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Beginning and duration of flowering period in selected arable weed species
Trefil, Daniel ; Holec, Josef (advisor) ; Václav, Václav (referee)
Arable weeds are usually perceived as harmfull organisms in crops. On the other hand, the weeds provide a stable source of food for insects and other invertabrates that feed on pollen and nectar. Majority of crops are not able to provide long-term food component for invertebrates because their flowering is synchronized. Arable weeds flower continously throughout the growing season. There is possible to find many flowering species for the whole year.
The main aim of the study was to determine the onset and duration time of flowering period for selected arable weed species. The observation was conducted at the Demonstration and experimental field of Faculty of Agrobiology, Food and Natural Resources neighbouring areas as well as demonstration plots with rare weed species that do not occur in fields naturally. Inventory of flowering species was performed weakly from 9th calendar week (after frost period) and finished at 48th calendar week. There were found and evaluated 160 plant species of which 67 were the rare species from demonstration plots.
First flowering weeds were photoperiodically neutral species, mainly from the group of winter annual weeds followed by ephemeral annual weeds. Among others, the late-flowering species were particulary from the group of summer annual weeds, but also some from perennial species.
During the first week of observation, 11 flowering species were found. The number gradually increased up to a maximum of 118 flowering species in the 27th calendar week; then the number of flowering plant species naturally decreased. Newly flowering species were being found until 36th calendar week. Weed differed significantly in onset of the flowering acording to perenniality, in most cases. Length of flowering period in individual species was in relation to particular families.
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Monitoring of the flowering time of selected arable weed species
Suran, Pavel ; Holec, Josef (advisor) ; Kolářová, Michaela (referee)
Flowers have an irreplaceable role in a sexual reproduction of plants. Flowers also offer the nutrients to high ammount of the insect species, both pollinators and parasitoid imagos. These insect species are depending on a beginning and a lenght of the plant flowering period and some are depending as well on a plant species diversity. Therefor it is important to monitor a flowering time of individual weed species.
The phase of the plant flowering is started, as well as by other things, by a certain temperature and a humidity. Some species might require a different value of these parameters. The beginning and the lenght of the weed flowering should correlate with a development of the temperature and the humidity during the observation period. This monitoring period was the year of 2015 and observed area was the Demontrational and experimentational land of the Faculty of Agrobiology, Food and Natural Resources of the Czech University of Life Science in Prague. During the observation period, the plant flowering times of the individual weed species were recorded on a weekly basis. In this study, the beginning and the end of the plant flowering time were evaluated for every weed species, that were observed on the observed area. Several of the observed species registered a pause in the flowering time, this pause was also evaluated. It was found out, that most of the species, that start flowering in the spring, started flowering roughly one or two months earlier. The plants capable of flowering during a moderate freezes flowered untill the very late autumn or even during november. The plant species, that start thein flowering in the summer were not affected by an increase in the temperature of the first months, but they were affected by the very high summer temperatures and these species stopped flowering and they either never flowered again, or they started flowring, once the temperature dropped.
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Meaning and contemporary situation in beekeeping
TUPÁ, Kateřina
This thesis is concerned by importance and current situation in breeding of bees. At first, thesis briefly describes characteristics of Honeybee (Apis mellifera) and its life cycle. At second, thesis summarizes information about ambitiousness of human work dedicated to breeding of a bee and manipulation with hive, which protective equipment is needed. At third, thesis points out the problematic caused by adverse effects like pests, diseases or mankind. Last but not least thesis deals with quality and production of bee products and current situation of beekeeping in the Czech Republic. Beekeeping is one of the oldest branches of human activity and in peoples' free time its importance is not small. Moreover, beekeeping has very important position in agriculture as a source for pollination of insect-pollinated and cross-pollinated plants, where it helps to increase the yields. Next, it has great importance in the branch of foods, mostly thanks to the production of honey. All of the bee products are highly prized in the pharmaceutical, healthcare and glass industry, where they are parts of nourishing and moisturizing preparations, medicaments and firming cements. Quality of hives is given by the experience of beekeeper and the possibility of financial support by grants assigned by Ministry of Agriculture of the Czech Republic. The objective of the thesis is to point out the importance of Honeybee in our landscape and to highlight the significance and quality of bee products. The researches show that the beekeeping is ib the Czech Republic on very high level, but there is lack of beekeepers.
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