Abstract The (de)hydrogenation properties of a TiFe intermetallic compound (IMC) alloy activated by cold rolling inside a glovebox at ambient temperature were investigated by kinetic measurements, x-ray powder diffraction (XRD), and transmission electron microscopy (TEM). Rate-limiting steps were identified by testing kinetic models on hydrogen absorption and desorption curves. To prevent surface poisoning during air exposure, the TiFe IMC was also cold rolled with polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE). The addition of either PTFE or UHMWPE to nanostructured TiFe by cold rolling did not produce a polymer-metal composite with O2 poisoning resistance, regardless of the polymer-mixing way adopted. This occurred because large surfaces of the particles were not adequately coated with polymer. The results identify challenges to the TiFe IMC polymer-covered material that must be overcome before a methodology can significantly contribute to the formation of nanostructured TiFe-polymer composites with enhanced hydrogen storage properties. The diffusion-controlled reactions in the cold-rolled TiFe IMC without polymer were prevalent in all cases, as predicted by the Jander three-dimensional diffusion model. The main contribution of this work regards estimation of the amount of hydrogen released, which was 0.60% after 6 min and reproducible for the three subsequent cycles.

Resumen: El maracuyá amarillo (Passiflora edulis f. flavicarpa) se adapta bien a temperaturas tropicales. En climas subtropicales, las bajas temperaturas del invierno limitan su crecimiento. Algunos tratamientos con bioestimulantes promueven la germinación y el crecimiento inicial de la plántula. El objetivo del trabajo fue evaluar la emergencia y el crecimiento de plántulas de maracuyá en diferentes fechas de siembra y tratamientos de las semillas. Se evaluaron dos tratamientos: aplicaciones de ácido giberélico (AG) 1.000 mg L-1 en el agua de imbibición de las semillas, y un estimulante compuesto (ST) de 90 mg L-1 de cinetina, 50 mg L-1 de ácido giberélico y 50 mg L-1 de ácido indolbutírico (AIB) aplicado sin dilución en las semillas (4 mL kg-1). Las fechas de siembra fueron 02/05, 22/05, 11/06 y 02/07, en 2013 y 2014. La tasa de emergencia con ST fue similar a la del testigo, pero se redujo con AG, que aumentó el tiempo desde la siembra hasta la emergencia. El crecimiento de plántulas, evaluado el 15 de septiembre de dos años, no se modificó significativamente con ningún estimulante. Las fechas de siembra no afectaron el porcentaje de emergencia, pero en las dos siembras más tardías la emergencia fue más lenta. El atraso en la siembra disminuyó el crecimiento de los plantines, y los modelos ajustados a la respuesta fueron diferentes en función de la característica evaluada y del año.

Summary: The yellow passionfruit (Passiflora edulis f. flavicarpa) is well adapted to tropical temperatures. Under subtropical conditions, winter temperatures limit its growth. Some treatments with biostimulants promote germination and seedling initial growth. The objective of this work was to evaluate emergency and growth of passionfruit seedlings under different seeding dates and seed treatments. Two stimulants were tested: gibberellic acid (GA) 1000 mg L-1 in water soaking and a stimulant (ST) composed of 90 mg L-1 kinetin, 50 mg L-1 gibberellic acid and 50 mg L-1 indolbutiric acid (IBA) applied without dilution (4 mL kg-1). Seeding dates were May 2, May 22, June 11 and July 2 for 2013 and 2014. Emergency in the ST treatment was similar to the control but was reduced by GA treatment. GA increased the time needed for the seeds to emerge. Seedling growth evaluated on September 15, in two years, was not significantly modified by any stimulant. Seeding dates did not influence emergency percentage, but in the two latest dates the emergence was slower. The later the sowing dates, the smaller the seedling growth, and the models fitted to the response were different according to the characteristics evaluated and the year.

The citrus canker, caused by Xanthomonas axonopodis pv. citri, is one of the main citrus diseases and has threatened the world's citriculture. In this study, the damage caused by citrus canker was quantified in a sweet orange culture, cv. Valencia [Citrus sinensis (L.) Osb.], grafted over 15 year-old Rangpur lime (C. limonia Osb.), in the municipality of Guatambu, SC, Brazil, in the crop of 2004/05. Evaluations of the number of fruits per plant (NF), fruit yield per plant (P), citrus canker incidence on the fruit (IFR), and incidence (IL) and severity (SV) of citrus canker on 80 leaves per orange tree were performed in the harvest period, applying diagrammatical scales. Plants had large variation in SV (0.16%-1.09%), IL (12.50%-56.25 %) and IFR (12.30%-56.09%). Linear regressions were significant between IL x SV, NF x SV, P x IFR, and NF x IFR. There was no significant difference (p>0.05) between the mean estimated values of IL in different quadrants of the crowns of the orange trees (N, S, L and O). Each 1% increase in IFR reduced 2.16 kg and 21.3 fruits per tree.

El cancro cítrico causado por Xanthomonas axonopodis pv. citri, es una de las principales enfermedades de los cítricos y tiene amenazada la industria de los cítricos en todo el mundo. En este trabajo se cuantificó el daño causado por el cancro cítrico en la producción de naranja dulce cv. Valencia /Citrus sinensis (L.) Osb.] injertada en limón 'Cravo' (C. limonia Osb.), con 15 años de edad, en el municipio de Guatambú, SC, Brasil, en la cosecha 2004/05. En el momento de la cosecha, se evaluó el número de frutos por planta (NF), el rendimiento de frutos por planta (R), la incidencia de cancro en los frutos (IFR) y la incidencia (IFL) y severidad (SV) de cancro en 80 hojas/planta, utilizando escalas diagramáticas. Las plantas presentaron gran variación en SV (de 0,16 a 1,09%), IFL (12,50 a 56,25%) y IFR (12,30 a 56,09%). Fue posible adaptarse regresiones lineales simples entre IFL x SV, NFx SV, R x IFR y entre NFx IFR. No hubo diferencias significativas (p> 0,05) entre los medios de IFL estimados en los diferentes cuadrantes de la copa de las plantas (N, S, E y O). A cada incremento de 1% en IFR se reduce la producción por planta en 2,16 kg y 21,3 frutos.

RESUMO Este trabalho foi conduzido com o objetivo de avaliar o comportamento de materiais inertes para controle de tombamento durante a emergência. Os tratamentos foram cobertura do sulco de semeadura com areia e serragem, tratamento químico com brometo de metila e uma testemunha. Os parâmetros avaliados foram percentagem e velocidade de emergência, percentagem de tombamento de pré e pós-emergência. Os dados obtidos permitiram concluir que, dentre os materiais inertes testados, a areia pode constituir-se em uma alternativa eficiente no controle do tombamento em sementeiras de repolho e beterraba, pois permitiu o maior número de plântulas emergidas e o menor número de plântulas tombadas não alterando a velocidade de emergência, enquanto que nas sementeiras de alface a utilização dos materiais inertes prejudicou a emergência normal das plântulas, não se constituindo em agente de controle eficiente.

SUMMARY The experiment was conducted in order to evaluate inert materials like protectors of seedlings against damping-off pathogens. The treatments tested were sand covering, sawdust covering, chemical treatment with methyl bromide and one control. It was evaluated the percentage and velocity of emergence, percentage of pre and post-emergence damping-off. The results showed that sand was the best inert material and that is possible to get itself a good alternative to control damping-off in nursery bed of cabbage, and sugarbeet. The utilization of inert materiais in lettuce nursery bed prejudiced the seedling emergence and did not get a good agent to control one.

Foi elaborada escala de 1 a 5, com base na severidade (% de área foliar afetada), para avaliação da reação de germoplasma de morangueiro à mancha de micosferela por Mycosphaerella fragariae.

It is being proposed key based on diseased severity for evaluation of strawberry germplasm reaction to leaf spot incited by Mycosphaerella fragariae