Feldversuche mit Biofumigation zur Reduktion des Chalara- Befalls auf Karotten

In order to reduce the infection with Chalara elegans and C. thievlaviopsis of organically produced carrots biofumigation treatments with Brassica juncea were carried out. In the two years of the experiment we could not find an infection reducing effect of the biofumigation treatment compared to the control treatment (fallow)

Programación del Taller Total : Etapa 2, etapa 3 : Documento de trabajo n° 2

Extraer del sitio los requerimientos y condicionantes que resultan de trabar sobre el mismo con determinada estrategia de intervención, de modo tal que al tenerlos evaluados permite plantear los modos de evaluación. Etapas 2 y 3.Fil: Soria, Víctor. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño; Argentina

Efficacy of herbicides against yellow nutsedge (Cyperus esculentus) plants originating from seeds

Erdmandelgras (Cyperus esculentus) ist ein gefürchtetes Unkraut. Es vermehrt und breitet sich hauptsächlich über Knöllchen aus. Es werden aber auch keimfähige Samen gebildet. Die Samen sind klein und verfügen dementsprechend über wenig Speicherstoffe. Erdmandelgrassämlinge sind zart gebaut und ähneln Süßgräsern (Poaceae). Daher vermuteten wir, dass Erdmandelgrassämlingspflanzen sensibler auf Herbizide reagieren als aus Knöllchen gekeimte Pflanzen. Im Gewächshaus wurden Erdmandelgraspflanzen aus Samen angezogen und mit Glyphosat, Bentazon, Bromoxynil, Pelargonsäure und Clethodim behandelt. Die Herbizidwirksamkeit wurde geschätzt und die Anzahl gebildeter Knöllchen bestimmt. Kein Verfahren zeigte eine volle Wirkung. 4 Wochen nach Behandlung konnte eine Wuchsreduktion um 84 % und 34 % in den Verfahren Glyphosat resp. Bentazon im Vergleich zur unbehandelten Kontrolle beobachtet werden. Bei den anderen Verfahren lag die Wuchsreduktion unter 15 %. In den Verfahren Glyphosat und Bentazon wurden deutlich weniger Knöllchen gebildet als in der unbehandelten Kontrolle. Zusammenfassend konnten wir unsere Hypothese nicht bestätigen. Bereits 6 Wochen nach Keimung waren die Sämlinge robust, vergleichsweise tolerant gegenüber den applizierten Herbiziden mit Ausnahme von Glyphosat und Bentazon und bildeten Knöllchen. Das bedeutet, dass bereits nach sehr kurzer Zeit aus Samen entstandene Erdmandelgrasnester die gleichen Probleme verursachen wie aus Knöllchen entstandene.Yellow nutsedge (Cyperus esculentus) is a troublesome weed. It reproduces and spreads mainly via tubers, but also viable seeds are produced. The seeds are very small and have little resources stored. The seedlings are very fragile and look like grasses (poaceae). We hypothesized that C. esculentus plants originating from seeds are more susceptible to herbicides than plants originating from tubers. Cyperus esculentus plants grown from seeds in the greenhouse were treated with glyphosate, bentazone, bromoxynil, pelargonic acid and clethodim. Herbicide efficacy was rated and produced tubers were counted. None of the treatments achieved full control. Four weeks after application a growth reduction of 84% was observed in the glyphosate treatment, whereas bentazone reduced growth by 34% compared to the control. In the other treatments, growth reduction was < 15%. In the glyphosate and bentazone treatment, considerably fewer tubers were produced than in the control. Concluding, we could not confirm our hypothesis. Already 6 weeks after germination seedlings were well developed, tolerant to the sprayed herbicides, except for glyphosate and bentazone, and produced tubers. This implies, that already after a short time Cyperus esculentus stands originating from seeds pose the same problems as the ones originating from tubers

Yield losses in vegetable and arable crops caused by yellow nutsedge (Cyperus esculentus) in farmers fields in Switzerland

Cyperus esculentus ist zu einem Problemunkraut in der Schweiz geworden. Trotz Sensibilisierungsanstrengungen werden die drohenden Ertragsverluste von noch nicht betroffenen Landwirten oft unterschätzt. Dementsprechend wird den Auswirkungen eines Erdmandelgrasbefalls zu wenig Beachtung geschenkt und Eindämmungs- und Bekämpfungsmaßnahmen werden oft nur zögerlich ergriffen.Ertragsverlustzahlen aus dem Ausland sind breit verfügbar. Diese Zahlen erwiesen sich aber nur als bedingt hilfreich, um Schweizer Landwirte zu sensibilisieren. Die Übertragbarkeit auf Schweizer Anbausysteme wurde bezweifelt. Um diese Datenlücke zu schließen, wurden entsprechende Ertragsdaten für verschiedene Kulturen auf Schweizer Praxisflächen erhoben (2013-2016). Erträge mit und ohne Besatz von C. esculentus wurden erhoben und dessen Deckungsgrad geschätzt. Auf den Flächen war eine praxisübliche, chemische Unkrautbekämpfung erfolgt. Für Zuckerrüben und Kartoffeln betrugen die Ertragsverluste durchschnittlich 67 % und 34 %, bei einer Cyperus-Bedeckung von 68 % respektive 44 %. Bei einem hohen Besatz (80-100 % Deckungsgrad) betrugen die Ertragsverluste in Lauch, Zwiebeln und Rosenkohl 86 %, 90 % and 93 %. In Karotten führte ein starker Befall zu einer Ertragsreduktion von 61 %. Bei so hohen Dichten war auch die Qualität des Ernteguts beeinträchtigt.Die Ergebnisse sollen dazu dienen, Schweizer Landwirte weiter zu sensibilisieren. Die Ergebnisse werden zudem Forschungsinstituten bzw. landwirtschaftlichen Beratungsinstitutionen in anderen Ländern zur Verfügung gestellt, die mit der gleichen Problematik konfrontiert sind.Cyperus esculentus has become a serious weed in Switzerland. Despite intensive awareness training unaffected farmers tend to underestimate the consequences of C. esculentus infestation, especially the potential yield losses. Hence, countermeasures are often taken hesitantly.Yield loss data from abroad is widely available. However, this data was of limited value to raise awareness in Switzerland, because its transferability to our production systems was questioned. To close this gap yield losses caused by C. esculentus were determined for different crops in farmers’ fields in Switzerland (2013-2016). Yield was assessed with and without C. esculentus infestation and its coverage was estimated. Standard herbicides had been applied in the fields. For sugar beet and potatoes average, actual yield losses of 67% and 34% were detected at C. esculentus coverages of 68% and 44%, respectively. High infestation (80-100%) in leek, onions and Brussels sprouts caused losses of 86%, 90%, 93%, accordingly. In carrots: A high infestation led to 61% yield loss. At these infestation levels yield quality was also negatively affected.In Switzerland, these figures are employed to further train farmers. The findings are presented here to make this more recent yield loss data available to colleagues facing the same problem in their countries

Five Total Maximum Daily Loads for Indicator Bacteria in Four Austin Streams

The report provides an overview of Waller Creek as well as detailed information about land use, flow duration, and TMDL of bacteria.EXECUTIVE SUMMARY: This document describes total maximum daily loads (TMDLs) for four Austin streams and their tributaries in which concentrations of indicator bacteria exceed the criteria used to evaluate attainment of the contact recreation use. The Texas Commission on Environmental Quality (TCEQ) first identified the impairments to the Spicewood Tributary to Shoal Creek (Segment 1403J) and Taylor Slough South (1403K) in the 2002 State of Texas Clean Water Act Section 303(d) List (TCEQ, 2002), adding Waller Creek (1429C) and Walnut Creek (1428B) when the list was updated in 2006. The impaired segments and corresponding assessment units (AUs) are: Spicewood Tributary to Shoal Creek (1403J_01); ? Taylor Slough South (1403K_01); ? Walnut Creek (1428B_05); ? Waller Creek (1429C_02, 1429C_03); Together these four freshwater streams total approximately 31.6 miles in length with watersheds covering 63.465 square miles. They are almost entirely within the City of Austin full purpose, planning, or exterritorial jurisdiction. They are almost entirely within Travis County, except that the Walnut Creek watershed includes a very small portion of Williamson County. Currently, there are not any permitted domestic wastewater discharges within the watersheds of any of these streams. The Walnut Creek Wastewater Treatment Facility (WWTF), operated by the City of Austin, discharges its effluent directly into the Colorado River instead of Walnut Creek. There are not any permitted industrial bacteria discharges within the watersheds. The Freescale Semiconductor WWTF only discharges bacteria-free process water. The primary loads are from various nonpoint sources that enter the streams via stormwater. The Spicewood Tributary to Shoal Creek is an intermittent freshwater stream approximately 1.4 mile in length from MOPAC/Loop-1 upstream to its headwaters near Spicewood Springs Road and Mesa Drive. The watershed is about 0.650 square miles and is entirely located in the City of Austin. There are no regulated wastewater discharges within this watershed. Taylor Slough South is a perennial freshwater stream approximately 1.1 mile in length from Lake Austin upstream to its headwaters near West 35th Street and MOPAC/Loop-1. The watershed is 0.650 square miles and is entirely located in the City of Austin. There are no regulated wastewater discharges within this watershed. Waller Creek is a perennial freshwater stream approximately 6.7 miles in length from its confluence with Lady Bird Lake upstream to its headwaters near Northcrest Boulevard and West St. Johns Avenue. The watershed is 5.648 square miles and is entirely located in the City of Austin. There are no regulated domestic wastewater discharges within this watershed. Walnut Creek is a perennial freshwater stream approximately 22.4 miles in length from its confluence with the Colorado River upstream to its headwaters near McNeil Drive and Parmer Lane. The watershed is approximately 56.517 square miles and is mostly in the City of Austin full purpose jurisdiction. However portions are in the planning, or exterritorial jurisdictions. Currently, there is only one industrial wastewater discharge located within its watershed, the Freescale Semiconductor plant, which only discharges bacteria-free process water into Walnut Creek AU 1428B_01. Escherichia coli (E. coli) are the preferred indicator bacteria for assessing the contact recreation use in freshwater, and were used for development of the TMDLs, with one exception. Fecal coliform bacteria were used for assessment of Walnut Creek AU 1428B_02 because it was the standard when data were collected in 1999. E. coli data are not currently available, but will be collected in the future. The criteria for assessing attainment of the contact recreation use are expressed as the number (or “counts”) of bacteria. The primary contact recreation use is not supported when the geometric mean of E. coli samples exceeds 126 most probable number (MPN) per 100 milliliters (mL), or the geometric mean of fecal coliform samples exceeds 200 MPN per 100 mL. For the 2012 assessment period, the geometric means of all AUs examined exceeded 126 MPN/100 mL E. coli or 200 MPN/100 mL fecal coliform, indicating non-support of primary contact recreation. Possible sources of indicator bacteria within the watersheds of the impaired AUs are stormwater runoff from regulated storm sewers, illicit discharges from storm sewers, sanitary sewer overflows (SSOs), and unregulated sources such as wildlife, unmanaged feral animals, and pets. Load duration curve (LDC) analyses of instream flows were used to estimate allowable pollutant loads and specific TMDL allocations. Because bacteria loads are usually highest at high flow, the very high flow regime was used as the critical flow for determining the TMDL. Predictions of future growth of existing or new domestic point sources were not necessary. The City of Austin has informed TCEQ that it intends to accommodate all growth with its central wastewater treatment system, which discharges directly into the Colorado River instead of these watersheds. The wasteload allocation (WLA) for regulated stormwater was based on the percentage of each watershed regulated under a Phase I or Phase II Texas Pollutant Discharge Elimination System (TPDES) stormwater permit. Compliance with these TMDLs is based on keeping indicator bacteria concentrations in the selected waters below the geometric mean criterion of E. coli less than 126 MPN/100 mL or fecal coliform less than 200 MPN/100 mL.Waller Creek Working Grou

Examining the accounts of oil spills crises in Nigeria through sensegiving and defensive behaviours

Purpose: The paper examines how oil multinational companies (MNCs) in Nigeria framed accounts to dissociate themselves from causing oil spills. Design/methodology/approach: We utilised data from relevant corporate reports, external accounts and interviews, and used sensegiving with defensive behaviours theoretical framing to explore corporate narratives aimed at altering stakeholders’ perceptions. Findings: The corporations gave sense to their audience by invoking scapegoating blame avoidance narrative in attributing the cause of most oil spills in Nigeria to outsiders (sabotage), despite potentially misclassifying the sabotage-corrosion dichotomy. Corporate stance was reinforced through justifying narrative, which suggested that multi-stakeholders jointly determined the causes of oil spills, thus portraying corporate accounts as transparent, credible and objective. Practical implications: With compensation to oil spills’ victims only legally permitted for non-sabotage-induced spills alongside the burden of proof on the victims, the MNCs are incentivised to attribute most oil spills to sabotage. On policy implication, accountability would be best served when the MNCs are tasked both with the burden of proof and a responsibility to demonstrate their transparency in preventing oil spills, including those caused by sabotage. Research implications: The socio-political dynamics in an empirical setting affect corporate accounts and how those accounts appear persuasive, implying that such contextual factors merit consideration when evaluating corporate accounts. For example, despite contradictions in corporate accounts, corporate attribution of oil spills to external factors appeared persuasive due to the inherently complicated socio-political dynamics. Originality/value: Crisis situations generate multiple and competing perspectives, but sensegiving and defensive behaviours lenses enrich our understanding of how crisis-ridden companies frame narratives to alter stakeholders’ perceptions. Accounts-giving therefore partly satisfies accountability demands, and acts as sensegiving signals aimed at reframing/redefining existing perceptions