Sueli Martins de Freitas Alves

Qualidade da aplicação aérea líquida com uma aeronave agrícola experimental na cultura da soja (Glycine Max L.)

Advances in aerial pesticide application technology of chemicals have been given in the direction of reducing the syrup volume, which can cause poor distribution and consequent irregular deposition. This study aimed to evaluate the quality of the syrup spray on aerial application in soybean crop (Glycine Max L.). For the application, an experimental agricultural aircraft was used, applying a spray volume of 20 L ha-1. A bright blue food coloring added to the syrup spray was used for the determination of the volumes stored in the leaves of the upper third, middle and bottom of the soybean plants. These leaves were washed, and the volume determined by spectrophotometry. To obtain the drops spectrum were used artificial targets set by water sensitive paper, distributed in the middle and upper third of the plants. Data were submitted to analysis of variance with a single factor, considering the different positions in the plant, and control cards were made from the lower and upper control limits. The aerial application of syrup spray in the soybean crop had lower values of the volumetric median diameter, relative amplitude and coverage on the middle third in relation of the upper third of the soybean crop. There was less of the syrup spray deposition in the lower third. The coverage indicators of the syrup spray showed that aerial application with the evaluated agricultural experimental aircraft is not under statistical process control, in other words, outside of the quality standard.

Condições de trabalho associadas ao uso de agrotóxicos na cultura de tomate de mesa em Goiás

O Estado de Goias, em 2005 foi o maior produtor de tomate do Brasil. Para garantir a producao e controlar as pragas que atacam essa cultura, o tomaticultor apoia-se em pacotes tecnologicos utilizando a aplicacao sistematica de produtos quimicos. Objetivou-se, neste trabalho, conhecer o cenario no qual os trabalhadores da cultura de tomate em Goias estao inseridos. Foram selecionados, por meio de amostragem sistematica, seis municipios: Bonfinopolis, Corumba de Goias, Goianapolis, Leopoldo de Bulhoes, Pirenopolis e Silvânia. Os dados foram obtidos a partir das visitas de campo realizadas no periodo de dezembro de 2004 a outubro de 2005 e foram utilizados os seguintes instrumentos: entrevista, questionario proposto aos trabalhadores que manipulam os agrotoxicos e a tecnica da observacao livre. A partir da analise das informacoes foi possivel concluir que esses trabalhadores estao constantemente expostos aos agrotoxicos e ha uma falta de preparo para a manipulacao dessas substâncias.

Compactação e recalque superficial de um Latossolo Vermelho em condição de campo e laboratório

The application of dynamic loads in the soil, produces stress in wheel/soil interface in surface and depth. The aim of this study was to evaluate the compaction and superficial settlement of an Oxisol under different traffic levels under field and laboratory conditions; and to propose a methodology for dynamic load test, from traffic of the pneumatic wheel, applicable in the laboratory. In the field an agricultural tractor was used and in laboratory a traffic simulator. In the two experiments a randomized block design in split plots with four replications was adopted. The plots consisted of two tire inflation pressure: 96.5 and 137.9 kPa, and the subplots were five traffic intensities: zero (control), one, two, four and eight passes of the tractor or wheel simulator, according to the experiment. The variables measured were density of dry soil, degree of compactness and superficial settlement. The first two variables were analysed in the depth of 0-0.10 m. The traffic simulator was adequate to reproduce the situation observed in the field.

ESTIMATIVAS DE ATRIBUTOS DE FÍSICOS E QUÍMICOS DE SOLO POR MEIO DE REDES NEURAIS ARTIFICIAIS

Soil physical and chemical analyses are relatively high-cost and time-consuming procedures. In the search for alternatives to predict these properties from a reduced number of soil samples, the use of Artificial Neural Networks (ANN) has been pointed out as a great computational technique to solve this problem by means of experience. This tool also has the ability to acquire knowledge and then apply it. This study aimed at using ANNs to estimate the physical and chemical properties of soil. The data came from the physical and chemical analysis of 120 sampling points, which were submitted to descriptive analysis, geostatistical analysis, and ANNs training and analysis. In the geostatistical analysis, the semivariogram model that best fitted the experimental variogram was verified for each soil property, and the ordinary kriging was used as an interpolation method. The ANNs were trained and selected based on their assertiveness in the mapping of considered standards, and then used to estimate all soil properties. The mean errors of ordinary kriging estimates were compared to those of ANNs and then compared to the original values using Students t-Test. The results showed that the ANN had an assertiveness compatible with ordinary kriging. Therefore, such technique is a promising tool to estimate soil properties using a reduced number of soil samples.

USO DE IMAGENS NA AVALIAÇÃO DA DESSECAÇÃO DE PLANTAS DANINHAS COM USO DE GLIFOSATO

O uso de agrotoxicos pode garantir eficiencia no controle de pragas, doencas e plantas daninhas, no processo de producao. Objetivou-se com este trabalho analisar o percentual de plantas daninhas dessecadas por meio de imagens em diferentes doses de glifosato e adjuvantes utilizando um pulverizado costal. O experimento foi conduzido no delineamento em blocos casualizados, com arranjo fatorial 3x2x3, sendo dezoito tratamentos e quatro repeticoes por tratamento. Os tratamentos foram constituidos da combinacao de tres doses de glifosato (1080, 1440 e 1800 g ha -1 ), com ou sem adicao do adjuvante, e tres dias de analise (7, 9 e 12 dias). A verificacao da porcentagem de plantas daninhas foi feito em quatro estagios apos a aplicacao, o primeiro dia, correspondendo ao dia da aplicacao, e sete, nove e dose dias apos aplicacao. Foram utilizados dois metodos, a analise de imagens digitais e da fita metrica, onde no metodo digital consistiu em obter imagens de cada tratamento nos quatro dias por meio de uma câmara digital e o metodo da fita metrica, consistiu em esticar uma fita metrica de 10 metros de comprimento demarcada a cada 0,01 m, onde foi verificado, a cada 0,10 m, a presenca ou ausencia de plantas daninhas. Ja o espectro de gotas foi avaliado utilizando etiqueta de papel hidrossensivel. A adicao de adjuvante e doses de glifosato nao influenciaram no espectro de gotas. O metodo digital pode ser considerado um metodo de boa precisao para avaliacao do controle. O uso de adjuvante nao influenciou na porcentagem de plantas daninhas dessecadas ao longo dos dias e nem das doses utilizadas.