Control Of Coffee Rust Research Articles

Production of New Biopesticides from Cymbopogon citratus for the Control of Coffee Rust (Hemileia vastatrix) under Laboratory and Field Conditions.

One of the diseases with the greatest economic impact on coffee cultivation worldwide and particularly in Peru is coffee rust (Hemileia vastatrix). The search for sustainable control methods as disease management strategies in coffee cultivation is necessary. The objective of this research was to determine the effectiveness of five biopesticides based on lemon verbena (Cymbopogon citratus) for the control of rust applied in laboratory and field conditions to allow the recovery of coffee (Coffea arabica L. var. typica) in La Convención, Cusco, Peru. Five biopesticides (oil, macerate, infusion, hydrolate and Biol) and four concentrations (0, 15, 20 and 25%) were evaluated. The biopesticides were evaluated under laboratory conditions (light and dark) at different concentrations. The design used was completely randomized in a factorial scheme. The biopesticides were incorporated into the culture medium and inoculated with 400 uredospores of rust, and the germination percentage was evaluated. Under field conditions, the biopesticides at the same concentrations were evaluated for 4 weeks after application. Under these field conditions, the incidence, severity and area under the disease progress curve (AUDPC) of selected plants with a natural degree of infection were evaluated. In the laboratory, the results showed that all biopesticides were effective in reducing the germination of rust uredospores to values <1% of germination in relation to the control, which showed values of 61% and 75% in the light and dark, respectively, independent of the concentration used, with no significant differences between them. In the field, 25% oil promoted the best response with values <1% and 0% incidence and severity, respectively, in the first two weeks after application. The AUDPC for this same treatment showed values of 7 in relation to 1595 of the control. Cymbopogon citratus oil is an excellent biopesticide that can be used to control coffee rust.

Towards an Eco-Friendly Coffee Rust Control: Compilation of Natural Alternatives from a Nutritional and Antifungal Perspective.

Hemileia vastatrix (HV) is the pathogen responsible for the coffee leaf rust (CLR) disease that has spread globally. CLR causes losses of up to a billion dollars annually and affects all types of crops regardless of their production regime (organic or inorganic). Additionally, smallholders produce approximately 80% of coffee in developing countries. The condition causes losses of up to a billion dollars annually. It affects all types of crops regardless of their production regime (organic or inorganic). Approximately 80% of coffee is produced by smallholders in developing countries. Until the 90s, shaded-production systems and native varieties were encouraged; however, the rapid spread of CLR has forced farmers to migrate towards inorganic schemes, mainly due to a lack of knowledge about natural alternatives to pesticides that can be implemented to control HV. Therefore, the purpose of this article is to compile the currently existing options, emphasizing two key factors that guarantee efficient rust control: selective fungicidal activity against HV and the nutrition of coffee crops. Thus, by comprehending how these natural compounds (such as plant, bacteria, fungi, animals, or algae metabolites) impact coffee rust proliferation. Furthermore, since a various range of biochar effects contributes to the control of foliar fungal pathogens through modification of root exudates, soil properties, and nutrient availability, which influence the growth of antagonist microorganisms, we present a review of the pathogen-suppressive effects of biochar, and new control strategies suitable for organic schemes can be developed.

Genetic and chemical control of coffee rust (Hemileia vastatrix Berk et Br.): impacts on coffee (Coffea arabica L.) quality.

The occurrence of diseases can alter coffee (Coffea arabica L.) metabolism, causing changes in the composition of coffee beans and beverage quality. However, little is known about which aspects of coffee quality are actually altered by rust (Hemileia vastatrix Berk et Br.) and by its main control methods. The effect of chemical and genetic methods for the control of coffee rust on the quality of coffee beans and beverage was investigated. Both genetic and chemical control reduce the damage caused by the disease in the composition of coffee beans. Genotypes with resistant ancestry, even with resistance breakdown, respond better to chemical control. The combination of genetic and chemical control favors an increase in the sugar content in the beans. Despite the fact that both genetic and chemical control are effective in reducing disease damage regarding the chemical composition of beans, the quality potential of Timor Hybrid genotypes associated with the cancellation of rust expression through the joint action of genetic and chemical control favors the composition of beans and, consequently, the quantitative assessment of sensory attributes, adding value to the final product. © 2020 Society of Chemical Industry.

Relationship between Sentinel-2 orbital data and in situ monitoring of coffee rust

Coffee rust (Hemileia vastatrix Berkeley & Broome) is the main coffee disease in Brazil. Coffee rust control is calendar-based and performed by applying chemicals in order to avoid the outburst of disease epidemics. The aim of this work was to identify coffee rust using multispectral orbital sensing through analyses utilising vegetation indices and coffee rust incidence, defoliation and yield data obtained in situ. Field samples were georeferenced using a high-accuracy global navigation satellite system receiver in two plots, in a 42-year-old, leaf rust susceptible coffee cultivar. Conventional chemical control of rust was performed in only one of the plots to serve as control. Coffee rust incidence in areas with and without chemical control was assessed over 5 months, from December 2018 to April 2019, a period with optimal environmental conditions for disease occurrence. Following analyses of different vegetation indices and data sampled in the coffee crop, Pearson’s correlations between the variables were verified. Reported correlations occurred mainly among coffee rust incidence levels in February 2019 and vegetation indices calculated using Sentinel-2 images from August 2018, September 2018 and February 2019 [IRECI r = 0.566; IRECI r = 0.493; NDMI r = − 0.518; NDVI(RE1) r = − 0.562; CI(RE1) r = − 0.573; MSR(RE1) r = − 0.569], in areas without coffee rust control. Indices based on relationships between bands in the Red-Edge and Near Infra-Red regions were more sensitive to spectral changes in vegetation due to variation in coffee rust occurrence over time.

Biofungicides evaluation in two coffee cultivars for Hemileia vastatrix control

El objetivo del presente estudio fue evaluar el efecto de biofungicidas elaborados con &lt;em&gt;Azadirachta indica&lt;/em&gt;, &lt;em&gt;Melaleuca alternifolia&lt;/em&gt; y la combinación de&lt;em&gt; Bacillus subtilis&lt;/em&gt; con &lt;em&gt;A. indica&lt;/em&gt; y &lt;em&gt;Syzygium aromaticum&lt;/em&gt;, en el control de la roya causada por &lt;em&gt;Hemileia vastatrix&lt;/em&gt;, en las variedades Garnica y Typica. Se establecieron experimentos en condiciones de campo en tres localidades: Lipuntahuaca, Chilocoyo y Cinco de Mayo, con plantas de cinco meses de edad. Se encontraron diferencias significativas entre biofungicidas y el testigo para la incidencia (P=0.04), área bajo la curva del progreso de la severidad (ABCPE) (P=0.04) y tasa de infección aparente (P=0.03). No se encontraron diferencias en severidad excepto en la última evaluación. &lt;em&gt;M. alternifolia&lt;/em&gt; indujo los valores más bajos de incidencia (34.4 %), ABCPE (61.8) y tasa de infección aparente (0.028), con porcentajes de reducción con respecto al testigo de 20.9, 14.2 y 39.1%, respectivamente. No se presentaron diferencias significativas entre las variedades Typica y Garnica para incidencia y severidad. Las plantas de la localidad de Lipuntahuaca tuvieron menor incidencia (26.9%) y severidad (2.3%) en comparación con Chilocoyo y Cinco de Mayo con 51.5 y 44.5 % (incidencia) y 4.2 y 3.4% (severidad), respectivamente (P&amp;lt;0.0001). Los biofungicidas no suprimieron la infección, pero los resultados sugieren que debe continuarse la investigación en este patosistema.

Infection model for analyzing biological control of coffee rust using bacterial anti-fungal compounds

Coffee rust is one of the main diseases that affect coffee plantations worldwide (Cressey, 2013 [10]). This causes an important economic impact in the coffee production industry in countries where coffee is an important part of the economy. A common method for combating this disease is using copper hydroxide as a fungicide, which can have damaging effects both on the coffee tree and on human health (Haddad et al., 2013 [13]). A novel method for biological control of coffee rust using bacteria has been proven to be an effective alternative to copper hydroxide fungicides as anti-fungal compounds (Haddad et al., 2009 [12]). In this paper, we develop and explore a spatial stochastic model for this interaction in a coffee plantation. We analyze equilibria for specific control strategies, as well as compute the basic reproductive number, R0, of individual coffee trees, conditions for local and global stability under specific conditions, parameter estimation of key parameters, as well as sensitivity analysis, and numerical experiments under local and global control strategies for key scenarios.

High throughput transcriptome analysis of coffee reveals prehaustorial resistance in response to Hemileia vastatrix infection

We provide a transcriptional profile of coffee rust interaction and identified putative up regulated resistant genes Coffee rust disease, caused by the fungus Hemileia vastatrix, is one of the major diseases in coffee throughout the world. The use of resistant cultivars is considered to be the most effective control strategy for this disease. To identify candidate genes related to different mechanism defense in coffee, we present a time-course comparative gene expression profile of Caturra (susceptible) and Híbrido de Timor (HdT, resistant) in response to H. vastatrix race XXXIII infection. The main objectives were to obtain a global overview of transcriptome in both interaction, compatible and incompatible, and, specially, analyze up-regulated HdT specific genes with inducible resistant and defense signaling pathways. Using both Coffea canephora as a reference genome and de novo assembly, we obtained 43,159 transcripts. At early infection events (12 and 24h after infection), HdT responded to the attack of H. vastatrix with a larger number of up-regulated genes than Caturra, which was related to prehaustorial resistance. The genes found in HdT at early hours were involved in receptor-like kinases, response ion fluxes, production of reactive oxygen species, protein phosphorylation, ethylene biosynthesis and callose deposition. We selected 13 up-regulated HdT-exclusive genes to validate by real-time qPCR, which most of them confirmed their higher expression in HdT than in Caturra at early stage of infection. These genes have the potential to assist the development of new coffee rust control strategies. Collectively, our results provide understanding of expression profiles in coffee-H. vastatrix interaction over a time course in susceptible and resistant coffee plants.

Evaluación de un bioinsumo a partir del jugo del fique (Furcraea spp.) para el control de la roya (Hemileia vastatrix) en el café, variedad Caturra

The aim of this article is to present an evaluation study of a bio-input made of fique extract (Furcraea spp.) in order to take control of the development and the spreading of rust (Hemileia vastatrix); a disease that directly attacks to the plant development of Caturra coffee variety decreasing the productivity and the quality of the grain. First, the leaves of fique, black common variety, are picked up in the municipality of Nariño; then, the juice of the leaves is extracted through a roller mill and it is stored in sterile containers for six days in order to obtain a fermentation natural process. After that, the juice is pasteurized to stop the fermentation process. In addition to this, a study of physicochemical characterization is carried out to determine pH, density, boiling point and soluble solids levels. A phytochemical analysis by thin layer chromatography (TLC) and a quantitative characterization (HPLC) are lead to ascertain the presence of secondary metabolites such as saponins, alkaloids, flavonoids, tannins, steroids. These metabolites have biocidal properties that can be considered for studies on coffee rust control, specifically, related to Caturra coffee variety. The research is conducted in Cielo Verde farm, located in vereda: La Pradera; municipaliy: Nariño; department: Nariño. These research is undertaken identifying the severity percentage of the pathogen utilizing the scale proposed by James Clive. Different concentrations of the bio-input are evaluated, 1.000, 10.000 y 100.000 μg/mL, determining the incident rate of the biocide of the rust on the leaves of the coffee crops.

Função de crescimento vegetativo de mudas de cafeeiro conilon a níveis de ciproconazol+tiametoxam e nitrogênio

Although the chemical control of coffee rust and the nitrogen fertilization are widely studied in Brazil, there are no documented studies that show this interaction in conilon coffee plants. Thus, the objective of this experiment was to study the interaction between the effects of nitrogen and cyproconazole+thiamethoxam in the growth of conilon coffee seedlings, cultivar Emcaper 8151 – Robusta Tropical, in controlled environment. For this, a completely randomized design was used, with four replicates, simple layout, with 13 levels of combinations of nitrogen and cyproconazole+thiamethoxam. The levels of nitrogen levels and cyproconazole+thiamethoxam were combined following a Box Berard increased to 3 (2k + 2k + 2k + 1) matrix model. The results show that the combinations of the recommended level of cyproconazole+thiamethoxam and nitrogen influenced negatively the analyzed variables of the conilon coffee plants, in the studied conditions.

EFEITO DE FUNGICIDAS TRIAZÓIS SOBRE O CONTROLE DA CERCOSPORIOSE EM MUDAS DE CAFEEIRO

RESUMO Fungicidas do grupo dos triazóis e suas misturas com inseticidas são convencionalmente empregados para o controle da ferrugem e do bicho mineiro na cultura do cafeeiro. Neste estudo avaliou-se o efeito desses produtos sobre o controle da cercosporiose, causada por Cercospora coffeicola, outra importante doença do cafeeiro. Três experimentos foram realizados em casa de vegetação com mudas de cafeeiro da cultivar Mundo Novo IAC 501, sendo os produtos aplicados na parte aérea e no substrato. Os produtos aplicados na parte aérea foram: epoxiconazol, epoxiconazol + piraclostrobina, tetraconazol, ciproconazol, oxicloreto de cobre, azoxistrobina e carbendazim e no substrato: ciproconazol + tiametoxam, triadimenol + dissulfotom e triadimenol. Testemunhas sem tratamento químico também foram incluídas nos três experimentos. As mudas foram inoculadas com suspensões preparadas com cinco isolados de C. coffeicola (3-4 conídios/mL). A incidência e a severidade da doença foram avaliadas de 20 até 56 dias após as inoculações. Com exceção do oxicloreto de cobre, todos os demais tratamentos foram eficientes no controle da cercosporiose. Os triazóis, com exceção do tetraconazol, apresentaram sintomas reversíveis de fitotoxicidade. Os produtos: ciproconazol + tiametoxam, epoxiconazol + piraclostrobina e carbendazim tiveram os maiores efeitos residuais, e mantiveram o controle da doença por até 56 dias após sua aplica ção. Os triazóis utilizados para o controle da ferrugem também são eficientes para o controle da cercosporiose do cafeeiro.

Evidence for hyperparasitism of coffee rust (Hemileia vastatrix) by the entomogenous fungus, Lecanicillium lecanii, through a complex ecological web

The entomogenous fungus, Lecanicillium lecanii is hyperparasitic on Hemileia vastatrix, the cause of coffee leaf rust in the laboratory, and has frequently been observed attacking it in the field. The existence of a complex ecological web involving the spatially clustered mutualism of an ant (Azteca instabilis) with a scale insect (Coccus viridis), where the scale insect was infected by L. lecanii, prompted a search for a spatial correlation between the attack of L. lecanii on the scale insect and the incidence of rust in a commercial coffee crop. A weak but statistically significant effect of hyperparasitic control of coffee rust was observed on two distinct scales: in a 45‐ha plot and on a scale of approximately 10 m. It was concluded that this effect was linked to an indirect effect of the ant–coccid mutualism, where L. lecanii was a parasite of the coccid.

Modelos de alerta para o controle da ferrugem-do-cafeeiro em lavouras com alta carga pendente

O objetivo deste trabalho foi desenvolver árvores de decisão como modelos de alerta da ferrugem-do-cafeeiro em lavouras de café (Coffea arabica L.) com alta carga pendente de frutos. Dados de incidência mensal da doença no campo coletados durante oito anos foram transformados em valores binários considerando limites de 5 e 10 pontos percentuais na taxa de infecção. Foi gerado um modelo para cada taxa de infecção binária a partir de dados meteorológicos e do espaçamento entre plantas. O alerta é indicado quando a taxa de infecção, prevista para o prazo de um mês, atingir ou ultrapassar o respectivo limite. A acurácia do modelo para o limite de 5 pontos percentuais foi de 81%, por validação cruzada, chegando até 89% segundo estimativa otimista. Esse modelo apresentou bons resultados para outras medidas de avaliação importantes, como sensitividade (80%), especificidade (83%) e confiabilidades positiva (79%) e negativa (84%). O modelo para o limite de 10 pontos percentuais teve acurácia de 79%, e não apresentou o mesmo equilíbrio entre as demais medidas. Em conjunto, esses modelos podem auxiliar na tomada de decisão referente ao controle da ferrugem-do-cafeeiro no campo. A indução de árvores de decisão é alternativa viável às técnicas convencionais de modelagem e facilita a compreensão dos modelos.

Biological control of coffee rust by antagonistic bacteria under field conditions in Brazil

Rust ( Hemileia vastatrix) is the most important coffee disease in Brazil. Organic coffee production has increased in the country and a research program aimed to develop alternatives to chemicals for disease control was required. Seven bacterial isolates, isolated from organic coffee plantings and selected in greenhouse tests, were evaluated under commercial organic crop conditions in 2005 (Experiment 1) and 2005/2006 (Experiment 2), in Machado, MG, Brazil. Ten treatments consisting of the seven bacterial isolates, copper hydroxide, calcium silicate and water were applied as three or four monthly sprays in Experiment 1 or 2, respectively. Rust severity and incidence were evaluated monthly. In Experiment 1, the sprays started in January when rust incidence was 23.8%, and none of the treatments reduced rust progress significantly. In Experiment 2, the sprays began in November 2005, when rust incidence was approximately 7.5%. There were significant differences ( P < 0.0001) between treatments regarding maximum incidence and severity (as assessed in June, 2006), the rate of increase of the incidence between November 2005 and June 2006 and for the areas under disease progress curves for both rust incidence and severity. Lower values for these treatments were obtained in the plots treated with copper hydroxide or Bacillus sp. isolate B157, and intermediate values with the Pseudomonas sp. isolate P286. In a third experiment conducted in 2007 in Ervália, MG, isolates B157 and P286 were also evaluated; isolate B157 reduced rust intensity as effectively as copper hydroxide. Isolate B157 is considered a potential biocontrol agent for coffee rust for organic crop systems in Brazil.

Effectiveness of acibenzolar‐S‐methyl, fungicides and antibiotics for the control of brown eye spot, bacterial blight, brown leaf spot and coffee rust in coffee

AbstractThis study was carried out to evaluate the potential of acibenzolar‐S‐methyl (ASM), combined or not combined with fungicides and antibiotics for the control of brown eye spot (Cercospora coffeicola) and bacterial blight (Pseudomonas syringae pv. garcae) in coffee seedlings, and ASM combined with conventional fungicide application schedules for the control of coffee rust (Hemileia vastatrix) and brown leaf spot (Phoma costarricencis) under field conditions in two coffee crops in the State of São Paulo, Brazil. ASM protected coffee seedlings against C. coffeicola when applied at the rates of 2.5 and 5 g of active ingredient per hectolitre of water (g a.i. hL−1), providing 34–55% of disease control, and against bacterial blight, when applied at the rates of 2.5, 10 and 20 g a.i. hL−1, with 38–57% of disease control. Tebuconazole (100 g a.i. hL−1) and azoxystrobin (10 g a.i. hL−1) showed the best results for brown eye spot control. Oxytetracycline + streptomycin, kasugamycin hydrochloride, oxytetracycline + metallic copper, copper oxychloride and mancozeb + copper oxychloride also controlled bacterial blight in levels similar to those shown by ASM. In the field experiments, all fungicide application schedules tested, cyproconazole (December, February, April), epoxiconazole (December, March), tetraconazole (December, February, April), cyproconazole (December, February) and azoxystrobin (January, March) were effective for coffee rust control and provided partial control of brown leaf spot. The results also showed that for all experiments, there was no synergistic effect of the combination of ASM with azoxystrobin, cyproconazole or cupric fungicides.

The intensity of a coffee rust epidemic is dependent on production situations

To gain a clearer understanding of conditions conducive to the development of coffee rust and improve disease control, we monitored the development of rust epidemics in 73 plots in Honduras, over 1–3 years depending on the case, focusing on coffee tree characteristics, crop management patterns, and the environment. A simple correspondence analysis was used to show that a link could be found between certain production situations and the intensity of coffee rust epidemics. Local characteristics specific to each plantation were particularly well linked to the intensity of coffee rust epidemics, whereas regional factors such as rainfall appeared to be of secondary importance. The yield and the number of leaves of the coffee trees were positively linked to epidemic development. Soil pH and fertilisation were negatively associated with epidemic development. Shade, when it did not limit yield, probably affected the microclimate in such a way that coffee rust incidence increased. Altitude was a serious constraint in disease development. These links were illustrated by a segmentation tree, which helped to define risk domains and rationalise coffee rust control. It also provided an understanding of how intensifying Arabica cultivation, through its effects on yield and soil acidification, increased the risk of a serious coffee rust epidemic occurring.

Coffee rust—epidemiology and control

The history and spread of coffee rust, from its first detection in Sri Lanka to the latest developments in Central America, are discussed. The epidemiology of the disease has been a subject of controversy in the past, but during the last decade most of the questions concerning the mode of spore dispersal seem to have been answered. Although it is necessary to investigate further the influence of host physiology on some epidemiological factors, such as latency and sporulation, sufficient is now known of the epidemiology of the disease to predict its behaviour in different regions and to devise provisional chemical control schedules. Copper fungicides still remain the most widely used chemicals but some of the more modern systemic fungicides are showing great potency. Advances in spraying techniques, with concomitant reductions in volumes and doses, have made chemical control more economic. The chemical control of coffee rust is greatly influenced by socioeconomic and physiographic factors as well as by the agronomy of the crop. Resistant varieties have so far played little part in coffee rust control, but some lines from Arabica-Robusta hybrids may show durable resistance.

The control of coffee rust in Kenya by fungicides

SUMMARYThe results are reported of a series of four factorial field trials carried out at Ruiru, Kenya, to determine the effect on the control of coffee rust (Hemileia vastatrix B. et Br.) of the main variables associated with the application of copper fungicides, i.e. concentration, volume per acre, leaf surface to which applied, time of application, and types of fungicide and application used.Rust control increased with log concentration, there being evidence for a linear relationship. As neither asymptotic nor optimal values occur the optimum for commercial practice must be determined by economics and possible phytotoxic effects.Control also increased with volume per acre, but adjusting the amount of spray residue via concentration was more effective and less wasteful of fungicide than via volume. Upper‐surface application was as effective as lower in one trial at all concentrations, and in another at the higher concentrations. It is considered that liberation of fungicide from upper surface residues by rain, and the presence of thick aggregations of these residues may be of importance for rust control.Differences in rust control following the use of three spraying machines were correlated with the differences in amount of spray residue on the leaves, there being a linear relation to log residue. For the same rust control, a mist‐blower with swirl‐plate atomisation required the greatest expenditure of fungicide per acre and a pneumatic hand‐sprayer, closely approached by a mist‐blower with spinning‐cage atomisation, the least. However, to obtain as heavy residues and as good rust control as with the hand‐sprayer, higher concentrations were necessary. At the same copper content of spray fluid no differences in rust control by Burgundy mixture, cuprous oxide (as ‘Perenox’) and copper oxychloride (as ‘Blitox’) were found. Some observations on the fungicides fermate, cuprous oxide in oil and captan were made. Captan did not increase foliage density. Evidence that this is directly influenced by copper sprays is presented.For reducing the amount (but not the percentage) of rust attack March and April sprays were most effective, January least, and October was intermediate. The earlier sprays reduced the effect of later ones. Reduction of inoculum in January to March did not reduce the July‐August rust peak. The implications are discussed.