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[This corrects the article DOI: 10.1371/journal.pone.0212289.].
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Pesticides aerial application may results in the drift to neighboring areas if some application technology is not well executed. This phenomenon should be minimized to reduce environmental risks and agricultural production costs. This work aimed to investigate the interaction of environmental conditions, surrounding distance, and application conditions influencing spray drift in aerial applications. Sampling data from aerial sprays were collected during three agricultural years (from 2012 to 2014) in fields cultivated with sorghum, millet, soybean, corn, and cotton. The following variables were evaluated: application swath width, application rate, distance from the applied field, wind speed, relative humidity, and temperature. The estimated Pearson's correlations and path analysis identified that application rate and distance from the applied field and application were the variables that most influenced drift. Equations relating spray drift in function of distance from the applied field and application rate were adjusted in function of the variable, and a response surface model was constructed to estimate drift. The major pesticide class sprayed with aircraft in the Brazilian Cerrado was insecticide, followed by fungicide. This scenario shows the potential hazard risk of spray drift over the environment. The concentration of the drift deposits decreased as surrounding distance and application rate were increased. A mathematical equation of drift prediction was established, where the variables that contributed most to drift deposits were surrounding distance and wind speed. Thus, it is very important to monitor and respect the wind speed limits during the aerial spraying, mainly when there is any risk potential associated with pesticide exposure over the downwind direction.
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Monitoramento Ambiental/métodos , Praguicidas/análise , Agricultura , Movimentos do Ar , Aeronaves , Algoritmos , Brasil , Umidade , Rodaminas/química , TemperaturaRESUMO
The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tietê as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promissão, and Nova-Avanhandava, located in the Tietê River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Guaçu reservoir, which belongs to the Mogi-Guaçu River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move coating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants.
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Sistemas de Informação Geográfica , Desenvolvimento Vegetal , Abastecimento de Água , Brasil , Coleta de Dados , Monitoramento Ambiental , Sedimentos Geológicos , Luz , Controle de Pragas , Astronave , Movimentos da ÁguaRESUMO
Grapevines (Vitis vinifera L.) are a good option for Brazilian growers using large amount of labor, resources and technology. Itália variety and its mutations require careful treatments since they are very prone to develop diseases. The aim of this study was evaluate the influence of droplet size and spray volume in the chemical deposition on grapevine leaves. The increase of the spray volume provided better deposition. There was no interaction between droplet size and spray volume as well as there was no influence of droplet size on the spray deposits on the leaves. The method can be considered adequate for the propose of this work.
A cultura da videira (Vitis vinifera L.) tem se mostrado como alternativa cada vez mais viável dentro da agricultura brasileira, utilizando grande contingente de mão-de-obra, elevado consumo de insumos e adoção de tecnologias atualizadas. Por serem altamente suscetíveis às doenças fúngicas, a variedade Itália e suas mutações somáticas exigem um cuidadoso tratamento fitossanitário, podendo necessitar de mais de 50 pulverizações num único ciclo. O objetivo deste trabalho foi avaliar a influência do tamanho de gota e do volume de aplicação na deposição de calda nas folhas da videira. Os resultados mostraram que o aumento do volume de calda propiciou maior depósito sem, entretanto, alterar o nível de perdas. Não houve interação entre tamanho de gotas e volume de calda, nem influência do tamanho das gotas no depósito de calda nas folhas. O método utilizado mostrou-se adequado aos objetivos deste trabalho.