Navegando por Autor "Lopes, Valdir"
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- ItemComprimento da cana planta em função de doses crescentes de boro no solo(Universidade Estadual do Norte do Paraná, 2024) Lopes, Valdir; Tiritan, Carlos Sérgio
- ItemEfeito da pressão do circuito de pulverização na taxa de sobrevivência dos agentes biológicos(Universidade Estadual do Norte do Paraná, 2026) Oliveira, João Paulo de; Matsumoto, Leopoldo Sussumu; https://orcid.org/0000-0001-5102-545X; http://lattes.cnpq.br/0857955043436449; Matsumoto , Leopoldo Sussumu; https://orcid.org/0000-0001-5102-545X; http://lattes.cnpq.br/0857955043436449; Dário, Gustavo; https://orcid.org/0000-0002-4648-6881; http://lattes.cnpq.br/5682942731827088; Nicolosi, Mateus Marrafon; http://lattes.cnpq.br/5740779198324583; Gandolfo, Marco Antonio; https://orcid.org/0000-0003-2314-3752; http://lattes.cnpq.br/5560552732033631; Lopes, Valdir; https://orcid.org/0000-0002-7407-7858; http://lattes.cnpq.br/0481390085872915The success of biological control and agricultural inoculation depends on maintaining the viability of microorganisms during the application technology process. This study aimed to evaluate the survival of Bacillus pumilus, Azospirillum brasilense, and Isaria fumosorosea subjected to different pressure levels (300 to 700 kPa) and recirculation times (0 to 40 min) within a spraying circuit. Viability was quantified through plate counting (CFU mL⁻¹) and quantitative real-time PCR (qPCR). The results demonstrated that cellular morphology is the determining factor in resilience to hydrodynamic stress. B. pumilus showed high stability across all treatments, attributed to the mechanical protection of its endospores. In contrast, A. brasilense (Gram-negative) exhibited high sensitivity, with drastic population declines (R2=0.93) as pressure and time increased, reaching non-detection via qPCR under 700 kPa. The fungus I. fumosorosea showed intermediate resistance, remaining stable up to 500 kPa but becoming vulnerable to the immediate impact of higher pressures (R2=0.76). It is concluded that extreme pressures cause structural damage and DNA fragmentation in vegetative cells and conidia. It is recommended to calibrate the working pressure according to the biological nature of the input, prioritizing low pressures and shorter recirculation times for non-spore-forming agents.
- ItemIntensidade e momento de ocorrência de chuvas após aplicação de herbicidas(Universidade Estadual do Norte do Paraná, 2023-04-29) Grande, Karen Caroline de Oliveira de; Gandolfo, Marco Antônio; https://orcid.org/0000-0003-2314-3752; http://lattes.cnpq.br/5560552732033631; Gandolfo, Ulisses Delvaz; https://orcid.org/0000-0001-6131-0289; http://lattes.cnpq.br/8520084377953959; Lopes, Valdir; https://orcid.org/0000-0002-7407-7858; http://lattes.cnpq.br/0481390085872915A presença de plantas daninhas nas áreas agrícolas é um dos principais desafios enfrentados pelos agricultores durante o cultivo de suas plantações. Para controlar essas plantas daninhas, os herbicidas são amplamente empregados como principal ferramenta de controle. No entanto, fatores ambientais, como chuvas que ocorrem após a aplicação dos herbicidas, podem comprometer significativamente a eficácia desses produtos no controle das espécies de plantas daninhas (Digitaria insularis L., Cenchrus echinatus, Eleusine indica L., Urochloa brizantha S.). Este estudo teve como objetivo avaliar o nível de controle de plantas daninhas com aplicações de herbicidas com duas intensidades de precipitação em dois momentos de ocorrência. Para isso, foi conduzido o experimento, com o herbicida cletodim associado ao glyphosate. Após aplicação, as plantas foram submetidas a precipitação simulada de 10 mm com duas intensidades (5 minutos e 30 minutos) e dois momentos (precipitação imediata e 1 hora após aplicação), além de duas testemunhas (sem aplicação dos herbicidas e com aplicação dos herbicidas). O experimento foi realizado em laboratório, onde foram avaliados os parâmetros do potencial hidrogeniônico (pH), condutividade elétrica e tensão superficial e biomassa fresca e seca. O controle foi determinado através da escala de ALAM (1974) associado com a equação determinada por BRANKOV et al., (2023). A eficiência de controle da calda dos herbicidas Glyphosate + Cletodim são dependentes da intensidade e do momento de ocorrência da precipitação após a aplicação, espécie de planta que se encontra no local e estádio de desenvolvimento das espécies. É necessário um período acima de 1 hora sem ocorrência de precipitação após a aplicação, para que a calda dos herbicidas Glyphosate + Cletodim não apresentem redução no controle das espécies de plantas.
- ItemMetodologia para determinação de deriva em diferentes alturas de barra e velocidades do vento com pontas de pulverização de jato cônico(Universidade Estadual do Norte do Paraná, 2025) Motta, Ana Beatriz de Oliveira; Oliveira, Rone Batista de; https://orcid.org/0000-0002-3071-4827; https://lattes.cnpq.br/2379804514613050; Oliveira, Rone Batista de; https://orcid.org/0000-0002-3071-4827; https://lattes.cnpq.br/2379804514613050; Lopes, Valdir; https://orcid.org/0000-0002-7407-7858; https://lattes.cnpq.br/0481390085872915; Alves, Guilherme Sousa; https://orcid.org/0000-0003-4877-0293; https://lattes.cnpq.br/7138496193657632; Gandolfo, Marco Antonio; https://orcid.org/0000-0003-2314-3752; https://lattes.cnpq.br/5560552732033631; Costa, Neumárcio Vilanova da; https://orcid.org/0000-0003-2576-7470; https://lattes.cnpq.br/8328839002732737; https://lattes.cnpq.br/2379804514613050; https://lattes.cnpq.br/0481390085872915; https://lattes.cnpq.br/5560552732033631; https://lattes.cnpq.br/8328839002732737; https://orcid.org/0000-0002-3071-4827; https://orcid.org/0000-0002-7407-7858; https://orcid.org/0000-0003-2576-7470The uniformity and quality of the spray depends on the stability of the spray boom height. The height of the sprayer boom, together with variations in weather conditions, causes displacements in the spray jet, by changing the opening angle or projection of the spray jet and the volumetric distribution, which leads to variations in the deposition of droplets on the target. The aim of this study was to develop a methodology to quantify the volume displaced in the projection of the conical jet at different spray boom heights and weather conditions. To this end, a pyramidal structure was developed as an experimental base, which was made based on theoretical calculations of the diameter of the projection of the conical spray jet from the tip, corresponding to each working height, 0.25 m, 0.50 m, 0.75 m, 1.00 m, 1.25 m and 1.50 m. The pyramidal structure was built with the aim of quantifying the volume displaced in the projection of the conical spray jet. The pyramidal structure is made of sheet metal and divided into 6 modules, with an outlet hole, and each module has the length of the opening in relation to the angle of the spray jet projection, being centered below the spray bar to collect the sprayed volume. The experiment was set up in a completely randomized design with 20 replications applied by JCI 80 01 spray tips, with a pressure of 500 kPa, and six spray bar heights. During the tests, weather conditions such as wind speed and direction, temperature and relative humidity were recorded. The displaced volume was positively correlated with boom height (r > 0.71), wind speed (r≥0.98), air temperature (r ≥ 0.94) and negatively correlated with relative humidity (r <- 0.94). The displaced volume of the jet is influenced by the height of the spray boom. Lower boom heights had lower losses and higher boom heights indicated a loss in displacement, with averages of 80%, reaching up to 98.49% at 1.50 m boom height. The pyramidal structure proved to be a methodology that makes it possible to evaluate the displacement of the spray jet projection in a complex field environment. It has a simple structure, low cost, is easy to use and reduces experimental time. The factors that most influenced jet displacement were wind speed and spray boom height, mainly 0.50m.