Periódicos
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
Navegar
4 resultados
Resultados da Pesquisa
Item 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 MirandaImproving 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.Item 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 SilvaCoffee 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.Item Application technology for chemically controlling coffee leaf miner in the cerrado of Minas Gerais State(Universidade Federal Rural da Amazônia (UFRA), 2017) Zampiroli, Renan; Alvarenga, Cleyton Batista de; Andaló, Vanessa; Rinaldi, Paula Cristina; Assis, Gleice Aparecida deLeaf miner is a major coffee tree pest that causes severe losses. Most farmers perform chemical control in an attempt to reduce damage to the crop. Thus, the current study aims to analyze spraying efficiency and control effectiveness according to the management plan adopted in a coffee farm in the Cerrado of Minas Gerais. The application used Arbus sprayer, model 2,000, at the pressure of 600 kPa. The droplet spectrum was analyzed using water-sensitive paper. The plant architecture influence on the application quality was evaluated through the droplet spectrum and control efficacy. We conclude that the plant crown height and depth affected application efficiency. Spraying was an effective phytosanitary control of coffee leaf miner, reaching 87.5% control efficiency ratio, considering that infestation was three times higher than that recommended for the applied pesticide at the time of application.Item Association of Heterorhabditis amazonensis and Beauveria bassiana aiming the control of Hypothenemus hampei(Editora UFLA, 2020) Moreira, Igor Bitencourt Lima; Andaló, Vanessa; Assis, Gleice Aparecida de; Faria, Lucas Silva de; Carvalho, Fabio Janoni; Zampiroli, RenanAmong the main problems for coffee production, it is possible to mention the occurrence of coffee borer, Hypothenemus hampei. In order to seek alternatives to control the pest, the proposed objective was to evaluate the interaction between Beauveria bassiana UFU01 and Heterorhabditis amazonensis MC01 on the control of coffee borer. Therefore, four experiments were set. In the first, B. bassiana UFU01, H. amazonensis MC01 and both entomopathogens associated were applied in bored fruits displaced in vermiculite. In the second experiment, the methodology was similar to the previous one; however, the fruits were immersed in the suspensions. In the third experiment was evaluated the transport of B. bassiana UFU01 conidia by H. amazonensis, checking the mortality of Tenebrio molitor. In the fourth experiment, the fungus and the nematode were added to Petri dishes containing agar-water simultaneously to observe if the nematodes could carry B. bassiana UFU01 conidia. The obtained data were subjected to analysis of variance and the Tukey test (p <0.05), for comparison between means and regression analysis. It was found that, when entomopathogens were applied to vermiculite, treatments using B. bassiana UFU01 and H. amazonensis alone caused the highest mortality of H. hampei adults. For larvae, there was no difference among treatments. The same was observed when the fruits were dipped in the suspensions, with no difference among treatments. As for T. molitor mortality, it was observed that there was no difference among treatments. However, when applied in combination, there was a higher mortality caused by B. bassiana compared to H. amazonensis. In the last experiment, juveniles and conidia were found on the opposite side of the dish, and it can be inferred that the presence of conidia was due to transport by infective juveniles.