Within the SIBEX study area greater concentrations of net-phytoplanklon biomass and numbers were found in waters with clearly defined physical characteristics of either Bellingshausen Sea (an area north and west of Anvers Island and northern part of the Bransfield Strait) or Weddell Sea (south eastern entrance to the Bransfield Strait). Low biomass and cell numbers occurred in the southern Drake Passage and in the south central Bransfield Strait, which in the latter case, appears to be a characteristic feature of ihsse waters during the entire phytoplankton growing season. Early summer blooms of Chaetoceros neglectus and C. tortissimum were mainly responsible for high values of phytoplankton biomass. Some diatoms, such as C. socialis were exclusively associated with Weddell Sea water; a replacement of one water type by another in the Bransfield Strait may considerably modify phytoplankton populations which are present there.
In the four-year experiment the impact of four different winter barley varieties and selected two- and three-component mixtures were tested. Reduced dosages of fungicides on disease reduction in the mixtures compared with pure stands were evaluated. The studies were carried out at two sites: Experimental Station for Variety Testing Słupia Wlk. (Wielkopolska region) and Plant Breeding Station Bąków (Opole District). Observations on powdery mildew occurrence during the vegetation season were done every 7–10 days. In order to compare the disease occurrence levels on different cultivars in pure stands and on their mixtures combined with different fungicide treatments the Area Under Disease Progress Curve (AUDPC) was evaluated. On the base of the AUDPC values the reduction of powdery mildew occurring in the mixtures due to epidemiological and ecological factors functioning in mixed stands were also evaluated. On the base of obtained results it can be stated that winter barley variety mixtures combined with different fungicide treatments do reduce the powdery mildew incidence comparing to pure stands and winter barley variety mixtures can constitute an alternative way of growing winter barley, especially at low-input and ecological agriculture.
This article presents the results of laboratory tests of the physical and mechanical properties of various types of sandstone selected from ten quarries from Carpathian flysch. The parameters were used to evaluate the quality of the sandstone and its suitability for use as armourstone in accordance with applicable standards and quality guidelines. The requirements of the BN-79/8952-31, EN 13383-1:2003 and the CIRIA, CUR, CETMEF (2007) standards were compared. Sandstone can display a large variability of parameters depending on its origin. This, in turn, results in a varying degree of its susceptibility to the destructive effects of water and climate.