Scaling up qualitative research to harness the capacity of lay people in invasive plant management.

Successful management of invasive plants (IPs) requires the active participation of diverse communities across land tenures. This can be challenging because communities do not always share the views of scientists and managers. They may directly disagree, have alternative views, or be unwilling to manage IPs. Reviews of IP social science identify opportunities to better understand the role of cultural processes and everyday practices to address these challenges. To scale up and leverage the insights of existing qualitative social science IP research, we used meta-ethnography to unlock accounts and interpretations of lay perspectives. Meta-ethnography is a form of qualitative research synthesis increasingly used beyond its origins in health and education to produce interpretive syntheses of an area of research. In the 7 phases of meta-ethnography, we systematically identified and synthesized 19 qualitative articles pertinent to lay experience and knowledge of IPs in diverse settings. Action and meaning regarding IPs were influenced by 6 meta-themes in personal and social life: dissonance, priorities, difference, agency, responsibility, and future orientations. Through descriptions and examples of each meta-theme, we demonstrated how the meta-themes are higher level structuring concepts across the qualitative research that we analyzed and we retained grounding in the in-depth qualitative research. We characterized the meta-themes as leverage points and tensions by which we reframed lay people in terms of capacity for reflective IP management rather than as obstacles. The meta-ethnography synthesis shows how leverage points and tensions emerge from everyday life and can frame alternative and meaningful starting points for both research and public engagement and deliberation regarding IP management. These insights are not a panacea, but open up new space for reflective and mutual consideration of how to effectively navigate often complex IP problems and address conservation and social and livelihood issues in dynamic social and physical environments.

El manejo exitoso de las plantas invasoras requiere de la participación de las diferentes comunidades participantes en la tenencia de tierras. Esto puede ser un reto porque las comunidades no siempre comparten las opiniones de los científicos y los gestores. Puede que las comunidades estén en desacuerdo directo con estas opiniones, tengan opiniones alternativas o no estén dispuestas a manejar las plantas invasoras. Las revisiones a las ciencias sociales de las plantas invasoras identifican oportunidades para entender de mejor manera el papel de los procesos culturales y las prácticas diarias para abordar estos retos. Usamos la meta-etnografía para revelar explicaciones e interpretaciones de las perspectivas comunes para aumentar y potenciar el conocimiento cualitativo de las investigaciones en ciencias sociales de las plantas invasoras. La meta-etnografía es una forma de síntesis de la investigación cualitativa que se usa cada vez más fuera de sus orígenes en la salud y educación para producir síntesis interpretativas de un área de investigación. En las siete fases de la meta-etnografía identificamos y sintetizamos sistemáticamente 19 artículos cualitativos correspondientes a la experiencia y el conocimiento no profesional de las plantas invasoras en diferentes escenarios. Las acciones y significados con respecto a las plantas invasoras estuvieron influenciadas por seis meta-temas en la vida personal y social: disonancia, prioridades, diferencia, agencia, responsabilidad y orientaciones a futuro. Por medio de descripciones y ejemplos de cada meta-tema, demostramos cómo estos son conceptos estructuradores de nivel más alto a lo largo de la investigación cualitativa que analizamos y mantuvimos basados en la investigación cualitativa a profundidad. Caracterizamos los meta-temas como puntos de potenciación y tensiones por la cual replanteamos a la gente común en términos de capacidad de reflexión en el manejo de plantas invasoras en lugar de considerarlas obstáculos. La síntesis de la meta-etnografía muestra cómo los puntos de potenciación y las tensiones emergen de la vida cotidiana y pueden plantear puntos de partida alternativos y significativos para la investigación, la participación pública y la deliberación en el manejo de plantas invasoras. Esta información no es la panacea, pero puede abrir un espacio nuevo para la consideración mutua y reflexiva de cómo navegar efectivamente los problemas complejos de las plantas invasoras y cómo abordar los temas de conservación social y de sustento en los ambientes dinámicos sociales y físicos.

Aqueous plant extracts in the control of Bidens pilosa L / Extratos aquosos vegetais no controle de Bidens pilosa L

Secondary compounds have allelopathic action on germination and growth, and initial development of seedlings and beggar tick can have its germination and growth affected by the action of allelopathic extracts. Thus, this work aimed to evaluate the allelopathic potential of Brachiaria (Brachiaria brizantha), sunflower (Helianthus annuus) and sorghum extracts (Sorghum bicolor) on germination and initial growth of beggar ticks (Bidens pilosa). For this, an experiment was conducted in a completely randomized design with four treatments and six replicates and brachiaria, sunflower and sorghum extracts and control (distilled water) treatments. Extracts were obtained using 200 g of plant material and 1,000 mL of distilled water. Seeds were distributed in gerbox containing two sheets of germitest paper moistened with treatments and taken to germination chamber. Germination was daily monitored, and ten days after, initial growth was evaluated. Extracts did not reduce germination. However, they caused increase in germination time, mainly by brachiaria extract. Seedlings submitted to brachiaria and sorghum extracts showed lower growth. Brachiaria and sorghum extracts showed no action on germination, but controlled the initial growth of beggar tick, being potential natural herbicides.(AU)

Compostos secundários têm ação alelopática sobre a germinação, crescimento e desenvolvimento inicial de plântulas, e a Bidens pilosa pode ter sua germinação e crescimento afetados pela ação dos extratos alelopáticos. Nesse sentido, objetivou-se avaliar o potencial alelopático de extratos de braquiária (Brachiaria brizantha), girassol (Helianthus annus) e sorgo (Sorghum bicolor) na germinabilidade e no crescimento inicial de picão-preto (Bidens pilosa). Para isso foi instalado um experimento no delineamento inteiramente casualizado, com quatro tratamentos e seis repetições, sendo eles extrato de braquiária, girassol, sorgo e o controle (água destilada). Os extratos foram obtidos utilizando 200 g de material vegetal fresco para 1.000 mL de água destilada. As sementes foram distribuídas em caixa gerbox contendo duas folhas de papel germitest umedecidas com os tratamentos e levadas para a câmara de germinação. Foi acompanhada diariamente a germinação e, após 10 dias, foi avaliado o crescimento inicial. Os extratos não causaram prejuízos à germinação, porém, provocaram demora em seu tempo de eclosão, sendo o extrato de braquiária o mais prejudicial. As plântulas submetidas aos extratos de braquiária e sorgo apresentaram menor crescimento. Os extratos de braquiária e sorgo não apresentaram ação sobre a porcentagem de germinação das sementes de picão-preto, mas controlaram o crescimento inicial das plântulas e podem ser indicados para possíveis herbicidas naturais.(AU)

Seeds of weeds as an alternative host of phytopathogens / Sementes de plantas daninhas como hospedeiras alternativas de fitopatógenos

Weeds compete with agricultural crops for water, light, nutrients and space, besides having an extensive seed bank. However, another aspect to be considered relates to few studies pointing out weeds as hosts of phytopathogenic fungi. Many fungi, the main cause of diseases in plants, are known to use seeds as an efficient means of survival and dispersal. The objective of this work was to evaluate the health of weed seeds and the pathogenicity of fungi associated to plants of agricultural importance. The seeds were collected manually in Cerrado areas located in the municipality of Gurupi, Tocatins, Brazil. The blotter test method was used to evaluate seed health. The incidence of fungi was evaluated through an individual analysis of seeds using a stereoscopic and an optical microscope. The pathogenicity of fungi from weed seeds was evaluated by inoculation in plants of agronomic interest and, when pathogenic, we inoculated them in the host plant of the fungus. Weed seeds have been identified in fungi of the genus Alternaria, Aspergillus, Bipolaris, Cladosporium, Curvularia, Fusarium, Nigrospora, Papularia, Rhizopus and Pythium. The seeds of Acanthospermum australe, Bidens pilosa, Cenchrus echinatus, Digitaria horizontalis, Echinochloa crus-pavonis, Eleusine indica, Ipomoea sp., Pennisetum setosum, Sida rhombifolia, Spermacoce latifolia, Tridax procumbens and Vernonia polyanthes carry and disseminate fungi that, once inoculated, cause infection in plants of agricultural importance, such as Oryza sativa, Phaseolus vulgaris, Vigna unguiculata, Zea mays and Glycine max.(AU)

As plantas daninhas competem com culturas agrícolas por água, luz, nutrientes e espaço, além de possuírem um extenso banco de sementes. Entretanto, outra vertente a ser considerada é quanto aos poucos estudos relacionando plantas daninhas como hospedeiras de fungos fitopatogênicos. É sabido que muitos fungos, principais causadores de doenças em plantas, utilizam as sementes como meio eficiente de sobrevivência e de dispersão. Dessa forma, o trabalho objetivou avaliar a sanidade de sementes de plantas daninhas e a patogenicidade dos fungos associados às plantas de importância agrícola. As sementes foram coletadas manualmente em áreas de cerrado localizadas no município de Gurupi, Tocantins, utilizando o método blotter test para avaliação da sanidade. A incidência dos fungos foi avaliada com auxílio de microscópio estereoscópico e ótico. A patogenicidade dos fungos oriundos das sementes de plantas daninhas foi avaliada por meio da inoculação em plantas de interesse agronômico e, quando patogênico, a inoculação foi na própria planta daninha hospedeira do fungo. Foram identificados os fungos dos gêneros Alternaria, Aspergillus, Bipolaris, Cladosporium, Curvularia, Fusarium, Nigrospora, Papularia, Rhizopus e Pythium. As sementes de Acanthospermum australe, Bidens pilosa, Cenchrus echinatus, Digitaria horizontalis, Echinochloa crus-pavonis, Eleusine indica, Ipomoea sp., Pennisetum setosum, Sida rhombifolia, Spermacoce latifolia, Tridax procumbens e Vernonia polyanthes transportam e disseminam fungos que, uma vez inoculados, causam infecção em plantas de importância agrícola, como Oryza sativa, Phaseolus vulgaris, Vigna unguiculata, Zea mays e Glycine max.(AU)

Level of environmental threat posed by horticultural trade in Cactaceae.

Ornamental horticulture has been identified as an important threat to plant biodiversity and is a major pathway for plant invasions worldwide. In this context, the family Cactaceae is particularly challenging because it is considered the fifth most threatened large taxonomic group in the world; several species are among the most widespread and damaging invasive species; and Cactaceae is one of the most popular horticultural plant groups. Based on the Convention on International Trade in Endangered Species of Wild Flora and Fauna and the 11 largest online auction sites selling cacti, we documented the international cactus trade. To provide an in-depth look at the dynamics of the industry, we surveyed the businesses involved in the cactus trade in South Africa (a hotspot of cactus trade and invasions). We purchased seeds of every available species and used DNA barcoding to identify species to the genus level. Although <20% of this trade involved threatened species and <3% involved known invasive species, many species were identified by a common name. However, only 0.02% of the globally traded cacti were collected from wild populations. Despite a large commercial network, all South African imports (of which 15% and 1.5% were of species listed as threatened and invasive, respectively) came from the same source. With DNA barcoding, we identified 24% of the species to genus level. Based on our results, we believe that if trade restrictions are placed on the small proportion of cacti that are invasive and there is no major increase in harvesting of native populations, then the commercial trade in cactus poses a negligible environmental threat. However, there are currently no effective methods for easily identifying which cacti are traded, and both the illicit harvesting of cacti from the wild and the informal trade in invasive taxa pose on-going conservation challenges.

Allelopathy of Bidens sulphurea L. aqueous extracts on lettuce development / Alelopatia de extratos aquosos de Bidens sulphureaL. no desenvolvimento de alface

ABSTRACT Allelochemical compounds are present in tissues of different plants` parts and also in other organisms, being released into the environment and thus affecting plants development. There is evidence that secondary metabolites produced by weeds may exhibit several allelopathic effects. This study aimed to evaluate allelopathic activity based on the interaction of aqueous extracts preparations and their concentrations obtained from Bidens sulphurea (Cav.) Sch. Bip. leaves on germination and seedlings development of Lactuca sativa L. cv. Grand rapids (lettuce). The extracts were obtained from fresh leaves and prepared by infusion, decoction, leaching and grinding methods, at concentrations of 0, 7.5, 15, 22.5 and 30%, with four replications with 25 lettuce seeds. Seven days after the percentages of abnormal seedlings and germination, shoot and root length (cm) were evaluated, while germination speed index (GSI) was daily determined and calculated. The experiment was completely randomized in a 4x5 factorial design, with four extract preparation methods and 5 concentrations. It was found out that the B. sulphurea aqueous extracts did not affect the germination and abnormal seedling development percentages in lettuce seeds. The aqueous extracts and their concentrations showed allelopathic effect for GSI, shoot and root length variables, despite their methods of preparation. This effect is not only inhibitory, but in some cases it was also stimulatory.

RESUMO Os aleloquímicos são compostos que estão presentes nos tecidos de diferentes partes das plantas e outros organismos, são liberados no ambiente e atuam no desenvolvimento das mesmas. Existem evidências de que os metabólitos secundários produzidos por plantas invasoras podem apresentar uma variedade de efeitos alelopáticos. O presente estudo objetivou avaliar a atividade alelopática através de interação das formas de preparo dos extratos aquosos e suas concentrações obtidas de folhas de Bidens sulphurea (Cav.) Sch. Bip. sobre a germinação e o desenvolvimento de plântulas de Lactuca sativa L. cv. Grand rapids (alface). Os extratos foram obtidos de folhas frescas e preparados sob a forma de infusão, decocção, maceração estática e trituração, nas concentrações de 0; 7,5; 15; 22,5 e 30%, com quatro repetições com 25 sementes de alface. Após sete dias foi avaliado a porcentagem de germinação e plântulas anormais, comprimento da parte aérea e raiz (cm), sendo diariamente as sementes avaliadas para o calculo do índice de velocidade de germinação (IVG). O delineamento experimental foi inteiramente casualizado, organizado em esquema fatorial 4x5, com 4 formas de preparo dos extratos e 5 concentrações. Foi possível constatar que os extratos aquosos de B. sulphurea não influenciaram o percentual de germinação e formação de plântulas anormais em sementes de alface. As diferentes formas de obtenção dos extratos aquosos e suas concentrações apresentaram efeito alelopático para as variáveis IVG, crescimento da parte aérea e comprimento da raiz não sendo o efeito somente inibitório, mas em alguns casos também de estímulo.

Seedling structure of Euphorbia L. and Chamaesyce Gray species / Estrutura da plântula de espécies de Euphorbia L. e Chamaesyce Gray

Chamaesyce prostrata (Aiton) Small, Euphorbia heterophylla L. and Euphorbia graminea Jacq. are weedy species that occur with relative frequency in the region of Maringá, Paraná State, Brazil. Data about the morphology and anatomy of seedlings of these species were obtained, with emphasis on significant structural differences of seedlings between species of Euphorbia and Chamaesyce. Seedlings are phanerocotylar and epigeal. Root is axial and triarch. Cotyledons are leaf-like and dorsiventral. Eophylls and prophylls are simple and dorsiventral. Morphological variations occur in the cotyledon shape of Euphorbia seedlings. It is remarkable the Kranz structure of leaves that occurs only in Chamaesyce.

Chamaesyce prostrata (Aiton) Small, Euphorbia heterophylla L. e E. graminea Jacq. (Euphorbiaceae) são espécies invasoras frequentes na região de Maringá, Paraná. Foram obtidos dados sobre a morfologia e anatomia das plântulas dessas espécies, com ênfase se há caracteres estruturais significativos das plântulas entre as espécies de Euphorbia e Chamaesyce. As plântulas são fanerocotiledonares e epígeas. A raiz é axial e triarca. Os cotilédones são foliáceos e dorsiventrais. Os eofilos e profilos são folhas simples e dorsiventrais. As variações mofológicas ocorrem no formato dos cotilédones das plântulas de Euphorbia. Sob o aspecto anatômico é especialmente notável a estrutura Kranz das folhas que ocorrem somente em Chamaesyce.

Efeito dos extratos de duas plantas medicinais do gênero Bidens sobre o crescimento de plântulas de Lactuca sativa L / Effect of extracts of two medicinal plants of the genus Bidens on the growth of Lactuca sativa L. seedlings

A alelopatia é a ação direta ou indireta de uma planta sobre a outra, sendo que compostos químicos alelopáticos são liberados por uma espécie vegetal para minimizar a competição com outras plantas. O presente trabalho avaliou o efeito dos extratos etanólicos das partes aéreas de duas espécies da família Asteraceae, consideradas medicinais: as Bidens pilosa e B. alba sobre o crescimento de plântulas de Lactuca sativa L.. Foram determinados os percentuais de crescimento da radícula e do hipocótilo. As duas espécies inibiram o crescimento da radícula e do hipocótilo. O extrato de B. pilosa inibiu o crescimento da radícula em 47,29% e o crescimento do hipocótilo em 60,63%. O extrato de B. alba inibiu o crescimento da radícula em 95,94% e do hipocótilo em 56,50%. Os resultados obtidos indicam que as duas espécies analisadas podem ser utilizadas na busca de novas moléculas herbicidas menos tóxicas ao meio ambiente e ao homem.

Allelopathy is the direct or indirect action of one plant on another by means of allelopathic chemicals that are released by one plant species to minimize the competition from other plants. Ethanolic extracts were prepared from aerial parts of two species of the family Asteraceae, used in traditional medicine, Bidens pilosa and B. alba (?beggar tick? in the USA). In this study, the extracts were tested for allelopathic effects on the growth of Lactuca sativa L. (lettuce) seedlings. The percent inhibition of radicle and hypocotyl growth was determined. Each species inhibited both radicle and hypocotyl growth: B. pilosa extract inhibited the growth of radicles by 47.29% and of hypocotyls by 60.63%, while B. alba extract inhibited that of radicles by 95.94% and hypocotyls by 56.50%. These results indicate that both of the species under study can be used in the search for new herbicide compounds that are less persistent in the environment and not toxic to humans.