Understanding the induction of plant defenses against viruses using biocontrol agents is essential for developing new strategies against these pathogens, given the ineffectiveness of chemical treatments. The ability of Trichoderma harzianum, strain T-22 (T22) to control Cucumber mosaic virus (CMV) in Solanum lycopersicum var. cerasiforme plants and the changes in the physiology of tomato treated/infected with T22/CMV were examined. Plant growth-promoting effects, photosynthetic performance, reactive oxygen species scavenging enzymes, and phytohormones were investigated. T22 improved tomato growth in terms of plant height and improved photosynthesis, total chlorophyll content and plant gas exchange. In contrast, CMV induced a negative effect on dry matter accumulation and inhibited the photosynthetic capacity. The analysis of plant hormones demonstrated that treating with T22 before or simultaneously to CMV infection, led to a systemic resistance by jasmonic acid/ethylene and salicylic acid signaling pathways. Conversely, systemic resistance was abscissic acid-dependent when T22 treatment was administered after the CMV infection. In conclusion, the data reported here indicate that the T22-based strategy may be the most effective measure against CMV.

A cobertura morta, oriunda da dessecação ou rolagem de plantas utilizadas para esta finalidade, faz parte do sistema de semeadura direta. Ao mesmo tempo que essa cobertura promove redução na densidade populacional das espécies invasoras, intercepta os herbicidas quando aplicados sobre sua superfície. Alguns autores têm sugerido aumentar as doses dos herbicidas, o que tem gerado polêmica sobre o assunto. Com o objetivo de estudar o comportamento do herbicida atrazine sobre cobertura morta, realizaram-se experimento de campo, bioensaios e análises cromatográficas de resíduos com esse herbicida, nas doses 0,0; 1,25; 2,50; 3,75 e 5,00 kg/ha do ingrediente ativo, aplicando-o em solo descoberto e sobre cobertura morta de palha de aveia preta, com 4,5 e 9,0 t/ha. Amostras de solo de 0 a 10 cm de profundidade foram coletadas após a aplicação, antes e depois de uma irrigação de 20 mm para uso em bioensaios e análises cromatográficas de resíduo. A irrigação foi realizada 24 horas após a aplicação do herbicida. Os resultados mostraram que, nas amostras de solo coletadas antes da irrigação, 85% de cada dose foi interceptada nos dois tratamentos com cobertura morta. A irrigação de 20 mm foi suficiente para lixiviar praticamente todo o herbicida da palha para o solo, não havendo diferença significativa com os teores encontrados em solo descoberto. A cobertura morta reduziu a população de Brachiaria plantaginea, única espécie presente no experimento, para 20 e 5 plantas/m2, respectivamente, nas coberturas com 4,5 e 9,0 t/ha de matéria seca, enquanto que em solo descoberto, a população da espécie foi de 700 plantas/m2. Os controles obtidos com as doses de 1,25 kg/ha, nas duas quantidades de palha estudadas, foram superiores ao controle obtido com a dose de 5,00 kg/ha em solo descoberto, indicando que a cobertura morta, por sí só, exerce bom controle de B. plantaginea. A ocorrência de chuva após a aplicação de atrazine na palha, melhora sua eficiência de controle.

Valerio M, Tomecek MB, Lovelli S & Ziska LH (2011). Quantifying the effect of drought on carbon dioxide‐induced changes in competition between a C3 crop (tomato) and a C4 weed (Amaranthus retroflexus). Weed Research51, 591–600. Summary Recent and projected increases in atmospheric carbon dioxide concentration ([CO2]) and subsequent effects on climate are likely to alter competitive outcomes of weeds and crops. Rising [CO2] per se could increase the competitive ability of C3 crops relative to C4 weeds. However, such an outcome may depend on other climatic variables. In this study, tomato, a C3 crop species, was grown from emergence to anthesis using replacement series mixtures with Amaranthus retroflexus, a C4 weed species at three different [CO2], 400, 600 and 800 μmol mol−1, with and without water stress. Under well‐watered conditions, leaf photosynthetic rates and plant height, leaf area and biomass all increased with elevated [CO2] for tomato relative to A. retroflexus, consistent with the kinetics of C3 photosynthesis. However, if water was limiting, a significant positive effect of [CO2] was noted for plant height and biomass of A. retroflexus with increased competition. This result may be related to a greater increase in leaf water potential with rising [CO2] for A. retroflexus relative to tomato under water stress. Overall, these are the first data to suggest that increases in atmospheric CO2 could still exacerbate crop losses from a C4 weed, even with a C3 crop, if drought occurs.

This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden.The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

This descriptive study aimed to verify factors which motivate compliance with hand hygiene on the part of the nursing team in a public hospital in Londrina, PR, Brazil, in 2012, and to propose strategies for improving this. A total of 135 nursing professionals participated, providing information on professional identification, continuing education, and the undertaking of hand hygiene. The motivation for complying with hand hygiene was linked to satisfaction in personal life for 45 (33.3%) and to satisfaction in the work for 58 (42.9%), as well as to autonomy for undertaking the nursing care, for 76 (56.3%). The motivational factors which influence compliance with the practice of hand hygiene were: professional development/growth, interest in the work, flexibility for prioritizing the care actions, autonomy, and participation in the decisions. These must be taken into account in planning the continuing education, so as to improve compliance with hand hygiene, as well as the quality of the care provided.

No abstract

The establishment and spread of invasive plants are often associated with a 'general-purpose genotype', with a corresponding high degree of phenotypic plasticity when introduced to a new environment. Evolutionary potential of invasive species following introduction should also be considered, however, as such changes can facilitate rapid range expansion. In this study, we utilised seed from three geographically distinct mid-Atlantic populations of an invasive species, Microstegium vimineum (Japanese stiltgrass), to assess whether populations varied in their biomass and reproductive responses to light and nitrogen under neutral glasshouse conditions. To assess evolutionary adaptation, we quantified and correlated the abiotic environment from each collection location with the final biomass and seed production of that population under common glasshouse conditions. For M. vimineum, growth and reproductive responses to a common set of abiotic parameters (e.g. light) under these conditions indicated considerable phenotypic variation between and within populations. Interestingly, the degree of variation of seed production and final biomass among populations in the glasshouse was strongly correlated with growing season length and cumulative degree days recorded near each population location. These latter data indicated that M. vimineum, introduced into this region <100 years ago, may be undergoing adaptive evolution. Although additional populations of M. vimineum need to be examined, this study suggests that local evolutionary adaptation may be occurring rapidly and could, potentially, be an important aspect in the establishment and spread of this invasive species.

Partial root-zone drying (PRD) is a deficit irrigation technique with great potential for water saving. A split-root experiment was conducted on tomato in controlled environment in order to test the response of two long-time storage cultivars to PRD. “Ponderosa” tomato, a cultivar with yellow fruits, was compared to “Giallo tondo di Auletta”, a local cultivar from southern Campania (Italy). Plants were subjected to three irrigation treatments: plants receiving an amount of water equivalent to 100% of plant evapotranspiration (V100); plants in which 50% of the amount of water given to V100 was supplied (V50); and plants where one root compartment was irrigated at 50% of water requirements and the other compartment was allowed to dry, and thereafter every side was rewetted alternatively (PRD). The highest levels of leaf abscisic acid (leaf ABA) (on average equal to 104 ng g^–1 FW) were measured in PRD and V50, at 70 days after transplantation. Root abscisic acid (root ABA) concentration in both PRD and V50 reached mean values of 149 ng g^–1 FW. There were differences for the irrigation regime in root ABA biosynthesis and accumulation under partial root-zone drying and conventional deficit irrigation (V50). Assimilation rate, stomatal conductance and intercellular CO₂ concentration decreased in relation to the irrigation regime by 22, 36 and 12%, respectively, in PRD, V50 and V100 at 50 days after transplantation. Ponderosa variety accumulated 20% more dry matter than Auletta and significant differences were observed in leaf area (LA). In both PRD and V50 of the two varieties, it was possible to save on average 46% of water. Our results indicate that there is still space to optimize the PRD strategy, so improving further the cumulative physiological effects of the root-sourced signaling system.