Micronutrientes no solo sob diferentes fitofisionomias no Pantanal da Nhecolândia, Mato Grosso do Sul.

A paisagem do Pantanal é composta por um mosaico de formações vegetais de aspectos diversos, que compreendem campos inundáveis, cerrado, cerradões e florestas. Aliado ao regime de inundação, os solos têm um papel primordial na diferenciação das comunidades vegetais. Este trabalho teve por objetivo avaliar o teor de micronutrientes no solo, nas camadas superficiais, sob diferentes fitofisionomias no Pantanal da Nhecolândia, visando contribuir com elementos para a caracterização dos ambientes do Pantanal. The landscape of the Pantanal is composed of a mosaic of vegetation of different aspects, which include flooded fields, arboreal savannah, forested savannah and forests. Coupled with the system of flood, the soils have a greater role in the differentiation of plant communities. This study aimed to evaluate the content of micronutrients in soil under different vegetation types in the Nhecolandia, aiming to contribute elements to characterize the environments of the Pantanal

Vigor de sementes e adubação nitrogenada na produtividade e qualidade fisiológica de sementes de trigo.

A utilização de sementes de qualidade, associada à adubação nitrogenada aplicada em doses e momentos adequados, pode aumentar a produtividade e o potencial fisiológico das sementes produzidas. Neste sentido, objetivou-se avaliar o efeito do vigor de sementes utilizadas na semeadura associado a combinações de doses e épocas de aplicação de nitrogênio sobre a produtividade e a qualidade fisiológica de sementes de trigo. O experimento foi conduzido com a cultivar BRS Gralha-Azul, sob delineamento de blocos casualizados em esquema fatorial 2x7, com quatro repetições. Os tratamentos consistiram em dois níveis de vigor de sementes (alto e baixo) associados a sete combinações de doses e aplicação da adução nitrogenada (N1- sem N; N2- 40 kg ha-1 de N no perfilhamento; N3- 80 kg ha-1 de N no perfilhamento; N4- 40 kg ha-1 de N na semeadura; N5- 80 kg ha-1 de N na semeadura; N6- 40 kg ha-1 de N na semeadura e 40 kg ha-1 de N no perfilhamento; N7- 20 kg ha-1 de N na semeadura e 60 kg ha-1 de N no perfilhamento). Foram avaliados: germinação, primeira contagem da germinação, comprimento e massa seca de plântulas, emergência de plântulas em areia, índice de velocidade e emergência, condutividade elétrica, massa de mil sementes e produtividade de sementes. A adubação com 20 kg ha-1 de N na semeadura e 60 kg ha-1 de N no início do perfilhamento foi o mais eficiente para a produção de sementes vigorosas da cultivar BRS Gralha-Azul. Sementes com alto vigor apresentam melhor potencial fisiológico. Os níveis de vigor de sementes e as combinações de épocas de aplicação e doses de nitrogênio não alteram a produtividade da cultura e a massa das sementes produzidas.Empregado da Embrapa Trigo na época da publicação

Wheat yield and seed physiological quality as influenced by seed vigor, nitrogen fertilization and edaphoclimatic conditions.

Abstract Wheat is one of the most important cereals grown in the world, and in Brazil, increasing national production is still a challenge. Nitrogen (N) supply can favor grain yield and the physiological quality of wheat seeds. However, the definition of adequate N rate and fertilization timing must consider genotype, cultivation environment, and initial seed vigor level. The aim of this work was to evaluate the effect of initial seed vigor and the combinations of rates and timings of N application on grain yield and seed physiological quality of wheat cultivars under different edaphoclimatic conditions. The experiment was carried out in Londrina and Ponta Grossa, state of Paraná, in a randomized block design in a 2 × 2 × 7 factorial scheme, with four replicates. Treatments consisted of two seed vigor levels (vigorous and non-vigorous seeds), two wheat cultivars (BRS Gralha-Azul and BRS Sabiá) and seven combinations of fertilization timings and N rates (kg ha-1) (control-0N; 20N at sowing and 60N at tillering; 40N at sowing; 80N at sowing; 40N at sowing and 40N at tillering; 40N at tillering; 80N at tillering). Number of emerged seedlings, vegetation index, shoot dry matter, number of fertile spikes m-2 and grain yield were evaluated. Additionally, the physiological potential of seeds produced in Londrina was evaluated by the testes of first count, germination, seedling emergence in sand and emergence speed index. The climatic conditions during the experiment, in both cultivation environments, were similar to average historical records, with some periods of water deficit. The highest grain yield was obtained with the BRS Gralha-Azul in Londrina, and with BRS Sabiá in Ponta Grossa. The use of vigorous seeds favored the stand establishment and the response of plants to N fertilization. The treatments 40N + 40N, and 40N + 0N favored the majority of evaluated variables. Both cultivars showed potential for the production of high physiological potential seeds in Londrina environment. Inadequate N supply impairs wheat grain yield and seed production. Key words: Nitrogen rates. Germination. Macronutrient. Seed quality. Triticum aestivum L. Resumo O trigo é um dos cereais mais importantes cultivados no mundo, sendo que no Brasil o aumento da produção nacional ainda é um desafio. A aplicação de nitrogênio (N) pode favorecer o aumento do rendimento de grãos e da qualidade fisiológica de sementes de trigo. Porém, a definição da dose correta de N e do momento adequado da adubação deve considerar o genótipo, o ambiente de cultivo e o nível de vigor inicial das sementes. O objetivo deste trabalho foi avaliar o efeito do vigor inicial de sementes e de combinações de doses de N e épocas de adubação sobre o rendimento de grãos e a qualidade fisiológica de sementes de cultivares de trigo em diferentes condições ambientais. O experimento foi conduzido em Londrina e em Ponta Grossa, Paraná, em delineamento em blocos casualizados em esquema fatorial 2 × 2 × 7, com quatro repetições. Os tratamentos consistiram em dois níveis de vigor de sementes (sementes vigorosas e não vigorosas), duas cultivares de trigo (BRS Gralha-Azul e BRS Sabiá) e sete combinações de épocas de adubação e doses de N (kg ha-1) (testemunha-0N; 20N na semeadura e 60N no perfilhamento; 40N na semeadura; 80N na semeadura; 40N na semeadura e 40N no perfilhamento; 40N no perfilhamento; 80N no perfilhamento). Foram avaliados: número de plântulas emergidas, índice de vegetação, matéria seca da parte aérea, número de espigas m-2 e rendimento de grãos. Adicionalmente, foi avaliado o potencial fisiológico das sementes produzidas em Londrina pelos testes de primeira contagem, germinação, emergência de plântulas em areia e índice de velocidade de emergência. As condições climáticas durante a condução do experimento, em ambos locais de cultivo, foram semelhantes aos registros médios históricos, com alguns períodos de déficit hídrico. O maior rendimento de grãos foi obtido com a BRS Gralha-Azul em Londrina e BRS Sabiá em Ponta Grossa. O uso de sementes vigorosas favoreceu o estabelecimento do estande e a resposta das plantas à fertilização com N. Os tratamentos 40N + 40N e 40N + 0N favoreceram a maioria das variáveis avaliadas. Ambas cultivares demostraram potencial para a produção de sementes de elevado potencial fisiológico no ambiente de Londrina. O suprimento inadequado de N prejudica o rendimento de grãos e a produção de sementes de trigo. Palavras-chave: Doses de nitrogênio. Germinação. Macronutriente. Qualidade de sementes. Triticum aestivum L. Highlights Vigorous seeds favor wheat crop establishment and productive performance. BRS Sabiá has higher yield in Ponta Grossa and BRS Gralha-Azul in Londrina. Nitrogen fertilization increases wheat grain/seed production. Inadequate N supply impairs wheat grain and seed production

Wheat yield and seed physiological quality affected by initial seed vigor, sowing density, and environmental conditions

Optimization of seed density range, combined with the use of quality seeds may help generate more profit from wheat production, as these factors affect grain yield and the quality of seeds. The aim of this study was to evaluate the effects of initial vigor level and sowing densities on the productive performance of the plants and the physiological performance of the seeds of two wheat cultivars in two cultivation environments. The experiment was carried out in the cities of Londrina and Ponta Grossa, Paraná, Brazil, in a randomized block design with four replications, following a 2 × 2 × 4 factorial scheme with two levels of seed vigor (high and low), two cultivars (BRS Gralha-Azul and BRS Sabiá), and four sowing densities (150, 250, 350, and 450 seeds m-2). The following characteristics were evaluated: emerged seedlings, shoot dry matter, spike density, vegetation index, and grain yield. Additionally, the physiological potential of the seeds produced in Londrina was evaluated by first germination count, germination, accelerated aging, seedling emergence, and emergence speed index tests. The increase in density up to 450 seeds m-2 favored the productive performance of the crop in both cultivation environments; however, it reduced the physiological performance of the seeds produced in Londrina. The cultivars BRS Gralha-Azul and BRS Sabiá had better performance and grain yield in Londrina and Ponta Grossa, respectively. High-vigor seeds favored the establishment of the stand, especially under unfavorable environmental conditions. Key words: Germination. Plant population. Seed quality. Triticum aestivum L

Matrix-assisted laser desorption ionization hydrogen/deuterium exchange studies to probe peptide conformational changes

AbstractHydrogen/deuterium (H/D) exchange chemistry monitored by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry is used to study solution phase conformational changes of bradykinin, α-melanocyte stimulating hormone, and melittin as water is added to methanol-d4, acetonitrile, and isopropanol-d8 solutions. The results are interpreted in terms of a preference for the peptides to acquire more compact conformations in organic solvents as compared to the random conformations. Our interpretation is supported by circular dichroism spectra of the peptides in the same solvent systems and by previously published structural data for the peptides. These results demonstrate the utility of MALDI-TOF as a method to monitor the H/D exchange chemistry of peptides and investigations of solution-phase conformations of biomolecules

Messages that increase women’s intentions to abstain from alcohol during pregnancy: results from quantitative testing of advertising concepts

Background: Public awareness-raising campaigns targeting alcohol use during pregnancy are an important part of preventing prenatal alcohol exposure and Fetal Alcohol Spectrum Disorder. Despite this, there is little evidence on what specific elements contribute to campaign message effectiveness. This research evaluated three different advertising concepts addressing alcohol and pregnancy: a threat appeal, a positive appeal promoting a self-efficacy message, and a concept that combined the two appeals. The primary aim was to determine the effectiveness of these concepts in increasing women’s intentions to abstain from alcohol during pregnancy.Methods: Women of childbearing age and pregnant women residing in Perth, Western Australia participated in a computer-based questionnaire where they viewed either a control or one of the three experimental concepts. Following exposure, participants’ intentions to abstain from and reduce alcohol intake during pregnancy were measured. Other measures assessed included perceived main message, message diagnostics, and potential to promote defensive responses or unintended consequences.Results: The concepts containing a threat appeal were significantly more effective at increasing women’s intentions to abstain from alcohol during pregnancy than the self-efficacy message and the control. The concept that combined threat and self-efficacy is recommended for development as part of a mass-media campaign as it has good persuasive potential, provides a balance of positive and negative emotional responses, and is unlikely to result in defensive or unintended consequences.Conclusions: This study provides important insights into the components that enhance the persuasiveness and effectiveness of messages aimed at preventing prenatal alcohol exposure. The recommended concept has good potential for use in a future campaign aimed at promoting women’s intentions to abstain from alcohol during pregnanc