Risk transmission between Latin America stock markets and the US: impacts of the 2007/2008 Crisis

The aim of this paper is to investigate whether the US subprime financial turmoil has had any statistically significant effect on the conditional volatility of stock prices in Latin America for which the BEKK methodology is adopted, developed by Engle and Kroner (1995). The t-student distribution is employed as it can provide a best fit for financial data. In order to do this study, we will investigate four Latin America emerging capital markets (Brazil, Argentina, Chile and Mexico) and the United States, considering the period of the recent financial crisis of 2007/2008, analyzing before, during and after the crisis period. Our results show that before the crisis there is no evidence of volatility spillovers from the North American stock market to Latin American ones. During the crisis, there is evidence of volatility spillover effects on some countries. Brazil and Chile affect the US volatility and Argentina, Chile and Mexico are affected by the US's. After the crisis, the volatility of all Latin American stock markets affect and are affected by the US market. These results show an increase in spillover effects from a shock to US stock market to Latin American countries after the 2007/2008 financial crisis.financial crisis, volatility spillover, Latin America

Adubação nitrogenada em videiras jovens e em fase produtiva: recuperação e distribuição na planta do nitrogênio adicionado no solo.

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Predicting soybean development with a simple photothermal dynamic algorithm

Predicting the occurrence of the critical period for soybean’s yield determination is important for farmers to decide on variety and sowing date with the objective to expose this period (during which yield is mainly determined) to the best environmental conditionsEEA PergaminoFil: Severini, Alan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Ecofisiología; ArgentinaFil: Álvarez Prado, S. Universidad de Buenos Aires, Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Otegui, María Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Ecofisiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Vega, Claudia Rosa Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Zuil, Sebastian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Reconquista; ArgentinaFil: Kavanová, M. Instituto Nacional de Investigación Agropecuaria (INIA). La Estanzuela; UruguayFil: Ceretta, S. Instituto Nacional de Investigación Agropecuaria (INIA). La Estanzuela; UruguayFil: Acreche, Martin Moises. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scholz Drodowski, R.F. Instituto Paraguayo de Tecnología Agraria (IPTA). Capitan Miranda; ParaguayFil: Serrago, R.A. Universidad de Buenos Aires, Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miralles, D.J. Universidad de Buenos Aires, Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Iron fertilization to enhance tolerance mechanisms to copper toxicityof ryegrass plants used as cover crop in vineyards.

Ryegrass (Lolium perenneL.) is a plant species that can express mechanisms of tolerance to copper (Cu)toxicity. Therefore, the agronomical approach of intercropping system with ryegrass may represent apromising tool to limit the onset of Cu toxicity symptoms in the other intercropped plants species,particularly when an inadequate nutrient availability like iron (Fe) shortage is also concurrently present.This study aimed at assessing the mechanisms involved in the mitigation of Cu phytotoxicity and thestress effects on plant growth, root morphology and nutrition of ryegrass fertilized with two different Fesources. To this purpose, seedlings of ryegrass were hydroponically grown for 14 days in controlledconditions with 4 different levels of Cu (0.2, 5.0, 25 and 50mM) and with either 100mM Fe-EDDHA or Fe-EDTA. Results show that high levels of Cu availability enhanced the root content of organic anions as wellas the root exudation. Different Fe fertilizations at the condition of 50mM Cu induced changes in rootphenolic compounds, citrate and fumarate contents and the exudation pattern of phenolic compounds.Differences in plant growth were not observed between the two Fe sources, although Cu concentration inplant tissue fed with Fe-EDTA was lower in the condition of 50mM Cu. The enhanced root exudation ofCu-complexing organic compounds (including phenolics) in ryegrass plants when exposed to excessiveCu availability could be at the basis of the ameliorated edaphic rhizosphere conditions (lower Cuavailability). For this reason, from the agronomical point of view ryegrass plants used in intercroppingsystems with crops like vine plants could represent a promising strategy to control Cu toxicity invineyard soils. Further studies under thefield conditions must be taken to support presentfindings.©2019 Elsevier Ltd. All rights reserved

Grape yield and must composition of "Cabernet Sauvignon" grapevines with organic compost and urea fertilization.

Urea and organic compost are applied as a nitrogen (N) source in vineyards. The aim of this study was to evaluate the yield, total N content in the leaves and the must composition in grapevines with the application of organic compost and urea. ?Cabernet Sauvignon? grapevines, in the 2008/2009 and 2009/2010 crop seasons were subjected to the application of 40 kg N ha-1 in the form of organic compost and urea; but there were also unfertilized grapevines. In both crop seasons, leaves were collected at the stages of full flowering and at the change in color of the berries, and the total N content were analyzed; grape yield was evaluated and enological attributes were determined in the must. The application of organic compost and urea did not affect the N content in the leaf nor the grape yield in the second crop season evaluated. However, in the first crop season, grape yield was greater in the grapevines with application of organic compost to the soil. The addition of N sources did not affect the total nutrient content in the must but, in the second crop season, the grape must from the grapevines with the addition of organic compost had a lower soluble solids concentration and a higher total acidity value, as well as tartaric and malic acid values. KEYWORDS: nitrogen, leaf analysis, Vitis vinifera L

Do cover crops compete with young grapevines for fertilizer nitrogen?

Vineyard soils of the Campanha Gaúcha region of Rio Grande do Sul are sandy and have low to medium organic matter content, displaying low natural ability to supply nitrogen (N). Therefore, maintenance of cover crops is essential or the protection of the soil surface from the impact of raindrops and water erosion. The application of nitrogen fertilizers is also necessary. However, cover crops can absorb part of the nitrogen applied in the soil, decreasing the availability to young vines, which may slow the growth of root and shoot, and thus, the beginning of grape production

Use of phosphorus fertilization and mycorrhization as strategies for reducingcopper toxicity in young grapevines.

Established vineyard soils may have high copper (Cu) contents due to the ongoing foliar applications of copper-based fungicides. In viticulture, the replacement of old vineyards with new vines is common practice, however,limited by Cu excess in soil and its toxicity to young grapevines. The application of phosphorus (P) and ar-buscular mycorrhizal fungi (AMF) inoculation are potential strategies to reduce Cu toxicity to young grapevines.This study aimed to assess the effects of phosphorus fertilization and AMF (Rhizophagus clarus) inoculation ongrowth and physiological parameters of young grapevines grown in soil with high Cu content. The experimentwas conducted in a greenhouse, where natural grassland soil was artificially contaminated by the addition of60 mg kg−1Cu. The soils were treated with and without AMF inoculation, combined with additions of 0, 40 and100 mg P kg−1. After 90 days of cultivation, grapevine plants were assessed for chlorophyllafluorescence,photosynthetic pigment contents, superoxide dismutase (SOD) activity, plant height, plant biomass, and con-centrations of Cu and P in roots and shoots. Phosphorus fertilization promoted increases in seedling growth(related to the increase of total P concentration in roots and shoots), soluble Pi concentration in leaves, and thequantum yield of the PSII (YII) (associated with a reduction in shoot Cu concentration). The AMF inoculationincreased the concentration of P in roots and shoots, soluble Pi in leaves and electron transport rate (ETR).Phosphorus fertilization and inoculation of grapevines with AMF are strategies capable of reducing Cu toxicity inyoung grapevines

Acúmulo de cobre e zinco em solos cultivados com videira no meio Oeste de Santa Catarina.

As aplicações sucessivas de fungicidas e caldas via foliar em videiras para o controle preventivo de doenças fúngicas, aumenta o teor de cobre (Cu) e zinco (Zn) nas camadas mais superficiais do solo. O trabalho objetivou avaliar os teores de Cu e Zn no perfil de solos com textura argilosa e com histórico de aplicação de fungicidas cúpricos na região Meio Oeste de SC. Em outubro de 2010, foram selecionados três vinhedos com idades de 4, 6 e 10 anos de idade, no município de Água Doce (SC). Em novembro de 2010 foram coletadas amostras de solo nas camadas de 0-5, 5-10, 10-15, 15-20 e 20-40 cm. Também foi coletado solo em uma área de mata nativa, adjacente aos vinhedos. Os solos foram secos, moídos, passados em peneira e submetidos as análises de Cu e Zn extraídos pelos métodos de EDTA (Na2-EDTA 0,01 mol L-1+acetato de amônio 1,0 mol L-1) com pH ajustado para 7,0. Os teores de Cu e Zn extraídos por HCl 0,1 mol L-1 e EDTA foram maiores nas camadas superficiais do solo, especialmente, no vinhedo mais antigo, onde o Cu migrou até 20 cm e o Zn até 15 cm.Resumo expandido

Alternativas de práticas agrícolas para o cultivo de videiras em solos com alto teor de cobre.

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