Mariana Rodrigues Bueno

Tamanho de gotas de pontas de pulverização em diferentes condições operacionais por meio da técnica de difração do raio laser

The present study aimed to evaluate the droplet spectrum of hydraulic nozzles, under different pressures and spray liquid compositions, using a laser particle size analyzer. In a completely randomized design, two air induction twin flat-fan nozzles (AD-IA/D 11002 and AD-IA/D11004) and two hollow-cone nozzles (MAG - 2 and MAG - 4) were evaluated, in factorial design 3 x 2: tree spray pressures (207, 276 and 345 kPa for twin flat-fan nozzles, and 414, 483 and 552 kPa for cone nozzles); and two spray liquid compositions (water and water plus phosphatydilcoline + propionic acid adjuvant). The addition of adjuvant reduced the volume median diameter for the AD-IA/D 11002 and 11004 nozzles; however it had an opposite effect with the MAG - 4 nozzles and not changed with the MAG - 2 nozzles. In adverse weather conditions, it is not recommended the use of hollow cone spray nozzle, even with the addition of adjuvant tested because of the high risk potential of drift.

Volumes de calda e adjuvante no controle de plantas daninhas com glyphosate

O sucesso de uma aplicacao de herbicida esta diretamente relacionado a uma boa deposicao da calda no alvo, com o minimo de perdas para o ambiente. Assim, o presente trabalho objetivou avaliar a deposicao e o controle de plantas daninhas promovido pela aplicacao de glyphosate em diferentes volumes de calda e com a adicao do adjuvante nonil fenol etoxilado. O experimento foi conduzido em delineamento de blocos casualizados com quatro repeticoes, em esquema fatorial 3x2, sendo tres volumes de calda (30, 60 e 150 L ha‑1) e duas composicoes (com e sem adjuvante adicionado ao tanque). Inicialmente, foi realizada a caracterizacao fisico-quimica das caldas pulverizadas. Foram avaliados, apos a aplicacao do glyphosate, utilizando pontas de pulverizacao hidraulicas de jato plano defletor: deposicao de calda no alvo, perdas para o solo e controle de plantas daninhas. O adjuvante promoveu alteracoes de pequena magnitude nas propriedades fisico-quimicas da solucao. Conclui-se que os menores volumes de calda proporcionaram maiores deposicoes nas plantas daninhas e menores perdas para o solo. O herbicida estudado proporcionou bom controle das plantas daninhas, independentemente da utilizacao do adjuvante e do volume de calda.

ELECTROSTATIC SPRAYING IN THE CHEMICAL CONTROL OF Triozoida limbata (ENDERLEIN) (HEMIPTERA: TRIOZIDAE) IN GUAVA TREES (Psidium guajava L.).

BACKGROUND Owing to the difficulty in reaching targets during pesticide applications on guava trees, it is important to evaluate new technologies that may improve pest management. In electrostatic spraying, an electric force is added to the droplets to control their movements such that they are efficiently directed to the target. The present study evaluated the performance of electrostatic and non-electrostatic spraying in the control of the guava psyllid, the deposition of the spray mixture on the leaves and the losses to the soil. RESULTS The deposition of the spray mixture was up to 2 times greater when using electrostatic spraying in comparison with non-electrostatic application. The losses of the spray mixture to the soil were up to 4 times smaller with the electrostatic spraying. Electrostatic spraying had better control of the psyllid. CONCLUSION It was possible to reduce the volume rate of application with electrostatic spraying without adversely affecting the control of the guava psyllid.

Deposição de calda e controle de plantas daninhas empregando pulverizador de barra convencional e com barra auxiliar, em volumes de calda reduzidos

Application technology directly influences the success of desiccation, supporting the effectiveness of weed control. This work evaluated herbicide deposition on the weeds, spray loss to the soil and the efficacy of weed control by two application technologies (conventional boom sprayer and auxiliary boom sprayer, by varying the spray volumes between them: 100 and 150 L ha-1 in the conventional system and 30 and 50 L ha-1 using the auxiliary boom). The experiment was conducted in a randomized block design with five replications. A tracer was added to the solution containing the herbicide glyphosate, to be detected by spectrophotometry. Spray deposition on the weeds did not differ depending on the presence or absence of the auxiliary boom, nor the spray volumes, showing the feasibility of using spray volumes between 30 and 50 L ha-1 with the auxiliary boom. Soil losses were higher when the conventional spray boom was used. The efficacy of weed control was very good, regardless of the treatment used.

Deposição de calda em plantas de soja empregando pulverizador com barra convencional e barra auxiliar

O deposito das gotas pulverizadas no alvo e fundamental para o exito nas aplicacoes de produtos fitossanitarios. Este trabalho avaliou a deposicao de calda em plantas de soja e as perdas para o solo promovidas por um pulverizador de barra convencional, dotado de pontas de jato plano, e por um pulverizador com barra auxiliar de arrasto, dotado de pontas de jato conico vazio, variando os volumes de calda: 150 e 200 L ha -1 no sistema convencional e 50 e 100 L ha -1 no sistema com barra auxiliar. Foi adicionado o tracador Azul Brilhante a calda para ser detectado por espectrofotometria em folhas da metade superior e inferior da soja e em placas de Petri colocadas junto ao solo. Avaliou-se o espectro de gotas por meio de papeis hidrossensiveis. As pontas de jato conico vazio, empregadas na barra auxiliar, promoveram gotas mais finas e mais uniformes. A deposicao de calda nas plantas de soja utilizando-se a barra auxiliar com ponta de jato conico vazio no volume de 100 L ha -1 foi semelhante as obtidas com a barra convencional. Em relacao as perdas para o solo, nao houve diferenca entre as tecnologias adotadas.

Deposição de calda na aplicação aérea e terrestre de fitossanitário na cultura da batata

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.