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Background: Erythrina poeppigiana (Leguminosae) is a high-growing plant with an orange flower that is widely distributed in tropical and subtropical countries. This particular plant is widely used in traditional medicine for gynecological complications and the treatment of various diseases. There exists no previous information regarding cytotoxic compounds from this plant. Objective: This research is to isolate cytotoxic compounds from E. poeppigiana. Methods: The isolation step was carried out using a combination of chromatographic techniques to obtain isolated three compounds (1, 2, and 3). Results: The chemical structure of isolated compounds was elucidated by spectroscopic methods and identified as β-erythroidine (1), 8-oxo-β-erythroidine (2), and 8-oxo-α-erythroidine (3). Compounds (1-3) showed cytotoxic activity against MCF-7 breast cancer line with IC50 values of 36.8, 60.8 and 875.4 μM, respectively. Conclusion: Three compounds have been successfully isolated from Erythrina poeppigiana (Leguminosae), showing cytotoxic properties against MCF-7 breast cancer line. Structure-activity relationship studies showed that the presence of enone moiety on compound 1 can reduce its cytotoxic activity towards MCF-7 breast cancer line.

El cultivo de café en México se produce bajo sombra con diversos árboles, incluyendo algunas especies fijadoras de nitrógeno, en sistemas denominados agroforestales. El presente estudio se llevó a cabo en el año 2018 en el municipio de Huatusco, Veracruz y el objetivo fue caracterizar los sistemas agroforestales de Inga vera y Erythrina poeppigiana (una plantación joven y otra adulta) en asociación con café; a través, de la medición de sus características físicas, como edad del arbolado, altura, grosor de plantas de café, porcentaje de sombra y las características químicas del suelo y foliar. Posteriormente, los resultados se compararon con un sistema de café-Juglans pyriformis, para observar las diferencias nutricionales existentes entre plantaciones con leguminosas y no leguminosas. Con estos datos, se propuso el uso de Erythrina poeppigiana como sombreado de café, la cual contribuye a mejorar el microclima y la fertilidad del suelo mediante la fijación biológica de nitrógeno.

Tesis (M.Sc) –CATIE, Turrialba (Costa Rica), 2022 La investigación se realizó en el cultivo de maíz (Zea maíz L) con el híbrido DK-390, a fin de determinar el comportamiento de las variables morfológicas cada 20 días después de siembra (DDS), el rendimiento en R3 (elote) a los 90 DDS y en madurez fisiológica a los 120 DDS, bajo dos tipos de sistemas agroforestales multiestrato (SAFM): sombra de cedro (Cedrela odorata) y sombra de poró (Erythrina poeppigiana). El estudio se llevó cabo en la Finca agrocomercial del Centro Agronómico Tropical de Investigación y Enseñanza (CATIE), en el cantón de Turrialba, Provincia de Cartago, Costa Rica (Figura 1).El diseño experimental en campo fue bloques al azar con tres réplicas. Con el fin de estimar el efecto de la sombra sobre las variables de crecimiento y rendimiento, los tratamientos consistieron en dos niveles de sombra: SC, SP y T, distribuidos en un diseño experimental en bloques al azar con tres réplicas. Los datos recolectados en campo se sometieron a un análisis de varianza mediante el programa InfoStat. Los criterios de Akaike (AIC), Bayesianos (BIC) basados en verosimilitud, se utilizaron para la selección del modelo con el mejor ajuste (Rivera et al. 2015). Se realizó una comparación múltiple de medias de tratamientos mediante la prueba de LSD de Fisher (p ≤ 0.05).

Erythrina poeppigiana belongs to Fabaceae family (subfamily Papillionoideae) and is commonly found in tropical and subtropical regions in Brazil. Herein, we described the purification and characterization of a new Kunitz-type inhibitor, obtained from E. poeppigiana seeds (EpTI). EpTI is composed by three isoforms of identical amino-terminal sequences with a molecular weight ranging from 17 to 20 kDa. The physicochemical features showed by EpTI are common to Kunitz inhibitors, including the dissociation constant (13.1 nM), stability against thermal (37–100 °C) and pH (2–10) ranging, and the presence of disulfide bonds stabilizing its reactive site. Furthermore, we investigated the antimicrobial, anti-adhesion, and anti-biofilm properties of EpTI against Gram-positive and negative bacteria. The inhibitor showed antimicrobial activity with a minimum inhibitory concentration (MIC, 5–10 µM) and minimum bactericidal concentration (MBC) of 10 µM for Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus haemolyticus. The combination of EpTI with ciprofloxacin showed a marked synergistic effect, reducing the antibiotic concentration by 150%. The increase in crystal violet uptake for S. aureus and K. pneumoniae strains was approximately 30% and 50%, respectively, suggesting that the bacteria plasma membrane is targeted by EpTI. Treatment with EpTI at 1x and 10 x MIC significantly reduced the biofilm formation and prompted the disruption of a mature biofilm. At MIC/2, EpTI decreased the bacterial adhesion to polystyrene surface within 2 h. Finally, EpTI showed low toxicity in animal model Galleria mellonella. Given its antimicrobial and anti-biofilm properties, the EpTI sequence might be used to design novel drug prototypes.

International audience; Conventional, intensively managed coffee plantations are currently facing environmental challenges. The use of shade trees and the organic management of coffee crops are welcome alternatives, aiming to reduce synthetic inputs and restore soil biological balance. However, little is known about the impacts of the different types of shade tree species on soil functioning and fauna. In this paper, we assess soil nutrient availability and food web structure on a 17-year old experimental coffee plantation in Turrialba in Costa Rica. Three shade types (unshaded coffee, shaded with Terminalia amazonia, and shaded with Erythrina poepiggiana) combined with two management practices (organic and conventional) were evaluated. Total C and N, inorganic N and Olsen P content, soil pH, global soil fertility, and nematode and microarthropod communities were measured in the top 10 cm soil layer, with the objective of determining how shade tree species impact the soil food web and soil C, N and P cycling under different types of management. We noted a decrease in soil inorganic N content and nematode density under conventional management (respectively -47% and -91% compared to organic management), which suggested an important biological imbalance, possibly caused by the lack of organic amendment. Under conventional management, soil nutrient availability and fauna densities were higher under shade, regardless of the shade tree species. Under organic management, only soils under E. poeppigiana, a heavily pruned. N-2 -fixing species, had increased nutrient availability and fauna density, while T amazonia shade had a null or negative impact. The effects of coffee management and shade type on soil nutrient availability were mirrored by changes in soil food web structure. Higher fertility was recorded in soil with balanced food webs. These results emphasize the importance of the choice of shade tree species for soil functions in low input systems, more so than in fertilized systems

The DynACof model was designed to model coffee agroforestry systems and study the trade-offs to e.g. optimize the system facing climate changes. The model simulates net primary productivity (NPP), growth, yield, mortality, energy and water balance of coffee agroforestry systems according to shade tree species and management. Several plot-scale ecosystem services are simulated by the model, such as production, canopy cooling effect, or potential C sequestration. DynACof uses metamodels derived from a detailed 3D process-based model (MAESPA) to account for complex spatial effects, while running fast. It also includes a coffee flower bud and fruit cohort module to better distribute fruit carbon demand over the year, a key feature to obtain a realistic competition between sinks. The model was parameterized and evaluated using a highly comprehensive database on a coffee agroforestry experimental site in Costa Rica. The fluxes simulated by the model were close to the measurements over a 5-year period (nRMSE = 26.27 for gross primary productivity; 28.22 for actual evapo-transpiration, 53.91 for sensible heat flux and 15.26 for net radiation), and DynACof satisfactorily simulated the yield, NPP, mortality and carbon stock for each coffee organ type over a 35-year rotation. Agence Nationale de la Recherche/[ANR-13-AGRO-0005]/ANR/Francia Montpellier Bioinformatics Biodiversity/[ANR-10-LABX-0004]/MBB/Francia UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI) UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Física

International audience; In Central America, coffee is mainly grown in agroforestry systems. This practice modifies the microclimate, which, in turn, influences coffee growth and development. However, modeling these microclimate modifications is a challenge when trying to predict the development of a disease in the understory crop, based on variables usually monitored in weather stations exposed to full sunlight. Furthermore, critical variables for plant disease development, such as leaf wetness duration and leaf temperatures, are generally not measured by weather stations. In our study, we sought to build models explaining daily minimum and maximum coffee leaf temperatures, daily coffee leaf wetness duration, and minimum and maximum air temperatures in agroforestry systems with a single shade tree species, which are common in Central America, and which were characterized by shade tree height, canopy openness and light gap distribution. The modeled variables were mainly explained by one or more meteorological variables provided by reference weather stations exposed to full sunlight. The presence of shade trees resulted in a buffer effect, reducing daily maximum air and leaf temperatures, and increasing daily minimum air and leaf temperatures. Moreover, except for the daily minimum air temperature under shade, shade tree characteristics affected these microclimatic variables. Indeed, the buffer effect on the daily maximum air temperature increased with shade trees 7 m tall or over, whereas for extreme leaf temperatures, this effect seemed to be further intensified by a dense and homogeneous canopy. The tallest shade trees also tended to provide conditions that reduced coffee leaf wetness duration. The coffee leaf stratum affected the daily maximum leaf temperature, with a top layer intercepting radiation for the lower strata, but had no effect on the daily minimum leaf temperature, detected at night. The models developed were simple equations allowing interpretation of shade tree height, the effects of canopy characteristics on the microclimate and were therefore useful for designing and managing agroforestry system. The more accurate models could be incorporated into an early warning system for coffee pests and diseases in the region.

Históricamente, la siembra del poró gigante o extranjero (Erythrina poeppigiana) como árbol de sombra en cafetales, ha sido una práctica agronómica común y de gran importancia en Costa Rica. Aunque se sabe que es de origen suramericano, no existe un documento específico que describa su origen geográfico exacto, así como por qué, cuándo y cómo fue introducido en Costa Rica. Por tanto, con base en varias fuentes, bastante dispersas, en este artículo se trata de contestar dichas preguntas, a la vez que sedescribe la manera en que la especie se diseminó y hasta desplazó a otras especies dominantes de leguminosas, como las guabas y los cuajiniquiles (Inga spp.), dependiendo de las diferentes regionescafetaleras del país. Asimismo, se identifica y reconoce a las personas e instituciones que hicieron posible este proceso.

The aim of this study was to evaluate the potential of the tropical forages morera (Morus alba L.), caraca (Erythrina poeppigiana (Walp.) O.F.Cook and gold button (Tithonia diversifolia (Hemsl.) A.Gray) as an alternative food source for fattening rabbits (Oryctolagus cuniculus L.) and its effect on their productive behavior. The experiment was carried out in the minor species program of Universidad Técnica Estatal de Quevedo, Ecuador. In this study was evaluated New Zealand male rabbits of 35 days of age and with an average weight of 475.47 ± 74.23 g, distributed in four treatments with six replicates in a complete block design. Treatments evaluated were as follows: T1: commercial concentrate ad libitum (control); T2: commercial concentrate 50 g + morera ad libitum; T3: commercial concentrate 50 g + caraca ad libitum, and T4: commercial concentrate 50 g + gold button ad libitum. To identify significant difference among treatments, an analysis of variance and aTukey's multiple range test (P

Cancer is the second cause of death after cardiovascular diseases in the world. Anticancer prevention used can cause undesirable things. Flavonoids are secondary metabolites derived from natural products that are useful for anticancer treatment. This study was performed to observe the cytotoxic activity of alpinumisoflavone from Erythrina poeppigiana, toward cervical cancer (Hela), colon cancer (WiDr), and hepatoma cancer (HepG2) cells. The cytotoxic activity of alpinumisoflavone was tested using (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide) assay. The percentage of cell mortality was calculated and the IC50 was calculated using probit analysis. The result shown that alpinumisoflavone has antiproliferative effect to colon cancer (WiDr), cervical cancer (Hela), and hepatoma cancer (HepG2) cells with the value of IC50 are 5.63, 7.18, and 18.08 µg/ml, respectively. Based on the value of IC50 alpinumisoflavone is very cytotoxic to colon cancer WiDr cell.

International audience; Huit ans de travaux de recherche sur les services écosystémiques dans une grande ferme caféière du Costa Rica (observatoire collaboratif Coffee-Flux, en système agroforestier à base de caféiers sous de grands arbres d'Erythrina poeppigiana, surface projetée de couronne de l'ordre de 16 %) ont suggéré plusieurs applications pour les agriculteurs et les décideurs. Il est apparu que de nombreux services écosystémiques dépendaient des propriétés du sol (ici des Andisols), en particulier de l'érosion, de l'infiltration, de la capacité de stockage de l'eau et des éléments nutritifs. Nous confirmons qu'il est essentiel de lier les services hydrologiques et de conservation au type de sol en présence. Une densité adéquate d'arbres d'ombrage (plutôt faible ici) permet de réduire la sévérité des maladies foliaires avec, en perspective, une réduction de l'usage de pesticides-fongicides. Un simple inventaire de la surface basale au collet des caféiers permet d'estimer la biomasse souterraine et la moyenne d'âge d'une plantation de caféiers, ce qui permet d'évaluer sa valeur marchande ou de planifier son remplacement. Le protocole de calcul actuel pour la neutralité carbone des systèmes agroforestiers ne prend en compte que les arbres d'ombrage, pas la culture intercalaire. Dans la réalité, si on inclut les caféiers, on se rapproche très probablement de la neutralité. Des évaluations plus complètes, incluant les arbres, les caféiers, la litière, le sol et les racines dans le bilan en carbone du système agroforestier sont proposées. Les arbres d'ombrage offrent de nombreux servies écosystémiques s'ils sont gérés de manière adéquate dans le contexte local. Par rapport aux parcelles en plein soleil, nous montrons qu'ils réduisent l'érosion laminaire d'un facteur 2, augmentent la fixation de l'azote (N2) atmosphérique et le pourcentage d'azote recyclé dans le système, réduisant ainsi les besoins en engrais. Ils réduisent aussi la sévérité des maladies foliaires, augmentent la séquestration de carbone, améliorent le microclimat et atténuent substantiellement les effets des changements climatiques. Dans notre étude de cas, aucun effet négatif sur le rendement n'a été enregistré.

Feedipedia.orgA programme by INRA, CIRAD, AFZ and FAO.Last updated on August 7, 2019; Poro (Erythrina poeppigiana)

El experimento fue conducido para determinar los coeficientes de digestibilidad y la energía digestible del Arachis pintoi, Stylozanthes guianensis, Erythrina poeppigiana, Centrocema macrocarpum y Pueraria phaseoloides. Se empleo el método directo, usando el mismo forraje como único alimento. El experimento tuvo dos fases, una de adaptación y una de colección de heces, con una duración de 15 y 5 días, respectivamente. Se utilizaron 25 cuyes machos en etapa de crecimiento distribuidos de tal manera que 5 cuyes correspondieron a cada leguminosa tropical evaluada. Los coeficientes de digestibilidad de los nutrientes del Arachis pintoi (51,96, 56,80, 29,46 y 71,32 por ciento de digestibilidad de la materia seca, proteína cruda, fibra cruda y extracto libre de nitrógeno, respectivamente) fueron cuantitativamente superiores a los otros tratamientos a excepción de la ceniza. Asimismo, los valores de energía digestible (en base seca) obtenidos fueron mayores en el Arachis pintoi (2,20 Kcal/g) que los otros forrajes. This study was carried out to determine the digestibility coefficients and digestible energy of Arachis pintoi, Stylozanthes guianensis, Erythrina poeppigiana, Centrocema macrocarpum and Pueraria phaseoloides. The direct method was used, using the same forage as the only food. The experiment had two phases, one for adaptation and one of faeces collection, with duration of 15 and 5 days, respectively. We used 25 male guinea pigs in growth stage distributed in order to get 5 guinea pigs for each tropical legume evaluated. The digestibility coefficients of nutrients were numerically higher for Arachis pintoi (51,96, 56,80, 29,46 y 71,32 percent of the dry matter, crude protein, crude fiber and nitrogen free extract digestibility, respectively) than for all the other treatments, except for the ash. Likewise, digestible energy values (in dry basis) were greater for Arachis pintoi (2,20 kcal/g) than for all other forages.

Hemileia vastatrix caused a severe epidemic in Central America in 2012−13. The gradual development of that epidemic on nearly a continental scale suggests that dispersal at different scales played a significant role. Shade has been proposed as a way of reducing uredospore dispersal. The effect of shade (two strata: Erythrina poeppigiana below and Chloroleucon eurycyclum above) and full sun on H. vastatrix dispersal was studied with Burkard traps in relation to meteorological records. Annual and daily patterns of dispersal were observed, with peaks of uredospore capture obtained during wet seasons and in the early afternoon. A maximum of 464 uredospores in 1 day (in 14.4 m3 of air) was recorded in October 2014. Interactions between shade/full sun and meteorological conditions were found. Rainfall, possibly intercepted by tree cover and redistributed by raindrops of higher kinetic energy, was the main driver of uredospore dispersal under shade. Wind gusts reversed this effect, probably by inhibiting water accumulation on leaves. Wind gusts also promoted dispersal under dry conditions in full sun, whereas they had no effect under shaded conditions, probably because the canopy blocked the wind. Our results indicate the importance of managing shade cover differentially in rainy versus dry periods to control the dispersal of airborne H. vastatrix uredospores.

Cancer is one of the most feared diseases and is considered the leading cause of death worldwide. Generally, cancer drugs are synthetic drugs with relatively more expensive prices and have harmful side effects, so many people turn to traditional medicine, for example by utilizing herbal medicine. Erythrina poeppigiana is one of the plants that can be used as a medicinal plant containing 10.11-dihidroerisodin compounds that are useful anticancer etnofarmakologi. The purpose of this study was to identify the target of 10,11 dihydroerisodin receptor compound as an insertiico anticancer candidate. The pure isolate was then tested physicochemically MS, UV-Vis, IR, 13C-NMR, 1H-NMR, to obtain the structure of 10.11-dihydroerisodin alkaloid compound which then to target receptors in silico. From the results of the study it was found that 10.11-dihydroerisodin compound can work on the Serine / threonine-protein kinase Chk1 receptor that serves as an anti-cancer candidate. Keywords : 10,11-dihidroerisodin, anti-cancer, target receptors

Historically, the planting of giant or foreign "poró" (Erythrina poeppigiana) as a shade tree in coffee plantations, has been a common and very important agronomic practice in Costa Rica. Even though it is well known that it is a South American tree, there is not a specific document that describes its exact geographic origin, as well as why, when and how it was introduced to Costa Rica. Therefore, based upon a number of quite scattered sources, in this paper we try to answer such questions, while describing the ways in which this species became widespread and even displaced previously dominant leguminous trees, like "guabas" and "cuajiniquiles" (Inga spp.), depending on different coffee-growing regions in the country. In addition, persons and institutions that made this process possible are identified and acknowledged. Históricamente, la siembra del poró gigante o extranjero (Erythrina poeppigiana) como árbol de sombra en cafetales, ha sido una práctica agronómica común y de gran importancia en Costa Rica. Aunque se sabe que es de origen suramericano, no existe un documento específico que describa su origen geográfico exacto, así como por qué, cuándo y cómo fue introducido en Costa Rica. Por tanto, con base en varias fuentes, bastante dispersas, en este artículo se trata de contestar dichas preguntas, a la vez que sedescribe la manera en que la especie se diseminó y hasta desplazó a otras especies dominantes de leguminosas, como las guabas y los cuajiniquiles (Inga spp.), dependiendo de las diferentes regionescafetaleras del país. Asimismo, se identifica y reconoce a las personas e instituciones que hicieron posible este proceso.

The aim of this study was to evaluate the potential of the tropical forages morera (Morus alba L.), caraca (Erythrina poeppigiana (Walp.) O.F.Cook and gold button (Tithonia diversifolia (Hemsl.) A.Gray) as an alternative food source for fattening rabbits (Oryctolagus cuniculus L.) and its effect on their productive behavior. The experiment was carried out in the minor species program of Universidad Técnica Estatal de Quevedo, Ecuador. In this study we evaluated New Zealand male rabbits of 35 days of age and with an average weight of 74.23 ± 75.47 g, distributed in four treatments with six replicates in a complete block design. Treatments evaluated were as follows: T1: commercial concentrate ad libitum (control); T2: commercial concentrate 50 g + morera ad libitum; T3: commercial concentrate 50 g + caraca ad libitum, and T4: commercial concentrate 50 g + gold button ad libitum. To identify significant difference among treatments, an analysis of variance and a Tukey’s multiple range test were carried out to compare the mean values of treatments. Variables measured were as follows: feed intake (FI); growth rate (GR); feed conversion rate (FCR); weight to channel (WC), performance to channel (PC) and profitability. Results show that the highest FI was recorded by T1, T2 and T4 (83.92 ± 4.31, 83.90 ± 1.08 and 81.72 ± 2.85 g dry matter.d-1, respectively); highest GR was found in T1 (28.81 ± 2.55 g); most efficient FCR was T1, T2 and T3 (2.93 ± 0.27, 3.34 ± 0.28 and 3.23 ± 0.19, respectively); and most efficient PC was T3 (56.00 ± 1.11 %) being also the most profitable (53 %). El objetivo de este estudio es evaluar el potencial de los forrajes tropicales (Morus alba L.), caraca (Erythrina poeppigiana (Walp.) O.F.Cook y mirasol o botón dorado (Tithonia diversifolia (Hemsl.) A.Gray) como fuente de alimento alternativo engorde de conejos, y su efecto sobre su comportamiento productivo. El experimento se realizó en el programa de especies menores de la Universidad Técnica Estatal de Quevedo, Ecuador. En este estudio evaluamos conejos machos de Nueva Zelanda de 35 días de edad y con un promedio de peso de 74,23 ± 75,47 g, distribuidos en cuatro tratamientos con seis réplicas en un diseño de bloque completo. Los tratamientos evaluados fueron los siguientes: T1: concentrado comercial a voluntad (control); T2: concentrado comercial 50 g + morera a voluntad; T3: concentrado comercial 50 g + caraca a voluntad, y T4: concentrado comercial 50 g + botón de oro a voluntad. Para identificar diferencias significativas entre tratamientos, se aplicó el análisis de varianza y se utilizó la prueba de rango múltiple de Tukey para comparar los valores medios de los tratamientos. Las variables medidas fueron las siguientes: ingesta de alimento (FI); tasa de crecimiento (GR); tasa de conversión de alimento (FCR); peso a canal (WC), rendimiento a canal (PC) y rentabilidad. Los resultados muestran que la FI más alta se registró con T1, T2 y T4 (83,92 ± 4,31, 83,90 ± 1,08 y 81,72 ± 2,85 g de materia seca.d-1, respectivamente); el GR más alto se encontró en T1 (28.81 ± 2.55 g); la FCR más eficiente fue T1, T2 y T3 (2.93 ± 0.27, 3.34 ± 0.28 y 3.23 ± 0.19, respectivamente); y la PC más eficiente fue T3 (56.00 ± 1.11%) siendo también la más rentable (53%).

The influence of vegetation on slope stability is well understood at the slope level but scaling up to the catchment level is still a challenge, partially because of a lack of suitable data to validate models. We tested the physical landslide model, LAPSUS_LS, which models slope stability at the catchment scale. LAPSUS_LS combines a hydrological model with a Limit Equilibrium Method model, and calculates the factor of safety of individual cells based on their hydrological and geomorphological characteristics. We tested two types of vegetation on slope stability: (i) coffee monoculture (Coffea arabica) and (ii) a mixed plantation of coffee and deep rooting Erythrina (Erythrina poeppigiana) trees. Using soil and root data from Costa Rica, we performed simulations to test the response of LAPSUS_LS to root reinforcement, soil bulk density, transmissivity, internal friction angle and depth of shear plane. Furthermore, we modified the model to include biomass surcharge effect in the calculations. Results show that LAPSUS_LS was most sensitive to changes in additional cohesion from roots. When the depth of the shear plane was fixed at 1.0 m, slopes were not unstable. However, when the shear plane was fixed to 1.5 m, the mixed plantation of coffee and trees stabilized slopes, but the coffee monoculture was highly unstable, because root reinforcement was low at a depth of 1.5 m. Soil transmissivity had a limited impact on the results compared to bulk density and internal friction angle. Biomass surcharge did not have any significant effect on the simulations. In conclusion, LAPSUS_LS responded well to the soil and vegetation input data, and is a suitable candidate for modeling the stability of vegetated slopes at the catchment level.

Tesis (M.Sc) -- CATIE, Turrialba (Costa Rica), 2016 Gran parte de los bosques tropicales actuales son parches relativamente pequeños, inmersos en una matriz agrícola. La condición de degradación actual, exige promover enfoques alternativos, eficientes y más económicos que las plantaciones típicas. Las estrategias de restauración activas (islas de árboles) pueden facilitar la recuperación natural de estos bosques en menor tiempo que la recuperación natural, porque aumentan la producción de hojarasca y la entrada de nutrientes al suelo. Se evaluó la dinámica de la producción, las entradas de nutrientes al suelo por la hojarasca y el efecto de los tratamientos de restauración sobre la descomposición de la hojarasca y el patrón de liberación de nutrientes de dos mezclas de hoja que contrastaban en sus contenidos iniciales de nutrientes. Los cuatro tratamientos de restauración comprenden: plantación (toda el área plantada), islas de árboles (siembra de árboles en seis parches de tres tamaños diferentes), control (regeneración natural), y bosque referencia (primario) 10-12 años después de su establecimiento. Los tratamientos se establecieron en parcelas de 50 × 50 m en cinco sitios replicados en el sur de Costa Rica. Las especies plantadas incluían dos especies nativas productoras de madera (Terminalia amazonia y Vochysia guatemalensis) intercaladas con dos especies fijadoras de nitrógeno (Inga edulis y Erythrina poeppigiana). La producción de hojarasca fue similar en plantación, bosque referencia e isla, pero todos ellos significativamente mayores comparado con regeneración natural (n=216; F=21,8; p

Background and Aims In Costa Rica, coffee (Coffea arabica) plants are often grown in agroforests. However, it is not known if shade-inducing trees reduce coffee plant biomass through root competition, and hence alter overall net primary productivity (NPP). We estimated biomass and NPP at the stand level, taking into account deep roots and the position of plants with regard to trees. Methods Stem growth and root biomass, turnover and decomposition were measured in mixed coffee/tree (Erythrina poeppigiana) plantations. Growth ring width and number at the stem base were estimated along with stem basal area on a range of plant sizes. Root biomass and fine root density were measured in trenches to a depth of 4 m. To take into account the below-ground heterogeneity of the agroforestry system, fine root turnover was measured by sequential soil coring (to a depth of 30 cm) over 1 year and at different locations (in full sun or under trees and in rows/inter-rows). Allometric relationships were used to calculate NPP of perennial components, which was then scaled up to the stand level. Key Results Annual ring width at the stem base increased up to 2·5 mm yr−1 with plant age (over a 44-year period). Nearly all (92 %) coffee root biomass was located in the top 1·5 m, and only 8 % from 1·5 m to a depth of 4 m. Perennial woody root biomass was 16 t ha−1 and NPP of perennial roots was 1·3 t ha−1 yr−1. Fine root biomass (0–30 cm) was two-fold higher in the row compared with between rows. Fine root biomass was 2·29 t ha−1 (12 % of total root biomass) and NPP of fine roots was 2·96 t ha−1 yr−1 (69 % of total root NPP). Fine root turnover was 1·3 yr−1 and lifespan was 0·8 years. Conclusions Coffee root systems comprised 49 % of the total plant biomass; such a high ratio is possibly a consequence of shoot pruning. There was no significant effect of trees on coffee fine root biomass, suggesting that coffee root systems are very competitive in the topsoil. (Resume d'auteur)

Assessing the spatial variability of soil organic carbon (SOC) is crucial for SOC monitoring and comparing management options. Topsoil (0–5 cm) SOC concentrations were surveyed in a coffee agroforestry watershed (0.9 km2) on Andisols in Costa Rica with uniform farm management. We encountered high values and large spatial variations of SOC, from 48.1 to 172 g kg− 1 in the dry combustion set (SOCref; n = 72) used for calibrating the visible-near-infrared reflectance spectroscopy (VNIRS) samples (SOCVNIRS; 350–2500 nm; n = 520). VNIRS using partial least squares regression was effective in predicting SOC (R2 = 0.85; a root mean square error (RMSE) = 12.3 g kg− 1) and proved an effective proxy measurement. We assessed several topographic, vegetation and andic soil property variables, of which only the latter (metal–humus complexes and allophanes) displayed strong correlations with SOCref concentrations. We compared Random Forest and three geostatistical approaches for the interpolation of SOC in unsampled locations. Ordinary kriging with SOCref yielded an RMSE of 28.0 g kg− 1. Random Forest was successful in incorporating many weakly and non-linearly correlated covariates with SOC (RMSE = 14.7 g kg− 1), provided Alp (the sodium pyrophosphate extractable aluminum), the best predictor of SOC (r = 0.85) but also the most costly variable to acquire. Co-kriging with Alp also showed high reduction in RMSE (16.0 g kg− 1). Co-kriging with SOCVNIRS only showed marginal reduction in RMSE to 24.2 g kg− 1 due to the presence of a high nugget effect. Local variability of SOC in this volcanic agroforestry watershed was dominated by andic properties whereas topographic or vegetation variables had very little impact. Estimation of SOC variability is recommended using inexpensive proxy measurements like VNIRS (RMSE = 12.3 g kg− 1) rather than spatial interpolation techniques. (Resume d'auteur)

To investigate the effects of microbial inocula and Erythrina poeppigiana pruning residues on soil K, NO3-, and NH4? concentrations, a greenhouse trial, a field experiment in an organic farm, and three in vitro tests were conducted. Under controlled conditions, weak, temporary effects (10 %) on maize seedling growth were observed on poor soils (taken from the 10-20 cm layer) in the first 2 weeks after application. Positive effects of pruning residue applications on soil K levels (0.09 cmol kg-1, on average) were detected in both the field and greenhouse study. However, significant effects due to the addition of microbial inocula on soil K concentrations were not detected in the field; thus, microbial applications were ineffective at enhancing nutrient availability under field conditions. In contrast, in the in vitro experiments, CO2 production was 31 % greater than that of untreated soil on the 8th and 15th days of incubation. These results highlight the importance of adding tree pruning residues to support coffee-plant nutrition. Experimental outcome data could be valuable for further studies focused on microbial application dosage and timing.

Frente a vacíos importantes de información sobre interacciones agroecológicas en la producción de café agroforestal, se estableció (año 2000) un ensayo de largo plazo que evalúa 20 arreglos de sistemas agroforestales (SAF) y Pleno Sol con diferentes niveles de insumos orgánicos y convencionales. El conocimiento generado posibilita entender cómo diseñar y manejar SAF que equilibren productividad y sostenibilidad. En 10 años, 15 tipos de SAF han permitido importantes niveles de productividad de café. Los SAF (manejos Alto Convencionales, AC) con Erythrina poeppigiana (poró) y E. poeppigiana. + Chloroleucon eurycyclum (cashá) fueron los que tuvieron las más altas producciones de café, aunque el último no fue diferente estadísticamente de otros 8 SAF que igualmente tuvieron resultados muy buenos. El SAF con E. poeppigiana AC fue estadísticamente igual que el café a Pleno Sol AC. La menor productividad la tuvo el SAF con Terminalia amazonia (amarillón) en manejo Bajo Orgánico (BO). De los arreglos estudiados, 19 presentaron rentabilidad positiva. En productividad de madera se destacaron los SAF con cashá con manejo Orgánico Intensivo (MO) y Moderado Convencional (MC) y los SAF con amarillón con manejo AC. Las variedades de café Costa Rica 95 y los híbridos Centroamericano y Milenio, con poró MC y BO, permiten productividad muy alta con costos más bajos. El rango de sombra en los SAF que permitió los mejores resultados de productividad de café fue 45 a 54%. Los SAF con E. poeppigiana han permitido producción total de biomasa muy altos (>10.000 kg ha-1). Los SAF MO fueron eficaces para evitar la acidificación de los suelos y mejorar sus propiedades físicas y químicas. Los SAF incrementaron la abundancia y biomasa de lombrices, contrario al Pleno Sol AC, donde los valores fueron bajos. Todos los SAF capturaron y almacenaron grandes cantidades de carbono y compensaron las emisiones de gases de efecto invernadero. En cambio, los sistemas a Pleno Sol emitieron más de lo que capturaron. La diversidad de aves y en particular la actividad de percha y sobrevuelo fueron mayores en los SAF que a Pleno Sol. Independientemente de la especie de sombra, el manejo AC reduce la diversidad de hierbas, mientras que los SAF con poró + cashá con manejos MC y MO presentaron la mayor diversidad de hierbas. Las menores incidencias del hongo de la roya, Hemileia vastatrix, ocurrieron en los sistemas a Pleno Sol AC y poró MO y AC. Las menores incidencias del hongo Cercospora coffeicola sucedieron en poró con maderables (MO, BO, MC) y sola (BO, MC).

La investigación se llevó a cabo luego de la última epidemia fuerte de ojo de gallo en el 2010, cuando se contabilizó $60 millones USD de pérdidas concent radas en las zonas del Valle Central y de Los Santos. En Costa Rica se presentan ataques cíclicos relacionados con el aumento de las precipitaciones y del inóculo y se prevé que pueda volver a presentarse una epidemia fuerte en 2016- 2017 debido a la posible afectación de un evento de La Niña. Por lo que se realizó esta investigación para evaluar el impacto relativo del inóculo primar io según la fuente sobre la epidemiología del ojo de gallo y diseñar estrategias agroecológicas basad as en ese conocimiento, para tratar de implementar un adecuado manejo de la enfermedad. Se realizó ent re 2011 y 2014 en la zona de Los Santos, Costa Rica. Se visitaron 27 fincas tanto de productores independientes como de asociados a las cooperativas de Tarrazú y Dota, así como la finca experimental del Centro Agrícola Cantonal de Tarrazú. El trabajo se compuso de pruebas de laboratorio, invernadero y campo. Se reportaron 13 nuevos géneros de plantas hospedantes, no fue posible recuperar Mycena citricolor a partir de suelo ni hojarasca y se documentó que el hongo está presente fuera del cont inente americano. Se determinó el índice de patogenicidad (IP) de 17 cepas del hongo, 15 proven ientes de vegetación acompañante, una recuperada de café CR95 (McK) y una de Caturra (McC a), usada como patrón de comparación. Once de las cepas fueron mantenidas in vitro previo a la prueba, los valores estuvieron entre 0 ,00 para la cepa proveniente de Erythrina poeppigiana (producida in vitro) y 18,87 para Bryophyllum calycinum (recuperada directamente de campo), la cepa McK pre sentó un IP de 9,94 y la cepa McCa de 3,67, ambas procedentes de campo. Todas las cepas in vitro tuvieron IP menor a las cepas de campo. Por otro lado, la eliminación del inóculo primario pres ente en la planta de café, a inicios de la época lluviosa, bajo las condiciones de esta investigación, redujo alrededor del 10% el porcentaje acumulado de enfermedad al final de la estación; mi entras que no se halló efecto de la presencia o ausencia de hojarasca sobre la epidemia. Se determi nó que el modelo logístico de desarrollo fue el que mejor describió la epidemia y se encontraron va lores de velocidad de desarrollo (r) entre 0,03 y 0,05 unidades por día. No se halló diferencia signi ficativa entre el ABCDE, tanto para promedio de lesiones como de geminíferos activos, para aplicaci ones de fungicida (642,78) y metabolitos secundarios de Trichoderma ya fuera al follaje (2472,72) o al suelo y hojaras ca (1695,41), probablemente debido a la alta variabilidad del sis tema. Se concluye que parte de la vegetación actúa como fuente de inóculo para el ojo de gallo, que el mantenimiento in vitro del hongo disminuye su patogenicidad y que no hay interacción entre el inó culo primario y la presencia de hojarasca sobre el desarrollo de la enfermedad en años con baja precip itación. Por último, no fue posible determinar con claridad el efecto de las aplicaciones de metabolit os secundarios de Trichoderma sobre la epidemia.