Revista Ceres

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9884

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Effect of air blast sprayer application speed on the dye retention of coffee leaves
(Universidade Federal de Viçosa, 2022-01-09) Alvarenga, Cleyton Batista de; Zampiroli, Renan; Rinaldi, Paula Cristina Natalino; Silva, Tulio Urban Lourenço Miranda
Improving the effectiveness of pesticide application for controlling insects, mites, and pathogens in coffee cultivation has been a major challenge for coffee farmers, researchers, and consultants. The present study aimed to assess the deposition and distribution of a brilliant blue tracer in the coffee canopy using Jacto’s Arbus 2000 Super Export EL and Kuhn’s Twister 2000 air blast sprayers at different application speeds (5 and 7 km h-1). The experiment was conducted using a randomized block design, with a 2 × 2 factorial arrangement (two sprayer models and two application speeds), with six replicates. After spraying, leaves were collected, and the deposition of the tracer was assessed using spectrophotometry. The canopy was divided into lower, middle, and upper heights, and subdivided into external and internal crown positions. The percentage difference in spray deposition between positions was termed relative spray deposition. Spray deposition in the internal crown differed only in the upper third section between sprayers. In the external crown, the application speed affected the deposition of tracer dye for both sprayers, whereas, in the internal crown, the application speed only affected the deposition of tracer dye in the upper crown section only when using the Arbus sprayer.
Effectiveness of coffee leaf miner control associated with spray deposition in coffee leaves
(Universidade Federal de Viçosa, 2020) Zampiroli, Renan; Alvarenga, Cleyton Batista de; Rinaldi, Paula Cristina Natalino; Andaló, Vanessa; Prado, Jair Rocha do; Gonçalves, Pablo Arthur Silva
Coffee production faces challenges due to the susceptibility of the crop to insects. Owing to the coffee leaf miner Leucoptera coffeella, which is one of the main insect pests, the technology for the application of phytosanitary measures becomes the main challenge for coffee growers. This study aimed to evaluate the effectiveness of coffee leaf miner control using different methods of application. The study was conducted in an experimental site in the municipality of Monte Carmelo – Minas Gerais. Spray depositions in different positions of the plant canopy and the effective control of coffee leaf miner were evaluated using the following application treatments: a hydropneumatic sprayer with varying spray volumes (200 and 400 L ha-1), two hollow-cone spray nozzles with the presence and absence of agricultural adjuvant, and electrostatic application using a spray volume of 200 L ha-1 with and without spray adjuvant. The addition of an adjuvant to the spray did not influence coffee leaf miner control; in contrast, a spray volume of 200 L ha-1 combined with the application of coarse droplets was efficient in the management of insect pest. The reduction in the rate of the application using coarse droplets increased the operational capacity and reduced spray drift potential.