På Sveriges järnvägsnät bekämpas ogräs med det kemiska bekämpningsmedlet glyfosat. En omställning är nu på gång och fler bekämpningsmetoder behöver introduceras, bland annat för att motverka resistensutveckling hos ogräsen. I detta arbete jämfördes bekämpning med pelargonsyra, hetvatten, vattenånga och elektricitet med avseende på effektivitet, kostnad, energi- och vattenåtgång. Glyfosat användes som referens. Jämförelsen gjordes genom att sammanställa tillgängliga forskningsrapporter. Bekämpningsmetodernas användbarhet analyserades genom att uppskatta resursåtgången för att ersätta den kemiska bekämpningen på linjen eller driftplatser, eller för att bekämpa restriktionsytor. Det undersöktes också huruvida kostnaden för ogräsbekämpning över tid har betydelse för val av ballastfri järnväg. Resultatet visade att de alternativa metoderna är både dyrare och kräver en högre energi- och vattenåtgång än glyfosat. De ger också en mindre effektiv ogräsbekämpning och upprepade behandlingar behöver därför göras under växtsäsongen. Detta i kombination med att de med dagens teknik appliceras i låg hastighet gör bekämpningen dyr och tidskrävande. För att kunna säga i vilken omfattning de alternativa bekämpningsmetoderna är möjliga att implementera behövs riktlinjer för vilken kostnad, effektivitet samt vatten- och energiåtgång som kan tolereras. Resultatet tyder på att det kan vara möjligt att införa alternativa bekämpningsmetoder på driftplatser och restriktionsytor. För att ersätta glyfosat längs hela järnvägslinjen behöver de utvecklas, speciellt med avseende på effektivitet. För bekämpning med hetvatten och vattenånga var den stora vattenåtgången en stor nackdel. Bekämpningsmetodernas kostnad utgjorde under 5 % av det totala underhållsbehovet på en ny järnväg av ballast. Den ökade kostnaden för ogräsbekämpning ledde som mest till att en ballastfri järnväg blev lönsam två år tidigare för de alternativa metoderna än för glyfosat. Valet mellan en ballasterad och ballastfri järnväg bedömdes inte påverkas nämnvärt av detta. Dock identifierades faktorer som kan göra bekämpningskostnaden högre än vad den här rapporten har kunnat påvisa. Vid en omställning från glyfosat till alternativa metoder bör man därför vid lönsamhetsberäkningar för ny järnväg vara vaksam på vad bekämpningen på det ballasterade alternativet skulle kosta. / Weeds are growing along the Swedish railway network. In order for them to not cause problems they are being removed chemically with the herbicide glyphosate. Due to problems such as a risk for an increase in weeds that are tolerant to glyphosate alternative methods for weed control are now being considered.  This report compared pelargonic acid, hot water, hot water steam and electricity as control methods in terms of efficacy, cost, energy and water consumption. Glyphosate was used as a reference. The comparison was made by reviewing available research articles. The usability of the control methods was then analysed by estimating the use of resources necessary to implement each method for three different scenarios. Whether the choice between a ballasted or fixed rail was affected or not by the cost for weed control was also investigated. The results showed that the alternative weed control methods required more energy and water than glyphosate. They also provide less effective weed control which means repeated treatments are necessary during the growing season. This, combined with a low application speed, makes the weed control expensive and time consuming. To be able to say to what extent each control method is possible to implement guidelines are needed for tolerated cost, effectiveness, energy- and water consumption. The result suggests that it is possible to introduce alternative control methods to a certain extent. However, in order to replace glyphosate along the entire main line, the methods all need to be developed, especially in terms of effectiveness. For hot water and steam treatment there is also a need for a decrease in water consumption.  The cost for weed control accounted for less than 5 % of the total cost for maintenance on a new ballasted railway. The rise in cost due to alternative weed management resulted in the fixed track becoming profitable up to two years earlier with the alternative management compared to glyphosate. The choice between a ballasted and fixed track was not considered to be significantly affected by this. However, factors were identified that could make the cost of weed control higher than this report showed. Therefore, when alternative methods are introduced, one should consider the cost for weed control on the ballasted track when making the choice between the two types of tracks.

I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. Altered hydrology has reduced historically high spring flow and prematurely initiated the historic summer drying period at SBW. This alteration has increased the coverage of invasive plants (e.g., P. arundinacea) causing a decrease in native plant cover and thus degrading ecological functions. SBW managers installed a water control structure (WCS) between SBW and the Columbia Slough/River system to impound winter rainfall and thus approximate the ecological benefits that natural flooding provided as well as reduce the abundance of P. arundinacea. Prior researchers conducted intensive vegetation and hydrological monitoring in 2003 (during the season immediately before WCS installation) and 2004. I conducted similar analysis in the fifth and sixth years, 2008 and 2009, following establishment of the WCS. Both study years, I determined percent cover of all vegetation on transects established in 2003. The results, including 2004, as well as 2008 and 2009 showed a reduced cover of P. arundinacea in areas experiencing at least 0.6 meters of inundation and an increased cover of native plant communities when compared to the 2003 baseline data. Native Carex aperta Boott. cover increased 7-fold from 0.3% to 2.3%; Polygonum species cover increased from 20.0% to 52.6%; and Salix lucida Muhl. ssp. lasiandra (Benth.) E. Murray cover increased from 10.9% to 15.5% cover. P. arundinacea declined by over one-third from 44.4% to 28.1% cover following water management. Since hydrology management began, the native Polygonum species community replaced P. arundinacea as the dominant species in the emergent zone. The results of this study refined the suggested depth of inundation needed to reduce P. arundinacea cover in such lake-wetland complexes as SBW from 0.85 meters (based on 2004 study results) to 0.6 meters. Shannon Diversity decreased following water management. The findings of this study demonstrated that water management can enhance native bottomland communities, especially those comprised of obligate wetland species, and reduce P. arundinacea cover in areas experiencing at least 0.6 meters of inundation.

Three studies were conducted to characterize and present early-seral competition between Douglas-fir seedlings and the surrounding vegetation communities during Pacific Northwest forest establishment. The first experiment served as the foundation for this dissertation and was designed to quantify tradeoffs associated with delaying forest establishment activities by introducing a fallow year in order to provide longer-term management of competing vegetation. A range of six operationally relevant treatments were applied over two growing seasons that included in the first (1) a no-action control, (2) a spring release only, (3) a fall site preparation without sulfometuron methyl followed by a spring release, as well as (4) a fall site preparation with sulfometuron methyl and a spring release. In the second year, there was (5) a fall site preparation without sulfometuron methyl followed by a spring release and also in the second year (6) a fall site preparation with sulfometuron methyl and a spring release. Treatments 5 and 6 were left fallow without planting during the first year. These treatments were applied in two replicated experiments within the Oregon Coast Range. After adjusting for initial seedling size, year-3 results indicated that plantation establishment and competition control immediately after harvest (i.e. no fallow period) enabled seedlings to be physically larger than those planted after a one year delay. At the Boot study site, limiting vegetation below 20% for the first growing season improved year-3 Douglas-fir seedling stem volume over 273 cm³. Delaying establishment activities one year and reducing competing vegetation below 11% enabled seedling volume after two years to be statistically the same as three year old seedlings in the no-action control, a volume range of between 148 to 166 cm³. Delaying forest establishment at Jackson Mast improved seedling survivorship over 88% when a spring heat event reduced survivorship of trees planted a year earlier to less than 69%. The combined effect of applying a fall site preparation and spring release was necessary to reduce competitive cover below 10% in the year following treatment and provided longer-lasting control of woody/semi-woody plants. Less intense control measures (i.e. no-action control and treatment 2) were not able to restrain woody/semi-woody plant cover which grew to nearly 40% at Boot and over 24% at Jackson Mast in three years. No treatment regime provided multi-year control of herbaceous species. Including sulfometuron methyl in the fall site preparation tank-mix did not have a negative effect on seedling growth or provide significant reductions in plant community abundance in the year following application when compared to similar regimes that did not include the chemical. Delaying establishment lengthened the amount of time associated with forest regeneration except on a site that accentuated a spring heat event. In the second study, horizontal distance and azimuth readings provided by a ground-based laser were used to stem map seedling locations and experimental unit features at Boot. These data were used to create a relative Cartesian coordinate system that defined spatially explicit polygons enabling, for the first time, the ability to collect positional data on competing forest vegetation within an entire experimental unit. Deemed "vixels" or vegetation pixels, these polygons were assessed for measures of total cover and cover of the top three most abundance species during the initial three years of establishment. An alternate validity check of research protocols was provided when total cover resulting from this vixel technique was compared to a more traditional survey of four randomly located subplots. The resulting linear regression equation had an adjusted R² of 0.90 between these two techniques of assessing total cover. When compared within a treatment and year, total cover differed by less than 12 percentage points between the two techniques. Analysis of year-3 woody/semi-woody plant cover produced by the techniques led to identical treatment differences. Two treatments resulted in woody/semi-woody cover of approximately 1500 ft² by the vixel method and nearly 40% cover by the subplot method while the remaining four treatments were grouped below 600 ft² or 20% cover, respectively. With continued refinement, these techniques could visually present forest development through all phases and provide long-term information used to bolster growth and yield models, measures of site productivity, as well as community ecology research. The third study evaluated the season-long gas exchange and biomass partitioning of four weedy plant species capable of rapidly colonizing Pacific Northwest regenerating forests. Cirsium arvense, Cirsium vulgare, Rubus ursinus and Senecio sylvaticus were studied at two sites. A greenhouse was used to introduce two levels of irrigation (well-watered and droughty). These species were also studied while growing among a larger vegetation community at a field site. Irrigation treatments had little impact on gas exchange rates. Species achieved maximum photosynthetic rates of 30, 20, 15 and 25 μmol CO₂ m⁻² s⁻¹ (respectively) prior to mid-July coinciding with an active phase of vegetative growth. As the season progressed, photosynthetic rates declined in spite of well-watered conditions while transpiration rates remained relatively consistent even when soil water decreased below 0.25 m³ H₂O/m³ soil. Water use efficiency was high until late-July for all study species, after which time it decreased below 5 μmol CO₂ · mmol H₂O⁻¹. Multi-leaf gas exchange measurements as well as biomass data provided a holistic view of plantlevel mechanisms used to shunt activity toward developing tissues. Herbaceous species had assimilation rates that differed vertically (within each species) by as much as 10 to 20 μmol CO₂ m⁻² s⁻¹ from July to September as lower leaves senesced in favor of those higher on study plants. Specific leaf area was greatest in June for all species then declined indicating species placed little effort into sacrificial early season leaves when compared to those higher on the plant that could continue to support flowering or vegetative growth. The study of seasonal gas exchange in the presence of declining water availability has helped to describe competitive mechanisms at work during forest regeneration as well as provide physiologic support for the application of vegetation management regimes. / Graduation date: 2013

No description available.

[ES] El desarrollo y uso biofungicidas y bioinsecticidas para el control de enfermedades y plagas ha sido objeto de una amplia atención por parte de la comunidad científica. Sin embargo, puede afirmarse que el desarrollo y uso de bioherbicidas está, desde el punto de vista de la investigación y su aplicación práctica en campo, en sus primeros estadios. Esta tesis doctoral, surgida desde el seno de una empresa del sector a través de un proyecto de investigación conjunto con la UPV, pretende profundizar en el análisis de los efectos producidos por los bioherbicidas en malas hierbas, contribuyendo a la cuantificación de su eficacia y evaluando los modos de acción, ya que consideramos que estos son los aspectos esenciales para el desarrollo industrial y en el avance del conocimiento científico. Concretamente, se ha partido del conocimiento previo de sustancias naturales bioherbicidas de los grupos de investigación del Instituto Agroforestal Mediterráneo de la Universitat Politècnica de València y de la Universidade de Vigo, así como de la experiencia en la formulación de compuestos naturales por parte de la empresa Seipasa S.A. El objetivo principal de esta investigación ha sido desarrollar un herbicida natural mejorado para su implementación en el mercado nacional e internacional. Dado que el ácido pelargónico ha demostrado su alta eficacia en campo para el de control de malas hierbas y que, por otra parte, resulta un activo de producción viable a nivel industrial fue escogido como activo principal para el desarrollo de los experimentos que componen esta investigación. Las altas dosis de ácido pelargónico necesarias para conseguir sus efectos bioherbicidas la concentración elevada del activo en los productos disponibles actualmente en el mercado hacen que económicamente no sea una alternativa real a los herbicidas de síntesis química. Por ello, en esta tesis se estudiaron las posibles sinergias de la combinación del activo principal (ácido pelargónico) con otras sustancias herbicidas naturales, sustancias viables de producir en términos de costes: el aldehído cinámico y el carvacrol. En el estudio y comprobación de la eficacia o capacidad de control, así como del modo de acción de cada uno de los compuestos seleccionados, se realizaron ensayos en diferentes condiciones experimentales. ¿ in vitro en placa Petri y condiciones controladas de temperatura y humedad. Ensayos de germinación, modo de acción y curvas de dosis respuesta en malas hierbas objetivo y en plantas modelo (Arabidopsis sp.) ¿ Ensayos en invernadero sin control de temperatura ni humedad. Ensayos en macetas y suelo con semillas de malas hierbas seleccionadas por su importancia agronómica (monocotiledóneas y dicotiledóneas). ¿ Ensayos en campo en parcelas seleccionadas por su amplia diversidad de malas hierbas en los cultivos leñosos escogidos (viñedo). En concreto, se determinó la actividad bioherbicida del ácido pelargónico (AP), carvacrol (CV) y aldehído cinámico (AC) de forma individual y de sus combinaciones en las diferentes condiciones experimentales citadas anteriormente, y frente a malas hierbas monocotiledóneas y dicotiledóneas como Amaranthus retroflexus L., Avena fatua L., Portulaca oleracea L., Chenopodium album L. y Erigeron bonariensis L. Los tres activos mostraron una potente actividad fitotóxica, alcanzando una elevada eficacia y nivel de daño en todas las especies, siendo el AP el más eficaz para el cuál se estudió el modo de acción. Gracias a estos estudios se determinó la curva dosis- respuesta, así como las concentraciones letales para el 50 y 80 % de la población de malas hierbas estudiadas. Se desarrollaron prototipos de formulaciones viables industrialmente de acuerdo con dichas concentraciones y se procedió al registro comercial de una de ellas. Se comprobaron las sinergias, efectos aditivos o antagónicos gracias a una triple comprobación nunca antes realizada con moléculas naturales, lo que caracteriza con novedad esta tesis doctoral. / [CA] El desenvolupament i ús de biofungicides i bioinsecticides per al control de malalties i plagues ha rebut una atenció generalitzada per part de la comunitat científica. No obstant això, es pot afirmar que el desenvolupament i ús de bioherbicidas està, des del punt de vista de la recerca i la seva aplicació pràctica al camp, en els seus primers estats. Aquesta tesi doctoral, sorgida des del si d'una empresa del sector a través d'un projecte de recerca conjunt amb la UPV, pretén aprofundir en l'anàlisi dels efectes produïts pels bioherbicidas en males herbes, contribuint a la quantificació de la seva eficàcia i avaluant els modes d'acció, ja que considerem que aquests són aspectes essencials per al desenvolupament industrial i en l'avanç del coneixement científic. Concretament, s'ha partit del coneixement previ de substàncies naturals bioherbicidas dels grups de recerca de l'Institut Agroforestal Mediterrani de la Universitat Politècnica de València i de la Universitat de Vigo, així com de l'experiència en la formulació de compostos naturals per part de l'empresa Seipasa S.A. L'objectiu principal d'aquesta recerca ha estat desenvolupar un herbicida natural millorat per a la seva implementació en el mercat nacional i internacional. Atès que l'àcid pelargònic ha demostrat la seva alta eficàcia en camp per al control de males herbes i, d'altra banda, resulta un actiu de producció viable a nivell industrial, va ser triat com a actiu principal per al desenvolupament dels experiments que composen aquesta recerca. Les altes dosis d'àcid pelargònic necessàries per aconseguir els seus efectes bioherbicidas i la concentració elevada de l'actiu en els productes disponibles actualment en el mercat fan que econòmicament no sigui una alternativa real als herbicides de síntesi química. Per això, en aquesta tesi es van estudiar les possibles sinergies de la combinació de l'actiu principal (àcid pelargònic) amb altres substàncies herbicidas naturals, substàncies viables de produir en termes de costos: l'aldehid cinàmic i el carvacrol. En l'estudi i comprovació de l'eficàcia o capacitat de control, així com del mode d'acció de cadascun dels compostos seleccionats, es van realitzar assajos en diferents condicions experimentals: In vitro en placa Petri i condicions controlades de temperatura i humitat. Assajos de germinació, mode d'acció i corbes de dosi resposta en males herbes objectiu i en plantes model (Arabidopsis sp.). Assajos en hivernacle sense control de temperatura ni humitat. Assajos en testos i terra amb llavors de males herbes seleccionades per la seva importància agronòmica (monocotiledònies i dicotiledònies). Assajos en camp en parcel·les seleccionades per la seva àmplia diversitat de males herbes en els conreus llenyosos escollits (vinya). Concretament, es va determinar l'activitat bioherbicida de l'àcid pelargònic (AP), carvacrol (CV) i aldehid cinàmic (AC) de forma individual i de les seves combinacions en les diferents condicions experimentals esmentades anteriorment, i davant de males herbes monocotiledònies i dicotiledònies com Amaranthus retroflexus L., Avena fatua L., Portulaca oleracea L., Chenopodium album L. i Erigeron bonariensis L. Els tres actius van mostrar una potent activitat fitotòxica, assolint una elevada eficàcia i nivell de dany en totes les espècies, sent l'AP el més eficaç pel qual es va estudiar el mode d'acció. Gràcies a aquests estudis es va determinar la corba dosi-resposta, així com les concentracions letals per al 50 i 80% de la població de males herbes estudiades. Es van desenvolupar prototips de formulacions viables industrialment d'acord amb aquestes concentracions i es va procedir al registre comercial d'una d'elles. Es van comprovar les sinergies, efectes additius o antagònics gràcies a una triple comprovació mai abans realitzada amb molècules naturals, la qual cosa caracteritza amb novetat aquesta tesi doctoral. / [EN] The development and use of biofungicides and bioinsecticides for the control of diseases and pests have received widespread attention from the scientific community. However, it can be asserted that the development and use of bioherbicides are, from the standpoint of research and practical field application, in their early stages. This doctoral thesis, originating from within a company in the sector through a joint research project with UPV, aims to delve into the analysis of the effects produced by bioherbicides on weeds, contributing to the quantification of their efficacy and evaluating the modes of action, as we consider these to be essential aspects for industrial development and the advancement of scientific knowledge. Specifically, this research has built upon previous knowledge of natural bioherbicidal substances from the research groups of the Mediterranean Agroforestry Institute at the Polytechnic University of Valencia and the University of Vigo, as well as the experience in formulating natural compounds by Seipasa S.A. The main objective of this research has been to develop an improved natural herbicide for implementation in the national and international markets. Given that pelargonic acid has demonstrated its high efficacy in the field for weed control and, furthermore, it is a commercially viable active ingredient at the industrial level, it was chosen as the primary active ingredient for the development of the experiments comprising this research. The high doses of pelargonic acid required to achieve its bioherbicidal effects and the elevated concentration of the active ingredient in currently available market products make it economically unfeasible as a real alternative to chemically synthesized herbicides. Therefore, this thesis explored the potential synergies of combining the primary active ingredient (pelargonic acid) with other natural herbicidal substances, economically viable substances in terms of production costs: cinnamic aldehyde and carvacrol. In the study and verification of the efficacy or control capacity, as well as the mode of action of each of the selected compounds, experiments were conducted under different experimental conditions: In vitro on Petri dishes under controlled temperature and humidity conditions. Germination assays, mode of action, and dose-response curves on target weeds and model plants (Arabidopsis sp.). Greenhouse trials without temperature or humidity control. Pot and soil trials with seeds of selected weeds of agronomic importance (monocotyledons and dicotyledons). Field trials in plots selected for their wide diversity of weeds in chosen woody crops (vineyards). Specifically, the bioherbicidal activity of pelargonic acid (AP), carvacrol (CV), and cinnamic aldehyde (AC) was determined individually and in combination under the aforementioned experimental conditions, against monocotyledonous and dicotyledonous weeds such as Amaranthus retroflexus L., Avena fatua L., Portulaca oleracea L., Chenopodium album L., and Erigeron bonariensis L. All three active ingredients showed potent phytotoxic activity, achieving high efficacy and levels of damage in all species, with AP being the most effective for which the mode of action was studied. Through these studies, the dose-response curve was determined, as well as the lethal concentrations for 50 and 80% of the weed population studied. Prototypes of industrially viable formulations were developed according to these concentrations, and the commercial registration of one of them was initiated. Synergies, additive effects, or antagonisms were verified through a triple verification never before conducted with natural molecules, which characterizes this doctoral thesis with novelty. / Muñoz Usero, M. (2024). Desarrollo de un producto herbicida natural respetuoso con el medio ambiente para el control biológico de arvenses [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/208223