Escuela de Ciencias Agrarias

URI permanente para esta comunidadhttp://10.0.96.45:4000/handle/11056/14688

La Escuela de Ciencias Agrarias (ECA) de la Universidad Nacional, genera conocimientos y capacidades por medio de la docencia, investigación, extensión y servicios, que contribuyen al desarrollo de la agricultura sostenible, los agronegocios y la competitividad, y de los espacios rurales y territoriales, para mejorar el desarrollo humano sostenible y equitativo de la sociedad.

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A female of Eudorylaimus sp with two vulvae.
(Universidad Nacional, Costa Rica, 2001) Esquivel Hernández, Alejandro
A female of Eudorylaimus sp, with two vulvae was found in Tempisque Conservation Area in Costa Rica. Thousands of nematodes have been prepared in Cobb's slides to study nematode diversity in Costa Rica; nevertheless, only one aberrant female has been found. The two vulvae are very close to each other and vaginal sclerotization plates show abnormal formation. There is no linkage between the uterus and the gonoducts and the ovaries are poorly developed. An absence of sperm and eggs suggests that the genital apparatus is not functional. Because identification at the species level teas not achieved, more specimens and studies are needed
Anxiolytic activity and active principles of Piper amalago (Piperaceae), a medicinal plant used by the Q’eqchi’ Maya to treat susto, a culture-bound illness
(Elsevier, 2016-06-05) Mullally, M.; Cayer, C.; Muhammad, A.; Walshe-Roussel, B.; Ahmed, F.; Sanchez-Vindas, PE.; Otárola Rojas, Marco Antonio; Merali, Zul; Cal, V.; Durst, Tony; Trudeau, Vance; Arnason, John
Ethnopharmacological relevance The medicinal plant, Piper amalago L. (Piperaceae), is used traditionally by Q'eqchi' Maya healers for the treatment of "susto" a culture-bound syndrome. Previous research suggests that susto symptoms may be a manifestation of anxiety. The objectives were to characterize the effect of ethanolic extract of P. amalago in behavioral assays of anxiety at doses representative of traditional use and to isolate active principles. Materials and methods Rats treated orally with low dose ethanolic extracts of P. amalago leaves (8-75 mg/kg) were tested in several behavioral paradigms including the elevated plus maze (EPM), social interaction (SI), and conditioned emotional response (CER) tests, and compared to diazepam, a positive control. The active anxiolytic principle was isolated by bioassay guided isolation using an in vitro GABAA competitive binding assay. Results Extracts had significant anxiolytic activity in all behavioral tests, with the strongest activity in the SI and the CER paradigms. In an in vitro GABAA competitive binding assay, a 66.5 μg/mL concentration of P. amalago ethanol extract displaced 50% of the GABAA-BZD receptor ligand [3H]-Flunitrazepam. Bioassay-guided fractionation identified a furofuran lignan, a molecule with structural similarity to yangambin, with high affinity for the GABAA-BZD receptor as the principle bioactive. Conclusion The results suggest that the ethnobotanical use of this plant may have a pharmacological basis in its anxiolytic activity, as demonstrated in animal behaviour tests.
Biomass dynamics of Erythrina lanceolata as influenced by shoot-pruning intensity in Costa Rica
(Springer, 2003) Berninger, Frank; Salas, Eduardo
Pruning of agroforestry trees, while reducing shade of the crops, usually reduces both biomass production and nitrogen fixation. Short pruning cycles are often not sustainable on the long run, because tree production declines over subsequent pruning cycles. We compared biomass and labile carbohydrate dynamics of Erythrina lanceolata Standley (Papilionaceae) shade trees under total and partial pruning regimes in a vanilla (Vanilla planifolia L.) plantation in South-western Costa Rica. The highest biomass production was measured in the unpruned control, followed by trees with 50% of the leaf pruned every three months, while total pruning every six months resulted in the lowest biomass pruduction. In the more productive treatments, a higher proportion of the production was in branches. Because, the N content of woody branches was high, they were important for nitrogen cycling. In the partial pruning treatment more nitrogen was returned to the soil from litter and woody branches than from pruned leaf. Sugar concentrations were not different between treatments and the dynamics of non-structural carbohydrates (sugar and starch) seems to depend more on plant phenology than pruning treatment. However, the starch concentrations in the total pruning were lower than in the other treatments.
Chemical composition of PM 2.5 particles in Salamanca, Guanajuato Mexico: Source apportionment with receptor models
(Science Direct, 2012-04) Herrera-Murillo, Jorge; Campos Ramos, Arturo; Ángeles García, Felipe; Blanco Jiménez, Salvador; Cárdenas, Beatriz; Mizohata, Akira
The National Institute of Ecology, through Management General for Environmental Research and Training (DGCENICA) carried out a sampling campaign where a total of 21 elements were determined in 140PM 2.5 samples from one sampling site located in the city of Salamanca, Guanajuato-Mexico between November 2006 and November 2007. The annual average PM 2.5 concentration was 45μg/m 3 almost three times the Mexican Annual standard for PM 2.5. Mineral, organic and elemental carbon were the most important components present in particles PM 2.5. Two advanced receptor models, UNMIX and positive matrix factorization (PMF) were used for PM 2.5 source identification. Four and six sources were identified by UNMIX and PMF, respectively, from a combined dataset including 15 chemical species. Source categories were determined based on both, component abundances in the source profiles, and their temporal characteristics. Overall, different sources were identified as the major contributors: heavy fuels combustion, traditional brick production-agricultural burning, crustal, road traffic and secondary organic aerosols.
Citrus Huanglongbing Caused by Candidatus Liberibacter asiaticus Present in the Northern Region of Costa Rica but Has Not Extended to Other Citrus-Growing Areas
(American Phytopathological Society, 2015-10-16) Molina-Bravo, Ramón; Stephens, Steve A.; Hilje-Rodríguez, I.; Blanco-Vargas, Marilyn; Villalobos-Navarro, D.; Gatjens-Boniche, Omar; Moreira-Carmona, L.; Villalobos-Müller, W.
Since 2011, citrus Huanglongbing (HLB, ex-greening) disease has been detected in Los Chiles, Costa Rica, close to the Nicaraguan border, by the State Phytosanitary Service (Servicio Fitosanitario del Estado; SFE) and by TicoFrut’s Agricultural Diagnostic Laboratory (Arredondo-Bernal et al. 1999; SFE 2011). However, there has not been a formal scientific report confirming its presence by two independent methods, nor has there been an update on the spread of the disease to other parts of the country
Current agro-climatic potential of Patagonia shaped by thermal and hydric patterns
(Springer, 2020-08-16) CAMPOY, Jose; Brendel, Andrea Soledad; del Barrio, Ricardo; Mora, Francisco; Orrego León, Elmer Adolfo; Rosales Flores, Johaner
Changes in thermal and hydric patterns affect crop growth. This research is aimed to assess temporal and spatial trends of 18 climatic and agro-climatic thermal and hydric indices in the north of Argentine Patagonia (39°–44°, south latitude), to establish the current and potential suitability of this region for agriculture in a context of climate change. The period of study was 1970– 2016, and it was focused on the last 20 years. Regional warming was indicated by the average increases of annual mean temperature (+ 0.2 °C decade−1 ), mean maximum temperature of the warm trimester (+ 0.3 °C decade−1 ), and extreme maximum temperature of the warmest month (+ 0.6 °C decade−1 ) during 1970–2016. This trend was also found in the 1996–2017 period. Mean minimum temperature of the cold trimester showed an uneven spatial and temporal trend, with increasing temperatures during 1970–2016 (+ 0.1 °C decade−1 ), but a negative trend (− 0.1 °C decade−1 ) over the last 20 years, which leads to an increasing regional trend in temperature amplitude. Negative trends in extreme minimum temperatures of April (− 0.3 °C decade−1 ), July and October (− 0.2 °C decade−1 ) imply more significant risks of cold damage for crops that exhibit sensitive phenological stages during this time. Thermal agro-climatic indices showed negative trends in winter chill (− 15.8 chill hours decade−1 considering the Weinberger method and − 20.8 chill hours decade−1 using Sharpe method) and higher accumulation of warm semester growing degree days (+ 38.8 GDD5 °C and + 32.3 GDD10 °C decade−1 ). Climatic and agro-climatic water indices showed that most of the region experienced decreasing water availability, mainly in the central-south and Andean subregions, showing annual precipitation trends of − 11.5 and − 31.2 mm decade−1 , respectively). If these thermal and hydric trends are maintained in the future, the region will evolve into an area of greater energetic availability but with some restrictions: lower winter chill that would affect very high-chill cultivars cultivated in the warmest regions, higher risk of extreme thermal events during crucial phenological periods of specific crops, and decreasing water availability that would mainly affect dryland farming and river basin recharge
Determinación de la sensibilidad a fungicidas de hongos asociados a la sintomatología de la muerte de corona en el cultivo de fresa (Fragaria x ananassa) en condiciones in vitro
(Universidad Nacional (Costa Rica), 2024) Elizondo Sibaja, Brenda; Calvo Araya, José Alonso
El cultivo de fresa (Fragaria ananassa D) en Costa Rica la fresa, representa una fuente de ingresos principalmente en zonas altas del país, donde se produce un desarrollo agrícola y económico producto de este cultivo. La producción en los últimos años se ha visto mermada por la presencia de diferentes plagas y enfermedades; entre ellas pudriciones de raíces, marchitamientos vasculares y pudrición de la corona de la fresa, la cual se caracteriza por síntomas de decaimiento acompañado de un amarillamiento y posterior necrosis de la corona. Para la realización del presente trabajo se muestreo la Finca el Fresal ubicada en el cantón de Vázquez Coronado 9°97´90,5”N83°98´81,7”W” en la provincia de San José que se dedica al cultivo de fresa, cuya altitud es de 1690 msnm. El aislamiento, identificación y evaluación de la sensibilidad a fungicidas de los patógenos aislados se realizó en el Laboratorio de Fitopatología de la Escuela de Ciencias Agrarias, Universidad Nacional. Se lograron aislar tres patógenos de la corona de fresa: Botrytis cinerea, Colletotrichum sp. y Pestalotiopsis sp., estos hongos fueron identificados con base en la morfología de su colonia, crecimiento de micelio y las características de sus estructuras reproductivas las cuales fueron idénticas a las reportadas para los hongos mencionados. Los estudios sobre la sensibilidad del patógeno a fungicidas son de suma importancia, ya que no existen en el país por tratarse de una enfermedad nueva y emergente. Se evaluó la sensibilidad in vitro mediante la técnica del cultivo envenenado de tres patógenos aislados de la corona de fresa mencionados con anterioridad a tres dosis (0.1; 1.0 y 10 ppm) de los fungicidas: metil tiofanato (Código FRAC1, Grupo químico tiofanato), oxicloruto de cobre (Código FRACM01, Grupo químico M), fosetyl-Al (Código FRACP07, Grupo químico etil fosfonato) utilizados comúnmente en el cultivo de fresa para el control de enfermedades. Los fungicidas utilizados resultaron altamente fungitoxicos a todos los aislados, destacándose metil tiofanato para el control de Colletotrichum sp. como el que obtuvo un mayor porcentaje (89.16%) de inhibición del crecimiento micelial (PIC). Los demás fungicidas tuvieron valores mayores a un 70% de PIC para los tres hongos fitopatógenos a excepción de metil tiofanato al ser evaluado sobre B. cinerea solamente logró un 69.46 de PIC. No hubo variabilidad ni diferencias estadísticamente entre las diferentes dosis de los fungicidas evaluados. Los resultados obtenidos determinan que los fungicidas evaluados logran inhibir el crecimiento de los patógenos evaluados en condiciones in vitro.
Dry-matter yields and crude protein and rumen degradable protein concentrations of three Arachis pintoi ecotypes at different stages of regrowth in the humid tropics
(Blackwell Publishing Ltd., 2005-08-15) Villarreal, M.; Cochran, R. C.; Roja-Bourrillón, A.; Rodríguez, R.; Wickersham, T. A.; Villalobos, L
Well-established stands of three ecotypes of Arachis pintoi (CIAT 17434, 18744 and 18748) were harvested from replicated plots (three blocks, each containing three plots for each ecotype) during the two dominant seasons (dry and wet) of the low altitude, humid tropics of Costa Rica. Each plot was further divided into six subplots so that, within each season, samples corres ponding to 4, 6, 8, 10, 12 or 14 weeks of regrowth could be collected. For each harvest, dry matter (DM) yield of the leaf, stem and whole plant, and the leaf:stem ratio, were recorded. Samples of the whole plant were analysed for crude protein (CP), rumen-degradable (RDP) and rumen-undegradable protein (RUP) concen trations. DM yield of the leaf, stem and whole plant increased with advancing period of regrowth but the effects of period of regrowth varied somewhat among ecotypes and across seasons. Generally, DM yield was greater during the wet than during the dry season. The greatest difference between ecotypes for stem and total DM yields was evident during the dry season. In general, DM contents were low in the whole plant, leaf and stem samples (<220 g kg)1 ) and increased with increasing period of regrowth. Increases in leaf:stem ratio were most dramatic during the dry season with greater periods of regrowth, although the ratio was fairly constant during the wet season. Whole-plant CP concentration was relatively high after short periods of regrowth (up to 279 g kg)1 DM) but declined with longer periods of regrowth; the relative decline was much greater during the dry season. The RDP concen tration was relatively constant during the wet season (mean 115 g kg)1 DM), but declined with longer peri ods of regrowth during the dry season (range 194– 111 g kg)1 DM). In general, the concentrations of RDP, on a CP basis, were greater during the dry season and ranged from 590 to 700 g kg)1 CP. Season, ecotype and period of regrowth all exerted an effect on RUP concentrations.
Four new species and five morphospecies of Ficophagus Davies & Bartholomaeus, 2015 (Nematoda: Aphelenchoididae) from Ficus subgenus Urostigma sect. Americana (Moraceae) in Central America
(Brill & The Hague Academy of International Law, 2017-05-02) Davier, Kerrie A.; Ye, Weimin; Kanzaki, Natsumi; Center, Barbara; Bartholomaesus, Faerlie W.; Herre, Edward Allen; Esquivel, Alejandro; Giblin-Davis, Robin
Four new species of Ficophagus were recovered from the sycones of Ficus spp. from the Subgenus Urostigma section Americana from Central America. The species are described here as Ficophagus bullenei sp. n., F. costaricanus sp. n., F. paraensis sp. n. and F. kayai sp. n. The new species are differentiated from other species of the genus by a combination of morphological characters including body length, position of the excretory pore, spicule shape, stylet form, length of the post-uterine sac, tail shape, sequence data of the ribosomal DNA 18S, 28S D2-D3 and mitochondrial DNA cytochrome oxidase subunit I, biogeographical range, and host wasp and Ficus species affiliations. In addition, five morphospecies are described from Ficus cahuitensis, F. citrifolia, F. dugandii, F. obtusifolia, and F. trigonata, respectively. The morphospecies are not formally named due to a lack of pertinent data/molecular sequences.
Free-living nematodes from nature reserves in Costa Rica. 4. Cephalobina
(Brill, 2003) Holovachov, Oleksandr; Esquivel, Alejandro; Bongers, Tom
Four species of Cephalobina: Geraldius bakeri, Diastolaimus croca, Trualaimus culeatus and Tricirronema tentaculatum are described and illustrated on the basis of material collected in Costa Rica. A scanning electron microscope (SEM) study of G. bakeri is given for the rst time. Diastolaimus croca is found to have a circle of six setiform processes anterior to the true labial setae. Detailed descriptions of the female reproductive system in G. backeri, D. croca and Macrolaimus sp. are given. The use of the female reproductive system and structure of the labial sensilla in the systematics of the family Chambersiellidae, together with its taxonomic placement, are discussed. Notes on the systematic position of the family Bicirronematidae and a key to the species of this family are given.
Identification and molecular characterisation of fifteen tropical isolates of the entomopathogenic fungus Metarhizium
(Taylor and Francis Ltd., 2020-02-26) Castro Vásquez, R. M.; Hernández Villalobos, S.; Vargas Martínez, A; González Herrera, A.; Montero-Astúa, Mauricio; Molina-Bravo, R.
Twelve Metarhizium isolates from Costa Rica, two from Honduras and one from Nicaragua were characterised using molecular and morphological information. Two gene sequences, TEF1-α and β-TUB, identified isolates as M. anisopliae, M. brunneum and M. robertsii, and has provided new sequence information. Eleven SSRs revealed fourteen different genotypes. Morphological variability coincided with allelic diversity within species. This work provides a starting point for the application of integral biocontrol programmes, but more comprehensive and detailed surveys are warranted to understand the species composition and genetic diversity of the Metarhizium in Central America. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group.
Molecular characterization of pseudomonodelphic dagger nematodes of the genus Xiphinema Cobb, 1913 (Nematoda: Longidoridae) in Costa Rica, with notes on Xiphinema setariae Tarjan, 1964
(Springer, 2016-12-16) Peraza-Padilla, Walter; Archidona-Yuste, Antonio; Ferris, Howard; Zamora-Araya, Tatiana; Cantalapiedra-Navarrete, Carolina; Palomares-Rius, Juan Emilio; Subbotin, Sergei; Castillo, Pablo
Pseudomonodelphic dagger nematodes of the genus Xiphinema are characterized by having one of the genital branches reduced and lacking an ovary. They are usually reported from tropical regions. Nematode surveys conducted during rainy seasons in Costa Rica resulted in detection of several Xiphinema costaricense populations, but also other pseudomonodelphic and didelphic species of Xiphinema. We undertook detailed integrative morphometric and molecular studies using D2-D3 expansion segments of 28S rDNA, and ITS1-rDNA. From those studies, we also identified several populations of Xiphinema krugi and two populations of Xiphinema setariae with characteristics in agreement with those of the original and later descriptions of these species. The phylogenetic analyses of these species with other representatives of Xiphinema spp. indicated that pseudomonodelphic species are phylogenetically related (X. costaricense and X. krugi). On the basis of ITS1 sequences of X. costaricense and X. variegatum from Brazil, as well as similar morphology and morphometrics of both species, the latter is proposed here as a junior synonym of the former. Also, our morphometric data showed some intraspecific variability within X. setariae, which in combination with the molecular evidence, suggests that X. setariae and X. vulgare need to be considered as a single taxon.
Polycyclic aromatic hydrocarbons in filterable PM2.5 emissions generated from regulated stationary sources in the metropolitan area of Costa Rica
(Elsevier, 2017-09) Herrera-Murillo, Jorge; Rojas Marín, José Félix; Mugica-Alvarez, Violeta; Solórzano Arias, David; Beita Guerrero, Víctor Hugo
This study analyzed the profiles of polycyclic aromatic hydrocarbons (PAHs) in filterable PM2.5 particles collected from a total of 71 boilers and 22 indirect type furnaces that burn liquid and biomass fuels in the Metropolitan Area of Costa Rica, from February 2014 to November 2015. Modified method NIOSH 5506 was used to analyze PAHs content present in the filter samples. The average concentration of PM2.5 showed values between 18 and 735 mg m−3, based on the source and fuel type used, while the total PAHs in the PM2.5 fraction ranged 1.02–592 μgm−3. For biomass boilers, the most abundant species were Benzo[g,h,i]perylene (BghiP) (35.7–46.5%), Indeno[1,2,3-cd]pyrene (IND) (20.6–27.1%), Benzo[a]pyrene (BaP) (5.2–14.7%) and Dibenzo[a,h]anthracene (DBA) (3.2–13.9%), while for liquid fuels IND (12.8–20.5%), BghiP (7.9–21.2%), Fluoranthene (Flu) (14.5–21.3%) and Pyrene (Pyr) (9.8–14.5%) prevailed. The particles from biomass furnace emissions present higher concentrations of PAHs classified by the U.S. EPA as probable human carcinogens causing a greater health risk than other fuels. Among the diagnostic concentration ratios examined, only BaP/(BaP+Chr), BaA/Chr, BaA/BaP and Pyr/BaP coefficients demonstrated codependency on the type of fuel used.
Polycyclic aromatic hydrocarbons in PM2.5 and PM10 atmospheric particles in the Metropolitan Area of Costa Rica: Sources, temporal and spatial variations
(Elsevier, 2017-03) Solórzano Arias, David; Herrera-Murillo, Jorge; Chaves Villalobos, María; Rojas Marín, José Félix; Beita Guerrero, Víctor Hugo
Polycyclic aromatic hydrocarbons (PAHs) concentrations in PM10 and PM2.5 particles were measured at 14 monitoring sites (12 for PM10 and 2 for PM2.5), located in the Metropolitan Area of Costa Rica, from January to November 2013. High-volume air samplers with pretreated quartz filters were used to collect the particles. The analytical determination was carried out using high-performance liquid chromatography (HPLC). The most abundant PAHs were benzo[a]anthracene, indeno(1,2,3-cd)pyrene, dibenz[a,h]anthracene and acenaphthylene. Ratios obtained by correlating the concentration of some PAHs, both PM10 and PM2.5, suggest that gasoline and diesel vehicles are the main sources in the area being studied. This is consistent with the results obtained when applying the positive matrix factorization (PMF) analysis, since vehicles accounted for 62–74% of total emissions in the area; burning wood fuel was the second source of emissions, contributing between 7 and 15%; and road dust was third, with almost 8%.
Quality differentiation of cocoa beans: implications for geographical indications
(Journal of the Science of Food and Agriculture, 2021-01-09) Hernandez , Carlos Eduardo; Granados, Leonardo
Geographical indications may stimulate collective actions of governance for quality control, trade and marketing as well as innovation based on the use of local resources and regional biodiversity. Cocoa production, however, dominated by small family agriculture in tropical regions, has rarely made use of such strategies. This review is aimed at understanding major research interests and emerging technologies helpful for the origin differentiation of cocoa quality. Results from literature search and cited references of publications on cocoa research were imported into VOSviewer for data analysis, which aided in visualizing major research hotpots. Co-occurrence analysis yielded major research clusters which guided the discussion of this review. Observed was a consensus recognizing cocoa quality resulting from the interaction of genotype, fermentation variables and geographical origin. A classic view of cocoa genetics based on the dichotomy of ‘fine versus bulk’ has been reexamined by a broader perspective of human selection and cocoa genotype evolution. This new approach to cocoa genetic diversity, together with the understanding of complex microbiome interactions through fermentation, as well as quality reproducibility challenged by geographical conditions, have demonstrated the importance of terroir in the production of special attributes. Cocoa growing communities around the tropics have been clearly enabled by new omics and chemometrics to systematize producing conditions and practices in the designation of specifications for the differentiation of origin quality.
Two new species and three morphospecies of Ficophagus Davies & Bartholomaeus, 2015 (Nematoda: Aphelenchoididae) from Ficus subgenus Pharmacosycea (Moraceae) in Central America
(Brill & The Hague Academy of International Law, 2017-03-15) Davies, Kerrie A; Ye, Weimin; Center, Barbara; Kanzaki, Natsumi; Bartholomaeus, Faerlie; Herre, Edward Allen; Esquivel, Alejandro; Giblin-Davis, Robin
Aphelenchoidid nematodes were collected from the sycones of Ficus subgenus Pharmacosycea from Central America. Two new species of Ficophagus were recovered, and are described herein as F. maxima sp. n. and F. yoponensis sp. n. from Ficus maxima and F. yoponensis, respectively. They are differentiated from other species of the genus by a combination of morphological characters including having C-shaped females and spiral males, EP opening close to the lips, a short to long post-uterine sac, spicule characters, three pairs of subventral caudal papillae, DNA sequence data, biogeographical range, and host wasp and Ficus species affiliation. The new species are differentiated from each other by spicule characters, length of the post-uterine sac, spermatheca shape, and female tail shape. In addition, three morphospecies were collected from sycones of Ficus glabrata, F. insipida and F. tonduzii, respectively. Their morphological descriptions are presented but these taxa are not formally named as they currently lack molecular data.

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