Periódicos
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
Navegar
95 resultados
Filtros
Configurações
Resultados da Pesquisa
Item Application rate and hydraulic tips used in remotely piloted aircraft affect the phytosanitary products in coffee plant canopies(Editora da Universidade Estadual de Maringá - EDUEM, 2024) Alvarenga, Cleyton Batista de; Zampiróli, Renan; Cunha, João Paulo Arantes Rodrigues da; Rinaldi, Paula Cristina Natalino; Cunha, Bruno Amâncio da; Faria, Layanara OliveiraMost coffee (Coffea arabica) phytosanitary management techniques are performed using ground-based equipment, and remotely piloted aircraft are a recent alternative. Therefore, this study evaluates the effect of different application rates and hydraulic tips used for spreading phytosanitary products on coffee crops using a remotely piloted aircraft, assisted by artificial targets and dye tracing. The experiment was a 4 × 3 factorial randomized block design with four tips (XR 110-01, TT 110-01, AIXR 110- 015, and TTJ60 110-02) and three application rates (8, 12, and 16 L ha-1 ). Hydrosensitive paper was used to analyze the droplet spectrum, and the Brilliant Blue tracer was used to detect spray deposition. The DJI Agras T20 remotely piloted aircraft was used to apply the phytosanitary product. Speed, flight height, and application range were maintained at 5.56 m s-1 , 2 m, and 5 m, respectively. The flight direction was perpendicular to the crop planting lines. The application rate and hydraulic tip jointly controlled the accumulation of droplets on the target according to its position in the plant canopy. Therefore, remotely piloted aircraft can be used in coffee phytosanitary management, particularly to control targets that predominately occur in the upper third of the plant canopy.Item Productivity and grain size of coffee grown in different weed management systems(Editora da Universidade Estadual de Maringá - EDUEM, 2021-03-09) Zaidan, Úrsula Ramos; Campos, Renata Cássia; Faria, Rodrigo Magalhães; Zaidan, Iasmine Ramos; Souza, Wendel Magno de; Santos, Ricardo Henrique Silva; Freitas, Francisco Cláudio Lopes deIntensive weed management is one of the most common practices in coffee cultivation areas. Consequently, some problems, such as soil degradation and the selection of herbicide resistant weed, have increased over time, but, if properly managed, weeds at coffee planting inter-rows can offer benefits of erosion control, nutrient recycling and crop sustainability. The aim of this study is to evaluate the effect of different weed management strategies on the productivity and coffee grain size, i.e., quality. The experiment is installed onto a resprouting Coffea arabica L. site, four years after it was established. Treatments are implanted at planting inter-row Urochloa ruziziensis, Pueraria phaseoloides, and spontaneous vegetation maintained by mowing, herbicides, and weeding. To measure dry matter accumulation, samples are taken with a 0.25 m2 square template at plots maintained by mowing and herbicide application. To evaluate the yield and granulometry, coffee fruits are harvested, processed and classified in a set of 14 sieves (grouped in flat or “moca” shapes). The methods of controlling herbicide and weeding show significance in relation to grain production, with the production of grains having a higher market value standing out, when compared with the other treatments. The accumulation of dry matter above soil, in treatments with herbicides and spontaneous vegetation positively influenced the early coffee productivity (2018), and with U. ruziziensis and spontaneous vegetation, positively influenced the productivity of late harvest (2019). The accumulation of dry matter on the soil tends to be positively linked to coffee productivity, especially in periods when there is a shortage of rain in the region under study; however, it cannot be stated that this influence relationship (causality) has a direct positive effect between dry matter mass production and productivity of future coffee plantations.Item Initial growth of coffee plants associated with the use of kaolinite and adjuvant(Universidade Federal de Lavras, 2023-04-04) Costa, Bruna Penha; Tsutsumi, Cláudio Yuji; Rego, Carlos Augusto Rocha de MoraesAbiotic stresses cause significant damage to coffee plants’ development. Seeking solutions to mitigate them, studies about antiperspirant action have been intensified, for instance, kaolinite, which produces a film of particles with reflexive properties. In this context, this experiment aims to evaluate the effects of applying kaolinite doses in different colors with or without the addition of adjuvant on biometric variables during coffee plants’ initial growth. The randomized block design was used with three repetitions in an incomplete factorial scheme with an additional treatment, resulting in 11 treatments and 33 plots. The first factor comprised three kaolinite doses (20, 40, and 60 g); the second factor had two kaolinite colors (white and cream), and the third factor was the absence or presence of an adjuvant, also including an additional treatment (control). The plot consisted of four seedlings of the cultivar IPR 100. It was observed that the plant height (PH), number of plagiotropic branches (NPB), leaf area index (LAI), leaf dry matter (LDM), shoot dry matter (SHDM), root dry matter (RDM), and total dry matter (TDM) presented significant differences. Regarding PH, the dose of 40 g of cream kaolinite increased 7.07 cm more than the control. For LAI, the dose of 40 g with adjuvant had a 97.65 increase. For LDM and TDM, the dose of 40 g of white kaolinite with adjuvant presented respective increases of 5.2 and 12.78 g. The application of white kaolinite with adjuvant increased SHDM by 4.52 g. For RDM, the dose of 40 g of white kaolinite with adjuvant increased 6.51 g more than the control. The dose of 40 g of white kaolinite with adjuvant had a higher effect on the biometric variables.Item Determinação de inibidores da germinação no espermoderma de sementes de café (Coffea arabica L.)(Associação Brasileira de Tecnologia de Sementes, 2002-03-01) Pereira, Carlos Eduardo; Von Pinho, Édila Vilela Resende; Oliveira, Denilson Ferreira; Kikuti, Ana Lúcia PereiraSementes de café apresentam germinação lenta, aumentando consequentemente o período de formação das mudas. A causa dessa germinação lenta, ainda não está elucidada. Aparentemente, a difusão de gases e da água tem papel secundário comparadas ao efeito de inibidores presentes. A presente pesquisa foi desenvolvida no Setor de Sementes do Departamento de Agricultura e no Laboratório de Química da Universidade Federal de Lavras. Em uma pesquisa preliminar, utilizando sementes de alface como indicadora de inibidores e extrato aquoso de espermoderma ("película prateada"), ficou evidenciada a presença de inibidores nesse tecido. Em uma segunda etapa o extrato aquoso da película prateada foi submetido a um fracionamento, em teste in vitro. Observou-se, por meio desse teste, que a fração ativa encontrava-se na fase metanólica, a qual foi concentrada sob vácuo e eluída através de coluna de sílica gel com metanol, água destilada e HCl 0,1M. Após concentração sob vácuo da fração ativa originou-se um sólido branco, que se mostrou homogêneo segundo análise por cromatografia em camada fina com placas de sílica gel. Por meio de análise de espectrometria de infravermelho, de massas e de ressonância magnética nuclear de ¹H e de 13C, atribuiu-se a tal sólido a estrutura da cafeína. Conclui-se que o espermoderma pode contribuir para a lenta germinação das sementes de café, possivelmente devido à presença de cafeína.Item Pulverização foliar em cafeeiro (Coffea arabica L.) II: aplicação de adubos potássicos(Universidade de São Paulo, Escola Superior de Agricultura, 1961-10-28) Menard, Louiz Neptune; Crocomo, Otto Jesu; Gomes, F. Pimentel; Campos, Humberto deThe uptake of potassium fertilizers, namely, KC1, K2S04 and KN03, by beans and coffee leaves was studied in the experiment described herein. The fertilizers were applied as leaf sprays at the rates of 2,25, 4,50 and 9,00 grams, of K20/tree split in 3 applications which were made every week; the proper amount of salts were dissolved in 1 liter of water with wetting agent. Fifteen days after the last application both beans and leaves were sampled for analysis. No leaf injury resulted from the potassium sprays. Leaf -K and bean -K was significantly raised as consequence of the foliar applications of the K- bearing salts.Item Estudos sobre a alimentação mineral do cafeeiro: VI Efeitos das deficiências de micronutrientes em Coffea arabica L. var. Mundo Novo cultivado em solução nutritiva(Universidade de São Paulo, Escola Superior de Agricultura, 1961-04-11) Malavolta, E.; Haag, H. P.; Johnson, C. M.Young coffee plants (Coffea arabica L., var. Mundo Novo) were grown in nutrient solution purified from micronutrients contaminants by the method of MUNNS & JOHNSON (1960). All plants, except those in the control treatment, wer given all macronutrients and all micronutrients except one which was omitted in order to induce its shortage. Symptoms of deficiency were obtained for all known micronutrients but chlorine. Measurements, observations and chemical analysis of leaves allowed the following main conclusions to be drawn. 1. The relative influence of micronutrients in growth-measured by the fresh weight of the entire plant - was as follows: -Fe -Zn -Cu -Mo -Mn complete = -B = -CI. that is: the omission of iron from the nutrient solution caused the severest reduction in growth; lack of B and Cl had no effect. 2. Symptoms of deficiency of B, Fe, Mn, and Zn were found to be in good agreement with those in the literature. Effects of Cu and Mo shortage, however, had not been described so far: In the case of the Cu-deficient plants, the younger leaves were distorted, having an "S" shape, due probably to lack of growth of the veins; they lost their green color and developed rather large, necrotic patches near the margins. When molybdenum was omitted from the nutrient solution yellow spots develop near the margen of subterminal (fully mature) leaves; they became necrotic; there was a characteristic downward curling of the leaf blade along the mid rib so that the opposite edges touched each other underneath. 3. The levels of micronutrients found in normal and deficient leaves are given in Table 4. It is hoped that those values will serve as a basis of judgement of micronutrient contents found in leaves of field grown plants.Item Adubação e irrigação de café: adubação combinada com irrigação no primeiro ano da instalação das covas(Universidade de São Paulo, Escola Superior de Agricultura, 1961-03-04) Graner, E. A.; Godoy Junior, C.; Godoy, O. PereiraThis paper deals with different types of fertilizer applications in coffee hill in the moment of transfering the plants to the field. During the first year, irrigation was applied in the dry season. After one year, the following characters were analised: plant height; plant diameter; number of productive branches; lenght and number of nodes in the first branch of the plant. The results obtained can be summarized as follows: the irrigation employed did not affect the treatments and mineral fertilizers combined with organic fertilizer were better than the others treatments used for comparisons.Item Diagnosis about the perspectives of precision applications of coffee growing technologies in municipalities of Bahia, Brazil(Universidade Federal de Lavras, 2022-06-09) Fagundes, Rozymario Bittencourt; Bolfe, Édson LuisBrazil is the largest coffee producer in the world and precision agriculture (PA) is essential for the efficient management of crops. However, one of the challenges is finding the best way to do it. In this sense, we sought to present in this article a diagnosis on the perspectives of Precision Agriculture technologies applicability in the production of coffee (or Precision Coffee Growing) in some municipalities in Bahia, for greater efficiency, economic and environmental sustainability. To achieve this objective, a virtual document was sent to coffee growers in the state of Bahia. The questionnaire was sent by email in 2021 and the WhatsApp application, reaching 457 producers, 34 of whom, from all productive regions of Bahia, responded. The rate of return was 7.4%, within the expected by the use of the application. Considering the return of 34 answered questionnaires, a margin of error of 14% was obtained at a reliability level of 90%. It was found that 59.3% of the respondents have a high prospect of using PA in coffee growing, 26.6% have a medium perspective and 11.1%, a low perspective. The research shows that 67.6% do not use PA in the fields and that 51.7% consider the lack of training as a major obstacle to the use of PA and other digital technologies. Thus, the conclusion is reached that there is a promising scenario in Bahia state for the application of PA in coffee growing, if there is training for the development of techniques in farming.Item Precision coffee growing: a review(Universidade Federal de Lavras, 2022-06-09) Santana, Lucas Santos; Ferraz, Gabriel Araújo e Silva; Santos, Sthéfany Airane dos; Dias, Jessica Ellen LimaPrecision Agriculture (PA) technologies introduction in coffee-growing is becoming essential to advances in sustainable cultivation and increase in output. Applications that involve PA techniques in coffee production are defined now as Precision Coffee growing (PC). Systematically explored, studies on the subject contribute to improvements in the area, relating soil variability to its impacts on plants. The PC’s scientific approach offers new forms of manage-ment and more security in coffee production. Aimed at reducing pesticides application and nutrients to the soil, contributing to sustainable development in coffee production. Initially, the research on coffee production had dealt with soil spatial variability, highlighting the geostatistical methods and specific ways to sample the soil. With technological advances in agriculture, new ways of monitoring spatial variability are available. In this context, studies are arising on spatial variability related to the plant, applying terrestrial, aerial and orbital sensors, possibly creating perspectives for monitoring and mapping coffee production. Artificial intelligence, Remotely Piloted Aircraft (ARP) products, harvesting yield sensors, automatic grain classifiers, and remote sensing stand out as new technologies under development in coffee production. These applications in PC involving multidisciplinary research demonstrate new relevant ways of improving crop managing and sustainability guaranteeing.Item Coverage plants in the management of skeletal coffee(Universidade Federal de Viçosa, 2022-06-13) Franco Junior, Kleso Silva; Florentino, Ligiane Aparecida; Calegari, Ademir; Mantovani, José Ricardo; Caixeta, Ivan Franco; Terra, Ana Beatriz CarvalhoCurrently, one of the most used practices in national coffee production is skeletal pruning, to preserve productive capacity, correct plant architecture, minimize the occurrence of diseases, among others. Also, it reduces the plants diameter, exposing the soil to climatic conditions, erosion, loss of moisture and nutrients, negatively affecting the development of coffee. The use of cover plants intercropped with coffee is presented as a technique to avoid and minimize these problems. Therefore, the objective of this research was to evaluate the effect of cover crops on the chemical and physical characteristics of the soil and the skeleton coffee tree. The experiment took place at Fazenda Boa Esperança, city of Serrania, South of Minas Gerais, from October/2017 to December/2018, in randomized blocks, composed of 8 treatments with and without cover crops. Three replicates per treatment were used, totaling 24 experimental plots, each with 14 plants, being the 10 central considered useful for evaluation. The cover crops contributed to the improvement of nutrient contents in the soil, maintained a better level of humidity and milder temperatures providing a greater development to the skeletonized coffee. They also positively influence weed control, but none could suppress all plants present in the research.