Cyperus esculentus - differences in growth and tuber production between cultivated and wild forms

Cyperus esculentus (yellow nutsedge) belongs to the world most important weeds on arable land. This species is classified as an invasive one in Central and North-western Europe. It is not yet present as a weed in the Czech Republic, but its occurrence in neighbouring countries and its ability to survive winters in this region must be taken into account. A cultivated form of C. esculentus, known as Chufa or Tiger nuts, is occasionally grown in home gardens as a crop for its edible tubers. In pot experiments we tested the growth of both forms, weedy and cultivated one. Weight of both fresh and dry biomass of plant parts (leaves, roots, rhizomes, tubers, inflorescences) was measured in monthly intervals from May till September 2012. Results show that there were no significant differences in leaf and root biomass. The weight of rhizomes was approximately 50-80 times higher in the wild form. Number of tubers was also higher in the wild form (max. 1118 pcs; crop max. 342 pcs in single pot), but the total weight of tubers was not significantly different. The cultivated form did not produce inflorescences at all, the wild form produced in average 13 inflorescences per plot. Based on our results we can state that growing of the cultivated form does not pose any risk – plants do not show intensive vegetative spread and do not produce inflorescences so crossing with the weedy form is not possible. The wild form can produce high amounts of rhizomes and tubers and is able to produce flowers under our conditions. That makes it a potentially dangerous weed in warmer regions of the Czech Republic.Keywords: Biomass production, crop, CYPES, invasive weed, yellow nutsedgeCyperus esculentus - Unterschiede in Wachstum und Knollenbildung zwischen Kultur- und WildformenZusammenfassungCyperus esculentus (Erdmandelgras) gehört zu den weltweit wichtigsten Unkräutern auf Ackerflächen. Diese Art ist klassifiziert als invasiv in Zentral- und Nordwesteuropa. Die Wildform kommt in der Tschechischen Republik nicht vor, aber in den Nachbarländern. Ihre Fähigkeit, die Winter in dieser Region zu überleben, muss berücksichtigt werden. Die Zuchtform von C. esculentus, als Chufa oder Tigernuss bekannt, wird gelegentlich in Hausgärten als Kulturpflanze wegen ihrer essbaren Knollen angebaut. In Gefäßversuchen haben wir das Wachstum der beiden Formen, Wild- und Kulturpflanze, getestet. Frisch- und Trockenmasse von Pflanzenteilen (Blätter, Wurzeln, Rhizome, Knollen, Blütenstände) wurden in monatlichen Abständen von Mai bis September 2012 gemessen. Die Ergebnisse zeigen keine signifikanten Unterschiede in der Blatt- und Wurzelbiomasse. Das Gewicht der Rhizome war bei der Wildform etwa 50- bis 80mal höher. Die Anzahl der Knollen war in der Wildform ebenfalls höher (max. 1.118 Stück/Gefäß) als bei der Zuchtform (max. 342 Stück/Gefäß). Das Gesamtgewicht der Knollen war nicht signifikant verschieden. Die Zuchtform bildete keine Blütenstände; die Wildform bildete durchschnittlich 13 Blütenstände pro Gefäß. Basierend auf unseren Ergebnissen können wir feststellen, dass der Anbau der Zuchtform keine Gefahr ist, denn die Pflanzen zeigen keine intensive vegetative Ausbreitung und bilden keine Blütenstände, sodass die Kreuzung mit der Wildform nicht möglich ist. Die Wildform bildet große Mengen an Rhizomen und Knollen und ist fähig, unter unseren Bedingungen zu blühen. Das macht dieses Unkraut in wärmeren Regionen der Tschechischen Republik potenziell gefährlich.Stichwörter: Biomasse-Produktion, CYPES, Erdmandelgras, invasives Unkraut, Knollenbildun

Seed ecology of Bromus sterilis L.

Bromus sterilis L. (barren brome) has become a troublesome weed of winter cereals in reduced tillage systems, mainly in South and North America, middle and Western Europe. In the Czech Republic, its importance has increased dramatically over the past 10 years. Barren brome is reported as a problem weed in other winter crops such as oil seed rape, in vineyards and in other cultivated places. In this study, the dormancy and germination under different temperatures, water and light regimes were investigated. Emergence from different depths and persistence in the soil profile were investigated under field conditions. The seeds of Bromus sterilis showed broad ecological valence to hydrothermal factors germinating in the wide range of 5 to 35 °C. Similarly, no strong effect on the germination in an environment with low water potential was observed. The response to light at various temperatures showed that seeds germinated better in darkness. The emergence declined significantly with burial depth (under 40 mm). The loss of primary dormancy was rapid in time and only 50% of the seeds germinated within 8 weeks after collecting from maternal plants. The seeds were not able to survive in the soil seed bank for a longer time and fall seeds lost viability 1 year after burial in a soil profile.Keywords: Bromus sterilis, emergence, germination, seed dormancy, viabilitySamenökologie von Bromus sterilis L.ZusammenfassungBromus sterilis L. (Taube Trespe) hat sich in den letzten Jahren zu einem problematischen Unkraut im Wintergetreide bei reduzierter Bodenbearbeitung, vor allem in Süd-und Nordamerika sowie in Mittel- und Westeuropa entwickelt. Seine Bedeutung hat auch in der Tschechischen Republik in den vergangenen 10 Jahren stark zugenommen. In dieser Arbeit wurden die Dormanz und Keimung unter verschiedenen Temperatur-, Wasser- und Licht-Regimen untersucht. Auch der Auflauf aus unterschiedlichen Bodentiefen und die Lebensfähigkeit im Boden wurden unter Feldbedingungen untersucht. Die Samen der Tauben Trespe zeigten breite ökologische Valenz in Bezug auf hydrothermale Faktoren und keimten in einem breiten Temperaturbereich von 5 – 35 °C. Ebenso wurde kein starker Einfluss des niedrigen Wasserpotentials auf die Keimung festgestellt. Die Samen keimen unabhängig von der Temperatur besser im Dunkeln als im Licht. Der Auflauf nahm signifikant mit der Bodentiefe (unter 40 mm) ab. Ein relativ rascher Verlust der primären Dormanz wurde beobachtet und die Samen keimten 8 Wochen nach dem Absammeln von den Mutterpflanzen nur noch zu 50 %. Die Samen waren nicht imstande in der Samenbank für längere Zeit zu überleben. Nach einem Jahr im Boden waren die Samen nicht mehr lebensfähig.Stichwörter: Auflauf, Bromus sterilis, Dormanz, Keimung, Lebensfähigkei

Measurement of Force Impact Taekwondo Athletes, Assessing the Possibility of Injury of Human Head

AbstractThe article presents the results of measurements impact taekwondo athletes to the board which opens after hitting stroke. Measured values are compared with the results of scientific studies that dealt with human head injuries due to the impacts of various kinds. Most often, these results were determined using cadavers bodies. Force action of the athletes on board was realized by direct punches which are combat sport led to facial parts of opponent. In their own measurement was determined time course of forces impinging on the dynamometer plate including size and direction of the force. Dynamometer measured forces to 10000 N. The frequency was set to 1000Hz. Estimate of accuracy was 0.5% of measured value. A composite plate was attached to a dynamometer using special steel structures. When comparing the results was found that the combat sport of taekwondo strikes, including other power effects (eg. others combat sports, falls, blows to the head in accidents, etc.) can cause fractures of the facial bones and even other human head trauma or cervical vertebrae

USING VARIOUS VISUALIZATION TECHNIQUES TO OUTLINE VULNERABILITY TO DROUGHT IN THE REPUBLIC OF MOLDOVA

Using visualization techniques to outline vulnerability to drought in the Republic of Moldova. This paper is a demonstration of use of various visualization techniques in representing the results on vulnerability to drought at various times scales in the Republic of Moldova. Monthly precipitation totals from simulated data at 10 km horizontal resolution with a regional climatic model RegCM, CRU TS2.10 land observation data set at 0.5ºx0.5º horizontal resolution and observations recorded at 15 meteorological stations in Moldova were used to compare the annual cycle of precipitation, seasonal variability of precipitation, and the spatial and temporal evolution of drought. The Empirical Orthogonal Functions (EOF) analysis was used to identify the principal modes of seasonal variability of precipitation over the country and the Standardized Precipitation Index (SPI) was calculated as an indicator of drought or wetness at various time scales (1 to 24 months). The period of analysis was 1960-1997. One of the visualization techniques was the Grid Analysis and Display System (GrADS) which is an easy manipulation and visualization tool for gridded and station meteorological data. We used it to represent the RegCM and CRU data on their grids. The kriging interpolation with a Gaussian model variance was selected as a suitable interpolation tool for the spatial distribution of the SPI and EOF over Moldova. For temporal diagram and mapping, Golden Software Surfer 9.0 and ArcGis Software 9.1 were used. The results presented with these visualization tools emphasize precipitation and drought characteristics over Moldova domain

Determination of College Expectations in OECD Countries: The Role of Individual and Structural Factors

Renowned international experts in higher education financing have argued that, owing to large government deficits, tertiary education will not be able to open up and meet growing demand unless cost-sharing principles and efficient student financial aid programmes are introduced. Opponents of cost-sharing in higher education object that introducing tuition fees will raise inequality in access to higher education. Drawing on OECD data, and focusing on college expectations, the authors argue that the effects of ability, gender, and socio-economic background on college expectations are primarily shaped by the characteristics of secondary education systems, such as the degree of stratification and vocational specificity of secondary schools, while the principal characteristics of the tertiary education system, such as enrolment rates and the model of financing, play a much less important role. The results clearly show that, after controlling for the effects of secondary school system characteristics, cost-sharing, as such or by degree, does not affect the formation of college expectations by ability, gender, and socio-economic background as much as the selectivity of the secondary school system does

Changes in weed community composition in a long-term trial with different crop rotations and herbicide treatments

The impact of herbicide application on weed community changes was studied in a long-term field experiment conducted since 1972 at two sites in the Czech Republic; Pernolec and Hněvčeves. The ongoing trial comprises multi-crop and simple crop rotations with 50 and 75% cereals, respectively. Three herbicide treatments were used: (1) untreated; (2) synthetic auxins (MCPA; 2,4-D; only in simple crop rotation) and (3) targeted herbicide combinations, including especially sulfonylureas, triazines, ureas and synthetic auxins. Weed species composition and weed density were assessed at the trial beginning, during the trial and in the present (2013-2016). Changes in weed flora composition were found out. In Hněvčeves, abundance of some species such as Galium aparine, Stellaria media, and Vicia spp. increased on untreated plots; the abundance of Apera spica-venti, Fumaria officinalis, and Tripleurospermum inodorum increased on treated plots. In Pernolec, some species receded in all variants, e.g. Myosotis arvensis, Raphanus raphanistrum, and Scleranthus annuus; the abundance of Centaurea cyanus, Tripleurospermum inodorum, Veronica spp., and Spergula arvensis increased in untreated plots. No significant differences affected by time and treatment were detected in population densities of Apera spica-venti, Arabidopsis thaliana, and Stellaria media. The species composition of the weed community was affected by explanatory variables in the following order: treatment < time < type of cultivated crop. The longterm study confirmed weed population shifts over time were caused by interaction between the management factors and environmental conditions

The Effects of Climate Change on Variability of the Growing Seasons in the Elbe River Lowland, Czech Republic

This research aimed to identify an approach for adaptation of agriculture to increased climate variability and projected changes, taking into account regional specificity of climate change. Changes in the timing of growing season (GS) parameters for both observation and models data were computed using daily mean temperatures for three thresholds that correspond to the physiological requirements of the vegetable types. This research included a new assessment of the potential impacts of climate change on the GS of vegetables grown in the Elbe River lowland, one of the largest farmed vegetable regions in Central Europe. To accomplish this, a comprehensive analysis was conducted of the spatiotemporal variability of the date of the beginning of the growing season (BGS), the date of the end of the growing season (EGS), and the length of the growing season (GSL) for the period 1961–2011. In addition, an assessment was made of the potential changes in the dates of the BGS, EGS, and GSL for the Elbe River lowland, simulated using the regional climate models. Prospective areas for growing thermophilic vegetables in the study region were also determined

Cytoplasmic male sterility as a biological confinement tool for maize coexistence: optimization of pollinator spatial arrangement

Cytoplasmic male sterility (CMS) allows efficient biological confinement of transgenes if pollen-mediated gene flow has to be reduced or eliminated. For introduction of CMS maize in agricultural practice, sufficient yields comparable with conventional systems should be achieved. The plus-cultivar-system in maize offers a possibility for biological confinement together with high and stable yields whereas pollinator amount and distribution within the CMS crop is crucial. The aim of this EU-funded study was to identify the best proportion (10, 15, and 20%) and spatial arrangement (inserted rows, mixed seeds) of the pollinator within the CMS maize cultivar under field conditions in the Czech Republic, in Germany and in Spain. In Germany and in the Czech Republic, a pollinator proportion of 10% produced significantly lower yield than the treatments with a pollinator proportion of 15% and 20%. Differences in yield between row and mix arrangements were not detected. No differences between the tested arrangements occurred in Spain. With respect to practical conditions, a pollinator proportion of 15% can be recommended for achieving a satisfactory yield. CMS maize cultivar released no or merely a small amount of pollen and self-pollinated plants developed no or only a small number of kernels indicating that currently recommended isolation distances between genetically modified (GM) and non-GM fields can be substantially shortened if the CMS confinement tool is used.info:eu-repo/semantics/publishedVersio

Testiranje korovske vrste Solanum nigrum L. na rezistentnost prema triazinskim herbicidima

Herbicide resistant weed biotypes usually occur after repeated application of herbicides. Atrazine was used in Serbia for many years and after its ban in 2006, herbicides with the same mode of action containing terbuthylazine started to be used for control of broadleaved annual weeds in maize. The aim of the study was to testa sensitivity of Solanum nigrum L. to PS II inhibiting herbicides. Seeds of the tested populations were sampled from sites on which atrazine had been continuously used (R) and from sites on which herbicides had never been used before (S). The PSII herbicide terbuthylazine (500 g l-1 a.i.) was applied as a commercial formulation by cabinet sprayer at rates of 187.5, 375, 750 and 1500 g of a.i per ha at the 4 leaves stage, and the chlorophyll fluorescence was measured one hour, one day and two days after treatment. Maximum quantum efficiency of PS II photochemistry (Fv/Fm) was calculated. The PCR analysis was also conducted with designing of specific primers for psbA gene. The R population plants were more tolerant than S population after application of all terbuthylazine rates, except for the highest. One day after herbicide application, the Fv/Fm values were higher for R (0.588) than for S population (0.405) at recommended rate. The sequence analysis did not show the nucleotide exchange in the specific region of the psbA gene responsible for resistance and we did not prove that the resistance is target site based.Rezistentni biotipovi korova se najčešće javljaju nakon višegodišnje primene herbicida. Nakon zabrane primene atrazina, 2006. godine, u upotrebu je uveden terbutilazin, herbicid iz grupe triazina sa istim mehnizmom delovanja - zaustavljanjem procesa fotosinteze putem blokade transporta elektrona u PS II. Cilj rada je utvrđivanje rezistentnosti vrste Solanum nigrum L. na PS II inhibitore. Semena S. nigrum su uzorkovana sa mesta na kojima nikada nisu primenjivani herbicidi (potencijalna S populacija) i sa mesta na kojima je atrazin primenjivan kontinuirano dugi niz godina (potencijalna R populacija). Herbicid na bazi terbutilazina (500 g l-1 a.m.), je primenjen kao komercijalna formulacija u količinama 187,5, 375, 750 i 1500 g a.m. po ha, u fazi 4 lista korova. Fluorescencija hlorofila je zatim merena 1 sat, 1 dan i 2 dana nakon tretiranja i izračunata je maksimalna kvantna efikasnost PS II (Fv/Fm). Nakon toga, PCR analiza je sprovedena korišćenjem specijalno dizajniranih prajmera za psbA gen. Biljke R populacije su bile tolerantnije na delovanje herbicida i razvile veću biomasu u odnosu na biljke S populacije.Vrednosti maksimalne kvantne efikasnosti (Fv/Fm) su, dan nakon primene terbutilazina u preporučenoj količini, bile veće kod biljaka R populacije (0,588) nego kod biljaka S populacije (0,405). Analiza sekvenci genoma nije pokazala da je došlo do promene u nukleotidu u specifičnom regionu psbA gena odgovornog za rezistentnost prema triazinskim herbicidima tako da nije potvrđeno da je osnova povećane tolerantnosti ili rezistentnosti vrste S. nigrum prema triazinskim herbicidima genetska modifikacija u mestu delovanja