Copper uptake, accumulation and physiological changes in adult grapevines in response to excess copper in soil.

Publicada online em 24 de setembro

Lixiviação de nitrogênio em um Cambissolo cultivado com pessegueiro e submetido à aplicação de composto orgânico.

A aplicação de composto orgânico em solos cultivados com pessegueiro pode potencializar a transferência de N por lixiviação. O trabalho objetivou avaliar a lixiviação de N em um solo cultivado com pessegueiro e submetido à aplicação de composto orgânico. Em um pomar comercial de pessegueiro no município de Bento Gonçalves (RS) foram instalados lisímetros a 20 cm de profundidade. O solo recebeu a aplicação de 0 e 144 litros de composto orgânico por planta-1 ano-1 nas safras de 2010, 2011 e 2012. A solução do solo foi coletada no período de julho a outubro de 2012 e submetida à análise de nitrato, amônio e N mineral. As maiores concentrações de N lixiviado foram encontradas no tratamento com 144 litros de composto orgânico por planta-1. A adubação com composto orgânico apresentou baixas concentrações de N lixiviado, o que pode contribuir com a redução de contaminação ambiental.Resumo expandido

The role of team compassion in mitigating the impact of hierarchical bullying

Copyright © The Author(s), 2023. Hierarchical bullying in public healthcare organizations is an entrenched negative behaviour that results in a range of adverse outcomes for staff, including diminished wellbeing. This study integrates social exchange and conservation of resources theories as a lens for formulating hypotheses and employs multilevel statistical modelling to examine whether team-level compassion moderates the impact of hierarchical bullying on wellbeing. Using multilevel statistical modelling, the study analysed cross-sectional data from 632 healthcare workers nested within 48 teams in a single public health district in Australia. The findings indicate that work teams with higher levels of team compassion can mitigate the negative effects of hierarchical bullying on employee wellbeing. The results imply that investing in developing compassion within teams is an effective strategy for mitigating some harmful effects of hierarchical bullying on employee outcomes

Influência do Etefon na distribuição de nutrientes e carboidratos e sobre o crescimento em videiras jovens.

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Copper accumulation in vineyard soils: Rhizosphere processes and agronomic practices to limit its toxicity.

Viticulture represents an important agricultural practice in many countries worldwide. Yet, the continuous use of fungicides has caused copper (Cu) accumulation in soils, which represent a major environmental and toxicological concern. Despite being an important micronutrient, Cu can be a potential toxicant at high concentrations since it may cause morphological, anatomical and physiological changes in plants, decreasing both food productivity and quality. Rhizosphere processes can, however, actively control the uptake and translocation of Cu in plants. In particular, root exudates affecting the chemical, physical and biological characteristics of the rhizosphere, might reduce the availability of Cu in the soil and hence its absorption. In addition, this review will aim at discussing the advantages and disadvantages of agronomic practices, such as liming, the use of pesticides, the application of organic matter, biochar and coal fly ashes, the inoculation with bacteria and/or mycorrhizal fungi and the intercropping, in alleviating Cu toxicity symptoms

A smart and sustainable future for viticulture is rooted in soil: How to face cu toxicity

In recent decades, agriculture has faced the fundamental challenge of needing to increase food production and quality in order to meet the requirements of a growing global population. Similarly, viticulture has also been undergoing change. Several countries are reducing their vineyard areas, and several others are increasing them. In addition, viticulture is moving towards higher altitudes and latitudes due to climate change. Furthermore, global warming is also exacerbating the incidence of fungal diseases in vineyards, forcing farmers to apply agrochemicals to preserve production yields and quality. The repeated application of copper (Cu)-based fungicides in con-ventional and organic farming has caused a stepwise accumulation of Cu in vineyard soils, posing environmental and toxicological threats. High Cu concentrations in soils can have multiple impacts on agricultural systems. In fact, it can (i) alter the chemical-physical properties of soils, thus com-promising their fertility; (ii) induce toxicity phenomena in plants, producing detrimental effects on growth and productivity; and (iii) affect the microbial biodiversity of soils, thereby influencing some microbial-driven soil processes. However, several indirect (e.g., management of rhizosphere processes through intercropping and/or fertilization strategies) and direct (e.g., exploitation of vine resistant genotypes) strategies have been proposed to restrain Cu accumulation in soils. Furthermore, the application of precision and smart viticulture paradigms and their related technologies could allow a timely, localized and balanced distribution of agrochemicals to achieve the required goals. The present review highlights the necessity of applying multidisciplinary approaches to meet the requisites of sustainability demanded of modern viticulture

Phosphorus fractions in sandy soils of vineyards in Southern Brazil.

As aplicações de fósforo (P) em vinhedos podem causar o acúmulo desse nutriente no solo e maximizar seu potencial poluente. Este trabalho objetivou quantificar as frações de acumulação de P em solos arenosos cultivados com videiras na região Sul do Brasil. Para isso, amostras de solo foram coletadas nas camadas de 0-5, 6-10 e 11-20 cm em uma área de campo nativo e em dois vinhedos: um com 14 anos de cultivo (vinhedo 1) e outro com 30 anos (vinhedo 2), localizados no município de Santana do Livramento, Rio Grande do Sul (RS), Brasil. As amostras foram secas, moídas e submetidas ao fracionamento químico de P. Os resultados evidenciaram que os teores de P inorgânico aumentaram até 20 cm de profundidade, principalmente no vinhedo 2, em especial nas frações lábeis extraídas por resina de troca aniônica e por NaHCO3, na fração moderadamente lábil, extraída por NaOH 0,1 e 0,5 mol L-1, e na fração não lábil, extraída por HCl 1 mol L-1, representando potencial de eutroficação das águas. As aplicações de fertilizantes fosfatados na adubação de correção e de manutenção nos vinhedos com maior tempo de cultivo aumentaram os teores de P na fração orgânica extraída por NaHCO3 na camada de 0-5 cm, e na fração moderadamente lábil extraída por NaOH 0,1 mol L-1, até 20 cm de profundidade

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

Oxidative stress as markers in identification of aluminum-tolerant peach tree rootstock cultivars and clonal selections.

Abstract: Peach rootstock and scion cultivars are selected in breeding programs considering resistance to pests and diseases, salt tolerance, drought tolerance, and vigor. However, rootstock tolerance to aluminum (Al), which is markedly present in tropical and subtropical soils of the world, is not considered. Thus, it is essential to define potential markers that can contribute to the selection of Al-resistant or Al-tolerant peach rootstocks. The objective of this study was to identify Al-tolerant peach tree rootstock cultivars and clonal selections using physiological and oxidative stress variables. A completely randomized experimental design was used in a 13 (rootstock cultivars and clonal selections) × 2 (with and without Al) factorial arrangement, with three replications. Nursery peach trees of own-rooted ‘BRS Mandinho’ (without rootstock) and nursery trees of ‘BRS Mandinho’ grafted on different rootstock cultivars and clonal selections were grown in a hydroponic system, consisting of two treatments, with and without 100 mg L-1 of Al. Dry biomass, photosynthetic variables, pigment concentration, hydrogen peroxide content, membrane lipid peroxidation, and activity of the antioxidant enzymes were evaluated. The total dry matter production of the own-rooted ‘BRS Mandinho’ trees and the SS-CHI-09-39 and SS-CHI-09-40 selections is affected by the Al presence, representing a decline of 35.4, 37.2, and 24.4 %, respectively, compared to the treatment with Al. The highest total dry matter production in Al presence was observed for the ‘Sharpe’ rootstock. ‘Capdeboscq’, DB-SEN-09-23, FB-ESM-09-43, JB-ESM-09-13, JAH-MAC-09-77, SAS-SAU-09-71, and VEH-GRA-09-55 rootstock selections are tolerant to Al. The use of physiological and biochemical variables shows potential for the selection of clonal rootstocks tolerant or resistant to Al. Resumo: Os porta-enxertos e cultivares de pessegueiro são selecionados em programas de melhoramento considerando a resistência a pragas e doenças, tolerância ao sal, tolerância à seca e vigor. Contudo, a tolerância do porta-enxerto ao alumínio (Al), que está marcadamente presente nos solos tropicais e subtropicais do mundo, não é considerada. Assim, é essencial definir potenciais marcadores que possam contribuir para a seleção de porta-enxertos de pessegueiro resistentes ou tolerantes ao Al. O objetivo deste estudo foi identificar cultivares de porta-enxertos de pessegueiro tolerantes ao Al e seleções clonais utilizando variáveis fisiológicas e de estresse oxidativo. O delineamento experimental utilizado foi inteiramente casualizado, em arranjo fatorial 13 (cultivares de porta-enxertos e seleções clonais) x 2 (com e sem Al), com três repetições. Pessegueiros de mudas 'BRS Mandinho' de raiz própria (sem porta-enxerto) e mudas de 'BRS Mandinho' enxertados em diferentes cultivares de porta-enxertos e seleções clonais foram cultivados em sistema hidropônico, composto por dois tratamentos, com e sem 100 mg L- 1 de Al. Foram avaliadas biomassa seca, variáveis fotossintéticas, concentração de pigmentos, teor de peróxido de hidrogênio, peroxidação lipídica de membrana e atividade de enzimas antioxidantes. A produção total de matéria seca das árvores 'BRS Mandinho' de raiz própria e das seleções SS-CHI-09-39 e SS-CHI-09-40 é afetada pela presença de Al, representando um declínio de 35,4, 37,2 e 24,4 %, respectivamente, em comparação ao tratamento com Al. A maior produção total de matéria seca na presença de Al foi observada para o porta-enxerto ‘Sharpe’. 'Capdeboscq', DB-SEN-09-23, FB-ESM-09-43, JB-ESM-09-13, JAH-MAC-09-77, SAS-SAU-09-71 e VEH-GRA-09 -55 seleções de porta-enxertos são tolerantes ao Al. A utilização de variáveis fisiológicas e bioquímicas apresenta potencial para seleção de porta-enxertos clonais tolerantes ou resistentes ao Al