Janusz Gołaszewski

Do the seeds of Solidago gigantea Aiton have physiological determinants of invasiveness

Solidago gigantea Ait. (goldenrod) belongs to the most expansive environmental weeds, and it is the most dangerous plant-invader of American origin in Europe. The species easily propagates vegetatively, but it also produces large amounts of wind-disseminated achenes that contribute to the colonization of new areas. A sound knowledge of the germination biology of goldenrods is required to control the spread of this invasive species. The objective of this study was to investigate selected aspects of germination of giant goldenrod achenes and to determine: the influence of temperature and humidity on seed dormancy and germination, the content of soluble carbohydrates in seeds and the sensitivity of seeds to selected phytohormones. Unlike native weed species of the same family, S. gigantea seeds did not display symptoms of innate dormancy, and high seed vigor was maintained after storage in a wide range of temperatures, in both dry and moist conditions. The physiological mechanisms behind those traits have not yet been fully explored, but they could be associated with the relatively high sucrose-to-hexose ratio in seeds and significant sensitivity to abscisic acid. More extensive research is required to explain the internal causes for the atypical behavior of goldenrod seeds during dry and moist storage, especially in the context of its invasiveness, because the species has a preference for sites located close to river banks.

Comparative Analysis of Energy Efficiency in Wheat Production in Different Climate Conditions en Europe

This paper presents results concerning energy efficiency of wheat production considered in the context of specific energy input variation in different climatic conditions of Europe as well as case studies on implementation of selected energy saving measures in practice. The source data collected from the six european union (EU) countries represent five agricultural regions of continental Europe and three climates: continental, temperate and Mediterranean. The life cycle assessment (LCA) methodology was applied to analyze the data excluding of pre-farm gate activities. The total primary energy consumption was decomposed into main energy input streams and it was regressed to yield. In order to compare energy efficiency of wheat production across the geographical areas, the data envelopment analysis (DEA) was applied. It was shown that the highest wheat yield (6.7 t/ha to 8.7 t/ha) at the lowest specific energy input (2.08 GJ/t to 2.56 GJ/t) is unique for temperate climate conditions. The yield in continental and Mediterranean climatic conditions is on average lower by 1.3 t/ha and 2.7 t/ha and energy efficiency lower by 14% and 38%, respectively. The case studies have shown that the energy saving activities in wheat production may be universal for the climatic zones or specific for a given geographical location. It was stated that trade-offs between energy, economic, and environmental effects, which are associated with implementation of a given energy saving measure or a set of measures to a great extent depend on the current energy efficiency status of the farm and opportunity for investment, which varies substantially across Europe