Abstract The expansion of residential areas has increased the demand for exotic and increasingly compact landscape plants. In this context, this work aimed to evaluate the effects of paclobutrazol (PBZ) and the timing of ethylene application on growth reduction and flowering anticipation in ornamental pineapples grown in pots. The randomized block design was used with factorial arrangement (2 x 5) and 4 replications and 4 plants per plot. The primary treatments are the presence and absence of PBZ. The secondary treatments were five times of floral induction with ethylene: 90; 120; 150; 180; 210 days after transplanting (DAT) the seedlings into the pots. It was evaluated the variables: height ratio between the heights of the pot and the plant; rosette diameter; leaves length ‘D’ and flowering index. At 255 DAT, although the plants did not respond to floral induction with ethylene, only those treated with PBZ were more compact and had different characteristics such as smaller size and a ratio below 1/3 of the height of the vase in relation to the plant that to favor its commercialization, in pot.

Resumo A diminuição das áreas residenciais tem aumentado a demanda por plantas paisagísticas exóticas e cada vez mais compactas. Neste contexto, o objetivo deste trabalho foi avaliar os efeitos do paclobutrazol (PBZ) e das épocas de aplicação de etileno na redução do crescimento e na antecipação da floração em abacaxizeiro ornamental cultivado em vaso. O delineamento experimental utilizado foi o de blocos ao acaso, em arranjo fatorial (2 x 5), com 4 repetições e 4 plantas por parcela. Os tratamentos primários foram a presença e a ausência de PBZ. Os tratamentos secundários foram cinco épocas de indução floral com etileno: 90; 120; 150; 180; 210 dias após o transplantio (DAT) das mudas, para os vasos. Foram avaliadas as variáveis: altura da planta; relação entre as alturas do vaso e da planta; diâmetro da roseta; comprimento da folha ‘D’ e índice de florescimento. Aos 255 DAT, apesar das plantas não responderem à indução floral com o etileno, apenas aquelas tratadas com PBZ apresentaram-se mais compactas e com características diferenciadas como menor porte e relação abaixo de 1/3 da altura do vaso em relação a da planta que favorecer sua comercialização, em vaso.

In this work we will present an introduction to the Physics of the Magnetic Monopole in the non – relativistic regime. The classical treatment of a system composed of an electrically charged point particle in the presence of a magnetic monopole at the origin, with its equations of motion and the study of the Dirac vector potential, will be developed throughout the present work. The issue of singularities and gauge transformations will also be addressed. At the end, we will list some models analogous to the magnetic monopole, using other physical systems.

Neste trabalho apresentaremos uma introdução à Física do Monopolo Magnético no regime não – relativístico. O tratamento clássico de um sistema composto por uma partícula pontual eletricamente carregada na presence de um monopolo magnético na origem, com suas equações de movimento e o estudo do potencial vetor de Dirac, será desenvolvido ao longo do presente trabalho. A questão das singularidades e as transformações de calibre serão também tratadas. Ao final, listaremos alguns modelos análogos ao monopolo magnético, utilizando outros sistemas físicos.

Abstract This study aimed to resveratrol supplementation (at 5 or 10 mg/kg) and a hydroethanolic extract of canjiqueira fruits (150 mg/kg) on female SWISS mice. Total cholesterol, high-density lipoprotein (HDL), triglyceride levels, gestation rates, and embryonic implantation rates in their female Offspring was evaluated. In conclusion, the consumption of canjiqueira fruit extract altered the lipid profile of their female offspring, and did not impact their reproductive performance. Supplementing female SWISS mice with 10 mg/kg of resveratrol increased total cholesterol, triglycerides, and HDL levels, thereby enhancing the reproductive efficiency of their offspring.

Abstract In this study we evaluated technological and functional properties of four commercial probiotic of Lactobacillus genus strains: one L. acidophilus strain and three L. casei group strains (L. casei, L. paracasei and L. rhamnosus). Technological properties were evaluated by free amino acids production, acidification profile, glucose consumption and cellular viability in fermentation of modified MRS medium. The functional properties were determined through the antibacterial activity against Gram negative pathogens, compatibility with probiotic strains and assimilation of prebiotics: lactulose, raffinose, fructooligosaccharides and agave inulin. Our results show that L. casei group strains displayed the best performance in free amino acids production and acidification profile, as well as higher inhibitory effect versus Salmonella and Shigella pathogen strains. However, L. acidophilus showed better prebiotics assimilation ability. Finally, all the strains were compatible with Bifidobacterium probiotic strains. This data suggests that these strains have potential use as adjunct cultures in fermented dairy foods, improving the nutritional and sensory value of the product, in addition to functional effect through their antibacterial activity and prebiotic assimilation capacity.

Resumen En este estudio se evaluaron propiedades tecnológicas y funcionales de cuatro cepas probióticas comerciales de Lactobacillus: una cepa de L. acidophilus y tres pertenecientes al grupo L. casei (L. casei, L. paracasei y L. rhamnosus). La capacidad fermentativa se evaluó a través de producción de aminoácidos libres, perfil de acidificación, consumo de glucosa y viabilidad celular durante la fermentación de medio MRS modificado. Las propiedades funcionales se evaluaron en términos de actividad antibacteriana contra patógenos Gram negativos, compatibilidad con cepas probióticas y asimilación de prebióticos: lactulosa, rafinosa, fructooligosacáridos e inulina de agave. Los resultados demuestran que las cepas del grupo L. casei produjeron mayor cantidad de aminoácidos libres y mejor perfil de acidificación, así como mayor efecto inhibitorio contra bacterias patógenas Sallmonella y Shigella. Sin embargo, L. acidophilus presentó mayor capacidad de asimilación de prebióticos. Finalmente, todas las cepas fueron compatibles con cepas probióticas de Bifidobacterium. Los resultados sugieren que las cepas evaluadas presentan potencial aplicación como cultivos adjuntos en alimentos lácteos fermentados, contribuyendo a mejorar el valor nutrimental y sensorial del producto, además de proveer un efecto funcional a través su actividad antibacteriana y capacidad de asimilación de prebióticos.

Abstract Early blight is a disease caused by Alternaria alternata in tomato and other vegetables. This fungus affects the leaves, stem bases and fruits, causing economic losses. Different fungicides are currently used to control fungal diseases; however, these increase production costs and pose a risk to health and the environment. Therefore, the use of biological products, including phytocystatins, represent an attractive alternative for the control of plant diseases. Phytocystatins are widely distributed proteins in plants, which inhibit the activity of cysteine-like proteases and affect the growth and development of some phytopathogenic fungi. Preliminary work showed in vitro tests that amaranth cystatin produced recombinantly in Escherichia coli, inhibited the growth and development of some phytopathogenic fungi, including Alternaria alternata. In the present work, the effect of foliar application of amaranth cystatin in the prevention and control of early blight in tomato plants was determined. Greenhouse tests carried out in the municipalities of Irapuato and Celaya, in the state of Guanajuato (Mexico), during 2018, show that the foliar application of amaranth cystatin (168 µg and 335 µg of cystatin/plant) prevents and controls the development of blight early in different tomato varieties in crops under commercial greenhouse production. These results show the potential of cystatin in the control of fungal diseases.

Resumen El tizón temprano es una enfermedad producida por Alternaria alternata en tomate y otras hortalizas. Este hongo afecta las hojas, bases de los tallos y a los frutos, produciendo pérdidas económicas. Diferentes fungicidas se utilizan actualmente para el control de enfermedades producidas por hongos, sin embargo, estos aumentan los costos de producción y representan un riesgo para la salud y el medio ambiente. Por lo tanto, el uso de productos biológicos, incluyendo las fitocistatinas, representan una alternativa atractiva para el control de enfermedades en plantas. Las fitocistatinas son proteínas ampliamente distribuidas en las plantas, las cuales inhiben la actividad de proteasas tipo cisteína y afectan el crecimiento y desarrollo de algunos hongos fitopatógenos. En trabajos preliminares se demostró en ensayos in vitro que la cistatina de amaranto producida de manera recombinante en Escherichia coli, inhibió el crecimiento y desarrollo de algunos hongos fitopatógenos, incluyendo Alternaria alternata. En el presente trabajo se determinó el efecto de la aplicación foliar de la cistatina de amaranto en la prevención y control del tizón temprano en plantas de tomate. Ensayos en invernaderos realizados en los municipios de Irapuato y Celaya, del estado de Guanajuato (México), durante 2018, muestran que la aplicación foliar de cistatina de amaranto (168 µg y 335 µg de cistatina/planta) previene y controla el desarrollo del tizón temprano en diferentes variedades de tomate en cultivos en producción comercial en invernadero. Estos resultados muestran el potencial de la cistatina en el control de enfermedades producidas por hongos.

Resumo O perfil dos estudantes na era da cultura digital mudou drasticamente, promovendo deslocamento de elementos que possibilitam o engajamento ao ensino adotado. Entretanto, mantém-se a necessidade de se buscar a aprendizagem significativa, capaz de superar a aprendizagem mecânica que grassa pelo sistema educacional brasileiro. Para isso, é necessário articular elementos e procedimentos tanto das Tecnologias Digitais de Informação e Comunicação quanto das estratégias ativas que fomentem aprendizagem significativa. Neste trabalho, é apresentada, discutida e avaliada uma sequência didática sobre óptica geométrica que abrange grande parte do conteúdo usualmente apresentado no Ensino Médio. Faz-se uso de vídeos, aplicativos e jogos para smartphones, modulados por uma Unidade de Ensino Potencialmente Significativas (UEPS), articulando aprendizagem significativa no contexto concreto da construção de um material instrucional. Também são referenciados mecanismos e estratégias que podem incorporar metodologias ativas no contexto da UEPS. A sequência didática foi aplicada a um conjunto de alunos do Ensino Médio e os resultados são apresentados, juntamente à análise reflexiva da aplicação e a sugestões de aprimoramento. De maneira geral, a UEPS produziu diversos indícios de aprendizagem significativa e acredita-se que, a partir das sugestões de aprimoramento, é capaz de possibilitar mais episódios de aprendizagem significativa nos estudantes.

Abstract The profile of students in the era of digital culture has drastically changed, which shifted the elements that enable their engagement to the adopted teaching methods. However, the need to seek meaningful learning of students in this context, capable of overcoming the mechanical learning that rages through the Brazilian educational system, remains. It is important to articulate elements and procedures of both Digital Information and Communication Technologies and active strategies capable of producing meaningful learning. In this paper, we present a didactic sequence about geometric optics that covers a large part of the content usually presented in high school. Smartphone games, apps and videos are used, modulated by the use of a didactic sequence based on Potentially Meaningful Teaching Units (PMTU), which articulates meaningful learning in the concrete context of the construction of an instructional material. Mechanisms and strategies that can incorporate active methodologies in the context of PMTU are also referenced. The didactic sequence was applied to a group of high school students and the results are presented, along with a reflexive analysis of the application and suggestions for improvement. Overall, PMTU has produced several indications of meaningful learning and it is believed that from the suggestions for improvement, it is capable of engaging students in more episodes of meaningful learning.

ABSTRACT During seed production, nutrients (nitrogen) and climatic conditions (water) can affect their physiological quality. Therefore, the influence of common bean cultivation with the use of more sustainable techniques such as co-inoculation with nitrogen-fixing bacteria and the reduction of the irrigation depth on the quality of the seed produced should be analyzed. The objective of this study was to evaluate the physiological quality of seeds coming from the common bean cultivation submitted to inoculation and co-inoculation with Rhizobium tropici and Azospirillum brasilense under two irrigation depths. The experiment conducted in the field consisted of randomized blocks with a split-plot design with two irrigation depths as plots (recommended and 75% of the recommended) and five forms of nitrogen supply as subplots (control non-inoculated with 40 kg ha- 1 of nitrogen in topdressing; control non-inoculated with 80 kg ha- 1 of N in topdressing; A. brasilense inoculation with 40 kg ha-1 of N in topdressing; R. tropici inoculation with 40 kg ha-1 of N in topdressing; and co-inoculation of A. brasilense and R. tropici with 40 kg ha- 1 of N in topdressing). Common bean cultivation with 40 kg ha-1 of N in topdressing without inoculation provides satisfactory physiological quality of seeds, and there is no need to apply higher doses of nitrogen and inoculation. Bean seeds can be produced with the recommended 75% depth, without decrease their quality.

RESUMO Durante a produção de sementes, os nutrientes (nitrogênio) e condições climáticas (água) podem afetar a sua qualidade fisiológica. A influência do cultivo do feijoeiro com a utilização de técnicas mais sustentáveis como a co-inoculação com bactérias fixadoras de nitrogênio e a redução da lâmina de irrigação sobre a qualidade da semente produzida deve ser analisada. Objetivou-se avaliar a qualidade fisiológica de sementes oriundas do cultivo de feijão submetido à inoculação e co-inoculação com Rhizobium tropici e Azospirillum brasilense sob duas lâminas de irrigação. O delineamento experimental em campo foi em blocos casualizados com tratamentos dispostos em esquema de parcelas subdivididas. Nas parcelas foram alocadas as duas lâminas de irrigação (recomendada para o feijão e 75% da recomendada) e nas subparcelas foram alocadas as cinco formas de fornecimento de nitrogênio (testemunha sem inoculação com 40 kg ha-1 de N em cobertura; 80 kg ha-1 de N em cobertura sem inoculação; inoculação de A. brasilense com 40 kg ha-1 de N em cobertura; inoculação de R. tropici com 40 kg ha-1 de N em cobertura; e co-inoculação de A. brasilense e R. tropici com 40 kg ha-1 de N em cobertura), com quatro repetições. O cultivo do feijoeiro com aplicação de 40 kg ha-1 de N em cobertura sem inoculação proporciona qualidade fisiológica de sementes satisfatória, não havendo a necessidade de aplicação de maiores doses de nitrogênio e inoculação. As sementes de feijoeiro podem ser produzidas com a lâmina de 75% da recomenda, sem diminuição da sua qualidade.

RESUMO A região do Cerrado tem grande capacidade para expansão da cultura do arroz de terras altas. No entanto, são necessários estudos envolvendo práticas que melhorem o desempenho da cultura, principalmente em sistema plantio direto. Objetivou-se verificar o efeito de coberturas vegetais em consórcio com milho no desenvolvimento e produtividade de arroz cultivado em rotação e adubado com nitrogênio em cobertura. O experimento foi irrigado por aspersão e desenvolvido nas safras 2014/2015 e 2016/2017. Utilizou-se o delineamento experimental em blocos casualizados, em esquema fatorial 5 x 4. Os tratamentos consistiram da combinação do efeito de restos culturais de milho exclusivo, milho + Crotalaria spectabilis, milho + guandu, milho + feijão de porco e milho + Urochloa ruziziensis, bem como doses de nitrogênio em cobertura no arroz (0 kg ha-1, 40 kg ha-1, 80 kg ha-1 e 120 kg ha-1). O cultivo do arroz de terras altas em rotação com milho + guandu foi favorecido pela maior cobertura do solo e oferta de nitrogênio, via ciclagem, em relação à rotação com milho exclusivo. O cultivo de milho + guandu no verão anterior propiciou incremento de 15 % na produtividade de grãos de arroz, semeado na rotação, em relação ao milho exclusivo. A aplicação de nitrogênio em cobertura influenciou positivamente na produtividade de grãos com as doses máximas estimadas de 46 kg ha-1 e 105 kg ha-1 de nitrogênio, respectivamente nas safras 2014/2015 e 2016/2017.

ABSTRACT The Brazilian Savannah region presents a great potential for the expansion of upland rice crops. However, studies are necessary to identify practices that can improve the crop performance, especially in no-tillage systems. This study aimed to assess the effect of cover crops in association with corn on the development and yield of rice cultivated in rotation and cover fertilized with nitrogen doses. The sprinkler irrigation system was used and the experiment was developed in the 2014/2015 and 2016/2017 harvest years, using a randomized block design, in a 5 × 4 factorial scheme. The treatments consisted of the crop remains combinations of single corn crop, corn + Crotalaria spectabilis, corn + pigeon pea, corn + jack bean and corn + Urochloa ruziziensis, as well as cover nitrogen doses (0 kg ha-1, 40 kg ha-1, 80 kg ha-1 and 120 kg ha-1) in the rice. The cultivation of upland rice in rotation with corn + pigeon pea was favored by the greater soil cover and nitrogen supply via cycling, if compared to the rotation with single corn crop. The intercropped corn + pigeon pea cultivation in the previous summer resulted in a 15 % increase in the yield of rice grains seeded in the rotation, when compared to the single corn crop. The cover nitrogen application positively influenced the grain yield with the maximum estimated doses of 46 kg ha-1 and 105 kg ha-1 of nitrogen, respectively in the 2014/2015 and 2016/2017 harvest years.

Abstract Strains of Bacillus subtilis increase plant growth and yield. Consequently, the application of Mexican native strains of B. subtilis on greenhouse-grown melon (Cucumis melo L.) plants should induced a significant improvement on plant development and fruit quality. The objective of this study was to evaluate the effect of LAL-36, BEB-23, BEB-22 and BEB-13 B. subtilis strains, native to Mexico, on melon plant development and fruit quality. The strains were placed separately into the rhizosphere of melon plants under greenhouse conditions. Plants were grown in clinoptilolite type zeolite. Five treatments were evaluated: four inoculated with one of the four B. subtilis strains and one control without bacterial inoculum. A completely randomized design with nine repetitions was used in the experiment. The data were statistically analyzed with a one way-ANOVA and a mean comparison using the Tukey’s test. The root wet and dry weight depicted a sustained tendency with the greatest values and with significant statistical differences with LAL-36 and BEB-22 strains. The greatest values for shoot dry weight were 164.76 g for the LAL-36 and 162.14 g for BEB-22. The highest value for root dry weight was 64.55 g with the LAL-36 strain. The greatest values in height and foliar area (482.22 cm2 and 398.41 cm2) were observed in the plants treated with BEB-23 strain. Utmost fruit yield (97.76 t ha-1) was observed in the plants inoculated with LAL-36 strain; this strain also induced exceptional fruit quality, although the differences were lower compared to the other. The inoculation of B. subtilis LAL-36 strain on melon plants caused the most outstanding effects during the production of greenhouse-grown melon fruits, increasing the yield in 20 %. Therefore, using Mexican native strains of B. subtilis is possible to obtain high quality melon fruits with increased profits.

Resumen Las cepas de Bacillus subtilis aumentan el crecimiento y el rendimiento de las plantas. Por lo tanto, la aplicación de cepas nativas mexicanas de B. subtilis en melón cultivado en invernadero (Cucumis melo L.) debería inducir una mejora significativa en el desarrollo de la planta y la calidad del fruto. El objetivo de este estudio fue evaluar el efecto de las cepas nativas de México de B. subtilis, LAL-36, BEB-23, BEB-22 y BEB-13, en el desarrollo de la planta de melón y en la calidad del fruto. Las cepas se colocaron por separado en la rizósfera de las plantas de melón en condiciones de invernadero. Las plantas se cultivaron en zeolita tipo clinoptilolita. Los tratamientos fueron cinco: cuatro inoculados con una de las cuatro cepas de B. subtilis y un testigo sin inóculo bacteriano. El diseño experimental fue completamente al azar con nueve repeticiones. Los datos se analizaron estadísticamente con ANDEVA de una vía y prueba Tukey para comparar las medias. Con las cepas LAL-36 y BEB-22, los pesos fresco y seco de la raíz mostraron tendencia constante de los valores mayores y diferencias estadísticamente significativas. Los valores mayores de peso seco del vástago fueron 164.76 g con LAL-36 y 162.14 g con BEB-22. El valor mayor de peso seco de la raíz fue 64.55 g con la cepa LAL-36. Los valores mayores en altura y área foliar (482.22 cm y 398.41 cm2) se observaron en las plantas tratadas con la cepa BEB-23. El rendimiento máximo del fruto (97.76 t ha-1) se observó en las plantas inoculadas con la cepa LAL-36; esta cepa también propició calidad excepcional del fruto, aunque las diferencias fueron menores comparadas con los otros tratamientos. La inoculación de la cepa B. subtilis LAL-36 en plantas de melón causó los efectos más destacados durante la producción de frutos con el cultivo en invernadero, aumentando el rendimiento en un 20 %. Por lo tanto, al usar cepas nativas mexicanas de B. subtilis se pueden obtener frutos de melón de alta calidad con mayores ganancias.

Abstract Background Centruroides hirsutipalpus, of the family Buthidae, is a scorpion endemic to the Western Pacific region of Mexico. Although medically important, its venom has not yet been studied. Therefore, this communication aims to identify their venom components and possible functions. Methods Fingerprinting mass analysis of the soluble venom from this scorpion was achieved by high-performance liquid chromatography and electrospray mass spectrometry. Furthermore, the soluble venom and its toxic effects were evaluated extensively via electrophysiological assays in HEK cells expressing human voltage-gated Na+ channels (hNav 1.1 to Nav1.6), CHO cells expressing hNav 1.7, potassium channel hERG 1 (Ether-à-go-go-related-gene) and the human K+-channel hKv1.1. Results The separation of soluble venom produced 60 fractions from which 83 distinct components were identified. The molecular mass distribution of these components varies from 340 to 21,120 Da. Most of the peptides have a molecular weight between 7001 and 8000 Da (46% components), a range that usually corresponds to peptides known to affect Na+ channels. Peptides with molecular masses from 3000 to 5000 Da (28% of the components) were identified within the range corresponding to K+-channel blocking toxins. Two peptides were obtained in pure format and completely sequenced: one with 29 amino acids, showing sequence similarity to an "orphan peptide" of C. limpidus, and the other with 65 amino acid residues shown to be an arthropod toxin (lethal to crustaceans and toxic to crickets). The electrophysiological results of the whole soluble venom show a beta type modification of the currents of channels Nav1.1, Nav1.2 and Nav1.6. The main effect observed in channels hERG and hKv 1.1 was a reduction of the currents. Conclusion The venom contains more than 83 distinct components, among which are peptides that affect the function of human Na+-channels and K+-channels. Two new complete amino acid sequences were determined: one an arthropod toxin, the other a peptide of unknown function.

Abstract The Peña Colorada mineralized area contains several iron oxide-apatite (IOA) deposits around the arguably richest known iron resource in Mexico. The Lower Cretaceous volcano-sedimentary host rock sequence has been subjected to several episodes of hydrothermal alteration, each accompanied by a distinct episode of faulting and intrusion (calc-alkaline to tholeiitic). Faulting is partly associated with the reactivation of cryptic structural corridors in basement rocks. High-resolution 40Ar/39Ar and apatite fission track (AFT) dating of this deposit and the adjacent Arrayanes prospect reveal the following sequence of events that range from the latest Cretaceous to the earliest Eocene: (1) intrusion of a 67.6 ± 3.5 Ma magnetite-bearing diorite with associated skarn/skarnoid metamorphism that was coeval or predated N-S to NNW-SSE faulting; (2) approximately 63.26 Ma syenite-like potassic alteration with disseminated magnetite, predated by N-S to NNW-SSE faulting and postdated by WNW-ESE faulting; (3) intrusion of 62.0 ± 2.5 Ma diorite and 59.39 ± 0.21 Ma andesite dikes that predate the main mineralization event at 55.72 to 54.84 Ma of large semi-stratabound massive and disseminated bodies; (4) intrusion of a 53.3 ± 3.0 Ma magnetite-bearing gabbro and 53 ± 2 Ma pegmatoid magnetite + fluorapatite veins at the Arrayanes prospect, which overlap the WNW-ESE faulting; (5) 50.70 to 48.18 Ma polymictic magnetite breccia as the last stage of mineralization in the area, predated by E-W faulting; and (6) reactivation of WNW-ESE faults and later NE-SW faults. Therefore, the total age span of the Peña Colorada deposit ranges between approximately 19 and 23 million years. The closeness in age between intrusions and mineralization in the Arrayanes prospect, their confinement between the WNW-ESE and E-W structural domains, and mingling or mixing structures between gabbro and diorite with an associated magmatic magnetite enrichment support the idea of a close genetic link between such intrusives and IOA hydrothermal mineralization. All mineralization events at Peña Colorada are associated with pervasive potassic to propylitic alteration, whereas at Arrayanes they are associated with dominant sodic alteration instead. Alteration features are suggestive of relatively shallow and deep formation of these deposits, respectively. Event 3 thermally reset fluorapatite in fragments of pegmatoid magnetite + fluorapatite + diopside associations (dated at 59 ± 2 Ma, AFT) within the polymictic breccia, which were sampled from a deep orebody (still to be found) and that would be likely associated with event 1 or 2. Consequently, exploration endeavors at depth at Peña Colorada may be considered promising. In this study, we use numerous geological and geochemical proxies to constrain the likeliest genetic model for the Peña Colorada and neighboring deposits: (a) the nearness in time and space between hydrothermal mineralization and magnetite-rich, tholeiitic, relatively oxidized intrusive rocks; (b) the occurrence of key mineral associations (i.e. magnetite + fluorapatite ± diopside veins); (c) the exclusive occurrence of fluorapatite in lieu of other apatites; (d) the composition in key major cations (Ca, Fe, Na, Mn) in fluorapatite; (e) the correlations between Ni/Cr vs. Ti values, between Ti+V vs. Ni/(Cr+Mn) values, between Ti+V vs. Al+Mn values, and Mg contents in magnetite; (f) pyroxene thermometry; (g) log f(O2) values calculated from Mn contents in fluorapatite; and (h) normalized REE patterns, and ΣLREE and ΣHREE contents in fluorapatite. These proxies indicate that IOA deposits in the Peña Colorada area have a hydrothermal origin with a strong magmatic influence (magmatic-hydrothermal iron oxide, or MHIO, deposits) that formed under high oxygen fugacities and “moderate” temperatures, and with a high geochemical affinity with IOCG and Kiruna-type deposits or the general IOCG “clan” (for both hydrothermal minerals and associated hypabyssal rocks). Relatively high Ti contents in magnetite, and high Ce and low Eu contents in fluorapatite in these deposits (with respect to typical compositions in IOCG “clan” deposits) are geochemical features still in need of further explanation. The correlation between regional and local structural domains and the geochronologic study in this paper constrain the possible ages of such domains as follows: (1) the N-S to NNW-SSE domain can be bracketed between 67.6 and 63.26 Ma, (2) the WNW-ESE domain between 63.26 and 59.39 Ma, (3) the E-W domain between 54.84 and 50.70 Ma, (4) the WNW-ESE to NW-SE domain is younger than 48.18 Ma, and (5) the NE-SW domain is still active. The structural analysis also shows that the massive orebody at Peña Colorada is partially stratabound but its emplacement was also controlled by low-angle Laramide faults, and that hydrothermal fluids were preferentially driven through volcano-sedimentary rocks. The latter characteristic is not only a matter of the stratigraphic distribution of relatively pervasive versus impervious rocks but also of the lateral distribution of such rocks due to N-S strike-slip faults. As additional results of this study, we determined that the conglomerates atop the host volcano-sedimentary sequence that were initially attributed to the Cerro de la Vieja Formation cannot be older than 67.6 Ma, and that the IOA deposits at Peña Colorada would be formed at depths of only a few hundred meters.

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RESUMO Técnicas sustentáveis de manejo na cultura do milho são necessárias, visando aumento de produtividade, minimizando custos e impactos ambientais. Objetivou-se com este trabalho avaliar diferentes coberturas vegetais (milheto, crotalária, guandu, milheto + crotalária, milheto + guandu e pousio), doses de N (0; 40; 80 e 120 kg ha-1) com e sem a inoculação de sementes com Azospirillum brasilense na cultura do milho, na região do Cerrado. O delineamento experimental foi o de blocos casualizados, em esquema fatorial 6x4x2, constituindo 48 tratamentos, com 4 repetições. O estudo foi realizado no município de Selvíria-MS. As coberturas vegetais, exceto o guandu no primeiro ano e pousio no segundo, produziram quantidade adequada de resíduo (6 t ha-1) para manter o sistema plantio direto na região de Cerrado, com destaque ao tratamento com milheto + crotalária. As produtividades de milho em sucessão à guandu e milheto + crotalária foram superiores. Em área de sistema plantio direto estabilizada, o fornecimento de nitrogênio via fertilizante, possibilita aumento de produtividade até a dose de 114 kg ha-1 de N. A inoculação com Azospirillum brasilense via semente, propiciou menor população final de plantas, altura de plantas e a massa de mil grãos.

ABSTRACT With the aim of increasing productivity, and minimising costs and environmental impact, sustainable management techniques are necessary when growing maize. The aim of this study was to evaluate different cover crops (millet, crotalaria, pigeon pea, millet + crotalaria, millet + pigeon pea and fallow) and doses of N (0, 40, 80 and 120 kg ha-1), both with and without seed inoculation with Azospirillum brasilense of the maize crop, in the Cerrado region of Brazil. The experimental design was of randomised blocks, in a 6 x 4 x 2 factorial scheme, comprising 48 treatments with 4 replications. The study was carried out in the town of Selvíria, in the State of Mato Grosso do Sul. Plant cover, except for the pigeon pea in the first year and the fallow in the second year, produced enough residue (6 t ha-1) to maintain the no-tillage system in the Cerrado region, especially the treatment with millet + crotalaria. Maize production in succession to the pigeon pea and the millet + crotalaria was higher. In an area with a stabilised no-tillage system, the supply of nitrogen using fertiliser, gives an increase in productivity up to a dose of 114 kg N ha-1. Inoculating the seeds with Azospirillum brasilense gave a smaller final plant population, less plant height and lower 100-grain weight.

RESUMO Este trabalho, desenvolvido no município de Selvíria, MS, nos anos agrícolas de 2011/12 e 2012/13 teve, como objetivo, avaliar a eficiência de Azospirillum brasilense na fixação de nitrogênio em arroz de terras altas, em função de doses e modos de aplicação do inoculante contendo a bactéria diazotrófica. Utilizou-se delineamento experimental de blocos ao acaso disposto em esquema fatorial 4 x 4 sendo 4 doses de inoculante (testemunha sem inoculação, 100, 200 e 300 mL do produto comercial ha-1) x 4 modos de aplicação (inoculação das sementes, aplicação no sulco de semeadura, pulverização do solo logo após a semeadura e pulverização foliar no início do perfilhamento das plantas) com 4 repetições. Durante a condução do experimento foram avaliados as características agronômicas, os componentes de produção e a produtividade da cultura do arroz. Conclui-se que o inoculante contendo Azospirillum brasilense promove acréscimo (19%) na produtividade de arroz de terras altas irrigado por aspersão, quando usado na dose de 200 mL ha-1, independentemente do modo de aplicação.

ABSTRACT The study was carried out in Selvíria-MS, in the 2011/12 and 2012/13 agricultural years, aiming to evaluate the efficiency of Azospirillum brasilense in nitrogen fixation in upland rice, as a function of doses and application methods of the inoculant containing this diazotrophic bacterium. The experimental design was randomized blocks, arranged in a 4 x 4 factorial scheme, with 4 doses of inoculant (control without inoculation, 100, 200 and 300 mL of the commercial product ha-1) and 4 application methods (seed inoculation, application in the sowing furrow, soil spraying after sowing, and foliar spraying at the beginning of plant tillering), with 4 replicates. During the experiment, the agronomic characteristics, production components and yield of the rice crop were evaluated. It was concluded that the inoculant containing Azospirillum brasilense promotes increase (19%) in the yield of upland rice under sprinkler irrigation when used at the dose of 200 mL ha-1, regardless of the application methods.

RESUMO A técnica alternativa de co-inoculação ou também denominada de inoculação mista com bactérias simbióticas e assimbióticas tem sido estudada em leguminosas, no entanto, existem poucos estudos em campo com feijoeiro e sobre a influência da quantidade de água irrigada. Dessa forma, objetivou-se com este experimento avaliar a eficiência da inoculação e co-inoculação de feijão com Rhizobium tropici e Azospirillum brasilense sob duas lâminas de irrigação. O experimento foi desenvolvido no período de outono/inverno dos anos de 2012 e 2013, no município de Selvíria (MS). O delineamento experimental foi em blocos casualizados em esquema de parcelas subdivididas, correspondente a duas lâminas de irrigação nas parcelas (recomendada para o feijão e 75% da recomendada) e cinco formas de fornecimento de nitrogênio (N) nas subparcelas (testemunha sem inoculação com 40 kg ha-1 de N em cobertura, 80 kg ha-1 de N em cobertura sem inoculação, inoculação de A. brasilense com 40 kg ha-1 de N em cobertura, inoculação de R. tropici com 40 kg ha-1 de N em cobertura, e co-inoculação de A. brasilense e R. tropici com 40 kg ha-1 de N em cobertura), com quatro repetições. A co-inoculação proporcionou aumento da nodulação no segundo ano de cultivo. Nenhum dos tratamentos avaliados aumentou a produtividade em relação à testemunha não inoculada com 40 kg ha-1 de nitrogênio em cobertura, que apresentou produtividade média de 2.200 kg ha-1. A utilização de 75% da lâmina recomendada proporciona produtividade de grãos semelhante a lâmina recomendada em feijoeiro de inverno.

ABSTRACT The alternative technique of co-inoculation or mixed inoculation with symbiotic and non-symbiotic bacteria has been studied in leguminous plants. However, there are few field studies with common beans and under the influence of the amount of irrigated water. Thus, the objective of this study was to evaluate the efficiency of inoculation and co-inoculation of common beans with Rhizobium tropici and Azospirillum brasilense under two irrigation depths. The experiment was carried out in the winter of 2012 and 2013, in Selvíria, state of Mato Grosso do Sul. The experimental design was composed of randomized blocks in split-plot scheme with two irrigation depths in the plots (recommended for common beans and 75% of the recommended) and five forms of nitrogen (N) supply in the split-plots (control non-inoculated with 40 kg ha- 1 of N in topdressing, 80 kg ha- 1 of N in topdressing, A. brasilense inoculation with 40 kg ha-1 of N in topdressing, R. tropici inoculation with 40 kg ha-1 of N in topdressing, and co-inoculation of A. brasilense and R. tropici with 40 kg ha- 1 of N in topdressing) with four repetitions. Co-inoculation increased nodulation in the second year of cultivation. None of the evaluated treatments increased the grain yield in relation to non-inoculated control with 40 kg ha-1 of nitrogen in topdressing, which presented average yield of 2,200 kg ha-1. The use of 75% of the recommended irrigation depth provides similar grain yield to the recommended irrigation depth in common beans cropped in winter.