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

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

Soil-Water Effects of Good Agricultural and Environmental Conditions Should Be Weighed in Conjunction with Carbon Farming

Soil-water practice is essential for farm sustainability, thereby establishing the reference level for agricultural policy of the European Union (EU). This paper focuses on the critical gap in the knowledge surrounding comparison of soil-water effects of Good Agricultural and Environmental Conditions (GAEC) and carbon farming. We aim to interrogate the tasks assigned to soil-water standards during the 2005–2020 timeframe and identify soil-water effects under selected soil-water GAEC topics. The farm-level and landscape-scale effects were weighed for each standard. The investigation included an extensive meta-review of documents that featured scientific work on sustainable practice. In each GAEC document, soil-water sustainability was weighed vis-a-vis carbon farming. Our main finding was that the identification of soil-water effects within GAEC was addressed both at farm-enterprise level (E) and landscape scale (L). This identification was very similar among the sampled Member States (Czech Republic, Hungary, Poland, and Slovakia). A small differentiation was detected in how exact the guidance under each standard was in each of these Member States, and hence how the prioritization was scored, ranging from 1, most influential, to 5, least influential. The scores that prevailed were 2.5–5 on the part of the scoring instrument. Carbon farming is a welcome addition to the corpus of good farming practice and is complementary to GAEC.</jats:p

Soil-Water Effects of Good Agricultural and Environmental Conditions Should Be Weighed in Conjunction with Carbon Farming

Soil-water practice is essential for farm sustainability, thereby establishing the reference level for agricultural policy of the European Union (EU). This paper focuses on the critical gap in the knowledge surrounding comparison of soil-water effects of Good Agricultural and Environmental Conditions (GAEC) and carbon farming. We aim to interrogate the tasks assigned to soil-water standards during the 2005–2020 timeframe and identify soil-water effects under selected soil-water GAEC topics. The farm-level and landscape-scale effects were weighed for each standard. The investigation included an extensive meta-review of documents that featured scientific work on sustainable practice. In each GAEC document, soil-water sustainability was weighed vis-a-vis carbon farming. Our main finding was that the identification of soil-water effects within GAEC was addressed both at farm-enterprise level (E) and landscape scale (L). This identification was very similar among the sampled Member States (Czech Republic, Hungary, Poland, and Slovakia). A small differentiation was detected in how exact the guidance under each standard was in each of these Member States, and hence how the prioritization was scored, ranging from 1, most influential, to 5, least influential. The scores that prevailed were 2.5–5 on the part of the scoring instrument. Carbon farming is a welcome addition to the corpus of good farming practice and is complementary to GAEC

POST Herbicide Combinations for Velvetleaf (<i>Abutilon theophrasti</i>) Control in Sugarbeet

Velvetleaf is one of the most significant and fastest spreading alien weeds in Europe, and it is a difficult weed to control in conventional sugarbeet. Laboratory experiments were carried out in 2007 and 2008 and field experiments were carried out in 2006, 2007, and 2008 with the aim of finding effective herbicide combinations and optimum timing of control. Herbicides containing the active ingredients phenmedipham, desmedipham, ethofumesate, clopyralid, and triflusulfuron were all tested at different timings. Phenmedipham + desmedipham + ethofumesate gave 87% velvetleaf control in pot experiments when applied at the growth stages of velvetleaf cotyledons and one true leaf, but only 27 to 42% control in field trials. Triflusulfuron gave 76% control in pot experiments and 83 to 88% control in field experiments. The timing of the first and second herbicide applications was very important: the first application of herbicides must be at the cotyledon stage of velvetleaf. A 1-wk delay in first application reduced herbicide efficacy by 8%. A 5-d period between the first and second treatments gave 93% control, while a 10-d period between the first and second treatments gave only 77% control. Sugarbeet yield decreased by 60 to 86% due to competition with velvetleaf when a standard herbicide combination (phenmedipham + desmedipham + ethofumesate) was used, and the velvetleaf produced between 6,700 and 14,800 seeds m−2. Inclusion of triflusulfuron in the herbicide treatment significantly reduced velvetleaf seed production to between 200 and 4,700 seeds m−2. In most cases, inclusion of triflusulfuron increased sugarbeet yield. Better velvetleaf control occurred in years when the sugarbeet canopy developed early and the index of leaf area of sugarbeet was higher.</jats:p