) was tested. The experiment was arranged in randomized blocks design with four replications on mucky-peat soil. In 2000–2001 sward of pasture mixtures was grazing (5 folds), while the meadow sward was mowed (3 cuttings). Share of Lolium perenne in fodder varied depending on method and year of utilization. In 2000, the share of Lolium perenne in swards was decidedly higher in meadow managed conditions, whereas in 2001 — in pasture conditions. Considering years of utilization, it must be stated that share of Lolium perenne L., especially Napoleon, Canasta, Pimpernel and Fanda varieties was maintained on stable level for two years in meadow sward, while share of this species in pasture sward was considerably higher in 2001 and the most persisted varieties were Bardonna, Barplus and Solen.

Evaluation of 15 Polish varieties of common orchard grass was performed in 1992–1998 at the Minikowo Experimental Station on mineral soils of the IVa class. The earliest variety Amera developed ears by 7 to 12 days earlier than the most late varieties Astera and Antosa, while the earing time was clearly connected with the sum of day average air temperatures necessary for earing. Yields, total protein and crude fibre content depended most of all on annual rainfall, importance of variety was lower. As can be concluded from the first cut yield, earlier varieties had a bit higher content of generative shoots and less leaves. In general, they yielded a bit better and contained more protein.

Renovation of the sward was done in 1998 on an idle grass of well-developed red fuscue community. For undersowing was used: FL — Festulolium 100%, M1 — Festulolium 50% + Festuca pratensis 20% + Dactylis glomerata 10% + Phleum pratense 20%, M2 — Festulolium 20% + Festuca pratensis 50% + Dactylis glomerata 10% + Phleum pratense 20%. The undersowing was done in the beginning of September 1998, after the old sward had been destroyed by rototiller. Evaluation of yielding and floristic composition of the regenerated sward was done in 1999 and 2000. Results pertaining to the floristic composition of the sward indicated that the sown species made 65% of the sward, while all grasses made ca. 95%. The share of Festulolium in the sward was dependent on the plants used to undersowing and the year of experiment. The yields from plots which had been sown solely by Festulolium (FL) were similar to those sown by mixtures M1 and M2.

During the years 1990–1998 a plot experiment was carried out at Falenty on mineral soil. The experiment was established in split-plot design with two factors: grass mixture (4 phenological types) and fertilization (3 levels of N fertilization: 120, 180 and 240 kg/ha with stable P and K fertilization). The components of mixtures were: Dactylis glomerata L., Festuca arundinacea Schreb., F. pratensis Huds., Arrhenatherum elatius (L.) P.B., Phleum pratense L., Bromus inermis Leyss., Poa pratensis L., F. rubra L. and Trifolium pratense L. The highestyields of DM for the whole period were observed in case of the moderate early mixture (12,2 t ha-1), a bit lower for the late mixture (11,6 t ha-1) and the moderate late mixture (11,3 t ha-1). The lowest yields were in case of an early mixture (10,8 t ha-1). The highest yields, about 20 t of DM per ha, were obtained in the first year of study. In the next years systematic decrease of yielding was observed to the level of 6–7 t DM per ha (1997–1998), independently on the level of N fertilisation. The share of grass species and their varieties in the mixtures differed from the structure established at sowing. In the 9th year of utilisation meadow grass (Poa pratensis L.) dominated in the early mixture (over 40%). Next frequent species was smooth brome-grass (Bromus inermis Leyss.): 31,1% in the moderate late mixture and 44,6% in the late mixture. In the moderate early mixture numerous plants of F. arundinacea (41,7%) were observed. A total retirement of red clover (Trifolium pratense L.) from a sward was stated together with appearance of strange species of grasses and herbs, including large amounts of Taraxacum officinale Web.

There are some foreign and few domestic reports on pastures use of alfalfa either as pure stands or as mixtures with grasses. Grazing mixtures is a common farming practice in many countries but still little known in our country. This type of managing mixtures on arable lands is not widespread in Europe, either. According to literature annual alfalfa species were initially used for grazing. Afterwards perennial alfalfa cultivars for grazing were developed. In the opinion of many authors the adaptation of alfalfa cultivars to grazing management relies on their morphology. The plants of pasture cultivars are characterized with a branchy habit, well developed root crowns, a large number of shoots, increased regrowth of vegetative organs from the root crowns, high persistence, grazing and trampling tolerance. Among important issues related to the grazing management of alfalfa-grass mixtures main attention in the study was paid to the choice of mixture components, yields, nutritional value, persistence, morphology, content of antinutritional substances, rate of digestion of alfalfa biomass, and length of grazing period.

The content of P, Ca, Mg, Cu, Zn and Mn was compared as well as relations between Ca and other components in eight species of papilionaceous plants (Trifolium pratense, T. repens, T. hybridum, T. dubium, Lotus corniculatus, Vicia cracca, Medicago lupulina, Lathyrus pratensis) and multispecies meadow sward with their considerable participation on background of some habitat factors. Before harvesting of Ist cut crop, samples of the multispecies meadow sward were taken from seminatural meadows and pastures of DynĂłw Plateau (South — Eastern Poland). The biomass of species of papilionaceous plants as well as samples of soil were taken. The results of chemical analyses were statistically worked out. Plant communities with large admixture of papilionaceous plants occuppied mineral soils of optimal or periodically excessive moisture level with acid or neutral reaction, characterized by low content of available P and K, and high content of Mn, and total forms of Cu, Zn and Mn. Most acidic and habitats were occupied by phytocenoses with Lotus corniculatus and Trifolium dubium. On average, most Ca and P was ascertained in biomass of Trifolium repens, most Mn in Trifolium hybridum, Cu in Trifolium pratense, and Mn in Vicia cracca and Trifolium hybridum. Proportions between calcium and other elements were mostly too wide. Multispecies meadow sward absorbed less Ca, Mg and Cu, and more Mn, in comparison to the papilionaceus plants.

The phytosociological examinations were made on the turn of May and June 2000 with Braun-Blanquets method on the permanent meadows in the Gorajec river valley. At the soft-grass and rye-grass meadows with considerable share of papilionaceous plants in the sward (over 10%) there were 40 floristic photos taken altogether. To determine microelements content, hay yield and its use value, meadow sward of 2 x 1 m2 area overgrown mostly with the Holcetum lanati association and Arrhenatheretum medioeuropaeum associations, was sampled before 1st cut harvesting. Moreover, from the area where flora specification was made, papilionaceous plants were also collected for examination. In the sward dry weight and in the papilionaceous plants the Zn, Cu, Fe, Mn microelements content was established by the AAS method. The research proved that hay from the mentioned communities in the Gorajec valley was of sufficient Fe availability, whereas poor in Zn. However, copper content in rye-grass meadow dry weight neared the optimum (Falkowski et al., 1990) or surpassed it slightly, while that in soft-grass one appeared lower than optimal. The papilionaceous plants showed high Fe content and differentiated Zn, Cu and Mn. Feeding value of soft-grass meadow hay was average or good (UVN from 4,51 to 6,49), whereas the feed coming from rye-grass meadows demonstrated very high number of use value (UVN from 6,19 to 9,90).

The objective of this research project was to assess the impact of fertilization with macro- and microelements on yields of meadow grass cv. Skrzeszowicka and timothy grass cv. Skrzeszowicka. Experiments were carried out in a 5-years long experiment established on black earth situated in the Mogilnica river valley with ground water level below 150 cm. Both macro-elements (N, P, K, Ca and Mg) and microelements (Cu. Mn, Zn and B) were applied into the soil. The obtained research results showed that both macro- and microelements had stronger impact on yields of Phleum pratense than on Poa pratensis. The highest increase in dry matter yields of the both grass species was recorded when NPK fertilizers were used in combination with Mg. It was found that especially Mg affected the development of tillers of both meadow grass and timothy grass increasing the number of both vegetative and generative shoots and, consequently, yields of these grasses.

The outcome of three — year research concerning the participation of meadow fescue cultivars and strains in floristic composition of cutting and grazing utilization sward has shown a week growth of this species. The average percentage of meadow fescue in grazing utilization was 6% in 1999, 7% in 2000, 9% in 2001, and in cutting utilization 6%, 14%, and 10% respectively. Irrespective of the utilization system, with NPK fertilization, perennial ryegrass was dominant. It’s percentage during the years of studies ranged from 24% to 39% in grazing utilization mixtures and from 33% to 51% in cutting utilization mixtures. In the last year of studies, in sward fertilized with PK there was a distinct rise of clover percentage. The percentage of white clover in grazing utilization ranged from 26% to 29% of the sward, and in the cutting utilization from 32% to 34%. Red clover in both cutting and grazing utilization has achieved a similar 8% level. Without fertilization the percentage of meadow fescue was low and during the years of studies ranged from 0,9% to 3% in grazing utilization and from 0,7% to 6% in cutting utilization. In this sward red fescue was dominant and in the last year of studies its percentage ranged from 39% to 45% of the yield mass.

In the years 1993–2000 wide range of geobotanical surveys were carried out in persistent meadows of central Poland, mainly in the Wielkopolska and Kujawy regions. The aim of the studies was recognition of ecological needs of legume species, which are typical for plant associations. The ecological needs and agricultural usefulness of 31 species from 33 associations of 9 classes were estimated. Significant differences were found among the species, according to an ecological spectrum. Typical stenobionts present in some phytocenoses and eurybionts present in almost all pratocenoses were identified.

Investigations on changes in sward species composition and pasture utilization value were carried out in the years 1999–2001 and revealed that site-climatic conditions as well as biological traits of species and their cultivars were crucial for the success of the applied treatment. Overdrilling with intensively growing mixtures of grasses (primarily tetraploid cultivars of ryegrasses) and legumes led to rapid alterations in sward plant species composition. This resulted in average yield increases ranging from 35% to 45% already in the year of sowing. The forage value of the swards, amounting to Fvs = 5,6 before renovation reached 8,7 in the autumn after renovation treatment. A similar value was found in the group of herbs and weeds, while their percentage share in the sward dropped by a half. The cost of seed and herbicide purchase and sowing, at the accompanying low labour expenditure and limited application of specialized machinery, allowed farmers to achieve considerable economic profits and produce cheap, high quality fodder.

The aim of the study was comparison of yielding and persistence of six Czech and one Polish grass varieties at different site and rates of nitrogen fertilization. The studies were carried out in pure stands in 1998–2000. The twin experiments were established in 1998 in two different sites: in Experimental Station at JaktorĂłw (Poland) and in Poprad-Matejovce (Slovakia). Seven varieties of four grass species were tested: three Czech Festulolium varieties: Bečva, Perun and Lofa, two Lolium multiflorum varieties: Polish Kroto and Czech Jiskra, the Mustang variety of Lolium perenne and the Lekora variety of Festuca arundinacea. Three doses of nitrogen fertilization 90, 150 and 210 kg·ha-1 were applied. The Perun, Lofa, Mustang and Lekora varieties yielded better in Poprad-Matejovce than at JaktorĂłw. It is connected, first of all, with higher amount of rainfall in the vegetation periods and with its more favorable distribution; the differences due to the year of study varied between 10–30%. Irrespective of the locality, the highest yields for three years have given the Lekora variety of Festuca arundinacea and the Festulolium varieties Perun and Lofa. Site conditions in Poprad-Matejovce let to survive for more persistent species and varieties. Already after the first year of study the Lolium multiflorum varieties Kroto and Jiskra and the Festulolium variety Bečva disappeared. The nitrogen fertilization had a clear favorable effect on the yields of tested species and varieties but the differences between the yields on doses of 150 and 210 kg ha-1 were not significant.