Erfahrungen mit der Bekämpfung von Ambrosia in der Schweiz – ein Rückblick

Die zweikeimblättrige, sommerannuelle Beifuß-Ambrosie (Ambrosia artemisiifolia L.) ist einerseits ein schwer bekämpfbares Ackerunkraut und andererseits ein invasiver Neophyt mit einem enormen Ausbreitungspotential. Mit mechanischen und mit chemischen Methoden gibt es sehr gute Möglichkeiten, die Beifuß-Ambrosie auf landwirtschaftlich genutzten Flächen zu bekämpfen. In Sonnenblumen sind die Möglichkeiten begrenzt, da Sonnenblume und Beifuß-Ambrosie biologisch nah verwandt sind. Dort auf dem Feld, wo die Hacke oder die Spritze nicht hinkommt, und auf dem wilden Stein- oder Komposthaufen, wo Unkraut nicht regelmäßig kontrolliert wird, kann sich die Beifuß-Ambrosie sehr schnell ausbreiten. In der Schweiz wurde vor einigen Jahren eine Melde- und Bekämpfungspflicht gesetzlich verankert. Die Meldepflicht förderte die Erstellung von parzellengenauen Verbreitungskarten. Die Bekämpfungspflicht führte schließlich dazu, dass sich die Pflanze nicht weiter verbreiten konnte, sie wurde aber auch nicht ausgerottet. Zahlen aus dem Kanton Genf belegen dies. Die Beifuß-Ambrosie macht am Feldrand nicht Halt; Verkehrswege, Baustellen, Kiesgruben und alle Arten von gestörten Böden sind anfällig auf eine Verseuchung mit Beifuß-Ambrosie. Regionale Ambrosia-Gruppen, denen Vertreter aller betroffenen Sparten angehören müssen, können das Verständnis über die Zusammenhänge der invasionsfördernden Faktoren fördern. Das verantwortungsvolle Tun des Einzelnen trägt dazu bei, dass auch ohne große finanzielle Mittel gute Bekämpfungsarbeit geleistet werden kann. Eine nachhaltige Bekämpfung wird nur durch das konsequente Unterbinden der Samenbildung erreicht. Der Lohn der Arbeit ist langfristig eine Reduktion der Pollenbelastung. Die Bekanntheit von der Beifuß-Ambrosie wird momentan nur durch fachliche Informationen und deren Weitergabe in den allgemeinen Medien genährt. Eine interessante Aufgabe wäre es, der Beifuß-Ambrosie gerade in unserer schnelllebigen Zeit zu einem Bekanntheitsgrad ähnlich der Brennnessel zu verhelfen.Stichwörter: Ackerunkraut, Bekämpfungspflicht, invasiver Neophyt, VogelfutterExperiences on Control of Common Ragweed in Switzerland – a reviewThe dicotyledonous summer annual common ragweed (Ambrosia artemisiifolia L.) is on the one hand a noxious arable weed and on the other hand an invasive neophyte with a great potential to spread. Various possibilities are known for control of common ragweed in agricultural fields with mechanical and chemical methods. Limits are set in sunflowers because sunflower and ragweed are botanically related. Because no weed control action results in 100% efficacy, common ragweed can propagate quickly in untreated corners of the field or in other disturbed soils. The legal obligation of reporting and control – introduced in Switzerland a couple of years ago – allowed the development of specific distribution maps and enhanced the quality of control measures. Facts and figures from the Canton of Geneva prove that the ragweed invasion has been stopped, but the species is not eradicated. The results of Geneva represent the results of good ragweed control in the whole country. Beside agriculture, traffic infrastructure, building sites, gravel pits and urban park and garden areas are sensible to ragweed invasion. This is why the formation of “Ambrosia Groups” helps to exchange experiences and to understand factors provoking the invasion. The responsibility of individuals helps to improve control efficiency even if financial funds are small. A sustainable control success depends on the efficiency to hamper seed production. The reduction of pollen quantity in the air in a long term is part of the earnings for the control effort. Actually, the publicity of common ragweed is fed by specialist information and its distribution in the media. It would be an interesting task to develop in our fast moving era an awareness level comparable to that of the stinging nettle.Keywords: arable weed, bird seed grain, invasive neophyte, obligation to contro

Implementation of control strategies against yellow nutsedge (Cyperus esculentus L.) into practice

Yellow nutsedge (Cyperus esculentus L.) is one of the most dangerous weeds in agriculture because of its high multiplication potential, its high risk of tuber dispersal with vehicles and machines and because of its limited control options. Yellow nutsedge control must always aim to prevent the formation of new tubers. Our control strategy is adapted to various infestation levels, which we distinguish “initial infestation”, “small infested zone” and “infested field”. In the case of “infested fields” questions arise on adaptation of the rotation or even on abandonment of crops. Our experiences showed that only s-metolachlor had good efficacy in reducing considerably the number of tubers. Less effective herbicides left back a number of surviving plants, themselves forming at least a reduced number of new tubers. The proposed control strategies are currently tested in a nationwide network of pilot fields in Swiss agricultural practice. The tuber numbers counted after the first year of control measures did not change dramatically. We observed a slight increase in tuber numbers in almost a third of the fields. The reduction of tuber numbers in the rest of the fields was lower than expected. Inaccurate estimation of the infestation level is always very likely, because the young shoots visible don’t give a reliable image on the real number of tubers in the ground. For improving the control strategies in regard to the reduction of tuber numbers, we recommend the combination of herbicide treatment, soil cultivation and competition by cover crops

Hot water versus herbicides – Swiss railways renounce herbicide use by 2025

Die Schweizerischen Bundesbahnen (SBB, CFF, FFS) verwendeten bis Anfangs der 1990er Jahre Atrazin, um die Vegetation am Gleis zu kontrollieren. Das Herbizid wurde großflächig und undifferenziert versprüht, was zu erheblicher Belastung von Grund- und Oberflächenwasser mit Herbizidrückständen führte. Mitte der 1990er Jahre war das Atrazin gänzlich von Glyphosat abgelöst worden. Kleine Teams gehen noch heute mit der Rückenspritze die Zugstrecken ab und applizieren das Herbizid mit der Rückenspritze. Auf Grund der aktuell weltweiten Bedenken gegen den Einsatz von Herbiziden und Pflanzenschutzmitteln allgemein haben sich die SBB zum Ziel gesetzt, Alternativen für die Vegetationskontrolle im Gleisbereich zu fördern und zu entwickeln. 2018 wurden erste positive Erfahrungen mit der Applikation von Heißwasser gemacht. Daraufhin bauten die SBB 2019 den Prototypen eines Heißwasserspritzzuges. Im Rangierbahnhof Basel bei Muttenz wurden die Effekte Heißwasserbehandlungen mit denen der Glyphosat Applikation und einer Kontrolle unbehandelt verglichen. Agroscope hat mit Vegetationsaufnahmen das Potential der Heißwasserapplikation aufgezeigt.Swiss railways (SBB, CFF, FFS) used atrazin up until the end of the 1980s along railway tracks for controlling the vegetation. The herbicide was sprayed in large scales and indiscriminate use. Glyphosate replaced atrazine as main herbicide from the early 1990s until today. Small crews walking along tracks apply the herbicide as single plant treatment with knapsack sprayers. Because of increasing discredit of glyphosate in public, Swiss railways decided to search for alternatives to herbicides. A tight goal was defined: within three years, a train running with 40 km/h on track must be able to apply hot water in sufficient quantities for killing the vegetation growing in the ballast and on the sidewalks. In 2018, first attempts were made for applying hot water on a railway tracks out of service. In spring 2019, a prototype of the spray train did its first steps – around 200 km – on open tracks spraying hot water day and night. The technique of the spray train is explained in this paper. Agroscope assessed the effects of hot water treatment compared with glyphosate application and “untreated” on four tracks in the Basel freight yard. The effects on vegetation of four treatments were compared and are presented

Predicting neurological outcome in adult patients with cardiac arrest: systematic review and meta-analysis of prediction model performance

This work aims to assess the performance of two post-arrest (out-of-hospital cardiac arrest, OHCA, and cardiac arrest hospital prognosis, CAHP) and one pre-arrest (good outcome following attempted resuscitation, GO-FAR) prediction model for the prognostication of neurological outcome after cardiac arrest in a systematic review and meta-analysis. A systematic search was conducted in Embase, Medline, and Web of Science Core Collection from November 2006 to December 2021, and by forward citation tracking of key score publications. The search identified 1'021 records, of which 25 studies with a total of 124'168 patients were included in the review. A random-effects meta-analysis of C-statistics and overall calibration (total observed vs. expected [O:E] ratio) was conducted. Discriminatory performance was good for the OHCA (summary C-statistic: 0.83 [95% CI 0.81-0.85], 16 cohorts) and CAHP score (summary C-statistic: 0.84 [95% CI 0.82-0.87], 14 cohorts) and acceptable for the GO-FAR score (summary C-statistic: 0.78 [95% CI 0.72-0.84], five cohorts). Overall calibration was good for the OHCA (total O:E ratio: 0.78 [95% CI 0.67-0.92], nine cohorts) and the CAHP score (total O:E ratio: 0.78 [95% CI 0.72-0.84], nine cohorts) with an overestimation of poor outcome. Overall calibration of the GO-FAR score was poor with an underestimation of good outcome (total O:E ratio: 1.62 [95% CI 1.28-2.04], five cohorts). Two post-arrest scores showed good prognostic accuracy for predicting neurological outcome after cardiac arrest and may support early discussions about goals-of-care and therapeutic planning on the intensive care unit. A pre-arrest score showed acceptable prognostic accuracy and may support code status discussions

Biological flora of Central Europe: Cyperus esculentus L

This paper presents information on all aspects of the biology of Cyperus esculentus L. (yellow nutsedge) and deals with its taxonomy, morphology, genetic diversity, distribution, habitat requirements, ecology and life cycle, with special emphasis on uses and cultivation, history of introduction, impact and management in Europe. C. esculentus is a tuber geophyte and most likely originates from the Mediterranean and Southwest Asia. It is a variable plant and four wild-type varieties are presently recognized, in addition to a cultivated form. C. esculentus reproduces primarily by its underground tubers, although abundant seeds are produced. In temperate climates, tubers usually sprout in late spring and the plant withers at the beginning of the winter. C. esculentus is only cultivated in the València region in Spain. Invasion foci emerged across Europe at the beginning of the 1980s and at present, C. esculentus is most abundant on arable land and in ruderal habitats, followed by riverine vegetation. In heavily infested regions of Europe, C. esculentus causes substantial yield losses in field crops and although different management strategies are available, C. esculentus remains difficult to control.Follak, S.; Belz, R.; Bohren, C.; Castro, OD.; Guacchio, ED.; Pascual-Seva, N.; Schwarz, M.... (2016). Biological flora of Central Europe: Cyperus esculentus L. Perspectives in Plant Ecology, Evolution and Systematics. 23:33-51. doi:10.1016/j.ppees.2016.09.003S33512

Exotic weed contamination in Swiss agriculture and the non-agriculture environment

Swiss farmers nowadays gain a great part of their income from ecological compensation areas, especially wildflower strips, instead of cash crops. Mainly Crisium arvense and invasive alien plant species such as Solidago ssp. are abundant in ecological compensation areas; Reynoutria ssp. is highly abundant in non-agricultural zones and increasingly abundant in agricultural fields; Ambrosia artemisiifolia is an annual weed in agriculture and mandatory to control in Switzerland. Here, we present the results of a survey of wildflower strips in ecological compensation areas. The results of field and pot trials with Solidago, Reynoutria and Ambrosia species are also presented, as well as strategies for Ambrosia control and the information campaign on Ambrosia in Switzerland. The major result we found that was that wildflower strips are infested by noxious weeds and invasive alien plant species. Infestation is in most cases not as alarming as it is sometimes presented in the daily press. Solidago, Reynoutria and Ambrosia species cannot always be fully killed by one control measure. A check of efficacy and repeated control is necessary to achieve complete killing. Abundance of these species in non-agricultural zones makes weed control methods subject to public discussions. The main outcome of the work with weed species interfering in agricultural and non-agricultural zones is the conclusion that guidelines are needed to concentrate financial and human resources on real problems such as public health or damage to infrastructure. Three elements – a collection of weak point sheets for noxious endemic and exotic weed species, a detailed list of costs for control methods, and a detailed list of restrictions for use of control methods in environmental zones, both adapted to a country or region – would allow any functionary in any region to choose adequate control methods

Report of the 12th EWRS International Symposium on Aquatic Weeds 2009

vokpk