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Stem canker of brassicas is a severe disease of oilseed rape in Australia, Canada and Europe, including Poland. The disease is caused by Leptosphaeria maculans and L. biglobosa - two pathogens belonging to the class Dothideomycetes. The species differ in pathogenicity, but they have identical shape and size of fruiting bodies and spores of the generative and vegetative stages. Both pathogens are often found together in infected tissues of oilseed rape plants. The main goal of the experiments was to measure the rate of pseudothecial maturation and to monitor ascospore concentration of L. maculans and L. biglobosa in air samples. The paper is the first investigation on the generative stage development of these two species in south-east Poland. The studies were done for three consecutive years (2005-2007), for six most important months in pathogen development and plant infection, including 3 months in the spring (March – May) and 3 months in the autumn (September – November). The stage of pseudothecial maturation was assessed visually, based on the development of asci and ascospores. Monitoring of spore concentration in the air was performed using a Hirst-type 7-day volumetric trap. It was proved that differences in pseudothecial maturation rate in south-east Poland, encompassing the climatic regions of the Carpathian Foothills and Cracow, do not exceed two weeks within one season. The first and the highest ascospore concentration dates depended on weather conditions in a particular season. The total number of spores during the studied seasons varied from 9 to12 spores/m3, which was from 70 to 90 times lower than the average from five other monitoring sites around Poland. The short exposition to spore showers and very small concentrations of L. maculans and L. biglobosa ascospores in air samples were the most probable reasons for relatively small damage of oilseed rape crops by stem canker in the south-east part of Poland.
The article presents the changes in the preferences of people vacationing in the forests of the Mazowiecki Landscape Park (MPK) in the years 2000−2012. The study covered the preferences for the frequency and duration of rest in the forest and the places and forms of recreation carried out in the MPK forests. These preferences were established on the basis of surveys conducted in the field. In 2000, a questionnaire was sent to 755 people vacationing in the MPK forests. In 2012, the survey covered 390 people vacationing within the MPK. In both cases, the survey involved people over 18 years of age. Preferences of respondents in both studies were compared using the chi−square independence test. The results showed that within twelve years the preferences of respondents in the frequency range of leisure, choice of the place and forms of recreation changed significantly. There was an increase in the number of respondents frequently utilising the MPK forests for recreation and leisure interested in areas equipped with appropriate recreational infrastructure. The share of respondents making such recreational activities in forests as horse riding, cycling and observing nature significantly increased, while the preferences for the duration of rest in the forest have not changed. Still, the MPK forests are primarily a place of the weekend rest. The results indicate that the preferences of recreational users of the forest are largely related to the scope of access to and management of the forest.
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