Development and Integration of Biocontrol Products in Branched Broomrape (Phelipanche ramosa) management in Tomato

Parasitic weeds of the genera Striga, Orobanche, and Phelipanche pose a severe problem for agriculture because they are difficult to control and are highly destructive to several crops. The present work was carried out during the period October, 2009 to February, 2012 to evaluate the potential of arbuscular mycorrhizal fungi (AMF) to suppress P. ramosa on tomatoes and to investigate the effects of air-dried powder and aqueous extracts from Euphorbia hirta on germination and haustorium initiation in Phelipanche ramosa. The work was divided into three parts: a survey of the indigenous mycorrhizal flora in Sudan, second, laboratory and greenhouse experiments (conducted in Germany and Sudan) to construct a base for the third part, which was a field trial in Sudan. A survey was performed in 2009 in the White Nile state, Sudan to assess AMF spore densities and root colonization in nine fields planted with 13 different important agricultural crops. In addition, an attempt was made to study the relationship between soil physico-chemical properties and AMF spore density, colonization rate, species richness and other diversity indices. The mean percentage of AMF colonization was 34%, ranging from 19-50%. The spore densities (expressed as per 100 g dry soil) retrieved from the rhizosphere of different crops were relatively high, varying from 344 to 1222 with a mean of 798. There was no correlation between spore densities in soil and root colonization percentage. A total of 45 morphologically classifiable species representing ten genera of AMF were detected with no correlation between the number of species found in a soil sample and the spore density. The most abundant genus was Glomus (20 species). The AMF diversity expressed by the Shannon–Weaver index was highest in sorghum (H\= 2.27) and Jews mallow (H\= 2.13) and lowest in alfalfa (H\= 1.4). With respect to crop species, the genera Glomus and Entrophospora were encountered in almost all crops, except for Entrophospora in alfalfa. Kuklospora was found only in sugarcane and sorghum. The genus Ambispora was recovered only in mint and okra, while mint and onion were the only species on which no Acaulospora was found. The hierarchical cluster analysis based on the similarity among AMF communities with respect to crop species overall showed that species compositions were relatively similar with the highest dissimilarity of about 25% separating three of the mango samples and the four sorghum samples from all other samples. Laboratory experiments studied the influence of root and stem exudates of three tomato varieties infected by three different Glomus species on germination of P. ramosa. Root exudates were collected 21or 42 days after transplanting (DAT) and stem exudates 42 DAT and tested for their effects on germination of P. ramosa seeds in vitro. The tomato varieties studied did not have an effect on either mycorrhizal colonization or Phelipanche germination. Germination in response to exudates from 42 day old mycorrhizal plants was significantly reduced in comparison to non-mycorrhizal controls. Germination of P. ramosa in response to root exudates from 21 day old plants was consistently higher than for 42 day-old plants (F=121.6; P<.0001). Stem diffusates from non-mycorrhizal plants invariably elicited higher germination than diffusates from the corresponding mycorrhizal ones and differences were mostly statistically significant. A series of laboratory experiments was undertaken to investigate the effects of aqueous extracts from Euphorbia hirta on germination, radicle elongation, and haustorium initiation in P. ramosa. P. ramosa seeds conditioned in water and subsequently treated with diluted E. hirta extract (10-25% v/v) displayed considerable germination (47-62%). Increasing extract concentration to 50% or more reduced germination in response to the synthetic germination stimulants GR24 and Nijmegen-1 in a concentration dependent manner. P. ramosa germlings treated with diluted Euphorbia extract (10-75 % v/v) displayed haustorium initiation comparable to 2, 5-Dimethoxy-p-benzoquinon (DMBQ) at 20 µM. Euphorbia extract applied during conditioning reduced haustorium initiation in a concentration dependent manner. E. hirta extract or air-dried powder, applied to soil, induced considerable P. ramosa germination. Pot experiments were undertaken in a glasshouse at the University of Kassel, Germany, to investigate the effects of P. ramosa seed bank on tomato growth parameters. Different Phelipanche seed banks were established by mixing the parasite seeds (0 - 32 mg) with the potting medium in each pot. P. ramosa reduced all tomato growth parameters measured and the reduction progressively increased with seed bank. Root and total dry matter accumulation per tomato plant were most affected. P. ramosa emergence, number of tubercles, and tubercle dry weight increased with the seed bank and were, invariably, maximal with the highest seed bank. Another objective was to determine if different AM fungi differ in their effects on the colonization of tomatoes with P. ramosa and the performance of P. ramosa after colonization. Three AMF species viz. GIomus intraradices, Glomus mosseae and Glomus Sprint® were used in this study. For the infection, P. ramosa seeds (8 mg) were mixed with the top 5 cm soil in each pot. No mycorrhizal colonization was detected in un-inoculated control plants. P. ramosa infested, mycorrhiza inoculated tomato plants had significantly lower AMF colonization compared to plants not infested with P. ramosa. Inoculation with G. intraradices, G. mosseae and Glomus Sprint® reduced the number of emerged P. ramosa plants by 29.3, 45.3 and 62.7% and the number of tubercles by 22.2, 42 and 56.8%, respectively. Mycorrhizal root colonization was positively correlated with number of branches and total dry matter of tomatoes. Field experiments on tomato undertaken in 2010/12 were only partially successful because of insect infestations which resulted in the complete destruction of the second run of the experiment. The effects of the inoculation with AMF, the addition of 10 t ha-1 filter mud (FM), an organic residues from sugar processing and 36 or 72 kg N ha-1 on the infestation of tomatoes with P. ramosa were assessed. In un-inoculated control plants, AMF colonization ranged between 13.4 to 22.1% with no significant differences among FM and N treatments. Adding AMF or FM resulted in a significant increase of branching in the tomato plants with no additive effects. Dry weights were slightly increased through FM application when no N was applied and significantly at 36 kg N ha-1. There was no effect of FM on the time until the first Phelipanche emerged while AMF and N application interacted. Especially AMF inoculation resulted in a tendency to delayed P. ramosa emergence. The marketable yield was extremely low due to the strong fruit infestation with insects mainly whitefly Bemisia tabaci and tomato leaf miner (Tuta absoluta). Tomatoes inoculated with varied mycorrhiza species displayed different response to the insect infestation, as G. intraradices significantly reduced the infestation, while G. mosseae elicited higher insect infestation. The results of the present thesis indicate that there may be a potential of developing management strategies for P. ramosa targeting the pre-attachment stage namely germination and haustorial initiation using plant extracts. However, ways of practical use need to be developed. If such treatments can be combined with AMF inoculation also needs to be investigated. Overall, it will require a systematic approach to develop management tools that are easily applicable and affordable to Sudanese farmers. It is well-known that proper agronomical practices such as the design of an optimum crop rotation in cropping systems, reduced tillage, promotion of cover crops, the introduction of multi-microbial inoculants, and maintenance of proper phosphorus levels are advantageous if the mycorrhiza protection method is exploited against Phelipanche ramosa infestation. Without the knowledge about the biology of the parasitic weeds by the farmers and basic preventive measures such as hygiene and seed quality control no control strategy will be successful, however.

Prevalence of intestinal parasites in small ruminants and their senstivity to treatments with ethnobotanical remedies in Cholistan, Pakistan

Livestock production contributes substantially to the livelihoods of poor rural farmers in Pakistan; strengthening pastoral communities plays an imperative role in the country’s thrive for poverty alleviation. Intestinal helminths constitute a major threat for pastoral livestock keepers in the whole country because chronic infestation leads to distinct losses in livestock productivity, particularly the growth of young animals. Synthetic anthelmintics have long been considered the only effective way of controlling this problem but high prices, side effects and chemical residues/toxicity problems, or development of resistance, lead to their very limited use in many pastoral systems. Additionally, poor pastoralists in remote areas of Pakistan hardly have access to appropriate anthelmintic drugs, which are also relatively expensive due to the long routes of transportation. The search for new and more sustainable ways of supporting livestock keepers in remote areas has given rise to studies of ethno-botanicals or traditional plant-based remedies to be used in livestock health care. Plant-based remedies are cheap or free of cost, environmentally safe and generally create no problem of drug resistance; they thus might substitute allopathic drugs. Furthermore, these remedies are easily available in remote areas and simple to prepare and/or administer. Cholistan desert is a quite poor region of Pakistan and the majority of its inhabitants are practicing a nomadic life. The region’s total livestock population (1.29 million heads) is almost twice that of the human population. Livestock husbandry is the primordial occupation of the communities and traditionally wealth assessment was based on the number of animals, especially goats and sheep, owned by an individual. Fortunately, about 60% of this desert region is richly endowed with highly adapted grasses, shrubs and trees. This natural flora has a rich heritage of scientifically unexplored botanical pharmacopoeia. Against this background, the present research project that was conducted under the umbrella of the International Center for Development and Decent Work at Kassel University, focused on a development aspect: in the Cholistan desert region it was firstly examined how pastoralists manage their livestock, which major health problems they face for the different animal species, and which of the naturally occurring plants they use for the treatment of animal diseases (Chapter 2). For this purpose, a baseline survey was carried out across five locations in Cholistan, using a structured questionnaire to collect data from 100 livestock farmers (LF) and 20 local healers (LH). Most of LF and LH were illiterate (66%; 70%). On average, LH had larger herds (109 animals) than LF (85 animals) and were more experienced in livestock husbandry and management. On average LF spent about 163 Euro per year on the treatment of their livestock, with a huge variability in expenditures. Eighty-six traditional remedies based on 64 plants belonging to 43 families were used. Capparaceae was the botanical family with the largest number of species used (4), followed by Chenopodiaceae, Poaceae, Solanaceae and Zygophyllaceae (3). The plants Capparis decidua (n=55 mentions), Salsola foetida (n=52), Suaeda fruticosa (n=46), Haloxylon salicornicum (n=42) and Haloxylon recurvum (n=39) were said to be most effective against the infestations with gastrointestinal parasites. Aerial parts (43%), leaves (26%), fruits (9%), seeds and seed oils (9%) were the plant parts frequently used for preparation of remedies, while flowers, roots, bulbs and pods were less frequently used (<5%). Common preparations were decoction, jaggery and ball drench; oral drug administration was very common. There was some variation in the doses used for different animal species depending on age, size and physical condition of the animal and severity of the disease. In a second step the regionally most prevalent gastrointestinal parasites of sheep and goats were determined (Chapter 3) in 500 animals per species randomly chosen from pastoral herds across the previously studied five localities. Standard parasitological techniques were applied to identify the parasites in faecal samples manually collected at the rectum. Overall helminth prevalence was 78.1% across the 1000 animals; pure nematode infestations were most prevalent (37.5%), followed by pure trematode (7.9%), pure cestode (2.6%) and pure protozoa infestations (0.8%). Mixed infestations with nematodes and trematodes occurred in 6.4% of all animals, mixed nematode-cestode infestations in 3.8%, and all three groups were found in 19.1% of the sheep and goats. In goats more males (81.1%) than females (77.0%) were infested, the opposite was found in sheep (73.6% males, 79.5% females). Parasites were especially prevalent in suckling goats (85.2%) and sheep (88.5%) and to a lesser extent in young (goats 80.6%, sheep 79.3%) and adult animals (goats 72.8%, sheep 73.8%). Haemonchus contortus, Trichuris ovis and Paramphistomum cervi were the most prevalent helminths. In a third step the in vitro anthelmintic activity of C. decidua, S. foetida, S. fruticosa, H. salicornicum and H. recurvum (Chapter 2) was investigated against adult worms of H. contortus, T. ovis and P. cervi (Chapter 3) via adult motility assay (Chapter 4). Various concentrations ranging from 7.8 to 500 mg dry matter/ml of three types of extracts of each plant, i.e. aqueous, methanol, and aqueous-methanol (30:70), were used at different time intervals to access their anthelmintic activity. Levamisol (0.55 mg/ml) and oxyclozanide (30 mg/ml) served as positive and phosphate-buffered saline as negative control. All extracts exhibited minimum and maximum activity at 2 h and 12 h after parasite exposure; the 500 mg/ml extract concentrations were most effective. Plant species (P<0.05), extract type (P<0.01), parasite species (P<0.01), extract concentration (P<0.01), time of exposure (P<0.01) and their interactions (P<0.01) had significant effects on the number of immobile/dead helminths. From the comparison of LC50 values it appeared that the aqueous extract of C. decidua was more potent against H. contortus and T. ovis, while the aqueous extract of S. foetida was effective against P. cervi. The methanol extracts of H. recurvum were most potent against all three types of parasites, and its aqueous-methanol extract was also very effective against T. ovis and P. cervi. Based on these result it is concluded that the aqueous extract of C. decidua, as well as the methanol and aqueous-methanol extract of H. recurvum have the potential to be developed into plant-based drugs for treatment against H. contortus, T. ovis and P. cervi infestations. Further studies are now needed to investigate the in vivo anthelmintic activity of these plants and plant extracts, respectively, in order to develop effective, cheap and locally available anthelmintics for pastoralists in Cholistan and neighboring desert regions. This will allow developing tangible recommendations for plant-based anthelminthic treatment of sheep and goat herds, and by this enable pastoralists to maintain healthy and productive flocks at low costs and probably even manufacture herbal drugs for marketing on a regional scale.

Estudio del entorno natural de la r??a del Eo

Se complementa con un cuaderno de campo cuyo registro es 17980051

Estrategias operativas en la resoluci??n de problemas matem??ticos en ni??os del Ciclo Medio de la EGB

Procedimiento que sigue el escolar al resolver un problema matem??tico. Campo heur??stico y formas arquet??picas. Escolares de quinto curso de EGB de la ciudad de Santander escogidos al azar. 102 ni??os de 4 colegios. Despu??s se reducen a 20 ni??os sin p??rdida de representatividad. Establecimiento de actos protot??picos por los cuales los ni??os resuelven sus problemas y ejercicios. Se establecen 5 ??reas: Conjuntos, Numeraci??n, C??lculo, Magnitudes y Geometr??a; los problemas se obtienen de un modo aleatorio, escogidos por los profesores de los colegios pertenecientes a la muestra. 20 problemas escogidos se presentan a los alumnos eligiendo aquellos resueltos por el 60-75 por ciento de los escolares, tomando uno de cada ??rea. Se reduce la muestra por el m??todo de elecci??n al azar. Se reelaboran los 4 problemas y se registra la conducta de los escolares en su resoluci??n. Parejas de observadores adiestrados, registros auditivos y visuales, c??digos de registro. T de Student, coeficiente de Scott, matrices de transaci??n y c??lculo de vectores l??mite. No aparecen. Faltan ??stas p??ginas.

??Tienen una personalidad distinta los adolescentes consumidores de psicoestimulantes?

Resumen tomado de la publicaci??n

Tradició i llegenda: Sant Narcís i les mosques

Presentació d’un dossier que tracta l’acostament crític a la figura del bisbe Narcís i als prodigis que li han estat atribuïts, així com a la producció historiogràfica i artística que ha generat el mite

??ngels dom??stics, ciutadanes republicanes, mestresses consumidores : evoluci?? de l'ideal de la feminitat als llibres escolars (1901-1978). '??ngeles dom??sticos, ciudadanas republicanas, amas consumidoras : evoluci??n del ideal de la feminidad en los libros escolares (1901-1978)'

Resumen tomado del autor. Esta comunicaci??n se enmarca dentro del proyecto de investigaci??n 'Educaci??n y socializaci??n en valores : aproximaci??n al an??lisis cualitativo de la evoluci??n de los valores presentes en las pr??cticas educativas y socializadoras vigentes dentro y fuera de la escuela desde la II Rep??blica espa??ola hasta la actualidad en la Comunitat Valenciana (1931-2004)', financiado por la Conselleria de Cultura, Educaci?? i Esport de la Generalitat Valenciana

Las unidades sil??bicas en el reconocimiento visual de palabras : procesos inhibitorios en el nivel l??xico

Investigar si el mecanismo de selecci??n l??xica en el nivel de palabra responde a una inhibici??n que la unidad que representa al 'imput' env??a a otras unidades tambi??n activadas. Saber adem??s, si el conjunto de candidatos l??xicos que compiten entre s?? se han activado a partir de unidades sil??bicas prel??xicas o por el contrario en base a unidades ortogr??ficas. Todo ello a trav??s de tareas en las que est?? implicada la funci??n lectora.. 243 alumnos de Psicolog??a participaron en los 7 experimentos que consta la presente investigaci??n.. En el primer experimento se ha puesto en evidencia que la s??laba se relaciona con los mecanismos de activaci??n e inhibici??n de candidatos l??xicos. En la serie de experimentos del segundo al quinto hemos tratado de ver cu??les son las condiciones id??neas bajo las que el est??mulo ser??a procesado utilizando como unidades prel??xicas s??labas. En el experimento dos la inhibici??n de nivel de letra no tiene ninguna influencia en el reconocimiento del est??mulo y hemos comprobado que son las unidades sil??bicas las que mantienen el contacto con el nivel l??xico superior. Tambi??n se ha comprobado que la frecuencia del contexto modula el tipo de unidades a utilizar en la relaci??n con el l??xico. Si el contexto es de baja frecuencia las unidades sil??bicas ejercen su efecto sobre el l??xico. Si el contexto es de alta frecuencia se utiliza la letra en su relaci??n con el l??xico ortogr??fico. En el experimento 5 se ha comprobado que existe un nivel l??xico ortogr??fico, que se desarrolla aproximadamente en los primeros 100 ms. y un segundo nivel sil??bico que se desarrolla a los 250 ms. aprox. Los resultados del experimento 6 apoyan un an??lisis del est??mulo auditivo en unidades sil??bicas y que la influencia de este an??lisis ha sido recogida en el nivel l??xico, lo que quiere decir que est?? relacionado con el acceso l??xico. Por los resultados del experimento 7 parece que no es la estructura de la s??laba lo que est?? produciendo la inhibici??n del experimento anterior. Parece ??nicamente el l??mite de la s??laba, su consideraci??n como un bloque con una longitud determinada, lo que est?? codificando el sujeto o lo que al menos, influye en la lectura del est??mulo test.. Cuando el est??mulo test se presenta auditivamente y toda su influencia ortogr??fica queda descartada, la s??laba es el ??nico patr??n subl??xico que parece producir efectos inhibitorios en la tarea de decisi??n l??xica utilizada. A la luz de estos datos apoyamos un modelo que no s??lo considera dos l??xicos, uno fonol??gico y otro ortogr??fico con conexiones inhibitorias intral??xicas, sino que deber??a a??adirse conexiones inhibitorias interl??xicas que dieran cuenta de la inhibici??n obtenida en estos experimentos en la lectura de una palabra que ha sufrido una previa influencia auditiva. Respecto a las unidades prel??xicas a tener en cuenta en el modelo, ser??a necesario considerar la s??laba como un nivel prel??xico que se relaciona con el l??xico mediante conexiones excitatorias. Esto no ha sido considerado por ning??n otro modelo que nosotros conozcamos, excepto el ya cl??sico de Spoehr y Smith /1973-1975/..

La alianza de estados insulares pequeños y la securitización del cambio climático en la convención marco de Naciones Unidas sobre cambio climático (1992-2012)

La presente monografía busca explicar el proceso de securitización realizado por la AOSIS del cambio climático en las COP de la CMNUCC. Esta investigación defiende que la AOSIS sí ha hecho dicho proceso a través de estrategias como el liderazgo moral y los nexos con actores no-estatales; pero dicho proceso no ha sido exitoso, dado el predominio del discurso del desarrollo sostenible en las negociaciones, el debilitamiento de la AOSIS como actor securitizador y el poco apoyo formal de las potencias emergentes y el bloque UMBRELLA. Para sustentar lo anterior, se realizará una revisión de informes científicos que demuestran que el cambio climático es una amenaza a la seguridad, y un estudio desde de la teoría de securitización de Thierry Balzacq, de los discursos dados por los estados AOSIS, de las COP y de las posiciones de algunos bloques de negociación sobre el cambio climático.

El consejo escolar en la ESO : funciones legales-funciones reales

Dossier

El pr??cticum en la formaci??n inicial del profesorado : dificultades, exigencias y desaf??os en el proceso de supervisi??n

La finalidad de la investigaci??n es profundizar en el conocimiento de la supervisi??n de las pr??cticas, como elemento clave de la formaci??n profesional del estudiante, adem??s de constatar si cumplen una funci??n formativa o es un tr??mite formal. El dise??o de la investigaci??n comprende la realizaci??n de varios estudios estad??sticos y un estudio de casos, cada uno de ellos cuenta con unos instrumentos espec??ficos. Los resultados se agrupan en diversos apartados: la concepci??n de la pr??ctica, complejidad de la funci??n supervisora, la coordinaci??n, la cualificaci??n y formaci??n espec??fica de los agentes de la supervisi??n. En el apartado de conclusiones destaca, entre otros aspectos, que los resultados de los estudios emp??ricos difieren de los del estudio de casos, despu??s de analizar estas diferencias, finaliza con unas reflexiones..

Los l??mites como campo de aprendizaje

Entre la prohibici??n y la obligaci??n se extiende el territorio de lo aceptable. Ambas fronteras delimitan el espacio de la convivencia. La vida social se desarrolla en un espacio delimitado por normas, que imponen l??mites y ofrecen posibilidades. Ante los conflictos con las normas o los l??mites, hay que ejercer la autoridad y la pedagog??a. Padres y educadores deben explicar la necesidad de los l??mites. Por otro lado, ante un l??mite se puede actuar respet??ndolo, resignarse sumisamente o transgredirlo. La transgresi??n puede ser por inmadurez o por desobediencia responsable. La autoridad educativa no consiste en prohibir y reprimir, sino en ayudar a tomar decisiones aut??nomas. Se debe ceder el poder a los alumnos para llegar a la autodisciplina. Y por ??ltimo, se debe confiar en que esta estrategia funcione sin estar pendiente de los resultados.

La formaci??n inicial del profesorado de lengua y literatura : presente y futuro

Resumen basado en el de la publicaci??n

Palacios de Madrid : Madrid 2010

Resumen tomado de la publicaci??n

Ense??anza de espa??ol como segunda lengua a personas adultas en la ciudad de Valencia : an??lisis de las necesidades sentidas

Memoria de m??ster (Universidad de Barcelona, 2012)