Programa de Pós-Graduação em Agronomia

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Atividade nematicida de extratos de Brugmansia suaveolens sobre Meloidogyne incognita
(Universidade Estadual do Norte do Paraná, 2026) Venâncio, Stéphany de Campos; Alves, Viviane Sandra; https://orcid.org/0000-0003-2381-8115; http://lattes.cnpq.br/3794580975938452; Alves, Viviane Sandra; https://orcid.org/0000-0003-2381-8115; http://lattes.cnpq.br/3794580975938452; Poletto, Rodrigo de Souza; https://orcid.org/0000-0002-7034-7865; http://lattes.cnpq.br/8774064317309922; Silva, Santino Aleandro da; https://orcid.org/0000-0002-1019-1926; http://lattes.cnpq.br/8341476195396585
Meloidogyne incognita stands out as one of the most aggressive and widely distributed species in tropical regions, causing severe damage to plant root systems. The need for alternatives to synthetic nematicides drives research into plant-based compounds with biological potential and lower environmental impact. In this context, the present study aimed to evaluate the nematicidal activity of aqueous and hydroalcoholic extracts from leaves and flowers of Brugmansia suaveolens (Solanaceae) on second-stage juveniles (J2) of M. incognita. The experiments were conducted under controlled laboratory conditions, using J2 obtained from infected tomato roots, processed with sodium hypochlorite solution and filtered through 250 and 500 mesh sieves. The suspensions containing J2 were exposed to two types of extracts (aqueous and hydroalcoholic) at different concentrations, and a negative control was performed with distilled water. The mortality of the juveniles was evaluated after 24 hours of exposure, and the data obtained were submitted to analysis of variance and Tukey's test (p<0.05). The aqueous extracts caused higher mortality of M. incognita J2, with the flower extract causing up to 98% mortality in all concentrations evaluated and showing no significant difference. The aqueous leaf extract, on the other hand, showed dose-dependent mortality, with values varying according to the dose tested. For the hydroalcoholic extracts, mortality was observed in the extracts obtained from flowers and leaves, with values ranging from 46 to 59% mortality. Analysis by gas chromatography coupled with mass spectrometry (GC-MS) for the detection and identification of volatile chemical constituents present in B. suaveolens extracts confirmed significant differences between the extracts, both in terms of the extraction method and the part of the plant used.
Biocontrole de fitopatógenos: uma perspectiva integrada de produção científica e estudos experimentais
(Universidade Estadual do Norte do Paraná, 2026) Martins, Livian Soares; Marques, Luis Eduardo Azevedo Lescano; https://orcid.org/0000-0003-0874-9211; http://lattes.cnpq.br/0477576296995064; Carvalho, Mayra Costa da Cruz Gallo de; https://orcid.org/0000-0002-1559-3828; http://lattes.cnpq.br/2844751503530944; Carvalho, Mayra Costa da Cruz Gallo de; https://orcid.org/0000-0002-1559-3828; http://lattes.cnpq.br/2844751503530944; Marques, Luis Eduardo Azevedo Lescano; https://orcid.org/0000-0003-0874-9211; http://lattes.cnpq.br/0477576296995064; Sichieri, Rafaella Cardoso; http://lattes.cnpq.br/7030413218339310; Reis, Guilherme Fonseca; http://lattes.cnpq.br/5675852978278805
The biological control has been widely studied as a sustainable strategy for the management of plant diseases caused by phytopathogenic fungi. This work aimed to evaluate the potential of Talaromyces stollii as a biocontrol agent of the soil phytopathogenic fungi Sclerotinia sclerotiorum and Macrophomina phaseolina and to analyze the evolution of scientific production on the molecular biology of biological control of plant diseases through a scientometric study. For the laboratory assays, T. stollii strain BCA1.1 was cultivated in dual culture on PDA with S. sclerotiorum and M. phaseolina. The action of volatile compounds and metabolites present in the supernatant obtained from the antagonist fungus culture on the growth of the phytopathogens was evaluated. For the scientometric analysis of publications on molecular mechanisms of antagonism between biocontrol agents and phytopathogens, data were collected from the Web of Science and Scopus databases between 1990 and 2024, analyzing indicators of scientific production growth, main thematic areas, authors, institutions, collaboration networks, and research trends. The experimental results showed that T. stollii inhibited both phytopathogens only in direct confrontation in dual culture. Macroscopic analysis of the plate revealed that the invasion of S. sclerotiorum initially occurred beneath and then above the mycelium, while in M. phaseolina the antagonist established itself over the mycelium through sporulation. Observations by optical light microscopy, using the adhesive tape method, allowed visualization of the typical hyphal coiling of mycoparasitism and the sporulation of the antagonist over the mycelium. Volatile compounds and non-volatile metabolites of T. stollii did not inhibit fungal growth. The results suggest that inhibition depends on direct contact, indicating that T. stollii may have potential in integrated management and in reducing chemical pesticides. The scientometric analysis showed that studies on molecular mechanisms of biocontrol began in 1990 and grew significantly from 2007 onwards, with an average annual rate of 9.99%. There was a shift from the study of classical agents, such as Trichoderma and Bacillus subtilis, to modern approaches involving genomics, transcriptomics, metabolomics, enzyme production, secondary metabolites, and complex ecological interactions. Biological control has evolved from traditional practices to a science guided by “omics,” highlighting genomic prospecting and rational formulation of biological agents. China, Brazil, and India stand out, with international collaboration networks and greater participation of the global south. Future perspectives include multifunctional agents, genetic engineering, optimization of antifungal metabolites, and integration with sustainable management. The integration between laboratory results and scientometric analysis reinforces the potential of T. stollii and indicates that advances in biotechnology and molecular biology may expand its practical application in the control of agricultural diseases.
Efeito 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/0481390085872915
The 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.
Efeitos da aplicação de microrganismo eficiente sobre crescimento, produção e qualidade de frutos de Solanum Lycopersicum L.
(Universidade Estadual do Norte do Paraná, 2026) Silva, Leandro de Oliveira; Kölln, Oriel Tiago; https://orcid.org/0000-0002-8507-9808; http://lattes.cnpq.br/8041626078120100; Porto, Petrônio Pinheiro; https://orcid.org/0000-0002-2999-7612; http://lattes.cnpq.br/1751366795715746; Porto, Petrônio Pinheiro; https://orcid.org/0000-0002-2999-7612; http://lattes.cnpq.br/1751366795715746; Pinto, Fabiana Gisele da Silva; https://orcid.org/0000-0002-0486-8486; http://lattes.cnpq.br/9361463429150328; Matsumoto, Leopoldo Sussumu; https://orcid.org/0000-0001-5102-545X; http://lattes.cnpq.br/0857955043436449
Contemporary agriculture faces increasing challenges related to sustainability, food security, and mitigation of environmental impacts. In this context, the tomato plant (Solanum lycopersicum L.), a vegetable crop of great economic and social relevance, serves as an ideal model for studies on plant-microorganism interactions. The objective of this dissertation was to evaluate the effects of applying effective microorganisms (EMs), particularly in the form of liquid bokashi/Tomita Microorganisms Technology (TMT), on the growth, yield, and fruit quality of tomato plants, also considering their interaction with arbuscular mycorrhizal fungi (AMF). The first article presents a systematic review, conducted according to the PRISMA protocol, which identified 2,450 records and included 31 studies. These studies demonstrate the benefits of the co-inoculation of AMF and EMs, such as increased phosphorus uptake, enhanced biomass accumulation, tolerance to abiotic stresses, suppression of pathogens, and improvements in fruit quality. The second article describes an experiment conducted under controlled conditions, using a completely randomized design (CRD) with seven treatments, in addition to a control, to evaluate different rates and application frequencies of the product associated with NPK 10-10-10 mineral fertilization. Treatments T1 (50 L ha⁻¹), T2 (100 L ha⁻¹), T3 (200 L ha⁻¹), and T7 (400 L ha⁻¹) received a single application, while treatments T4 (50 L ha⁻¹), T5 (100 L ha⁻¹), and T6 (200 L ha⁻¹) received two applications at the same rate. The control received no application of the product. The evaluated variables included vegetative growth parameters (plant height, leaf number, leaf area), fresh and dry biomass accumulation, yield (fruit number and weight), and quality parameters (soluble solids content, firmness, and color). The results demonstrated that split application of TMT promoted a significant increase in plant height (up to 22% compared to the control), leaf area (average increase of 18%), dry biomass accumulation (25% increase), and yield (20% increase in both fruit number and weight). In contrast, single application concentrated effects on vegetative growth, without significant gains in reproductive output. It is concluded that the use of effective microorganisms, associated with mycorrhizal symbiosis, represents a promising strategy to strengthen tomato cultivation in sustainable agricultural systems, reducing the need for synthetic fertilizers and pesticides while reconciling productivity, quality, and environmental conservation in line with the principles of regenerative agriculture.
Hidróxidos e carbonatos na dinâmica do pH do solo: efeitos na microbiota e no desenvolvimento da cultura da soja
(Universidade Estadual do Norte do Paraná, 2026) Silva, Matheus Hashimoto da; Silva, Marcos Augusto Alves da; https://orcid.org/0000-0002-5570-8677; http://lattes.cnpq.br/4973981237909142; Nicolosi, Mateus Marrafon; http://lattes.cnpq.br/5740779198324583; 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; Alves, Karina Aline; https://orcid.org/0000-0002-8916-0224; http://lattes.cnpq.br/6915234182529881
In agriculture, soil amendments play a crucial role in supplying nutrients, correcting pH, and promoting a range of vital benefits for healthy plant development. In this context, this study aimed to evaluate the efficiency of pH correction at different soil depths in soybean cultivation, considering the application of amendments composed of calcium and magnesium hydroxides and carbonates, in order to determine the most suitable parameters for the use of these elements. The treatments were organized in a randomized complete block design (RCBD) with four replications, using plots of 2.7 m wide by 5 m long, totaling an area of 13.5 m² per plot. The trial included a total of 14 treatments, organized as follows: control (T1); applications of hydroxides and carbonates, in granular and powder form, at doses corresponding to 50, 100, and 150% of the recommended dose, all associated with the biological mixture (T2 to T13); and a treatment composed only of the biological mixture (T14). The biological mixture was composed of Bacillus amyloliquefaciens, Bacillus subtilis, Bacillus aryabhattai, Trichoderma sp., Bradyrhizobium japonicum, and Azospirillum brasiliense, which were mixed and applied to the soil 31 days after crop emergence. The following variables were considered for evaluation: pH correction in the 0-10, 0-20, and 20-40 cm soil depth layers; changes in calcium, magnesium, and phosphorus levels; root system dry mass (RSM); shoot dry mass (SDM); number of pods per plant (NPP); thousand-grain weight (TGW); final crop yield (bags ha⁻¹); and monitoring of soil microbiological activities. The application of hydroxides resulted in a greater increase in soil pH in both evaluated depth layers compared to the application of carbonates. Forty-five days after the application of the amendments, it was observed that, in the 0–10 cm layer and at the highest dose used (1,428 kg ha⁻¹), the hydroxides raised the soil pH from 4.7 to 5.4, while carbonate, at the same dose, increased it to 4.9. The correction of the soil pH promoted a more favorable environment for the microbiota, increasing biological activity and nutrient availability. The improvement of the chemical and biological components of the soil resulted in greater root development and an increase in the number of pods per plant, culminating in increased soybean crop productivity.
Influência do condicionador de solos nos atributos químicos, microbiológico e produtividade do milho segunda safra
(Universidade Estadual do Norte do Paraná, 2026) Costa, Eduardo Almeida da; Silva, Marcos Augusto Alves da; https://orcid.org/0000-0002-5570-8677; http://lattes.cnpq.br/4973981237909142; Nicolosi, Mateus Marrafon; http://lattes.cnpq.br/5740779198324583; Kölln, Oriel Tiago; https://orcid.org/0000-0002-8507-9808; http://lattes.cnpq.br/8041626078120100; Osipe, Jethro Barros; https://orcid.org/0000-0001-6453-3090; http://lattes.cnpq.br/9692340257207288; Matsumoto, Leopoldo Sussumu; https://orcid.org/0000-0001-5102-545X; http://lattes.cnpq.br/0857955043436449
Soil conditioners play a fundamental role in modern agriculture, as they contribute to improved plant development and promote enhancements in soil microbiota, favoring a more balanced and active rhizosphere. In this context, the present study aimed to evaluate the efficiency of peat- and humic acid-based soil conditioners on soil microbiology and chemistry, as well as on the phytochemical parameters of corn (Zea mays L.). The experiment was conducted in a randomized complete block design (RCBD) with four replications. The treatments were as follows: T1 – Control; T2 – Methylobacterium symbioticum; T3 – 100 kg ha⁻¹ of granulated conditioner + M. symbioticum; T4 – 200 kg ha⁻¹ of granulated conditioner + M. symbioticum; T5 – 300 kg ha⁻¹ of granulated conditioner + M. symbioticum; T6 – 100 kg ha⁻¹ of powdered conditioner + M. symbioticum; T7 – 200 kg ha⁻¹ of powdered conditioner + M. symbioticum; T8 – 300 kg ha⁻¹ of powdered conditioner + M. symbioticum; T9 – 100 kg ha⁻¹ of powdered conditioner enriched with Trichoderma asperellum + M. symbioticum; T10 – 200 kg ha⁻¹ of powdered conditioner enriched with T. asperellum + M. symbioticum; and T11 – 300 kg ha⁻¹ of powdered conditioner enriched with T. asperellum + M. symbioticum. In the control treatment, 300 kg ha⁻¹ of urea was applied, while in the treatments containing M. symbioticum, there was a 30% reduction in the urea dose. The following parameters were evaluated: plant height, shoot dry mass (SDM), root dry mass (RDM), microbiological attributes, soil chemical analysis, thousand-grain weight (TGW), and final yield (kg ha⁻¹). It was observed that treatment T11, with 300 kg ha⁻¹ of powdered conditioner + Methylobacterium symbioticum, showed an increase of 1,190.4 kg ha⁻¹ compared to the control. Furthermore, all treatments with soil conditioners promoted improvements in soil microbiological attributes. Therefore, it can be concluded that soil conditioners play an important role, and the best treatment among those evaluated was the one containing powdered soil conditioner enriched with Trichoderma asperellum + Methylobacterium symbioticum.
Metodologia 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/0000-0003-2576-7470
The 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.
Quintais produtivos e segurança alimentar: práticas agroecológicas no Norte Pioneiro do Paraná
(Universidade Estadual do Norte do Paraná, 2025) Wesgueber, Nataly de Oliveira; Poletto, Rodrigo de Souza; https://orcid.org/0000-0002-7034-7865; https://lattes.cnpq.br/8774064317309922; Silva, Diego Contiero da; https://orcid.org/0000-0002-4291-034X; https://lattes.cnpq.br/6613984286184275; Franco, Danilo Miralha; https://orcid.org/0000-0002-8246-8429; https://lattes.cnpq.br/121602191337518; Hata, Fernando Teruhiko; https://orcid.org/0000-0003-0590-743X; https://lattes.cnpq.br/9498242631830029; Alves, Viviane Sandra; https://orcid.org/0000-0003-2381-8115; https://lattes.cnpq.br/3794580975938452
Family farming, which is predominant in the state of Paraná, accounts for approximately 90% of rural establishments. A significant portion of these properties are smaller than one fiscal module, limiting their economic viability and compromising both food security and household income. In this context, productive home gardens emerge as a sustainable, low-cost, and highly diverse agroecological alternative. These spaces contribute directly to the production of healthy food, the preservation of traditional knowledge, and the generation of complementary income. This study aimed to characterize productive home gardens in the Northern Pioneer region of Paraná, analyzing their impact on food and nutritional security, eating habits, and the autonomy of the families involved. The research employed semi-structured questionnaires applied to family farmers who maintain productive home gardens, collecting socioeconomic data, diversity of cultivated species, management practices, and the frequency of consumption of fresh and ultra-processed foods. The results showed that most gardens are managed by women and rely on sustainable practices such as organic fertilization, biological pest control, and agroecological preparations. A wide variety of vegetables, fruits, medicinal and culinary plants was observed, promoting balanced diets. Despite the increasing presence of ultra-processed foods, those grown in home gardens still dominate the families' diets, highlighting their role as tools of nutritional and cultural resistance. In addition to promoting food sovereignty, these gardens contribute to biodiversity conservation, reduced dependency on external inputs, and improved quality of rural life. A biodiversity-rich, regionally adapted, and easily replicable garden model was developed, reinforcing its potential as a strategy for sustainable rural development and food security.
Terbutilazina na entressafra: período de segurança pré-semeadura e seletividade para soja em solos de textura contrastantes
(Universidade Estadual do Norte do Paraná, 2026) Osipi, Carlos Botelho Pereira; Osipe, Jethro Barros; https://orcid.org/0000-0001-6453-3090; http://lattes.cnpq.br/9692340257207288; Kölln, Oriel Tiago; https://orcid.org/0000-0002-8507-9808; http://lattes.cnpq.br/8041626078120100; Osipe, Jethro Barros; https://orcid.org/0000-0001-6453-3090; http://lattes.cnpq.br/9692340257207288; Gustavo, Dário; https://orcid.org/0000-0002-4648-6881; http://lattes.cnpq.br/5682942731827088; Dias, Roque de Carvalho; https://orcid.org/0000-0001-5433-5373; http://lattes.cnpq.br/5490315867189084
Chemical weed control during the off-season allows interventions when weeds are still at earlier growth stages and broadens the range of available herbicide modes of action, which supports herbicide rotation. However, this practice also raises concerns about residual activity on the succeeding crop and the potential risk of crop injury. Terbuthylazine has emerged as a potential alternative to atrazine. Understanding its behavior in soils with contrasting textures, as well as its potential to injure currently used soybean cultivars, is essential for establishing safe recommendations. This study aimed to: (i) determine the minimum interval required between terbuthylazine application and soybean sowing in sandy- and clay-textured soils; and (ii) identify differences in soybean cultivar sensitivity to terbuthylazine. To address objective (i), two field experiments were conducted in Assis, São Paulo State, Brazil (sandy Oxisol, 15% clay) and Bandeirantes, Paraná State, Brazil (clayey Rhodic Eutrudox, 60% clay), using terbuthylazine rates of 0.6 and 0.8 kg a.i. ha⁻¹ applied at 48, 36, 24, 12, and 0 days before soybean sowing (cultivar NK 6630). For objective (ii), the sensitivity of five soybean cultivars was evaluated under greenhouse conditions based on crop injury, chlorophyll content (SPAD index), fresh mass, and dry mass. In the sandy soil, the minimum safe interval was 32 days for both herbicide rates. In the clayey soil, no effect on yield was observed, regardless of rate or application timing. Genotypic variability in cultivar response was observed: NK 6630 was the most sensitive material, showing greater crop injury and lower SPAD values, whereas Monsoy 6601 was the most tolerant, with lower levels of crop injury.
Variabilidade da cobertura com diferentes modelos de pontas de pulverização na cultura do milho
(Universidade Estadual do Norte do Paraná, 2025) Silvério, Marcio Aparecido; 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; Gandolfo, Marco Antonio; https://orcid.org/0000-0003-2314-3752; https://lattes.cnpq.br/5560552732033631; Antuniassi, Ulisses Rocha; https://orcid.org/0000-0002-3154-8664; https://lattes.cnpq.br/9754851029548502; https://lattes.cnpq.br/2379804514613050; https://lattes.cnpq.br/5560552732033631; https://lattes.cnpq.br/9754851029548502; https://orcid.org/0000-0002-3071-4827
The quality of the application is directly related to the choice of the spray nozzle model and the leaf angle presented by the crop. Given the scarce literature on the subject, this study aimed to evaluate different spray nozzle models in terms of application coverage on corn leaves with vertical and horizontal angles in the plant. The experiments were conducted in both field and laboratory settings. Twelve spray nozzle models with different spray projection angles were analyzed: flat fan, pre-orifice flat fan, air-induction flat fan, deflector flat fan, dual flat fan, inclined-angle flat fan, and hollow and full cone nozzles. The application rate was standardized at 100 L ha−1, controlled by pressure, flow rate, and boom travel speed. The spray solution used in the applications was composed of a fluorescent orange tracer at a concentration of 2.5 g L−1. The field experiment followed a randomized block design with four replications, six plants per repetition, and three distinct crop stages (V5/V6, V7, and VT). In the laboratory experiment, a completely randomized design was used, with four replications and two artificial plants. After application, the leaves were detached, sectioned, and images were captured in a dark environment under ultraviolet light. The images were then automatically processed to quantify spray droplet coverage. Coverage was analyzed in the upper, middle, and lower regions of the corn plant and the artificial plant, as well as in the adaxial, abaxial, basal, middle, and apical regions of the corn leaves. The results were interpreted using a dendrogram, applying dissimilarity analysis techniques based on the Euclidean distance method and complete hierarchical clustering, considering the spray nozzle models and the coverage analysis locations. Experiments with targets or leaves positioned vertically showed greater variability among groups, resulting in less similarity between nozzles and the evaluated plant and leaf regions. In contrast, experiments with horizontal targets allowed for a better definition of the relationships between nozzles and coverage in different plant regions, indicating similar performance in specific regions such as the lower and middle sections. Coverage was well-defined in regions of lower variability (basal > middle > apical) and (adaxial > abaxial) compared to those with greater variability (whorl, upper, middle, and lower). Additionally, differences exist among nozzles within the same flat-fan and cone- jet classes, highlighting distinctions in nozzle models based on spray angle design, pressure, and droplet classification.

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