Interferência da redução no volume de aplicação sobre o controle da mancha preta (Guignardia citricarpa Kiely) em frutos de laranja 'Valência'

The chemical control of the causal agent of citrus black spot (CBS) has been highlighted for the excessive required number of sprayings, considerably increasing citrus production costs. Improvements in the spray efficiency and reductions in the quantity of phytosanitary products have already been searched, but the results of that practice are not consistent yet for its use at commercial scale. Thus, the aim of the present study was to evaluate the interference of reduced spray volumes in black spot control in citrus fruits. The experiment was carried out in commercial citrus orchard with 16-year-old plants of 'Valencia' variety, during 2007 agricultural season. Treatments consisted of three spray volumes: 3.5; 4.5 and 8.5 liters.plant-1, applied with Arbus 2000/Export airblast sprayer with special manifold of hydraulic nozzles, using fungicides and periods recommended for the disease control, totaling four sprayings plus a control treatment (without spray). The disease incidence and severity were evaluated by visual diagrammatic scale of notes in two different periods (preharvest and harvest), at three plant heights (low, middle and top) and three horizontal sections (entrance, frontal and exit) in two sides of the plant. The fallen fruits were counted every fifteen days, for previously selected plants, from the beginning of maturation to harvest, and the production was quantified (kg.plant-1). The disease incidence and severity were significantly lower when sprayings were done with 8.5 liters.plant-1 in the first evaluation period (pre-harvest), but in the harvest period there were not differences between the same parameters when 4.5 or 8.5 liters.plant-1 were sprayed. None of those treatments reduced the disease on the top section of plants, compared to control. The plant sections with fruits more exposed to sun rays, top and right side of the plant, demonstrated higher disease incidence and severity. The volume reduction from 8.5 to 4.5 liters.plant-1 can be adopted for citrus orchards without damaging the CBS control level.

Cobertura e depósito de calda fitossanitária em plantas de café pulverizadas com equipamento original e adaptado para plantas altas

The objective of this study was to evaluate the coverage of spray droplets on coffee plants as well as their deposition using a sprayer with and without adaptation of an auxiliary branch for tall plants. The experiment was conducted following a randomized block design with six treatments and four replications to evaluate the percentage of coverage for the spraying liquids in water sensitive paper fixed at four quadrants and two heights (lower and upper) of the plants, and the spray deposit with metallic marker (MnSO4) on sheets in the same positions of the water sensitive paper in two spray volumes (450 and 750 L h(-1)). The experiment was conducted in October 2011 in the town of Patroc nio-MG, and the experimental plots consisted of 30 plants of Catua IAC-99, with approximately 12 years of age and average height of 3.50 meters. The experiments were conducted following a randomized block design with six treatments and four replications to evaluate the coverage and deposition, in two spray volumes (450 and 750 L ha(-1)). Leaves were collected in four positions and also at the top four in the lower canopy. The results of the evaluations were analysed statistically by F test and for comparison of means by Tukey test at 5% probability. The auxiliary branch installed at the rear of the equipment is the most suitable when compared to use of equipment without this feature or installed in the front of the equipment. Furthermore, the application volume of 450 L ha(-1) results in coverages and deposits of spraying liquids equivalents to volume of 750 L ha(-1), considered sufficient according to the parameters evaluated.

Qualidade da aplicação de inseticida em amendoim (arachis hypogaea l.), com e sem adjuvantes na calda, sob chuva simulada

The present work aimed to evaluate the volumetric distribution profiles, droplet spectra, surface tension, contact angle of droplet and the spraying liquid deposition over the peanut leaves (Arachis hypogaea L.), under artificial rain, in comparison with deposition without rain, using two hydraulic nozzle models of plain fan and insecticide spraying liquids with and without adjuvants addition. It were used a patternator for volumetric distribution analysis, a laser particles analyzer to evaluate droplet spectra produced by SF 110015 and XR 110015 nozzles and tensiometer for droplet tension and contact angle. The spraying liquids evaluated were: water, lambda-cialotrina, lambda-cialotrina + nitrogen fertilizer and lambda-cialotrina + mineral oil. All experiments followed a completely randomized design. Data were submitted to variance analysis by F test and the means comparisons by Scott-Knott test at 5% of probability. According to the results, it must be considered the maximum spacing in spray boom usage of 50 and 90 cm between the nozzles SF110015 and XR110015, respectively. The adjuvants effects on droplet spectra have shown addicted to the nozzle and the product used, and the adjuvants addition to the spraying liquid affected the potential risk of drift; The Volumetric Median Diameter (VMD) of produced droplets by nozzles filled into thin class and were not influenced by the adjuvants. The nitrogen fertilizer adjuvant may be indicated to promote improvements on coverage and droplet deposition on target.

Interação pontas-adjuvantes na estimativa do risco potencial de deriva de pulverizações

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribuição espacial da deriva de produtos fitossanitários em pulverizações na cultura da laranja

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Métodos de coleta de deposição para ensaios de deriva em aplicações aéreas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae): caracterização macroscópica e determinação de inseticida e época de aplicação para controle

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Arranjo de semeadura da soja sobre o rendimento da cultura e da tecnologia de aplicação de produtos fitossanitários

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desempenho de pontas de pulverização quanto a indução de ar nas gotas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Espectro de gotas gerado por diferentes adjuvantes e pontas de pulverização

The application technology shows many parameters related to the quality of the application, one is the droplet spectrum, which is influenced by the spray nozzles and the adjuvant used. Therefore, the objective of this work was estimate the behavior of the droplet spectrum generated with different nozzles and different adjuvants. The experiment was installed containing four solutions from different type adjuvant dilution, as vegetal oil, mineral oil, surfactant and drift reduction, which were applied with two nozzle, one pre-orifice flat fan (DG 8003 VS) and other of air induction flat fan (AI 8003 VS), totaling 8 treatments with 3 repetitions. The experiment was realized in ideal weather conditions for spraying. The treatments averages were compared using Confidence Interval at 95% probability and the correlations between variables were analyzed using Pearson at 5% of probability. The analysis of droplet spectrum showed different behavior for each adjuvant and nozzle. The surfactant treatment showed VMD superior for all treatments when sprayed with AI nozzles. For the %vol.<100 µm the lowest value found was for the AI nozzle in combination with the surfactant. The significant correlations found for the nozzles AI and DG were negative between VMD and %vol.<100 µm. It can be concluded that the values of DMV and %vol.<100 µm showed that the nozzle with pre-orifice have droplet spectrum more prone to drift. The surfactant showed to be the best drift reduction technique when combined with the AI nozzle.

Adjuvantes na deposição de aplicações aéreas e terrestres

The Asian rust currently is the main disease of soybean culture, having as characteristics the difficult control, by start at the bottom of plants where penetration of the droplets is harder. The fine droplets has been used with the intention of improve the penetration and increase efficiency of agrochemicals, but that are losses by drift easily. New products have been developed to increase deposition of the drops at targets. The aim of this work was evaluate the TA- 35 capacity to improving the deposition of fungicides spray solution with or without mineral oil by aerial and ground applications. Was used a factorial 3x2, three spray solutions composed by Priori Xtra (concentrated suspension of azoxystrobin 200 g L-1 + cyproconazole 80 g L-1 ) mixed with adjuvants, Nimbus (emulsifiable concentrate containing aliphatic hydrocarbons 428 g L-1 ) and TA-35 (soluble concentrate containing sodium lauryl ether sulfate, surfactants, sequestering agents and emulsifiers), in aerial and ground applications. In ground applications was used 50 L ha-1 , TXA 8002 VS spray nozzles and on aerials was used 15 L ha-1 , Turboaero atomizer, both applying fine droplets. Was utilized the Brilliant Blue (FD & C n. 1) tracer to determine the deposits. There were used glass slides as targets to collect spray droplets. After to extract the tracer of the targets using distilled water, the samples were analyzed by spectrophotometry, thereby was possible quantify the tracer deposited on each glass slide. A study to evaluate possible losses of the tracer by degradation or retention also was done. The comparative analysis of treatments was done by statistical method "Confidence Interval for Differences Between the Averages" with 95% of confidence degree (IC95%). There was degradation or retention of the tracer between the processes of application of the droplets and the processing of the samples. The deposition averages with the presence of TA-35 were greatest for both sprayers however, there were not significant differences among the treatments. The viability of TA-35 use may consider other parameters or complementary studies.

Influência de adjuvantes no espectro de gotas de ponta com indução de ar

This study aimed to verify the influence of adjuvants on the droplet spectrum of an air induction nozzle. The experiment used nine spray solutions, one including only water and eight containing adjuvants: Nimbus® (mineral oil), Óleo vegetal Nortox (vegetal oil), Li-700® (a mixture of lecithin and propionic acid), Agral® (nonyl phenoxy poly ethanol), In-Tec® (nonyl phenol ethoxylate), Antideriva (nonyl phenol ethoxylate), Silwet® L-77 Ag (copolymer polyester and silicon) and TA 35 (sodium lauryl ether sulfate). A flat fan air induction nozzle Hypro® Guardian Air 110 03 was used for the droplet spectrum evaluation. The study was conducted at the Laboratory for Particle Size Analysis (Lapar), at FCAV/UNESP, Jaboticabal/SP - Brazil. The determination of the droplet spectrum characteristics (Volume Median Diameter/VMD, percentage of droplets smaller than 100 micrometers and span) was carried out by a particle size analyzer by laser diffraction Mastersizer S (Malvern Instruments). For statistical analysis the mean values were compared using Confidence Interval at 95% (CI 95%). The results showed that for the Hypro® GA air induction nozzle the oil based adjuvants (Óleo Vegetal Nortox e Nimbus®) increased the VMD. The percentage of droplets smaller than 100 micrometers was lower for the Agral®, Antideriva, In-Tec® e TA 35, in comparison with the Óleo Vegetal Nortox and Li-700®. The span was higher for the oil based adjuvants (Óleo Vegetal Nortox e Nimbus®) and lower for the TA 35 (sodium lauryl ether sulfate), showing that the TA 35 adjuvant has a potential to improve the quality of the droplet spectrum of the Hypro® GA 11003 nozzle.

Construção e validação de um túnel de vento para ensaios de estimativa da deriva em pulverizações agrícolas

The aim of this study was to build and validate a low cost reduced-scale wind tunnel for drift evaluation on pesticide application technology. The work was carried out at the NEMPA - Núcleo de Ensaio de Máquinas e Pneus Agroflorestais (NEMPA), FCA/UNESP, Departamento de Engenharia Rural, Botucatu/SP, Brazil. The wind tunnel main characteristics were an open circuit and a closed working section with a fan blowing air into the tunnel. Screens were fitted downstream after the fan in order to stabilize the air flow on the working section. The tunnel was built with 3.0 mm eucalyptus hardboard, with a total length of 4.8 m and a squared section of 0.56 m. The air flow was provided by a 180 W axial fan. The system was adjusted and calibrated to provide a laminar and stable flow at 2.0 m s-1. Validation studies were carried out by using a Teejet XR 8003 flat fan nozzle at 200 kPa (medium droplets) to apply a spray solutions containing water plus a food dye (Blue FDC) at 0,6% m v-1 mixed with two adjuvants: a polymer based anti drift formulation at 0,06% m v-1 and a sodium lauryl ether sulfate based surfactant at 0,2% v v-1. After a 10-second application the drift was collected on nylon strips transversally fixed along the tunnel at different distances from the nozzle and different high from the bottom part of the tunnel. Drift deposits were evaluated by spectrophotometry. The wind tunnel had low levels of turbulence and high repeatability of the data, which means that the flow was uniform and able to be used for carrying out measures to estimate drift. The validation results showed that the tunnel was effective to enable comparative drift measurements on the spray solution used in this work making possible the evaluation of drift risk potential under those spray technologies. The use of an adjuvant based on a polymer reduced the amount of drift from the nozzle compared to the surfactant.

Eficácia do flutriafol e do flutriafol + tiofanato metílico aplicados com gotas finas ou médias no controle da ferrugem asiática da soja

The aim of this study was to evaluate the influence of fine and medium droplets in the performance of flutriafol and thiophanate methyl + flutriafol for the control of Asian Soybean Rust (Phakopsora pachyrhizi Sydow & Sydow). The experiment was a 2 x 2 factorial design (2 droplet sizes x 2 fungicides) resulting in four treatments with six replications. The experimental area was set up with 24 plots (50 x 21 m). In each plot there was a central assessment area with 10 x 20 m. To the each plot there was a non-treated area placed in opposed direction to the wind. The evaluations of rust control were made by of the calculation of incidence (percentage of plants with rust), severity (level of infection), defoliations and soybean yield. The results were analyzed by the calculation of the confidence interval at 90%. The study was set up in curative control conditions with average infestation of 68.6%, average severity in the lower part of the canopy was of 35.9% and on the upper parte it was 4.57%. The results of severity, defoliation and productivity did not show statistical difference among the treatments. However, it was observed that in general there was tendency of better results with the application of flutriafol alone comparing with thiophanate methyl + flutriafol, since there was a small difference between two commercial products in the flutriafol active ingredient content (62.5 g ha-1 to the flutriafol alone and 60 g ha-1 to the thiophanate methyl + flutriafol). There was no statistical difference between fine and medium droplets. This fact can be explained by the characteristics of systemic action of the flutriafol and by the type of control made (curative). The flutriafol, being a systemic fungicide is less sensitive to the better coverage provided by the smaller droplets and, on the curative control, the amount of product deposited can became more import than coverage, mainly on the superior part of the leaves. These leaves are healthier than the inferior leaves that in general are the first to become completely compromised by the rust, losing importance to the plant. By this reason, medium droplets appear to have offered similar performance even not offering advantages in the leaf coverage. This fact may become important because in the practical side of the use of medium droplets, since this may increase the amount of time to spray, mainly because the fine and very fine droplets have more limitations related to drift and evaporation.

Inspeção periódica de pulverizadores nas principais regiões de produção de soja no Brasil

The aim of this study was to evaluate the evolution of calibration and maintenance practices for crop sprayers on soybean production areas in Brazil, in the 2006 and 2007 seasons, based on the Project IPP data. Therefore, the evaluation covered issues related to calibration, maintenance condition and the main components of 103 sprayers distributed in the following states: Rio Grande do Sul (35), Paraná (60), and, Mato Grosso do Sul (8). The evaluations were done at the rate of one sprayer per farm. The most frequent problems were related to the pressure gauge, spray leaks and calibration errors greater than 50% of the desired volume rate. The analysis of the application rate showed a tendency for the farmers to apply volume rates below the desired value. In 2006 the errors of the application rate were significant, with 70.4% for Rio Grande do Sul State, 74.5% for Paraná State and 37.5% for Mato Grosso do Sul State. In 2007 there was a reduction of errors, with averages of 50.0% for Rio Grande do Sul and 66.7% for Paraná. In general terms, the results showed improvements on the use, maintenance and calibration processes for crop sprayers on the areas covered by the Project IPP, with reductions on average indexes for calibration errors, leaks and bad tips, among other issues.