RESUMO As doenças foliares da soja afetam o índice de área foliar (IAF) e a estrutura principal para a fotossíntese e a produtividade. O objetivo deste estudo foi propor uma nova metodologia para determinar o início das aplicações de fungicidas, com base no IAF, na taxa de aplicação e na inclusão de um fungicida multissítio, para controlar a ferrugem asiática da soja (FAS). O estudo foi implementado no delineamento de blocos casualizados e em dois locais, com quatro repetições em um esquema fatorial triplo mais um tratamento adicional (4 × 2 × 2 + 1), sendo 4 IAF da soja (0,9, 1,8, 3,6 e 6,1) indicadas para iniciar as aplicações de fungicida; dois volumes de pulverização (70 e 120 L ha-1); com ou sem fungicida multissítio (mancozeb), e tratamento sem fungicidas. A deposição de calda sobre as plantas não diferiu entre os manejos estudados para o IAF de 1,8 e 3,6. Os tratamentos incluindo fungicida multissítio em IAF de soja entre 3,6 e 6,1, em ambos os volumes, apresentaram resultados de controle superior. Os maiores rendimentos foram observados quando a aplicação de fungicida começou em 3,6 de IAF para os dois volumes. A melhor relação entre controle de doenças e produtividade ocorreu quando as aplicações começaram em 3,6 de IAF com 70 L ha-1 e fungicida multissítio.

ABSTRACT Soybean foliar diseases negatively affect leaf area index (LAI) and compromise the main structure for photosynthesis and grain yield. The objective of this study was to propose a new methodology to determine the commencement of fungicide application based on the soybean LAI, spray volumes, and the inclusion of a multisite fungicide to control Asian soybean rust (ASR). The study was implemented in a randomized block design at two locations, with four replicates in a factorial scheme plus one additional treatment (4 × 2 × 2 + 1) - four soybean LAI (0.9, 1.8, 3.6, and 6.1) indicating the initiation stages of fungicide applications, two spray volumes (70 and 120 L ha-1), with or without multisite fungicide (mancozeb), and a control treatment without fungicide. The spray deposition on plants did not differ between the treatments for 1.8 and 3.6 LAI. Treatments including the multisite fungicide for LAI between 3.6 and 6.1 for both spray volumes presented superior ASR control results. The highest soybean yields were observed when fungicide application started at 3.6 LAI for both spray volumes. The best correlation between disease control and grain yield occurred when the applications started at 3.6 LAI with 70 L ha-1 spray volume and the multisite fungicide.

ABSTRACT The use of ultra-coarse droplets for herbicide application reduces the risk of drift but may compromise the coverage and efficacy of the treatment. The objective of this work was to evaluate the use of ultra-coarse droplets, in different spray volumes, in the application of dicamba herbicide in association with glyphosate, for the control of weeds in two field trials. The first trial was conducted in a 5 x 2 factorial design, with five spray volumes (58, 72, 96, 144, and 177 L ha-1) and two air induction flat-fan spray tips (MUG 110015 - MagnoJet and TTI 110015 - Teejet). The control efficiency of Commelina benghalensis and the spray deposition on the target were evaluated by detecting a tracer using spectrophotometry. The second was conducted in a 2 x 2 factorial scheme, using two volumes (100 and 125 L ha-1) and two tips (MUG 11002 and TTI 11002). The control efficiency of Conyza spp. and fresh matter were evaluated. The different spray volumes and tips did not differ in relation to the deposition of the tracer. The use of ultra-coarse droplets was adequate for weed control. The TTI and MUG tips gave similar and adequate control performance starting at 96 L ha-1. Increasing the volume above 100 L ha-1 did not result in better control.

ABSTRACT An adequate combination of factors involved in the technology used for phytosanitary product application contributes to an efficient spray deposition on the target. The objective of this study was to use multivariate analysis to characterize the magnitude of effects and the order of influence of three factors that interfere with the quality of phytosanitary product application in coffee plants. An entirely randomized design was adopted, with four repetitions, using a 2 × 2 × 3 factorial scheme, with two classes of droplets quality (fine and coarse), two application rates (250 and 400 L ha-1), and the use of adjuvants (with no adjuvant or with Fighter®and Aureo® adjuvants). The quality of the application was determined by jointly analyzing the spray deposition on three thirds of leaves, in their internal and external layers, the runoff to soil, coverage, droplet density, relative amplitude, and the volumetric median diameter. The results underwent analysis of variance (ANOVA) to measure the effect sizes (η2). After testing the assumptions of multivariate analysis, clustering and principal component analyses were performed. The class of droplets was found to be the most influential factor in the quality of the phytosanitary product application (spray deposition and runoff to soil). When focusing on spray deposition on leaves, the second-most influential factor was the application rate and the relation between the application rate and the adjuvants. For the other variables, the second-most influential factor was the application rate.

ABSTRACT For the successful application of phytosanitary products, it is essential to understand the spraying process well. The present work aims to evaluate the spectrum and speed of the droplets produced by different spray nozzle models with air induction, working under different operating conditions. The experiment was conducted using an entirely randomized design with five repetitions in a 3 × 3 × 3 factor scheme that incorporates three nozzle models (ADIA, AIXR, and GA), three nominal flows (0.76, 1.14, and 1.51 L min−1), and three operating pressures (200, 300, and 400 kPa). The spectrum and speed of the droplets were determined directly using a real-time droplet analyzer based on high-resolution image analysis. The spray nozzle model interfered with the results. The ADIA promoted Dv0.5 (VMD) higher than AIXR and GA, reaching differences of up to 90%. The increase in pressure promoted a reduction in the droplet size; however, there was no well-defined behavior for the relationship between the flow rate and droplet size. The ADIA and AIXR gave rise to greater uniformity of the droplets in most of the evaluated conditions. The increase in pressure promoted an increase in the speed of the droplets. However, the effect of the nozzle model on this parameter was dependent on the flow.

ABSTRACT It is a well-known fact that the application of pesticides can be improved using an electrostatic spray due to the reduction of the application rate and increase in deposition on plant targets. However, little information exists on the use of such technology in maize crops. Thus, this study is aimed to evaluate the spray deposition on maize resulting from spray application using an electrostatic sprayer in combination with low application rates and different spray compositions. A field experiment was conducted in a randomized block having a 2×2×2 factorial design with two application rates (95 and 52 L ha-1), with or without the spray electrification, and with or without the synthetic adjuvant. The droplet electrification ability, interference of the electrical conductivity of the spray solution, losses of spray solution to the soil, and spray deposition on maize plants were evaluated for two cases of insecticide applications. The Faraday cage method was used to determine the spray electrification ability of the equipment. The spray deposition on plants and the losses to the soil were analyzed using a tracer (food coloring dye) added to the spray solution that was subsequently detected by spectrophotometry. It was seen that the electrostatic sprayer improved the spray application efficiency, which responded positively to the increase in the electrical conductivity of the spray solution. The deposition of the electrified spray solution on the upper third canopy of maize was found to be higher; the spray solution electrification also reduced the losses to the soil, regardless of the application rate.

ABSTRACT The use of insecticides is common in pest management in wheat crops but may lead to higher production costs and environmental contamination. Therefore, a more comprehensive and uniform distribution of plant protection products in the desired target is recommended. The objective of this study is to evaluate the effect of different spray nozzles, application rates, and adjuvants on droplet spectrum and spray deposition in wheat crops. The physicochemical characteristics of the spray mixture, droplet spectrum, and spray deposition in wheat plants were evaluated. The lower application rate (75 L ha−1) combined with the use of the twin flat fan tip AS7030 and the adjuvant sodium lauryl ether sulfate (SLES) yielded droplets with a larger diameter. However, insecticide spraying using hollow cone tip MGA 015 without adjuvants provided the highest percentage of droplets susceptible to drift. SLES significantly decreased the percentage of drift by increasing droplet size, and the adjuvant silicone, d-limonene, and polyester copolymer increased spray deposition. The evaluated adjuvants increased the electrical conductivity and reduced the surface tension of the spray mixtures. These results indicate that it is possible to reduce the application rate from 150 to 75 L ha−1 without affecting spray deposition on wheat leaves.

Apesar da ampla distribuição do tatu-canastra Priodontes maximus, esta espécie apresenta baixas densidades em populações não conectadas. Aqui, relatamos 12 novos registros, incluindo cinco atropelamentos rodoviários de P. maximus em diferentes pontos de Cerrado e um em fragmento de Floresta Atlântica no centro-oeste do Brasil. Além dos registros relevantes, discutimos o efeito negativo da perda de espécimes por atropelamentos em estradas, o qual é um problema sério para a conservação e manutenção de populações locais de tatu-canastra.

Despite the widespread distribution of the giant armadillo Priodontes maximus, this species is found at low densities, often in disrupted populations. Here we report 12 new records, including five incidents of roadkill of P. maximus in different points of the Cerrado and one in an Atlantic Forest fragment in central-western Brazil. In addition to the relevant records, we discuss the negative effects of roadkills, which is a serious issue for the conservation and maintenance of local populations of giant armadillo.

ABSTRACT The aim of this study was to evaluate the spectrum and the velocity of droplets produced by nozzles with and without air induction, under different pressures and flow rates. The experiment was conducted in a completely randomized design with five replications, in a factorial 2 x 3 x 3 (two spray nozzles, three flow rates and three operating pressures). The spray nozzles with and without air induction of the Hypro manufacturer (GA and VP) were evaluated, with nominal flow rates of 0.76; 1.14 and 1.51 L min-1 and pressures of 200, 300 and 400 kPa. The spectrum and velocity of the droplets were determined directly, using a Visisize Portable P15 (Oxford Lasers, Imaging Division). The pressure increases further reduction of the VMD and the relative amplitude, and increases the droplet velocity. The droplets generated by the spray nozzles with air induction showed on average amplitude 1.54 times higher than the droplets generated by spray nozzles without air induction. The droplet velocity showed little variation between the nozzles with and without air induction with the same pressure and flow rate, however, spray nozzles with larger flow rates and pressures produced droplets with higher velocities.

ABSTRACT Farmers are seeking pesticide treatments with lower application rates and higher travel speeds. However, this can lead to a poor quality of the application. The aim of this study was to evaluate the spray deposition on soybean crop and the droplet spectra using different application rates and speeds. The experiment was conducted in soybean (R5 stage), M 6410 IPRO variety. Six treatments involving two application rates (80 and 150 L ha-1) and three speeds (10, 15 and 20 km h-1) were evaluated through a self-propelled sprayer. A characterization study of the spray droplets was conducted through the evaluation of water sensitive papers. The spray deposition study was carried out. For this, a marker was added to the application to be detected by absorbance in spectrophotometry. The use of spray nozzles with higher nominal flow, as well as lower pressures, produced droplets of larger sizes. The application rate of 80 L ha-1 provided equal and higher spray retention in the lower and upper leaves of the plants, respectively. The three speeds did not influence the deposition on soybean plants.

ABSTRACT: The use of aerial application with electrostatic charge is an alternative to improve the quality of insecticide applications in soybean crop. The objective of this study was to evaluate the drift and chemical control of the caterpillar and stink bug complex promoted by aerial applications of insecticide in the soybean crop, using electrostatic spray system and rotary atomizers. The insecticide Thiamethoxam + Lambda cyhalothrin was applied with a Cessna 188 Ag Truck agricultural aircraft in two treatments: SPE® electrostatic system, with 54 SPE-5 nozzles and 10 L ha-1 application rate, and Travicar model® 05165 rotary atomizer, with 55° angle blades and application rate of 20 L ha-1. Drift was evaluated through quantification of active ingredient, by means of liquid chromatography, on nylon strings set 20, 40, 80, 160 and 320 m downwind from the applied area. Control efficiency was measured by counting caterpillars and stink bugs found five days after application. The droplet spectrum was also evaluated through water sensitive papers placed in the target area. It was verified that the hydraulic nozzles, associated with the electrostatic system, generated lower drift, but there was no difference in pest control efficiency, in relation to the rotary atomizers.

ABSTRACT Pesticide drift is an issue in modern farming, mainly for crops under constant spraying as soybeans. This study aimed at assessing drift and pest control for aerial applications in soybean crops. Hydraulic nozzles and rotary atomizers, regulated to a wide spectrum of droplet sizes, sprayed thiamethoxam plus lambda-cyhalothrin using an agricultural aircraft Ipanema 202A at volume rate of 20 L ha−1. Treatments consisted of testing two devices: a rotary cage atomizer (Micronair AU 5000) with blade angles of 65° for larger droplets, and with angle of 55° for smaller ones; and a set of adjustable nozzles (Stol model) with deflector angle of 90° for smaller droplets, and with angle of 30° for larger ones. Drift was evaluated through quantification of active ingredient, by means of liquid chromatography, on nylon strings set 20, 40, 80, 160 and 320 m downwind from the applied area. Control efficiency was measured by counting caterpillars and stinkbugs found five days after spray. Rotary atomizers produced lesser drift compared to adjustable nozzles at the designed setting. Furthermore, drift can be reduced through a suitable regulation of the devices, keeping an effective pest control.

ABSTRACT The aim of this study was to evaluate the spectrum, the velocity and the potential drift risk of droplets sprayed by nozzles with and without air induction, with the addition of mineral oil to the spray solution. The experiment was conducted in a completely randomized design with five replications; in a factorial model 2 × 2 (two spray nozzles and spray solution with and without mineral oil Assist®). Spray nozzles with and without air induction were evaluated, with nominal flow rate of 1.14 L min−1 and pressure of 300 kPa. The spectrum and the velocity of droplets were evaluated directly, using a droplet analyzer (VisiSize D30) in real time based on the analysis of high-resolution images. The drift potential was evaluated in an open circuit wind tunnel. The data were submitted to analysis of variance and comparison test. In general, the addition of mineral oil (1.5% V V−1) resulted in an increase in the velocity of droplets, reduced drift and more homogeneous droplet spectrum. Air induction nozzles promoted larger and less homogeneous droplets, but they little affected the velocity of the droplets. There is an inverse correlation between drift potential and volume median diameter (VMD), which indicates that VMD can be used to predict the behavior of drift risk.

ABSTRACT The coffee crop requires great spray ability to penetrate into the plant canopy during the application of pesticides. The aim of this study was to evaluate the spray deposition on leaves of coffee plants and the chemical control of the leaf miner provided by the application of different spray nozzles, with and without the use of an auxiliary boom. The deposition on the upper, middle and lower parts of the plants and the losses to the soil were evaluated using a tracer quantified by spectrophotometer. We also evaluated the chemical control of the leaf miner, counting the larvae, after the application of the insecticides cartap and fenpropathrin. The trial was carried out in a randomized block design, with four replications, in a factorial model (2×2+1): with and without the auxiliary boom, three spray nozzles (hollow cone – MAG 02, flat fan – AD 11002 and air induction hollow cone – TVI 8002) and a control. The use of the auxiliary boom increased the deposition in the lower part of the plants but decreased in the middle part, besides the increase in the runoff. The different nozzles do not provided differences in the deposition, showing the technical feasibility in the use of the hollow cone nozzles with coarse droplets and flat fan. All the chemical control decreased the leaf miner population, without differentiation.

O cafeeiro apresenta diversos desafios para a tecnologia de aplicação dos produtos fitossanitários, principalmente no que se refere à penetração da calda no dossel da cultura e à redução da deriva. Objetivou-se analisar a deposição de calda pulverizada na folhagem do cafeeiro e a perda para o solo, proporcionada pela aplicação com diferentes taxas e pontas de pulverização. O experimento foi conduzido no esquema fatorial 2 x 2 e oito repetições, sendo os fatores pontas de pulverização (jato cônico vazio - ATR e jato cônico vazio com indução de ar - TVI) e taxas de aplicação de calda (200 e 500 L ha-1). Em todos os tratamentos as aplicações foram realizadas utilizando-se um pulverizador hidropneaumático e o marcador Azul Brilhante, o qual foi quantificado por espectrofotometria. Para avaliação de depósito foram coletadas folhas das metades superior e inferior das plantas e também lâminas de vidro já posicionadas junto à superfície do solo. O uso de pontas com indução de ar mostrou-se viável quanto à deposição de calda no cafeeiro, principalmente junto ao uso da maior taxa de aplicação. O emprego da menor taxa (200 L ha-1) mostrou-se viável junto ao uso da ponta de jato cônico vazio. A ponta com indução de ar proporcionou maiores perdas para o solo.

The coffee crop (Coffea arabica L.) has many challenges for the pesticide application technology, mainly with respect to the spray penetration in the orchard and drift reduction. The aim of this study was to evaluate the spray deposition on leaves of coffee plants and the loss to the soil provided by the application with different spray volumes and nozzles. The study was conducted using a factorial model 2 x 2, with two nozzles (hollow cone - ATR and hollow cone with air induction - TVI) and two rates (200 and 500 L ha-1). The brilliant blue tracer was added to the tank, which was detected by spectrophotometry after the application using an airblast sprayer. Leaves were collected from the upper and lower parts of the plant canopy and glass slides were positioned on the ground under the plant canopy, to collect the drained drops. The use of hollow cone nozzles with air induction together with the use of higher spraying rate (500 L ha-1) was feasible on the spray deposition in the coffee leaves. The lower spray rate (200 L ha-1) was feasible together with hollow cone nozzle. The hollow cone with air induction nozzle resulted in higher losses to the soil.

O objetivo deste trabalho foi avaliar a deposição de calda pulverizada na cultura da batata e o espectro de gotas promovidos pela aplicação aérea e terrestre. O experimento foi repetido em duas épocas, em lavouras comerciais de batata, no delineamento inteiramente casualizado, em esquema fatorial 6 x 2, sendo seis formas de aplicação (aérea, a 15 e 30 L ha-1 com atomizador rotativo, e terrestre, a 200 e 400 L ha-1, com pontas de jato plano duplo, com indução de ar e jato cônico vazio); e duas composições de calda (água e água mais o adjuvante fosfatidilcoline + ácido propiônico). Avaliaram-se deposição de calda no dossel da cultura, perdas para o solo e deriva, pela técnica da adição de traçador para quantificação por espectrofotometria, e espectro de gotas, por meio da análise de papéis hidrossensíveis. A adição do adjuvante, de forma geral, proporcionou maior retenção de calda nas folhas inferiores e superiores. A diminuição do volume de aplicação proporcionou boa deposição de calda no alvo, sendo uma alternativa para aumento da capacidade operacional. A aplicação aérea mostrou-se tão eficiente quanto as aplicações terrestres na deposição de calda no alvo. A utilização do adjuvante não interferiu no diâmetro da mediana volumétrica e na percentagem do volume de gotas pulverizadas menores que 100 μm.

The aim of this study was to evaluate the sprayed liquid deposition in potato crop and the droplet spectrum, promoted by aerial and ground applications. The experiment was conducted in duplicate, in commercial potato crops, in completely randomized design, in a factorial model 6 x 2: six application methods (aerial, with rotative atomizer at 15 and 30 L ha-1, and ground, at 200 and 400 L ha-1 with air induction twin flat-fan and hollow-cone nozzles) and with two spray liquid compositions (water and water plus phosphatydilcoline + propionic acid adjuvant). It was evaluated spray liquid deposition in the crop canopy, run-off and drift, by addition of a tracer for quantification by spectrophotometry technique and the droplet spectrum by image analysis of water-sensitive papers. In general, the adjuvant addition provided a better spray liquid retention into lower and upper leaves. The decrease of spray volume provided a good spray liquid deposition on target that was contribute for an increase of the operational capacity. The aerial application was as efficient as the ground applications on the spray liquid deposition on the target. The use of adjuvant did not modify the volume median diameter and the percentage of spray volume in droplets smaller than 100 µm diameter.