Views of economics students on entrepreneurship and factors influencing its development

Celem opracowania jest empiryczne zbadanie poglądów młodzieży akademickiej o zjawisku przedsiębiorczości i czynnikach kształtujących jej rozwój. Badania ankietowe przeprowadzono na próbie losowej stu studentów studiów ekonomicznych. Ich wyniki wykazały, że młodzież akademicka postrzega przedsiębiorczość głównie przez pryzmat nabywanych umiejętności praktycznych (pracy w czasie studiów, praktyk studenckich i innych rodzajów działalności zawodowej), a także przyswajania wiedzy teoretycznej na wykładach i ćwiczeniach. Co więcej, w opinii studentów, ważnym czynnikiem w kształtowaniu się postawy przedsiębiorczej człowieka jest proces jego wychowania, a zwłaszcza wzorce i wartości wyniesione z domu rodzinnego.The aim of the paper is to conduct survey research regarding students’ views of entrepreneurship as a social phenomenon and the factors affecting its development. The survey was performed on a random sample of a hundred students of economics and related disciplines. The results of the study show that the students perceived entrepreneurship mainly as a collection of acquired practical skills (developed through academic education, student work experience programmes, and other professional activities), as well as during lectures and classes attended at university. Additionally, students thought that the upbringing process – the patterns and values instilled by parents – might be an important determinant of entrepreneurial attitude.Barbara Roszkowska-Mądra: [email protected] Parfieniuk: [email protected] Studnicki: [email protected] Roszkowska-Mądra – Wydział Ekonomii i Zarządzania, Uniwersytet w BiałymstokuAngelika Parfieniuk – Wydziału Ekonomii i Zarządzania, Uniwersytet w Białymstokudr Marcin Studnicki – Wydział Rolnictwa i Biologii, Szkoła Główna Gospodarstwa Wiejskiego w Warszawie6(72)21723

Adaptation patterns of winter wheat cultivars in agro-ecological regions

Multi-environment trials are commonly used to assess cultivar adaptation patterns under different environmental conditions and to help make effective cultivar recommendations for growers. An example of a multi-environment trial system used for cultivar recommendations is the Polish Post-registration Variety Testing System. A common approach in cultivar recommendations is to evaluate the adaptability of cultivars across, or for, specific trial locations. However, the locations of the trials and the fields where a farmer will grow a crop are hardly ever in the same place. Therefore, it would be better to group the trial locations into regions and give recommendations for the whole region. The aim of this study is to evaluate the grain yield adaptation patterns of 62 modern winter wheat cultivars in six agro-ecological regions of Poland for two crop management intensities over five growing seasons. The analysis of the grain yield data was performed separately for each intensity using single-stage approaches in linear mixed models. We ascertained that winter wheat yield variability was in the main determined by agro-ecological region and their interactions, and to a small extent by the cultivar effect. Cultivars Sailor and Linus were widely adapted to all agro-ecological regions studied for both crop management intensities. It is highly probable that these two cultivars will obtain high yield in all agro-ecological regions as well as with both crop management intensities studied. We observed high compatibility rankings between locations for both crop management intensities. High compatibility of the cultivar rankings in the trial locations also provides high precision when determining regions

Four-way data analysis within the linear mixed modelling framework

Cultivars have to be evaluated under different crop management systems across agro-ecosystems and years using multi-environment trials (MET) before releasing them to the market. Frequently, data collected in METs are arranged according to cultivar (G), management (M), location, (L) and year (Y) combinations in a four-way G x M x L x Y data table that is highly unbalanced for cultivars across locations and time. Therefore, we present the restricted maximum likelihood method (REML) for linear mixed models (LMM) with a factor analytic variance-covariance matrix for assessing cultivar adaptation to crop management systems and environments based on unbalanced datasets. Such a multi-environmental trial system has been in operation in Poland for winter wheat (Triticum aestivum L.) in the form of the Post-registration Variety Testing System (PVTS). This study aimed to illustrate the use of LMM in the analysis of unbalanced four-way G x M x L x Y data. LMM analysis provided adjusted means of grain yield for 51 winter wheat cultivars bred in different regions in Europe, tested across 18 trial locations and seven consecutive cropping seasons in two crop management intensities. The application of the four-way LMM with a factor analytic variance-covariance matrix is a complementary and effective tool for evaluating the unbalanced G x M x L x Y table. Cultivars tested had different adaptive responses to the Polish agro-ecosystems separately for each of the crop management intensities. Wide adaptation in both crop management systems was exhibited by cultivars Mulan and Jenga bred in Germany

Evaluation of adaptability to environments of varieties in multiple annual trials: a case study of winter wheat

Celem pracy jest przedstawienie statystycznej metody wnioskowania o adaptacyjnej reakcji odmian na zróżnicowane warunki środowiskowe w miejscowościach, na podstawie danych kompletnych z jednorocznej serii doświadczeń przedrejestrowych oraz ilustracja zastosowania i ocena przydatności tej metody dla plonu ziarna pszenicy ozimej. Rozpatrywane dane doświadczalne stanowią dwukierunkową kompletną klasyfikację o postaci odmiana × miejscowość. Obserwacje plonu odmian poddano analizie statystycznej metodą wykorzystującą mieszany model wielowymiarowy, realizowaną przez programy komputerowe Sergen 4 i Eksplan 2. Badane odmiany pszenicy ozimej zostały podzielone na grupy o jednorodnych średnich genotypowych za pomocą analizy skupień metodą Warda. Proponowana metoda może być wspomagającym narzędziem w pracach hodowlanych do rozróżniania rodzajów adaptacyjnej reakcji odmian pszenicy ozimej na warunki środowiskowe, umożliwiając efektywne poszukiwanie genotypów o szerokiej i wąskiej adaptacji.The objective of this work is presenting the statistical procedures and method of inference about varieties’ responses to different environmental conditions in tested locations based on balanced dataset from annual pre-registration trials. Considered data set consisted of two-way genotype × environments classification. The two factor mixed model approaches included in Sergen 4 and Eksplan 2 softwares were used for analysis of the grain yield data. The evaluated winter wheat varieties were classified to groups with similar responses to the environments using Ward’s method for cluster analysis. Proposed statistical methods may be supporting tools in the breeding processes to differentiate the types of adaptive response to the environments in winter wheat varieties and enabling an effective search for genotypes with wide and narrow adaptation

Sampling methodology to establish a core collection of plant genetic resources: an overview of research

Kolekcje podstawowe są podzbiorem obiektów wybranych z aktualnie zgromadzonej kolekcji (kolekcji wyjściowej) zasobów genowych, tak aby reprezentowały, z minimalna liczbą duplikatów, one różnorodność genetyczną w kolekcji wyjściowej. Tworzenie tego typu kolekcji ma na celu redukcje kolekcji wyjściowej do rozsądnej liczby obiektów co ułatwi systematyczną i pełną ocenę zmienności genetycznej w kolekcji dla wielu cech genotypowych oraz markerów molekularnych. Kolekcje podstawowe odgrywają ważną rolę w zarządzaniu i wykorzystaniu kolekcji zasobów genowych w badaniach i programach hodowli roślin. Opracowano wiele metod służących do tworzenia kolekcji podstawowych z już istniejących kolekcji roślinnych zasobów genowych. Ważnym aspektem w trakcie tworzenia kolekcji podstawowej jest dobór odpowiedniej metody pobierania próby. Metody pobierania próby są powszechnie stosowane do wyboru próby, która tworzą reprezentatywne kolekcje podstawowe z kolekcji wyjściowej.A core collection is a sample of an entire crop germplasm collection, selected to adequately represent, with a minimum of redundancies, the genetic diversity in the entire collection. The purpose of forming plant core collections is generally to reduce the entire collection to a manageable size that facilitates easier systematic and rigorous characterization and evaluation of the genetic diversity in that collection for numerous phenotypic descriptors and for molecular attributes. These activities have the key importance for effective maintaining, managing and sustainable utilization of plant genetic resources for research and crop breeding programs. Many methods have been developed to construct core collections from the entire collections. In the establishing of core collections, the specifying of an appropriate sampling strategy is critical. A sampling strategy is the methodology of selection such a sample that adequately represents the variation or diversity in a population from which has been drawn

What Could Arrest an Eriophyoid Mite on a Plant? The Case of Aculops allotrichus from the Black Locust Tree

Aculops allotrichus is a vagrant eriophyoid that lives gregariously on the leaves of the black locust tree. This study demonstrated that conspecifics can have a significant impact on A. allotrichus females on unprofitable, old black locust leaves and can arrest them on those leaves. The effect was more pronounced in females that were exposed to artificially injured individuals than to intact ones. They not only prolonged their sojourn on leaf discs with pierced conspecifics, but also preferred the leaf disc halves with damaged individuals to clean ones. Aculops allotrichus is the first described herbivore in which artificially injured conspecifics, instead of causing alarm, keep the foraging individuals within a risky patch. Other objects, such as artificially injured or intact heterospecifics, pollen or sand, were irrelevant to the eriophyoid females on old leaf patches. In tests with old leaves of maple, magnolia and hard kiwi vine, the females postponed their movement from non-host leaf discs, which suggests that they may need more time to recognise and evaluate unfamiliar plants than familiar ones

Long-Term Yield Variability of Triticale (×Triticosecale Wittmack) Tested Using a CART Model

Triticale is a promising food crop that combines the yield potential and grain quality of wheat with the disease and environmental tolerance of rye. The objective of this study was to evaluate the impact of genotype, environment and crop management on spring and winter triticale yield variability, using data from 31 locations across the whole of Poland, from 2009 to 2017, with the Classification and Regression Tree (CART) analysis. It was found that CART is able to detect differences in spring and winter triticale successful growth. The yield variability of spring triticale was more dependent on the soil quality than winter triticale because of a shorter cycle duration, which increases sensitivity to nutrient supply and weather conditions. Spring triticale also needs to be sown as soon as possible to ensure a successful establishment. A strong dependence of yield variability on the availability of water for the winter triticale was observed. When growing winter triticale in Poland, with periodic excess water especially during autumn and early spring, the use of fungicides and growth regulators should be taken into account

Ectoparasitism of the Flightless <i>Drosophila melanogaster</i> and <i>D. hydei</i> by the Mite <i>Blattisocius mali</i> (Acari: Blattisociidae)

Predatory mites dispersing by means of insects are often ectoparasites and may use various tactics to get onto the host, counteract its defenses, and diminish its survival. Blattisocius mali is a promising biological control agent which has been reported as transported by several drosophilid species. Our goal was to determine the type of relationship between this mite and fruit flies. We used flightless females of Drosophila melanogaster and D. hydei, which were commercially raised as live pet food. The predatory females mostly attacked the tarsi of the flies and then preferentially moved to the cervix or close to coxa III, where they eventually drilled their chelicerae and started feeding. Although both fly species used similar defensive tactics, more B. mali females did not attack D. hydei or did so with a delay, and a higher percentage of mites fell off the D. hydei tarsi during the first hour of observation. After 24 h, we noted the increased mortality of flies exposed to the presence of mites. Our study indicates the ectoparasitic relationship of B. mali with drosophilids. However, further research is needed to confirm the transport of this mite on wild D. hydei and D. melanogaster, both in the laboratory and under natural conditions