Field evaluation of biocontrol agents against black-foot and Petri diseases of grapevine.

BACKGROUND: Black-foot and Petri diseases are the main fungal diseases associated with young grapevine decline. Two field experiments were established to evaluate the preventive effect of two potential biocontrol agents (BCAs), that is Streptomyces sp. E1 + R4 and Pythium oligandrum Po37, and three BCA-commercial products containing Trichoderma atroviride SC1, Trichoderma koningii TK7 and Pseudomonas fluorescens + Bacillus atrophaeus on fungal infection in grafted plants and plant growth parameters. RESULTS: The effectiveness of some BCA in reducing the incidence and severity of both diseases was dependent on the plant part analyzed and the plant age. No single BCA application was able to control both diseases. Streptomyces sp. E1 + R4 were able to reduce significantly the infection of the most prevalent black-foot disease fungi while P. oligandrum Po37 and Trichoderma spp. were able to reduce significantly Phaeomoniella chlamydospora and Phaeoacremonium minimum (Petri disease) infection. BCA treatments had no effect on the shoot weight, and root weight was significantly lower in all BCA treatments with respect to the control. CONCLUSIONS: The combination of the disease-suppressive activity of two or more beneficial microbes in a biocontrol preparation is required to prevent infection by black-foot and Petri disease fungi in vineyards.

Occurrence and Diversity of Black-Foot Disease Fungi in Symptomless Grapevine Nursery Stock in Spain.

In this study, 3,426 grafted grapevines ready to be planted from 15 grapevine nursery fields in Northern Spain were inspected from 2016 to 2018 for black-foot causing pathogens. In all, 1,427 isolates of black-foot pathogens were collected from the asymptomatic inner tissues of surface sterilized secondary roots and characterized based on morphological features and DNA sequence data of the nuclear ribosomal DNA-internal transcribed spacer region, histone H3, translation elongation factor 1-alpha and ß-tubulin genes. Eleven species belonging to the genera Dactylonectria, Ilyonectria, Neonectria, and Thelonectria were identified, including Dactylonectria alcacerensis, D. macrodidyma, D. novozelandica, D. pauciseptata, D. torresensis, Ilyonectria liriodendri, I. pseudodestructans, I. robusta, Neonectria quercicola, Neonectria sp. 1, and Thelonectria olida. In addition, two species are newly described, namely D. riojana and I. vivaria. Twenty-four isolates representing 13 black-foot species were inoculated onto grapevine seedlings cultivar 'Tempranillo'. The pathogenicity tests detected diversity in virulence among fungal species and between isolates within each species. The most virulent species was D. novozelandica isolate BV-0760, followed by D. alcacerensis isolate BV-1240 and I. vivaria sp. nov. isolate BV-2305. This study improves our knowledge on the etiology and virulence of black-foot disease pathogens, and opens up new perspectives in the study of the endophytic phase of these pathogens in grapevines.

Intimidación entre pares (bullying) en el ámbito escolar. Comparación de la percepción de los docentes con la de sus alumnos. / Bullying at school. A comparison of the perception of teachers and students

Introducción: La intimidación entre pares es un problema frecuente en el ámbito escolar, con consecuencias a corto y largo plazo. Objetivos: Analizar las percepciones sobre este problema que poseen docentes de escuelas públicas de la ciudad de Bahía Blanca (2012) y la medida en la que estas percepciones coinciden con las de los alumnos. Métodos: Estudio cuali-cuantitativo en docentes y alumnos de cuarto a sexto grado que combino una encuesta (muestreo por conveniencia) por medio de cuestionario validado PRECONCIMEI (versiones alumnos y docentes) y grupos de discusión con docentes. Resultados: Encuestas: 407 niños/as y 37 docentes. Seis grupos de discusión en los que participaron 19 docentes en total. Percepción de niños/as: 36% manifiesta haber estado involucrado en situaciones de intimidación; 14% y 36% opino que las familias y docentes, respectivamente, "deberían hacer algo" para que se solucione el problema. Percepción de docentes: 38% opina que la intimidación es un problema grave, aunque predomina una conceptualización mas acotada (casos puntuales de agresión física por alumnos varones). Reconocen que tanto la familia como los docentes tienen un rol esencial en la prevención de este problema, aunque señalan que el rol docente estaría muy condicionado por factores externos. Conclusiones: Docentes y alumnos perciben a la intimidación como un hecho frecuente, aunque en los primeros predomina una conceptualización mas acotada. Si bien ambos reconocen que la familia posee un rol clave, los alumnos le otorgan menor relevancia. En contraste, el rol docente es jerarquizado tanto por los niños/ as como por sus docentes.

Introduction: Intimidation among peers is a frequent issue in school environments with short and long term consequences. Objetive: To analyze the perceptions of Bahía Blanca city public school teachers (2012) on this problem and the extent to which these perceptions are in agreement with those of the students. Methods: Quali-quantitative study of teachers and students from fourth to sixth grade combining a survey (convenience survey) using the PRECONCIMEI validated questionnaire (student and teacher versions) and discussion groups with teachers. Results: Surveys: 407 children and 37 teachers. Six discussion groups in which 19 teachers participated in total. Perception of Children: 36% expressed to have been involved in bullying situations; 14% and 36% said that families and teachers, respectively, "should do something" to solve the problem. Perception of Teachers: 38% considered that bullying is a serious problem although the concept is more circumscribed -special cases of physical aggression by male students. They recognized that both the family and the teachers have a key role in preventing this problem, although they pointed out that the role of teachers would be largely conditioned by external factors. Conclusions: Teachers and students perceive bullying as a frequent event, although in the former a more circumscribed conceptualization prevails. Although both recognize that the family has a key role, students consider this less relevant. In contrast, the role of teachers is prioritized both by the children and their teachers.

Effect of the seasoning method on the chemical composition of oak heartwood to cooperage.

The effect of various oak wood seasoning methods, natural seasoning in open air, artificial seasoning in a kiln, and a mixed method that combines open air and kiln drying, on the chemical composition in American ( Quercus alba) and French ( Quercus petraea) oak was studied. The results confirm the evolution of ellagitannins in wood, low molecular polyphenols, and volatile compounds in relation to oak species and seasoning method. Natural seasoning in open air can be considered a superior method to mixed or artificial drying for wood seasoning in cooperage. It was more effective in reducing the excess of ellagitannins, especially in French oak wood. Moreover, the evolution of wood volatile compounds was more positive in the natural seasoning than mixed or artificial drying, since it led to woods with higher aromatic potential (larger concentrations of compounds such as volatile phenols, phenolic aldehydes, furanic compounds, and cis- and trans-beta-methyl-gamma-octalactones) than mixed or artificial methods. However, the three seasoning methods showed similar effectiveness regarding the desired reduction of off-flavors compounds.