Coffee Science_v.15, 2020

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12726

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Physical and mechanical properties of the wood of coffee trunks and branches
(Editora UFLA, 2020) Velloso, Nara Silveira; Magalhães, Ricardo Rodrigues; Santos, Fábio Lúcio; Nunes, Márcio Felipe Pinheiro Neri; Vicentini, Bruno
Knowledge of the physical and mechanical properties of coffee plants is essential to the development of mechanisms that perform the harvesting of their fruits by the principle of mechanical vibrations; however, these properties have yet to be determined in the laboratory. In this context, the present study aimed to determine the mechanical and physical properties of coffee plants through tensile and compression tests by means of a universal testing machine. Elasticity modulus, Poisson’s ratio, and specific mass were determined for specimens developed from the trunks and branches of 20 samples whole coffee plants, Coffea arabica variety, Catuaí Vermelho cultivar. The elasticity modulus was determined by the slope of the secant line in the elastic region of the stress-strain curve. Poisson’s ratio was determined by direct measurements in regions previously marked on the specimens. The conventional specific mass was obtained by the ratio between the mass of specimens and their volume. The methodology allowed the studied properties and a database to be obtained, and they can be used as a basis for the development and operation of the mechanism used in the mechanical and semi mechanical harvesting of coffee fruits. The results obtained indicate the following values for elasticity modulus of the trunk, performed from compression tests: 1090.94 MPa in the longitudinal direction and 108.60 MPa in the cross-sectional direction. For elasticity modulus of the branches, performed from tensile tests in the longitudinal direction: 507.72 MPa. For Poisson’s ratio, determined by direct measurements: 0.25 for the trunk and 0.09 for the branches. And for specific mass: 1070.05 kg.m-3 for the trunk and 1036.33 kg.m-3 for the branches.
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, Renan
Among 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.
Motives for coffee consumption at coffee shops in Mexico
(Editora UFLA, 2020) Cruz-Flores, Maryan Ariadne; Espinoza-Ortega, Angélica; Thomé-Ortiz, Humberto; Vizcarra-Bordi, Ivonne
Coffee is one of the main sources of foreign exchange for developing countries. Mexico accounts only 2.68% of the world coffee production, but represent the most important source of foreign exchange in the agricultural sector. The Mexican coffee began to be recognized in recent years, and despite the increase of the consumption, Mexico is not considered an important consumer. The objective was to analyse the motives for coffee consumption at coffee shops with quality labels. A national and a transnational company were selected in central Mexico to carry out a total of 600 questionnaires. The questionnaire had four sections: frequency of consumption, Food Choice Questionnaire (FCQ), some images of coffee quality labels, and a socio-economic. The data were analysed using multivariate statistics, factor and cluster analysis. Indifferent, Pragmatic and Hedonic-Dependent consumers were identified; who are mostly young and middle-aged, single, childless and college educated. Their interest in attending coffee shops is to socialize; they are not interested in quality labels which have negative implications for the use of this type of labels in Mexico.
Soil chemical attributes in coffee growing with different agronomic techniques
(Editora UFLA, 2020) Voltolini, Giovani Belutti; Silva, Larissa Cocato da; Alecrim, Ademilson de Oliveira; Castanheira, Dalyse Toledo; Resende, Laís Sousa; Rezende, Tiago Teruel; Guimarães, Rubens José
The objective was to evaluate the chemical attributes in a coffee growing area, according to different agronomic techniques used and their associations. The experiment was conducted in the field, from January 2016 to October 2018. Coffee was planted in January 2016, with Mundo Novo IAC 379-19 coffee seedlings, with a spacing of 3.6 m between rows and 0.75 m between plants in the planting row. The factors under study were arranged in a 3x2x5 factorial scheme, making a total of 30 treatments. In the plots, three soil managements were randomized (soil cover with polyethylene film, soil cover with brachiaria-grass and conventional management of spontaneous vegetation). In the subplots, two types of fertilizers (conventional and increased-efficiency fertilizer). In the sub-subplots, four soil conditioners (coffee husk, phosphogypsum, water retention polymer, organic compost), and the control without conditioner. Aimed to evaluate soil chemical attributes in coffee growing with different agronomic techniques through the evaluation of: soil pH, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum saturation (m) and base saturation (V%). The use of fertilizers combined with the application of organic compost or coffee husk, provide increased soil pH, as well as the use of ecological management of brachiaria-grass. The use of organic compost as a soil conditioner increases phosphorus availability in the soil. Coffee husk, as a soil conditioner, is an efficient potassium source for the coffee crop. The use of organic compost and phosphogypsum increases the calcium and magnesium contents in the soil. The use of organic compost and coffee husk was efficient in increasing the base saturation grown with coffee. The use of organic compost, coffee husk and phosphogypsum reduced aluminum saturation in the soil. Treatments associated with the use of organic compost improve calcium, phosphorus and magnesium levels, increase pH and base saturation, besides decreasing aluminum saturation.
Quality of Coffea canephora beverage as a function of genotype, processing method and grain size
(Editora UFLA, 2020) Lima, Julião Soares de Souza; Silva, Samuel de Assis; Fonseca, Abel Souza da; Pajehu, Levi Fraga
After harvesting, the coffee beans tend to lose quality during fruit processing and grain storage, thus affecting the quality of the obtained beverage. The objective of this research was to evaluate the quality of the beverage obtained from conilon coffee (Coffea canephora) for seminal (S) and clonal (C) genotypes, two processing methods of the coffee cherries (natural and peeled), different sizes of coffee beans determined by sieves and two storing periods of 45 and 90 days. The coffee cherries were dried, natural (N) and peeled (P), on cement floor in greenhouse and classified through the 13, 14, 15, 16 and 17 sieves. After 45 days of storage, it is observed that the overall score (OS) of the beverage prepared from peeled clonal (PC) and natural seminal (NS) coffee beans increased with increasing bean size (sieves 15 and 16). The treatments PS13, PS14, PS15, PS16, PC15 and PC16 were significantly different, however, the overall score (OS) decreased after samples were stored for 90 days. It is concluded that after storing the coffee bean samples for 45 and 90 days, the OS decreased significantly for peeled seminal coffee (PS) sieves 13, 14, 15, and 16 and peeled clonal coffee (PC) sieves 15 and 16.
The influence of natrural fermentation on coffee drink quality
(Editora UFLA, 2020) Pereira, Leandro Ferreira Bernardes; Franco Junior, Kleso Silva; Barbosa, Camila Karen Reis
Coffee quality refers to various methods used in farming, selective harvesting that assist in quality preservation and drying methods to be performed. Some drying methods that are being performed fermentation procedures have helped in obtaining specialty coffees. The objective of the research was to evaluate the effects of controlled natural fermentation of coffee through the temperature and time and its influence on the quality of coffee, according to the prescribed attributes in SCAA methodology, the type of coffee drink and time for drying grain. The research was carried out at Lavrinha farm, located at Poço Fundo (south of Minas Gerais), with coffee fruits of Catuaí Vermelho IAC 144 cultivar and selective and manual harvesting. The treatments with temperature-controlled fermentation of 30 and 40 °C (1, 2, 3, 6 and 12 hours) and the control treatment were used with three replications in a randomized block system (DBC) in a factorial scheme. After fermentation, the batches were dried to 11.5% humidity and evaluated according to the SCAA (2015) methodology. The natural fermentation induced by temperature (°C) and time (hours) directly influenced the drink quality, resulting in a coffee with a score of 82 to 84 points, with attribute aggregation and special classification. Natural fermentation with temperature up to 40 °C and time control of 3 ,1 and 24 hours resulted in an improvement in coffee quality by 84 points.
Growth of robusta coffee after the application of herbicides to control Urochloa ruziziensis
(Editora UFLA, 2020) Silva, Karolina Flôres da; Shipitoski, Ricardo Moraes; Costa, Jhene Thais Dittmann da; Nardis, Barbara Olinda; Souza, Paulo Sérgio de; Araujo, Lourismar Martins; Andrade, Fabrício Ribeiro
The growth of coffee plants can be severely affected by competition with other plants, being necessary to the management of these, which can be performed by controls manual, mechanical, biological and chemical methods. This study aimed to evaluate the growth of coffee robusta due to no control of Urochloa ruziziensis (cv. Common) and control by manual weeding and herbicides in post emergence, seeking the most appropriate method. The experimental design was completely randomized, with four replicates of four treatments: control (no control of the U. ruziziensis); manual weeding; oxyfluorfen (1.44 kg a.i. ha-1); paraquat + diuron (0.40 + 0.20 kg a.i. ha-1) and glyphosate (1.92 kg a.i. ha-1), with the spray volume equivalent to 200 L ha-1. The herbicides were applied directly on the U. ruziziens plants 60 days after planting. 30 days after treatment, the following were evaluated: a, b and total chlorophyll content, stem diameter, plant height, number of leaves, leaf area, orthotropic and plagiotropic branches, dry shoot biomass, dry root biomass and root growth. U. ruziziens, when not controlled, caused a 42% reduction in the leaf area of robusta coffee in relation to those that were controlled through manual weeding. The herbicide oxyfluorfen and weeding were the most suitable for the control of U. ruziziens in the cultivation of coffee, since they did not affect seedling growth. Failure to control U. ruziziens or weeds leads to reduced growth of robusta coffee plants, except in the height due to the etiolation caused by competition with U. ruziziens.
Mathematical modeling of dehydration resistance of pericarp tissues and endosperm in fruits of arabic coffee
(Editora UFLA, 2020) Dias, Camila de Almeida; Andrade, Ednilton Tavares de; Lemos, Isabella Àvila; Borém, Flávio Meira; Westerich, Diogo Nogueira; Silva, Ana Claudia Almeida da
Coffee represents an important source of income for producers and for the Brazilian economy, being the second product in the country’s agricultural exports. Unlike other agricultural products, freshly harvested coffee has a high fruit water content, approximately 60% (dry base). It is fundamental to optimize the drying process for cost reduction and quality maintenance, making it necessary to understand the interdependence relation of the tissues of the pericarp and the coffee endosperm during the dehydration of the fruit. The objective of this work was to elaborate a drying model for the constituent parts of coffee fruits evaluating the resistance of each of the pericarp tissues and endosperm. The experiment was set up in a 4x6 factorial scheme (4 relative humidity of the drying air and natural, pulped natural coffee, pericarp tissues and endosperm: 1 - natural coffee and 2 – pulped natural coffee, 3 - exocarp + a portion of mesocarp, 4 - mesocarp, 5 - endocarp, 6 - endosperm]) in a completely randomized design with four replicates. The results were analyzed through analysis of variance and regression, using the statistical software STATISTICA 5.0®. The resistance to water outflow, regardless of the processing or the fruit part of the coffee, is greater when the coffee is dried with the lowest relative humidity. The natural coffee was the treatment that presented greater resistance, while the lower resistance was presented by the exocarp + a portion of mesocarp.
Resistance of new Coffea canephora clones to root-knot nematode (Meloidogyne incognita) in the western amazon
(Editora UFLA, 2020) Rudnick, Vaneide Araújo de Sousa; Vieira Junior, José Roberto; Fernandes, Cleberson de Freitas; Rocha, Rodrigo Barros; Teixeira, Alexsandro Lara; Ramalho, André Rostand; Espindula, Marcelo Curitiba; Santos, Anderson Vieira; Anjos, Elize Francisca Mendes dos; Uchôa, Francisco Paiva
Root-knot disease is among the main diseases affecting coffee crop. The plant selection to the development new resistant cultivars is among one the most efficient methods of control. The present work aimed to quantify the resistance responses of Coffea canephora clones to root-knot nematode Meloidogyne incognita in the Western Amazon. For this, 17 previously selected clones were evaluated in three experimental trials, carried out in the municipalities of Ji-Paraná and Porto Velho, Rondônia. The resistance to root-knot nematodes M. incognita were evaluated by the numbers of gall in the roots (NG) and by the reproductive factor (RF). The resistance response was also interpreted according the genetic diversity of the clones based in their morphological traits. The clones BRS3210, C12, BRS2314, BRS3137 and BRS1216 are resistant to M. incognita with RF of 0.34, 0.62, 0.79, 0.86 and 0.98, respectively. BRS3213, C125, C15, BRS2336, BRS3220 and C09 clones were classified as susceptible, with RF of 1.93, 1.95, 2.00, 2.31, 2.32 and 2.35. The BRS3193, C160 and BRS2357 clones were classified as very susceptible, with RF values of 3.03, 4.41 and 5.82, respectively. The clustering based on the genetic diversity of morphological traits indicated that genotypes more similar to the Robusta botanic variety had lower RF. The hybrid plants showed intermediate degrees of resistance indicating the segregation for the character of the M. incognita resistance. The clones BRS3210, C12, BRS2299, BRS2314, BRS3137 and BRS1216 expressed resistance responses to M. incognita with potential for growing resistant genotypes in the Western Amazon.
Identification of acid-tolerant coffee genotypes in a coffee germplasm collection of Colombia
(Editora UFLA, 2020) Acuña-Zornosa, Ricardo; Sadeghian-Khalajabadi, Siavosh
One of the limitations of coffee production in many regions of Colombia is the soil acidity. According to historical soil chemical analysis records, more than 50% of coffee farms have pH values below 5.0. Because acid-tolerant coffee varieties are not available, farmers use calcareous additives to correct the problem, which incurs associated labor and input costs. The objective of this work was to identify acid-tolerant genotypes of Coffea arabica. For two contrasting soils in the coffee-growing area of Colombia (Andisol and Entisol), the effect of soil acidity on the growth of 20 genotypes of Coffea Arabica during the seedling stage was evaluated. The genotypes were wild accessions that make up the Colombian Coffee Germplasm Collection and the Castillo ® Naranjal Variety, used as commercial material. Six months after the seedlings were transplanted into soils treated with or without acidity correction additives, the weight of the dry matter of the roots, stems and leaves was recorded. Later, the acid-tolerant genotypes were identified by means of the quadrant method and the tolerance index. The Timor Hybrid and Rume Sudan genotypes were identified as tolerant of the acidity of the two soil types. These genotypes could be used as progenitors in a coffee breeding program leading to a commercial coffee variety tolerant to soil acidity.
Sensory Q-Grader evaluation of fermented arabica coffees by yeast (Saccharomyces cerevisiae) and lactic bacteria (Pediococcus acidilactici) cultures
(Editora UFLA, 2020) Rodrigues, Sandy Dias; Coelho, Vinicius Serafim; Freitas, Valdeir Viana; Brioschi, Alessandra; Brioschi Júnior, Dério; Guarçoni, Rogério Carvalho; Pereira, Lucas Louzada; Eller, Monique Renon; Cardoso, Wilton Soares
The objective of this study was to evaluate sensorially, by professional Q-Grader, the beverage coffee from fermentation natural and fermentation with the use of yeasts and lactic acid bacteria as starter cultures in wet coffee processing. The Arabica coffee was harvested at two different altitudes in Espírito Santo State. Both coffees went through 04 treatments: inoculated with starter cultures Saccharomyces cerevisiae (YML) or Pediococcus acidilactici CCT 1622 (LAF), natural fermentation (NF) (not inoculated) and Control, without fermentation (WF). The coffee was processed by just the wet process. After process and roasting, the sensorial analysis was performed to understand the impact of fermentation processing in the coffee quality, and was performed by 6 Q-Graders, following SCA protocol. The study evidenced that the use of natural fermentation or starter cultures during post-harvest coffee contributed to obtain a quality beverage with pleasurable sensorial characteristics, punctuated by the tasters in the overall score obtained and also by the high sensory scores in attributes such as fragrance, acidity, aftertaste and the different perceived aromas. This work demonstrates for coffee growers that fermentation technology is not intuitive but requires an understanding of the relationship of the microorganisms with the coffee and the environment. In addition to the other chemical aspects of roasting and brew coffee.
Screening for phosphate-solubilizing fungi from colombian andisols cultivated with coffee (Coffea arabica L.)
(Editora UFLA, 2020) González-Osorio, Hernán; Botero, Carmenza E. Góngora; Rivera, Rubén Darío Medina; Vega, Nelson Wálter Osorio
Phosphate (P) bioavailability is severely constrained in volcanic ash soils due to its high fixation rate. To overcome this problem the use of P-solubilizing fungi (PSF) has been proposed gaining recently great attention. To provide a better understanding of the dynamics of PSF in soils and to establish criteria for screening effective PSF a series of studies were conducted. PSF were isolated from coffee plantations grown in a Typic Udivitrand (QU), a Pachic Fulvundand (CH), and a Typic Melanudand (Ti). Fifty-five isolates (28 from CH, 19 from Ti, and 8 from QU) produced index of P solubilization among 16 and 106 10-6 kg dm-3 using as P source phosphate rock. The results suggest that the microbial P solubilization was not only associated to the decrease in the culture medium pH, but also the production of organic acids is associated with the most effective PSF. The higher production of organic acids seems to be associated with a lower fungal colony growth rate likely due to a carbon/energy drainage. The soil P-fixation capacity, soil organic content and degree of humification seems to control the relative abundance of PSF in the soils tested. In soils cultivated with coffee Phlebia gender is reported, for the first time, as a PSF.
Coffee crop science metric: a review
(Editora UFLA, 2020) Pabon, Carlos David Rodriguez; Sánchez-Benitez, Juliana; Ruiz-Rosero, Juan; Ramirez-Gonzalez, Gustavo
Coffee is one of the leading worldwide drinks; therefore, it represents highly valued trade. However, coffee is a complex food from sowing to harvesting, processing, packaging, selling and consuming, although coffee is important in most of its stages, no studies have analyzed the dynamics of global coffee research. This paper presents an analysis of the evolution of Coffee related international research. It is based on the renowned literature databases published by Scopus and Web of Science. The parameters studied included growth of publications, the main journals, countries, institutions, and an author keywords analysis according to their relationship with topics such as agronomy, health, economy, chemistry or biological compound, product and unclassified words. Interest in harvesting techniques and coffee side factors have been increasing through last years in an exponential trend. Producer and consumer countries have composed a synergy with their research interest, that allows stating an upcoming growing in techniques headed to the quality beverage. The contribution is to visualize state of the art in the area of coffee knowledge to generate trends for future research.
Effect of water stress and Coffee ringspot virus on coffee leaf temperature and its relationship with Brevipalpus yothersi population
(Editora UFLA, 2020) Nunes, Matheus Mancini Porfírio; Vechia, Jaqueline Franciosi Della; Andrade, Daniel Júnior de
The Brevipalpus yothersi Baker mite is a vector of Coffee ringspot virus (CoRSV), the causing agent of coffee ringspot disease. Knowing the mite-host interaction and the variables that improve the development of the mite are important in order to manage the disease. The aim of this work was to study the relationships of cause and effect between water availability and leaf temperature on population fluctuation of B. yothersi on coffee plants Coffea Arabica L. Inside a greenhouse, plants under four levels of field capacity: 25, 40, 55 and 70% were arranged in two groups: (1) infestation of viruliferous B. yothersi with CoRSV and (2) no mite infestation. Following the transfer of mites to coffee plants, leaf temperature was measured daily in order to calculate the Daily Water Stress Index (DWSI). At the end of this experiment, the mites present on coffee plants were quantified and leaf samples were collected for leaf nitrogen content measurements. It was found that plants infested with B. yothersi indicated higher values of DWSI and lower levels of leaf nitrogen content when compared to non-infested plants. Furthermore, plants on higher water availability revealed higher populations of B. yothersi.
Biochemical parameters of an Oxisol submitted to high doses of gypsum in the coffee culture
(Editora UFLA, 2020) Naves, Andrêssa de Paula; Silva, Aline Oliveira; Barbosa, Marisângela Viana; Pinto, Flávio Araújo; Santos, Jessé Valentim dos; Saggin Junior, Orivaldo José; Guimarães, Paulo Tácito Gontijo; Carneiro, Marco Aurélio Carbone
The objective of this study was to determine the influence of increasing doses of agricultural gypsum on the quality of the soil biochemical parameters in coffee cultivation (Coffea arabica L.) over two climatic seasons in the Brazilian Cerrado. Soil samples were collected in two seasons (dry and rainy season), at 0.00 – 0.10 m depth of an Oxisol, submitted to doses 0 (GSA); 3.5 (G3.5); 7.0 (G7.0) and 14 (G14) t ha-1 of agricultural gypsum in the coffee planting line. The biochemical parameters evaluated were: total organic carbon (TOC); microbial biomass carbon (MBC); soil basal respiration (SBR); absolute enzymatic activities [Urease, acid phosphatase, hydrolysis of fluorescein diacetate (FDA)], and enzymatic activity per unit of MBC. The significant effect (p ≤ 0.05) of gypsum doses was observed for MBC and SBR, which were higher in the treatment with G7.0 application. TOC, the enzymatic activities of Phosphatase and the FDA showed no differences between treatments. On the other hand, the specific enzymatic activities by MBC were used to describe the differences between the doses of gypsum applied, generally with greater activity in treatments G7.0 and G14. The accumulated coffee productivity was higher in G14 treatment. The results presented confirmed that the biochemical parameters of the soil are key in the evaluation of changes in soil use, and that the increase in gypsum favors activity and microbial biomass.
Indaziflam: Leaching and control of Urochloa plantaginea in applications on coffee litter with different rainfall simulations
(Editora UFLA, 2020) Silva, Paulo Vinicius da; Santos, Mayck José dos; Tronquini, Sergio Mateus; Giraldeli, Ana Ligia; Dias, Roque de Carvalho; Inácio, Estela Maris; Monquero, Patricia Andrea
Coffee litter and the rain that occurs after the application of pre-emergence herbicides impact on their leaching and weed control effectiveness. The objective of this study was to evaluate the leaching and control effectiveness of indaziflam, applied on coffee litter, and under simulations of different amounts of rainfall. Two experiments in greenhouse were conducted with the application of indaziflam (0.1 kg of active ingredient - a.i. - ha-1), in a completely randomized design. The first involved the leaching of the herbicide using Urochloa plantaginea as a bioindicator, in a 8 x 4 factorial arrangement, with eight depths in the PVC column (0-0.05; 0.05-0.1; 0.1-0.15; 0.15-0.2; 0.2-0.25; 0.25-0.3; 0.3-0.35; 0.35-0.4 m) and four amounts of straw (0; 1; 3 and 5 t ha-1), this factor was isolated for rainfall simulations (10, 20 and 40 mm). The second experiment tested the effectiveness in controlling U. plantaginea, in a 4 x 3 factorial arrangement, with four amounts of litter (0; 1; 3 and 5 t ha-1) and three amounts of rainfall (10, 20 and 40 mm). Both experiments had four repetitions and controls without application of the herbicide. In leaching, a greater effect of indaziflam was found at a depth of 0-0.05 m, and the higher the simulated rainfall, the greater the phytotoxicity observed in U. plantaginea, with 39.75%, 52.50% and 92.06%, for rainfall amounts of 10, 20 and 40 mm, respectively. U. plantaginea showed high susceptibility to control by the herbicide indaziflam, and the lowest control, 82%, was observed when indaziflam was applied on 5 t ha-1 with simulation of rainfall at 10 mm. The increase in the amount of litter on the soil surface, combined with lower amounts of rainfall can reduce the leaching of indaziflam and the control of U. plantaginea.
Using unmanned aerial vehicle and machine learning algorithm to monitor leaf nitrogen in coffee
(Editora UFLA, 2020) Parreiras, Taya Cristo; Lense, Guilherme Henrique Expedito; Moreira, Rodrigo Santos; Santana, Derielsen Brandão; Mincato, Ronaldo Luiz
Nitrogen is an essential element for coffee production. However, when fertilization do not consider the spatial variability of the agricultural parameters, it can generate economic losses, and environmental impacts. Thus, the monitoring of nitrogen is essential to the fertilizing management, and remote sensing based on unmanned aerial vehicles imagery has been evaluated for this task. This work aimed to analyze the potential of vegetation indices of the visible range, obtained with such vehicles, to monitor the nitrogen content of coffee plants in southern Minas Gerais, Brazil. Therefore, we performed leaf analysis using the Kjeldahl method, and we processed the images to produce the vegetation indices using Geographic Information Systems and photogrammetry software. Moreover, the images were classified using the Color Index of Vegetation and the Maximum Likelihood Classifier. As estimator tool, we created Random Forest models of classification and regression. We also evaluated the Pearson correlation coefficient between the nitrogen and the vegetation indices, and we performed the analysis of variance and the Tukey-Kramer test to assess whether there is a significant difference between the averages of these indices in relation to nitrogen levels. However, the models were not able to predict the nitrogen. The regression model obtained a R2 = 0.01. The classification model achieved an overall accuracy of 0.33 (33%), but it did not distinguish between the different levels of nitrogen. The correlation tests revealed that the vegetation indices are not correlated with the nitrogen, since the best index was the Green Leaf Index (R = 0.21). However, the image classification achieved a Kappa coefficient of 0.92, indicating that the tested index is efficient. Therefore, visible indices were not able to monitor the nitrogen in this case, but they should continue to be explored, since they could represent a less expensive alternative.
Implications of the cut type and apex length of stem cuttings used for the production of plantlets of Conilon coffee
(Editora UFLA, 2020) Verdin Filho, Abraão Carlos; Freitas, Silvio de Jesus; Comério, Marcone; Volpi, Paulo Sérgio; Colodetti, Tafarel Victor; Rodrigues, Wagner Nunes; Fonseca, Aymbiré Francisco Almeida da; Posse, Sheila Cristina Pruculi; Fontes, Alexandre Gomes; Christo, Bruno Fardim; Vieira, Luciano Junior Dias
Producing plantlets of Conilon coffee within the specific recommendations and with a high level of quality is fundamental since it is capable of promoting the initial development of the crops. To identify the best protocol to prepare the stem cuttings is fundamental to the process of plantlet production of the species. In this context, this study aimed to evaluate the implications of the type of apex cutting and the length of the remaining apex of stem cuttings to produce plantlets of Conilon coffee (Coffea canephora). To this end, two trials were conducted in the Marilândia Experimental Farm (Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural, Marilândia-ES). The first trial evaluated the types of apex cutting (straight or bevel cut), and the second trial studied the different lengths of the remaining apex (0.5, 1.0, 1.5, 2.0, and 2.5 cm). Characteristics of the vegetative growth and photosynthetic traits of the plantlets of Conilon coffee were evaluated after 120 days of cultivation in a nursery. The biomass accumulation of the plantlets of Conilon coffee produced by stem cutting may be favored by the use of bevel cut on the apex. The length of the remaining apex does not seem to have a expressive effect over the quality or growth of the plantlets, being only possible to observe effects for leaf area and biomass accumulation.
Rooting biostimulants for Coffea arabica L. cuttings
(Editora UFLA, 2020) Azevedo, Harianna Paula Alves de; Carvalho, Alex Mendonça de; Vidal, Douglas Alves; Santos, Heloisa Oliveira dos; Doria, Joyce
In the rooting process of Arabica coffee cuttings, plant hormones are used for inducing root formation. However, synthetic molecules cannot be used to form organic seedlings. The objective of this work was to evaluate the effect Cyperus haspan extract and different concentrations and types of humic substances on Arabica coffee cuttings. Arabica coffee shoots were collected, and cuttings containing at least two buds were taken. The experiment had a three-factor design, 2 (presence or absence Cyperus haspan extract) x 2 (humic or fulvic acid) x 4 (0, 10, 25 and 50 mg dm-³ concentrations). The following vegetative data were evaluated: shoot height (cm), survival, remaining leaves, leaf pairs, vigor, number of shoots,root length, area root, volume root, diameter root and fresh and dry mass were also evaluated. The enzyme activity of H+-ATPase, catalase, superoxide dismutase, alcohol dehydrogenase and esterase was also quantified. The results showed that the Arabica coffee cutting rooting rate was increased when treated with humic acid at a concentration of 10 mg dm-³ in the presence of Cyperus haspan extract. The lowest oxidative stress was observed in the 10 mg.dm-³ humic and fulvic acid treatments, regardless of the use of the extract.
Evaluation of the effect of Azospirillum brasilense inoculation on arabic coffee seedlings
(Editora UFLA, 2020) Silva, Leonardo Caixeta da; Barbosa, Camila Karen Reis; Franco Junior, Kleso Silva
In fabaceae, Azospirilum is used in association with Rhizobium bacteria to promote biological nitrogen fixation, making the plant tolerant to water stress and resulting in better nutrient utilization, obtaining a plant more productive and vigorousand increase roots for better nutrient uptake by the plant. However, there are no studies using coinoculation in Coffee. The objective of the study was to evaluate the effect of different doses of A. brasilense on the development of coffee seedlings. The experiment was carried out in Machado, southern Minas Gerais. The experimental design was completely randomized (DIC), with five treatments and nine replications, totaling 45 experimental plots. The experimental unit consisted of pots of 12 liters of capacity with a substrate composed of 70% soil and 30% of tanned manure and a coffee seedling of cultivar Catuaí Vermelho IAC 144. Treatments were composed with different doses (0, 0.75, 1.5, 2.25 and 3.0 mL) of Azospirillum brasilense inoculant from the Micro-Chemistry laboratory, Azofix®, having Ab-V5 strains, 1 x 108 cfu. mL-1 viable cells per mL. From stage V7, the seedlings received eight applications with a seven-day interval. The applying was done in the late afternoon, under favorable environmental conditions, using a hand sprayer. Evaluations were performed 150 days after the first application. The variables evaluated were shoot height (ALT) (cm); shoot fresh matter (MFPA) (g); root fresh matter (MFR) (g); leaf fresh matter (MFF) (g); stem diameter (DIA)(mm) and pivoting root length (CRP) (cm). It is concluded that the inoculation of coffee seedlings with bacteria of the species Azospirillum brasilense promotes greater growth of the pivoting root as well as the fresh matter of the whole root system of coffee seedlings.