RESUMO O estresse salino ocasiona perda no rendimento das culturas, principalmente aquelas de grande importância econômica e socioalimentar, como o maracujazeiro. Com isso, objetivou-se nesta pesquisa avaliar os efeitos da adubação com silicato de cálcio na mitigação do estresse salino em mudas de maracujazeiro amarelo. O experimento foi conduzido em ambiente protegido, no delineamento experimental de blocos casualizados, arranjados em esquema fatorial 4 x 3, referente a quatro concentrações de silicato de cálcio (0; 2,22; 4,44 e 6,66 g por planta) e três níveis de salinidade da água de irrigação - CEa (0,5; 1,7 e 4,0 dS m-1), com quatro repetições, considerando como unidade experimental cinco plantas. As mudas da cultivar BRS GA1 foram produzidas em recipientes com capacidade para 0,5 dm3, preenchidos com a mistura de solo, areia lavada e esterco bovino curtido, na proporção 1:1:1 (v:v). As plantas receberam aplicações de silicato de cálcio conforme as doses estudadas em três parcelas, aos 30, 45 e 60 dias após a semeadura. Aos 90 dias após a semeadura às plantas foram avaliadas quanto ao crescimento e acúmulo de biomassa. A utilização de água com salinidade de 4,0 dS m-1 restringiu o crescimento e o acúmulo de biomassa das mudas de maracujazeiro. O uso de silicato de cálcio na dose de 3,5 g por planta mitiga o estresse salino em mudas de maracujazeiro cultivar BRS GA1 quando irrigadas com água salina.

ABSTRACT Salt stress causes losses in the yields of crops, especially those of great economic and social-food importance, such as passion fruit. The objective of this study was to evaluate the effects of fertilization with calcium silicate on the mitigation of salt stress in yellow passion fruit seedlings. The experiment was conducted in a protected environment, in a randomized block design, arranged in a 4 x 3 factorial scheme, referring to four concentrations of calcium silicate (0; 2.22; 4.44 and 6.66 g per plant) and three levels of irrigation water salinity - ECw (0.5; 1.7 and 4.0 dS m-1), with four replicates, considering five plants as experimental unit. BRS GA1 seedlings were produced in 0.5-dm3 containers filled with a mixture of soil, washed sand and aged bovine manure, in a ratio of 1:1:1 (v:v:v). Plants received calcium silicate applications according to the studied doses in three plots, at 30, 45 and 60 days after sowing. At 90 days after sowing, plants were evaluated for growth and biomass accumulation. The use of water with salinity of 4.0 dS m-1 restricted the growth and biomass accumulation of passion fruit seedlings. The use of calcium silicate at dose of 3.5 g per plant mitigates salt stress in seedlings of passion fruit cultivar BRS GA1 when irrigated with saline water.

ABSTRACT Most of the forensic comparison of soils has focused on the clay and silt fractions at the expense of the coarser particles. This study aimed to test the potential of elemental and physical analyses in the sand fraction from subtropical soils to discriminate samples collected in areas under different parent material (claystone and marble) and in areas with the same parent material at a simulated crime scene. Scanning electron microscopy coupled to an energy dispersive X-ray spectrometer (SEM-EDS) analysis was used on the finer sized sand particles (0.05-0.25 mm). X-ray diffraction (XRD) and particle size distribution (PSD) analyses were performed on the whole sand fraction. These methods did not provide clear discrimination of the sand of the soils sampled in the subtropical environment. This can be explained by the large homogenization observed in the sand fraction related to its chemical (EDS), physical (particle size distribution), morphological (SEM), and mineralogical (XRD). Under tropical and subtropical conditions, the chemical weathering processes dissolve most of the primary minerals, such as the feldspars, biotite, and Fe-bearing particles, and concentrates quartz in the sand fraction. In these environments, we recommend the prioritization of the finer soil fractions for forensic studies, both inorganic and organic.

ABSTRACT Soil traces are useful as forensic evidence due to their potential to transfer and adhere to different types of surfaces on a range of objects or persons. Several works have been developed in forensic soils, under different analytical approaches. However, in Brazil, only the researches from the Group of the Federal University of Paraná have developed works with soils under a forensic approach. Focus has been given on the sequential chemical analyses and mineralogical techniques once they presented a large potential to discriminate soil samples, even that originated from the same bedrock. In this way, this work aimed to test a Standard Operating Procedure (SOP) for forensic soil sampling and an analytical protocol in Brazil between the academy and the scientific police through a blind simulated crime scene scenario. Samples were collected at four sites located in the Curitiba Metropolitan Region. All soils were classified as Inceptisol ( Cambissolo ), and the parent material in Curitiba is claystone and in Colombo is limestone. Around 3 g of sample composed by silt + clay fraction were isolated and analyzed by sequential chemical procedure: i) extraction of poorly ordered iron and aluminum oxides with ammonium oxalate (AO); ii) extraction of crystalline iron oxides with sodium dithionite-citrate-bicarbonate (DCB); and iii) extraction of poorly ordered aluminosilicates and gibbsite with NaOH 0.5 mol L-1. All data were transformed by square root and formed a data matrix subsequently analyzed in a principal component analysis (PCA). Most of the samples were properly grouped according to their provenance at all four sites tested, showing the potential of the Standard Operating Procedure (SOP) in a real crime scene. The sampling procedures presented in the SOP were detailed enough to allow the appropriate police work in forensic cases in any part of Brazil. As future considerations, modifications to the sample treatment and analytical protocol could be made depending on the context of the forensic work. Intense anthropogenic activities, such as domestic waste disposal in urban areas, would potentially reduce the discrimination power of such a proposed chemical analytical protocol.

RESUMO Considerando que o comportamento de anti-predação de peixes-presas podem variar de acordo com a estratégia de caça de predadores, investigaram-se experimentalmente as respostas fisiológicas de cardumes de Astyanax bimaculatus (Linnaeus, 1758) na presença de duas espécies de peixes piscívoros com diferentes modos de caça: senta-espera e busca ativa. Além disso, avaliou-se a influência das condições de visibilidade subaquática sobre a interação entre predadores e presas. Para isso, realizou-se um experimento para testar as hipóteses de que (i) os níveis plasmáticos de cortisol e glicose variam de acordo com a estratégia de caça dos peixes piscívoros, e (ii) em ambiente com elevada turbidez não haverá redução nos níveis plasmáticos de glicose e cortisol devido à incapacidade da presa em reconhecer com precisão os predadores através de estímulos não visuais. Os resultados evidenciam que a presença de peixes piscívoros aumenta os níveis plasmáticos de cortisol das presas, mas não houve diferença significativa entre os tratamentos com piscívoros de diferentes estratégias de caça. Não foi observada alteração significativa nos níveis de glicose plasmática entre tratamentos com água transparente e água túrbida. Assim, conclui-se que as mudanças fisiológicas na espécie de peixes-presa utilizada não variam com o modo de caça do predador e é, portanto, necessário considerar a habilidade das presas de reconhecer e avaliar a ameaça de predação, independentemente da estratégia de caça do piscívoro.

ABSTRACT Considering that the anti-predation behaviour of prey fishes may vary with predator hunting strategy, we experimentally investigated the physiological responses of Astyanax bimaculatus (Linnaeus, 1758) shoals to the presence of two piscivorous fish species with different hunting modes: sit-and-wait and active pursuit. In addition, we evaluated the influence of underwater visibility conditions on the interaction between predator and prey. We tested the hypotheses that: (i) prey plasma cortisol and glucose levels vary according to piscivore hunting strategy, and (ii) no reduction in plasma glucose and cortisol levels takes place in turbid environments due to the inability of prey to accurately recognise predators by non-visual signals. The results revealed that the presence of piscivorous fish increased plasma cortisol levels in prey, with no significant difference recorded between the two hunting strategy treatments. We also observed no significant change in plasma glucose levels in different water transparency conditions. Thus, we conclude that physiological changes in the selected prey fish do not vary with predator hunting mode, and it is therefore necessary to consider the ability of the prey to recognise and evaluate danger, regardless of piscivore hunting strategy.

O nitrogênio é o nutriente mais requerido pelas plantas por assumir funções importantes no metabolismo vegetal. Na cultura do girassol, sua deficiência causa desordem nutricional, sendo o nutriente que mais limita a produção. Além disso, doses elevadas podem aumentar a incidência de pragas e doenças afetando a produção de grãos. Conduziu-se o experimento com o objetivo de avaliar a resposta da cultura do girassol (Helianthus annuus L.) irrigado, submetido a diferentes doses de nitrogênio aplicado parceladamente, em cobertura. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições. Os tratamentos consistiram de quatro doses de nitrogênio (0, 20, 40 e 80 kg ha-1), na forma de uréia. A adubação nitrogenada em cobertura proporcionou um aumento em todas as características estudadas, sendo que a dose de N de máxima eficiência técnica para se ter uma boa produtividade é de 55 kg ha-1 de N para o cultivo do girassol, na região de Cassilândia-MS.

Nitrogen is the most required nutrient by plants for exerting important functions in the vegetable metabolism. In sunflower crop, its efficiency causes nutritional disorder, being the nutrient that most limits the yield. Besides, high doses may increase the incidence of pests and diseases, affecting the yield. Hereafter, this experiment was carried out with the aim of evaluating the response of the irrigated sunflower crop (Helianthus annuus L.) submitted to different doses of side dressing nitrogen fertilization applied uncovered nitrogen in small parts. A randomized complete block design, with four replications was used. The constituted by four doses of nitrogen (0, 20, 40, and 80 kg ha-1), as urea. Side dressing nitrogen fertilization provides increase in all characteristics studied, and the dose of N of maxim suitable technical efficiency to have a good yield is of 55 kg ha-1 of N for the cultivation of the sunflower irrigated in the region of Cassilândia, Mato Grosso do Sul State.

O objetivo deste trabalho foi avaliar genótipos de capim-elefante (Pennisetum purpureum Schum.) quanto à resistência à cigarrinha-das-pastagens (Mahanarva spectabilis). Para avaliação da antibiose, aos trinta dias após o plantio, cada planta foi infestada com seis ovos próximos à eclosão, em delineamento inteiramente casualizado, com 30 genótipos e dez repetições. Quarenta e cinco dias após a eclosão das ninfas, avaliou-se a porcentagem de sobrevivência do inseto-praga nos diferentes genótipos. Para avaliação da não-preferência, foram quantificados, quinzenalmente, o número e tamanho de ninfas por vaso, em plantas mantidas em casa de vegetação, onde adultos de M. spectabilis eram periodicamente liberados, em delineamento inteiramente casualizado, com três repetições por genótipo, em dois períodos de amostragem. Os genótipos Cameroon de Piracicaba, Pioneiro, Cuba 169, Santa Rita, Mineiro Ipeaco, Mercker Comum de Pinda e CNPGL 96-27-3 foram selecionados quanto à resistência, pelo mecanismo de antibiose. O número e o tamanho médio das ninfas variaram significativamente em razão do genótipo de capim-elefante, no estudo da não-preferência. Os genótipos Roxo de Botucatu e Pioneiro são candidatos à testemunha suscetível e resistente, respectivamente, pelo mecanismo de antibiose, e os genótipos Cameroon e Cameroon Piracicaba são promissores pelo mecanismo de não-preferência.

The objective of this work was to evaluate genotypes of elephant grass (Pennisetum purpureum Schum.) regarding resistance to the spittlebug Mahanarva spectabilis. For antibiosis evaluation, each plant was infested with six eggs near hatching, thirty days after planting, in a completely randomized design with 30 genotypes and ten repetitions. Forty-five days after the nymphs hatched, the insect survival rate was evaluated on the different genotypes. For nonpreference mechanism evaluation, the size and number of the nymphs per pot were assessed every 15 days, in plants kept at greenhouse, where adults of M. spectabilis were periodically released, in a completely randomized design, with three repetitions per genotype in two sampling periods. Cameroon de Piracicaba, Pioneiro, Cuba 169, Santa Rita, Mineiro Ipeaco, Mercker Comum de Pinda and CNPGL 96-27-3 genotypes were selected for resistance, by antibiosis mechanism. In the study of the nonpreference mechanism, the number and average size of the nymphs varied significantly as a function of the elephant grass genotype. Roxo de Botucatu and Pioneiro genotypes are, respectively, susceptible and resistant check candidates by the antibiosis mechanism, and Cameroon and Cameroon Piracicaba genotypes are promising by the nonpreference mechanism.