Agronomía Mesoamericana journal is a continuous publication with an annual open issue that begins in January and closes in December. Edited in the Universidad de Costa Rica, its objective is to disseminate original scientific information in Spanish or English language, through the publication of articles, short communications, technical notes and literature reviews, related with food and agriculture sciences from anywhere in the world, emphasized in tropical and subtropical zones. Agronomía Mesoamericana implements interoperability protocols that allow the journal to be harvested by other content distribution systems. It supports this process through the OAI-PMH protocol (Open Archives Initiative Protocol for Metadata Harvesting) that allows the transfer of scientific and open access digital resources. URL OAI-PMH https://revistas.ucr.ac.cr/index.php/agromeso/oai
Classification of water deficit in blueberry plants using low-cost thermography and artificial intelligence
Introduction. Water deficit stress is a limiting factor in blueberry (Vaccinium corymbosum L. ‘Biloxi’) production. Infrared thermography detects this stress, but its high cost limits its adoption. Objective. To develop and validate a low-cost system, based on low-resolution thermography and a multilayer perceptron architecture, for the automatic classification of water status in blueberry plants under controlled conditions. Materials and methods. A longitudinal single-case design, structured as a computational proof of concept, was used with a ‘Biloxi’ plant in a micro-greenhouse in Cundinamarca, Colombia, for 53 days, between June and August 2025. A microcontroller managed a matrix thermal sensor (32 × 24 pixels), environmental sensors, and an RGB camera, and logged data every 20 min. A labeled dataset (“healthy” or “stressed”) was generated using an empirical Crop Water Stress Index. A multilayer perceptron with a 768-30-1 architecture was trained. Results. The model reached the target mean squared error in eleven epochs. The final validation accuracy was 99.34 %. The confusion matrix showed four false negatives and one false positive, which evidenced the discrimination capability. Conclusions. Low-resolution thermal patterns contain sufficient information for a multilayer perceptron to classify water status in blueberry plants under controlled conditions. This methodology constitutes a low-cost and accessible alternative for precision agriculture.
Copyright (c) 2026 Jaime Andrade Ramirez, Gina Maribel Valenzuela, Gabriel Martinez Roldan, Juan Fuentes Rojas (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Evaluation of fermentation methods for Brassicaceae leaves with bionematicidal potential
Introduction. In broccoli cultivation (Brassica oleracea var. italica, family Brassicaceae), leaves constitute a by-product with a high content of glucosinolates, the precursors of isothiocyanates (ITC) with potential nematicidal activity. Fermentation can promote ITC formation; however, information comparing the effects of different fermentative methods is limited. Objective. To evaluate different fermentation methods for broccoli leaves in order to determine which is the most efficient for ITC production, as an indicator of the nematicidal potential of the fermented materials.. Materials and methods. The experiments were carried out at the Instituto Nacional de Tecnología Agropecuaria (INTA), Ángel Gallardo, Santa Fe, Argentina, between October 2018 and February 2019.Broccoli leaves were collected, ground, and subjected to spontaneous fermentation at 15 and 25 °C, and to lactic, enzymatic, and mixed fermentations at 25 °C. Each fermentation lasted 55 hours, with sampling every 6 hours for ITC and pH analysis. ITCs were analyzed following extraction with 75% ethanol (1:1, w/v), followed by centrifugation.. Quantification was performed by spectrophotometry at 460 nm using ferric nitrate and a calibration curve (6-30 mg/L) prepared with sodium thiocyanate standards. Results. Spontaneous fermentation exhibited similar behavior at 15 and 25 °C, with greater ITC stability during the first 19-25 hours, coinciding with pH values between 5.0 and 6.0. Assisted fermentations did not increase ITC concentrations compared with spontaneous fermentation (p > 0.05), despite greater medium acidification. Conclusions. Spontaneous fermentation at ambient temperature for 19-20 hours was identified as the simplest and most cost-effective approach for producing fermented materials with potential bionematicidal activity for nematode management, achieving ITC concentrations comparable to those obtained with assisted fermentation methods while maximizing the period of ITC stability.
Copyright (c) 2026 Natalia Celia Giacomino, Betiana Bergia, Daniela Cecilia Franzi, Eleodoro Eduardo Del Valle, Nora Rosa Aimaretti (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Digital tools to evaluate the efficacy of herbicides on Avena fatua L. in wheat
Introduction. When using a visual scale to evaluate herbicide efficacy against wild oat (Avena fatua L.) in wheat crops, inaccuracies may occur because the values obtained depend on the observer’s subjective criteria. Objective. To evaluate digital instruments as an alternative to visual observation for measuring the effects of herbicides on Avena fatua L. Materials and methods. The instruments evaluated were the soil plant analysis development meter (SPAD) and the GreenSeeker sensor, which measures the intensity of light reflected by plants. Three wheat-producing areas with wild oat problems were selected during the fallÐwinter 2020Ð2021 growing season in the Mexicali Valley, Baja California, Mexico. In each area, an experiment was conducted using a randomized complete block design with six treatments: one treatment was the untreated control, and the other five consisted of acetolactate synthase- and acetyl-coenzyme A carboxylase-inhibiting herbicides applied against A. fatua L. The measured variables were the percentage of visually observed damage and the height and density of wild oat plants. Pearson correlation and regression analyses were performed using the values obtained both visually and with digital instruments. Results. In all three experiments, correlations were observed among all the measurement methods used. Each hundredth of a GreenSeeker reading corresponded to 2.66 % control, while each SPAD unit corresponded to 4.21 % control. Conclusions. The SPAD meter and GreenSeeker sensor can be used to evaluate the efficacy of acetolactate synthase- and acetyl-coenzyme A carboxylase-inhibiting herbicides against A. fatua L. in wheat.
Copyright (c) 2026 Andrés González Ruiz, Carlos Enrique Ail-Catzim, Carlos Alfonso López Orona, Raymundo Medina-López, Mitzi Dayanira Estrada Acosto, Guadalupe Alfonso López-Urquídez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Growth response of cilantro (Coriandrum sativum L.) cultivated hydroponically under contrasting cover and nutrient regimes
Introduction. Coriander (Coriandrum sativum L.) cultivation in tropical regions faces challenges related to climate variability and hydroponic systems, requiring optimized strategies for irrigation, nutrition, and crop protection to improve productivity. Objective. To evaluate the effect of two types of protective cover (a plastic roof and 30 % red shade mesh) and two levels of nutrient concentration (high and low) on the growth and yield of hydroponically grown coriander during two rainy seasons. Materials and methods. The study was conducted at the Fabio Baudrit Moreno Agricultural Experiment Station in Alajuela, Costa Rica, during the rainy season of 2015 and 2016, using a hydroponic system with a stone-powder substrate. Two environmental conditions, protected and unprotected, and two nutrient levels, low and high, were evaluated using a randomized complete block design with split plots. Climatic variables, drainage electrical conductivity, cumulative drainage, nutrient leaching, crop growth, and yield were recorded. In 2015, a transparent plastic roof was used, whereas in 2016, red shade mesh providing 30 % shade was used. Data were analyzed using InfoStat statistical software, applying analysis of variance and Tukey’s test to compare main effects and interactions. Results. In 2015, protection and the high nutrient concentration increased plant height, marketable fresh biomass, dry biomass, and growth rate; additionally, protection reduced cumulative drainage. In 2016, yield response depended on nutrient concentration, with higher values under the high-nutrient treatment and no effect of protection. Conclusions. The high nutrient concentration promoted the growth and yield of coriander. Impermeable protection provided greater benefits than shade mesh because of its ability to reduce water entry, drainage, and nutrient losses.
Copyright (c) 2026 Alejandro Betancourt-Flores, Freddy Soto-Bravo (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Effect of doses of nitrogen in the agronomy and physiology of yellow passion fruit
Introduction. The passion fruit plant is important as fresh fruit and in the agroindustry, since its rich in minerals and vitamins and also has potential for domestic consumption and exportation. It has been shown that nitrogen (N) has an influence on fruit yield but there is no information on the optimal N range for maximum production. Objective. Determine the agronomic, physiological, and phenological response, yield and quality of fruit in the cultivation of parchita passion fruit against different doses of nitrogen. Materials and methods. At the Universidad Central de Venezuela, Maracay, Venezuela from April 2014 to march 2015, passion fruit plants were planted in a completely randomized design, six replicates, and six plants per experimental unit, a control (8 g N plant-1 (T1)) was evaluated and three doses of N (100 (T2), 200 (T3) and 300 (T4) g plant-1), an a dose of 50 and 300 g plant-1 of P2O5 and K2O, respectively were evaluated. The evaluated variables were: plant height, number of leaves, photosynthesis rate (A), transpiration (E), stomach conductance (Gs), chlorophyll index (CI), total leaf N content in doses at flowering and fruiting, yield, and fruit quality. Results. Higher doses of N obtained higher values in height, number of leaves, plant precocity, chlorophyll index, net photosynthesis, and foliar N content and lower values in T1. The variables Gs, A and E, did not show significant differences between the treatments. A 55 % yield reduction was obtained in the control treatment compared to the 200 g N plant-1 treatment which obtained the highest yield. The average fruit weight was significantly higher in T3. Conclusion. The best nitrogen dose in passion fruit plants was 200 g N plant-1.
Copyright (c) 2020 Gustavo Adolfo Rodríguez-Yzquierdo, Carmen Amalia Basso-de-Figuera, Marta Barrios-García, Rommel Igor León-Pacheco, Mercedes Pérez-Macias (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Pea production and commercialization in the department of Nariño-Colombia
Introduction. Traditional agricultural production systems prevail in the southern region of Nariño, however, the area harvested from transitory potato, corn and beans crops has been decreased. To address this problem, pea planting has been strengthened, which is marketed in local and regional markets. The department of Nariño is the first pea producer in Colombia, and in 2018, 9425 ha were reported, with an average yield of 1.19 t ha-1. The farmers in the study area are traditional and show technical limitations of production and commercialization. Objective. The objective of the investigation was to analyze the production and commercialization of peas in the department of Nariño. Materials and methods. The research was descriptive and allowed to establish costs, production volumes, planting times, product characteristics, prices, and marketing during 2012. The target population included producers, municipal intermediaries, wholesalers and retailers, and association leaders located in the pea-producing municipalities. Results. The Andean variety was the most sown, the post-harvest losses were 52 %, the prices vary due to the seasonality of production, and the greater volume of production was channeled through intermediaries. Conclusions. The production and commercialization of peas in Nariño presents difficulties that requiere sowing planning to balance production volumes, access development credit, train and organize farmers, and foster strategic alliances to guarantee conditions in the value chain.
Copyright (c) 2020 Francisco Javier Torres-Martínez, Carlos Nelson Rivadeneira-Miranda, Álvaro José Castillo-Marín (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Spodoptera frugiperda (Lepidoptera: Noctuidae) infestation in maize and its management using mulberry organic residues
Introduction. Soil incorporation of Morus alba biomass mitigates Spodoptera frugiperda damage in maize, through the release of bioactive secondary metabolites with antifeedant properties. Objective. To characterize farmer perceptions of Spodoptera frugiperda severity and evaluate the efficacy of Morus alba residue incorporation as a sustainable management strategy in the Mocache canton, Ecuador. Materials and methods. The research was conducted between December 2023 and May 2024. The study consisted of two phases: a survey of farmers and a field experiment. The farmers were surveyed regarding the agronomic practices they implemented to manage S. frugiperda. The experiment was conducted in the locality of Jesús del Gran Poder and consisted of three treatments: i) a control without pest management or residue incorporation (Control); ii) soil incorporation of 1 t ha⁻¹ of a mixture of maize residues (80 %) and fragmented mulberry cv. Tigreada (20 %) (M+M); and iii) the application of methomyl insecticide. The variables of severity of infestation and agricultural yield were evaluated. A randomized complete block design with three treatments and three replicates was employed. Treatment means were compared using Duncan’s multiple range test (α = 0.05). Statistical processing was performed using the InfoStat package. Results. Residue incorporation reduced severe foliar damage (grades 4-5) to 29.6%, significantly lower than the control (36.1%; p < 0.05). Grain yield reached 4.1 t ha⁻¹ with residues, statistically comparable to methomyl (4.6 t ha⁻¹) and 17 % higher than the control (3.5 t ha⁻¹). Conclusions. The high perception of severity of S. frugiperda by farmers corresponds with high levels of infestation, associated with inadequate agronomic practices and poor technical training. The maize and mulberry residues incorporated into the soil reduce severity and allow obtaining yields like the insecticide, validating its effectiveness as a management alternative in Ecuador and similar regions.
Copyright (c) 2026 Ramiro Remigio Gaibor-Fernández, Sergio Florentino Rodríguez-Rodríguez, Paula Marisol Plaza-Zambrano, Lázara Meilín Infante-Diéguez, Ramon Jaime Holguín-Peña, Wilson Geobel Ceiro Catasú (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Climatic conditions and jersey cattle dairy production on two altitudinal levels
Introduction. Precipitation, temperature, radiation, and relative humidity vary according to height, this causes the presence of microclimates that affect the productivity of the animals. Objective. Associate the climatic conditions present in the productive systems with dairy production of a pure Jersey herd in two altitudinal floors of the province of Cartago, Costa Rica. Materials and methods. In retrospect, during the year 2016, the productive information of two dairy farms, located at 660 and 1800 m.a.s.l. was evaluated. From the first farm, the records of 61 animals in a twelve-year period (12,083 data) were analyzed; while in the second, the lactations of 387 animals in a five-year period (13,820 records) were analyzed. Observations included: identification of the cow, day of generation of the record, month, year, daily milk production, lactation days, calving number, animal age, temperature, precipitation, solar radiation and average relative humidity. Results. The lactation days, the lactation number (3-5), the age of the animal (3.7 to 5.8 years), and the calving number affected the daily milk production on both farms (p<0.001). At 1800 m, when the precipitation was greater than 5 but less than or equal to 10 mm day-1 and the relative humidity greater than 80 but less than 90 % day-1 (p<0.001), milk production decreased. On the other hand, at 660 m the effect came from relative humidity less than or equal to 70 %. The environmental temperature had a significant effect in both altitudes. Conclusion. The conditions of temperature, humidity, precipitation, and radiation in each ecosystem, generated differences in the productivity of the animals, related to the type of forages and the thermal sensation to which the cattle was exposed, which caused heat or cold stress.
Copyright (c) 2020 Juan Federico Conejo-Morales, Rodolfo WingChing-Jones (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Purines discharge capacity of a liquid manure spreading tank
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Liquid manure can improve soil structure and crop productivity, but calibrated equipment is needed to achieve uniform distribution. Objective. The objective of this work was to determine at the field level, the appropriate combinations of operation of a liquid manure distribution tank and a tractor that commands it to achieve a uniform distribution of slurry and diluted manure. Materials and methods. The experiment was carried out during July 2016 at the Experimental Station “Alfredo Volio Mata” of the Universidad de Costa Rica, in Ochomogo of Cartago, Costa Rica. A plowed and harrowed plot of 5000 m2 was used where twenty plastic containers were placed, arranged in two rows separated, 4 m between and within rows. A manure tank coupled to a tractor was used and the treatments were four travel speeds (four low gears of the tractor) and a fixed degree of acceleration (442 rpm). The measured variables were the capacity and volume of discharge per unit area, and the covered area. Results. The discharge and dispersion of liquid manure in the different gears was highly significant (p<0.01), being the discharge per unit of area greater in the low gears. The relative discharge between the different working speeds was quantified, and the highest discharge gear (Gear I) equivalent to 52 m3 ha-1, was set as 100 %, in gear II the relative discharge was 65 % compared to the first. In gears III and IV, the volumes were 24 and 17 m3 ha-1 respectively. Conclusion. The low gears distributed more material per m2 favorable in more demanding crops, while with higher marches more area can be covered with less material.
Copyright (c) 2020 Carlos Boschini-Figueroa, Claudio Fabián Vargas-Rodríguez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Morphological characterization of commercial genotypes of Mangifera indica L. in the dry tropics of Guanacaste
Introduction. The morphological and physicochemical characterization of mango (Mangifera indica L.) determines the variability among cultivated materials. Despite its economic importance, the documentation of mango genetic resources remains limited. Objective. To characterize the morphological diversity of ten commercial mango genotypes conserved in the dry tropic of Guanacaste, Costa Rica. Materials and methods. The study was conducted at the Santa Cruz Experimental Farm, University of Costa Rica, Guanacaste, Costa Rica, in 2025. Ten commercial genotypes were evaluated using descriptors from the International Plant Genetic Resources Institute. Dendrometric and foliar variables were recorded, such as trunk circumference, growth habit, crown shape, and leaf characteristics. Total weight, length, circumference, pulp, peel, and seed weight, as well as the length-to-circumference ratio and soluble solids content (°Brix), were measured. Statistical analysis included normality tests, Kruskal-Wallis tests, principal component analysis, and hierarchical clustering. Results. Fruit traits showed the greatest genetic variability, with high coefficients of variation for total weight (35.01 %) and pulp weight (39.32 %). The genotypes Edwards, Pope, and Earlygold produced larger fruits, while Fair Child, Davis Haden, and M13768 produced smaller fruits. Soluble solids content ranged from 13,5 to 21,1 °Brix. Fair Child, Yulie and Edwards recorded the highest values. Principal component analysis explained 85 % of the total variation, and hierarchical clustering grouped the genotypes into three groups based on fruit size and °Brix. Conclusions. The evaluated genotypes exhibited high morphological diversity and represent valuable resources for the conservation and improvement of the crop in the dry tropic of Guanacaste.
Copyright (c) 2026 Dalila Solano-Rojas, Jairo Mora-Prendas, José Andrés Rojas-Chacón (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Diversified cowpea cropping design in the Sudan Savannah of Ghana
Introduction. Climate change and low-intensity cropping technologies limit cowpea [Vigna unguiculata (L.) Walp.] yield in sub-Saharan Africa. Objective. To implement and optimize high-intensity climate-smart cropping systems for cowpea. Materials and methods. Cowpea was planted using four seeds per hill, spaced at 75 × 20 cm in a randomized complete block design with four replicates, and later thinned to the required stand at the Savanna Agricultural Research Institute, Manga, Ghana, in 2021 and 2022. Four planting designs were used: a single row with two plants per hill at the center of the ridge (66 667 plants/ha); a single row with one plant per hill at the center of the ridge (33 333 plants/ha); a double row with two plants per hill on both sides of the ridge (133 333 plants/ha); and a double row with one plant per hill on both sides of the ridge (66 667 plants/ha). Days to 50 % and 90 % flowering, pod load and pod length, number of seeds per pod and 100-seed weight, and grain and biomass yields were recorded. Results. Planting designs and plant densities had no effect on the number of days to flowering. A single row with two plants per hill or a double row with one plant per hill increased pod load. A single row with two plants per hill or a single row with one plant per hill improved the number of seeds per pod. Planting a single row of two plants per hill or a double row of two plants per hill optimized grain and biomass yields. Conclusions. Different planting designs and plant densities can enhance pod load, improve the number of seeds per pod, and optimize cowpea grain and biomass yields.
Copyright (c) 2026 Emmanuel Asibi Aziiba, Richard Dormatey, Peter Quandahor (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Identification methods for Tomato brown rugose fruit virus (ToBRFV) in México
Introduction. The tomato brown rugose fruit virus (ToBRFV) was first reported in Israel and Jordan in 2014, causing damage to tomato crops in protected agriculture. Objective. To collect information on the known distribution, current situation, and detection methods of ToBRFV. Development. Between 2018 and 2019, the presence of the virus was confirmed in Mexico, the United States, China, Germany, Turkey, the United Kingdom, and Italy. Electron microscopy and serological tests have been used to detect the virus, but these cannot differentiate ToBRFV among other tobamoviruses. The most effective diagnostic technique for detection is specific oligonucleotides developed from the isolates from Israel and Jordan. Hygiene protocols are the most important step in preventing infections. Conclusion. Efforts to control ToBRFV are currently focused on the use of strict sanitation and detection practices in seed and plant, using molecular reverse transcriptase polymerase chain reaction (RT-PCR) techniques with specific oligonucleotides, which avoid false positives.
Copyright (c) 2020 Luis Ismael Nolasco-García, Juan Luis Marín-León, Jorge Eric Ruiz-Nieto, Jesús Hernández-Ruíz (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Comparison of agricultural and economic productivity of sustainable and conventional papaya in Michoacan, Mexico
Introduction. In Buenavista, Michoacan, Mexico, the area planted with papaya (Carica papaya L.) is of the Maradol Roja variety and most farmers use a conventional agricultural production model, where the productivity and profitability of the crop is not known with certainty. culture; therefore, it is important to know these two variables in order to obtain an efficient production that in the medium term allows them to improve the socio-economic environment of the farmers. Objective. Compare a sustainable agricultural production model against the conventional papaya production model, to identify agricultural production and the cost-benefit ratio. Materials and methods. The experiment was carried out in the municipality of Buenavista, Michoacan, Mexico during 2015. It was characterized by having two experimental units, one treatment per unit [sustainable and conventional] with a simple randomized sampling. Fruit weight, total soluble solids, and fruits per plant were evaluated. Statistical analysis included Levene’s test, Kolmogorov-Smirnov, and Lilliefors test, ANOVA and non-parametric Mann-Whitney U test. Economic analysis was carried out with the indicators: total investment cost, total income, cost-benefit ratio, profitability, and break-even point. Results. The sustainable model showed for fruit weight 1.71 kg, 38.06, fruits per plant, total investment cost of USD $ 8,736.83 ha-1, cost-benefit ratio of 2.24, and an equilibrium point of 38.47 %. The conventional model showed 2.20 kg in fruit weight, 53.72 fruits per plant, a total investment cost of USD $ 9,262.03 ha-1, cost-benefit ratio 1.08, and an equilibrium point of 90.11 %. Conclusion. The conventional model was economically unfavorable, so it is suggested to gradually improve it until it becomes profitable. The sustainable model proved to be very economically attractive and to have efficient use of local natural resources.
Copyright (c) 2020 José Mario Miranda-Ramírez, Omar Aguilar-García, Diana Miranda-Medina (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Detection of viruses in sweet potato (Ipomoea batatas L.) using qPCR
Introduction. Sweet potato (Ipomoea batatas) is a root crop very susceptible to viral diseases, which have been associated with crop yield reductions of over 50 %. In the Costa Rican sweet potato plantations the presence of feathery mottle virus (SPFMV), chlorotic stunt virus (SPCSV), and leaf curl virus (SPLCV) have been reported, for the development of adequate control programs, early detection and identification is necessary through the use of sensitive and efficient techniques. Objective. The objective of this research was to estimate the incidence of SPFMV, SPCSV, and SPLCV in sweet potato plantations using qPCR. Materials and methods. In 2018 foliar tissue samples were collected from eighty plants showing viral symptoms from twenty-five sweet potato plantations distributed in four provinces in Costa Rica. The detection of the three viruses was performed by qPCR with the use of primers and specific hydrolysis probes. Results. In 92 % of the plantations studied, the presence of virosis was found. The Sweet potato virus disease (SPVD) defined as the combined infection of SPFMV and SPCSV, was the most common viral disease found in all plantations. The plantations located in Sabanilla, El Cacao, and La Guacima were the only ones to present the three viruses studied. The SPLCV virus was only detected in the Limón and Alajuela provinces. Conclusion. It is possible to make an early detection of three of the most frequent sweet potato viruses with the use of qPCR which would contribute to certified seed production programs.
Copyright (c) 2020 Ingrid Varela-Benavides, Carla Trejos-Araya (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Owner perceptions and management of stereotypic behaviors in four horse breeds in Costa Rica
Introduction. There is little information about stereotypic behaviors in stock-type sport horses and paso horses in Costa Rica. The lack of knowledge regarding stereotypic behaviors, such as cribbing, weaving, and stall walking in horses, affects their welfare. Objective. The objective of this study was to monitor the status of stereotypic behaviors and the management reported by owners of horses registered in ACRICAMDE and ASCACOPA in Costa Rica.Materials and methods. A cross-sectional survey was conducted from June through September 2018 in Costa Rica to gather information on horse behavior and current management practices of 552 horses of the breeds Quarter Mille, Appaloosa, American Paint Horses and Costa Rica Paso. The database collected was analyzed using descriptive statistics. Results. Almost half of the horse owners (48.4 %) reported stereotypic behaviors, being cribbing the most observed (86.2 %), followed by stall walking (24.1 %) and weaving (13.8 %). Most owners and managers (89.7 %) have tried to stop horses from performing stereotypic behaviors with anti-cribbing collars and by increasing social contact with other horses as the most common approaches. Fewer hours of grazing were reported (2 or less, or none) while there were horses without access to pasture (35.7 %). Conclusion. Horse owners of the breeds included in this study lacked knowledge of stereotypic behaviors. In order to improve management of these behaviors, more training is required to avoid further complexities under the current conditions.
Copyright (c) 2020 Ana Margarita Arias-Esquivel, Carissa L. Wickens, Luis A. Villalobos-Villalobos (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Fusarium wilt by tropical race 4: Current status and presence in the American continent
Introduction. Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense, tropical race 4, is considered the most lethal disease of the musaceae because it can survive on the ground for more than twenty years, without effective control. Objective. Review the current status and significant features of this disease and indicate the potential impact risk in Latin America and the Caribbean countries in the face of its recent report in Colombia. Developing. It has several races: race 1 attacks clones of the Silk (Musa AAB) and Gros Michel (Musa AAA) subgroups and was responsible for the loss of the world banana market in 1958, dominated by the latter, being replaced by Cavendish clones (Musa AAA). Race 2 attacks clones of the Bluggoe subgroup (Musa ABB); and race 4, through its tropical and subtropical variants, attacks all Cavendish clones, and those susceptible to race 1 and race 2. There are no natural clones that can replace the current ones. Tropical race 4 (R4T), has spread in different continents, causing multimillion dollar losses, with extreme limitations for its eradication, and recently is a cause for concern in Latin American and Caribbean (LAC) countries, due to its recent report in the Colombian Guajira. Conclusion. The deficient control, and ignorance of thr traits of the pathogen and the disease, make necessary the development of research for its early diagnosis, management strategies, education measures, and / or promotion of contingency plans. Recently it was detected in Colombia, which implies high risk for the rest of the countries of the LAC region (with emphasis on Ecuador, Panama, and Venezuela), due to the constant flow of people (including tourists) and commercial transactions, being necessary in a way it is imperative to review the risk analysis in this new scenario.
Copyright (c) 2020 Gustavo E. Martínez-Solórzano, Juan C. Rey-Brina, Rafael E. Pargas-Pichardo, Edwuar Enrique-Manzanilla (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Technical-economic assessment of supplementation frequency over grazing steer in Córdoba, Colombia
Introduction. Beef production is affected by stationarity forage production and fed cost. Feed frequency evaluations according to pasture could suggest an appropriate practice for profitability improvement. Objective. To evaluate technically and economically the frequency of supplementation of Brahman fattening steers in grazing. Materials and methods. In the middle valley of the Sinú river, Colombia, 108 steers were used distributed in a split-plot design into three pastures (Cynodon nlemfuensis, Megathyrsus maximus, and Brachiaria hybrida, main plot) and three supplementation schemes (subplot): daily (STD), every two days (SDpM) and without supplementation (SS). The daily weight gain (GPD) and morphometric characteristics were evaluated in steers. In the carcass: weight, yield, length, leg perimeter, fat thickness, and compactness index. The biophysical data results fed the financial evaluation of the implemented technology. Results. An interaction of pasture and supplementation frequency over daily weight gain was detected (p<0.05). The highest GPD was observed in animals of the STD treatment for the grass C. nlemfuensis (680 g day-1), while a B. hybrida cv Mulato II in SDpM recorded the lowest GPD with 500 g day-1. An effect (p<0.05) of the diet on body length was observed (150 vs. 152 cm for not supplemented and supplemented steers, respectively). There were no differences (p<0.05) between treatments over carcass characteristics. Conclusions. The biological response in GPD did not compensate for the differential operating cost in the supplemented animals. It is necessary to evaluate new diets with raw materials and inclusion levels that contribute to the increase in animal production, to generate a detectable change in the animal and economic response.
Copyright (c) 2020 Lorena Inés Mestra-Vargas, Wilson Andrés Barragán-Hernández, Diego Andrés Medina-Herrera, Hernando Flórez-Díaz (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Fatty acids composition of genotypes of Jatropha curcas L., in Colombia
Introduction. Jatropha curcas L. (JC) is a specie with the potential to use its oil as a biofuel and its quality is recognized by the composition of the fatty acids present. Objective. The objective of this work was the identification and quantification of fatty acids of JC genotypes of the Jatropha Colombia Collection. Materials and methods. During the years 2012-2014 the experiment was conducted in Espinal-Tolima, Colombia, in a randomized complete block design with fifteen genotypes. The lipid profile of the genotypes was determined by chromatography GC-MS and GC-FID. Results. Ten types of fatty acids were detected in the oil: five saturated (myristic, palmitic, margaric, stearic, arachidic); three monounsaturated (palmitoleic, oleic and eicosenoic), and two polyunsaturated (linoleic and linolenic). The proportion was higher in monounsaturated acids (45.44 %) and polyunsaturated acids (34.18 %) and lower in saturated acids (20.37 %). In the monounsaturated, the oleic predominated (44.62 %); in polyunsaturated linoleic (33.95 %) and in saturated palmitic (12.41 %) and stearic (7.43%). The results found allowed the classification of JC oil as monounsaturated-polyunsaturated (oleic-linoleic), which coincided with what was reported worldwide. Conclusion. Based on the lipid profile, it can be inferred that the oil of the fifteen genotypes evaluated in Colombia is suitable for use as biodiesel.
Copyright (c) 2020 Luis Fernando Campuzano-Duque, Fernando Cardeño-López (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Regulated deficit irrigation and its effect on the nutrition, productivity and quality on passionfruit
Introduction. Water stress has been recorded as one of the main environmental factors responsible for seasonal fluctuations in passion fruit yields. However, there is a shortage of information on the influence of water stress on different components of growth. Objective. To evaluate the controlled deficit irrigation (RDC) technique in the passion fruit cultivation (Passiflora edulis Sims) and its possible effects on plant nutrition, efficient use of water, crop productivity and fruit quality. Materials and methods. An trial was conducted during the years 2013 and 2014 in the Experimental Field of the Institute of Agronomy, Universidad Central de Venezuela, Maracay, Venezuela; under tropical dry forest conditions. The statistical design was randomized blocks with three irrigation treatments (R1= 100 % of Eto (reference evapotranspiration), R2= 66 % of Eto, and R3= 33 % of Eto), in the non-critical phenological phases of the crop, four replications and twelve plants per experimental unit. Flowering and fructification were defined as critical phases. Nutritional variables (N, P, K, Ca and Mg content in leaf tissue, and N, K and Ca content in sap), production efficiency (efficient water use, kg fruit plant-1 and kg fruit ha-1) and fruit quality ( physical and chemical variables) were evaluated. Results. The application of RDC did not affect the nutritional variables or the crop yield. As regard to fruit quality, only significant differences were presented for percentage (%) of peel and juice, however, the values with R2, the values were not limiting in both variables. Conclusion. The restriction of the water supply in non-critical phases did not affect the agronomic performance of the plant.
Copyright (c) 2020 Gustavo Adolfo Rodríguez-Yzquierdo, Carmen Amalia Basso-de-Figuera, Gabriel Díaz Reyes, Rommel Igor León-Pacheco (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Production and quality of Tithonia diversifolia and Sambucus nigra high andean colombian tropic
Introduction. Among the limitations of the livestock systems of the Colombian high tropic is fodder seasonality. The use of silvopastoral systems could be a strategy to maximize food production and guarantee a supply of nutrients throughout the year. Objective. To evaluate in Tithonia diversifolia and Sambucus nigra established in a silvopastoral system, the effect of two ages and cutting heights on morphometric, production, and nutritional quality variables. Materials and methods. The study was conducted at the Obonuco Research Center of the Corporacion Colombiana de Investigacion Agropecuaria (AGROSAVIA) (Pasto, Colombia) between January and November 2018. A random block design was established in factorial arrangement with four treatments (two ages and two cutting heights) for each species (T1:60 days*20 cm, T2:60 days*50 cm, T3:80 days*20 cm, T4:80 days*50 cm for T. diversifolia and T1:60 days*30 cm, T2:60 days*50 cm, T3:90 days*30cm, T4:90 days*50 cm for S. nigra). Results. The productive variables showed significance in T. diversifolia with higher dry matter (DM kg/bush) at 80 days (30.6 ton ha-1 year-1) and S. nigra at 90 days (14.4 ton ha-1 year-1); the number of branches and shoots showed higher values in T4 for T. diversifolia (127.10 branches/bush and 819.65 shoots/bush). The nutritional quality of T. diversifolia and S. nigra was significantly higher at 60 days; with 26.73 % and 26.25% crude protein, digestibility of 75.45 %, and 76.28 %, and net lactation energy of 1.58 and 1.60 Mcal kg-1 DM, respectively. Conclusion. Biomass production (DM) and resurgence capacity increased when harvested at 80 days in T. diversifolia and 90 days in S. nigra; however, a better nutritional quality was presented at cutting ages of 60 days in the high tropic of Nariño, which evidenced its productive potential for cattle feeding.
Copyright (c) 2020 Carolina Guatusmal-Gelpud, Laura Dayana Escobar-Pachajoa, Diego Hernán Meneses-Buitrago, Juan Leonardo Cardona-Iglesias, Edwin Castro-Rincón (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Detection of the 35S promoter by real-time PCR as a transgenicity indicator in food and Gossypium sp.
Introduction. Genetically modified crops (GMC) are of particular interest due to their impact on the global economy. Therefore, as a general concern, many countries have established some regulations in regards to genetically modified organisms (GMOs). In Costa Rica, the cultivation of GMOs has been practiced since 1991; however, there´s a lack of studies that monitor the execution and compliance with the biosafety regulations. Objective. The objective of the present study was to identify the presence or absence of transgenicity in processed foods for human and animal consumption, as well as in cotton seeds. Material and methods. The real-time PCR technique was used to target the 35S promoter sequence, derived from the cauliflower mosaic virus (CaMV), as a marker to detect the presence of transgenes in processed foods for human and animal consumption as well as in wild or cultivated cotton seeds collected nearby a GM cotton farm in May 2017. Results. In the analyzed samples there was a high incidence of an 82 bp fragment, corresponding to the 35S promoter sequence, being absent only in organic corn crops and their derivatives (tortillas, corn powder). Results suggest the presence of GMO traces in the Costa Rican food market, additionally it reveals the urgency of implementing adequate labeling for food traceability. Furthermore, the presence of transgenic cotton in the vicinity of a GM cotton farm was identified, suggesting the relevance of surveillance in aspects of biosafety and genetic manipulation of crops. Conclusion. The presence of traces for GMOs in Costa Rican processed food, demonstrates the importance of continuing this monitoring to provide enough elements for a critic discussion about food traceability and potential transgene flow into wild plant material.
Copyright (c) 2020 Karen Oviedo-Bolaños, Jaime García-González, Stefany Solano-González, Claudio Martínez-Debat, Carolina Sancho-Blanco, Rodolfo Umaña-Castro (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Productive characteristics of forage crops for supplementation in milk production systems, Nariño, Colombia
Introduction. Grass is the main source of feed for ruminants, however, it is not able to provide the nutrients required for its maintenance and productivity, added to this, in the high tropics is very noticeable the seasonality of fodder production, so it is very important to know other feeding alternatives. Objective. Characterize and evaluate ten forage crops as alternative sources of supplementation in milk production systems in the high tropic of Nariño. Materials and methods. The study was carried out in three localities (L1, L2 and L3) representative of the milk basin of the department of Nariño between november 2016 and september 2017. A Random Complete Blocks (BCA) design was used with ten treatments Vicia faba (espadrille), Vicia faba (red), Vicia faba (common), Zea mayz var. ICA V-305, Raphanus sativus L., Beta vulgaris, Avena sativa var. Cayuse, Phalaris sp., Medicago sativa L. var. moapa, Medicago sativa L. var. 10 10, three repetitions and comparison of averages to 0.05. A the time of harvest it was estimated: green forage yield and dry matter, crude protein (PC), neutral detergent fibre (FDN)), acid detergent fibre (FDA), lignin, hemicellulose, dry matter digestibility, and net lactation energy (ENL). Results. The outstanding species were the bean (the three varieties) and fodder beet for its yield and nutritional quality, which presented values between 7.48 and 20.24 % for PC and 1.14 and 1.49 Mcal kg-1 for ENL. Differences between treatments were presented for each locality, both in productive and nutritional variables. Conclusion. The forage species with the highest productive yield and nutritional quality were the three bean varieties (red, common, and espadrille) and beet.
Copyright (c) 2020 David Felipe Nieto-Sierra, Diego Hernán Meneses-Buitrago, Sonia Patricia Morales-Montero, Filadelfo Hernández-Oviedo, Edwin Castro-Rincón (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Herd management information systems to support cattle population research: the VAMPP® case
Introduction. Livestock information systems, besides being indispensable for the daily management of the herd, can serve as a basis for research at the population level. Objective. The objective of the study was to analyze the role of the VAMPP® system as a source of information for cattle population research over 32 years of evolution in Costa Rica. Materials and methods. A statistical analysis of the system database (VAMPP®) covering the period between 1987 and 2018 was carried out. Trends in the dissemination and adoption of the system were evaluated according to period, area, production system, and herd size. The use of information for the exploration of trends by breed and area was exemplified. The contribution of the system at the academy level and production of scientific literature was quantified. Results. 2285 herds (88.8 % specialized dairy and 11.2 % dual purpose) were counted with an average of 9.4±7.9 years of follow-up in the VAMPP® system. The areas with greater diffusion were the very humid premontane forest (29 %) and very humid tropical forest (25 %). The average size of the herd was 124±255 adult cows. The system contains records on 404 316 cows, mostly of Holstein (36.3 %), Jersey (24.6 %), and Holstein×Jersey (20.9 %) breeds. The database includes information on 1,249,557 calvings, 16,223,260 records of daily milk production, and 443,108 health events, predominantly related to mastitis (35.6 %) and laminitis (14.1 %). The system has been used for the elaboration of at least 74 investigations leading to academic degrees and the production of 71 scientific articles, mainly related to health and genetic issues. Conclusion. The information obtained from the VAMPP® system has allowed a detailed characterization of the productive performance of local dairy cattle.
Copyright (c) 2020 Z. Sánchez-Hernández, C.S. Galina-Hidalgo, B. Vargas-Leitón, J. Rojas-Campos, S. Estrada-König (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Quantification and characterization of waste generated during milking of Jersey cattle
Introduction. Inadequate management and improper disposal of residues generated in dairy farming can cause environmental and sanitary problems. Therefore, it is necessary to obtain information on the quantity and composition of the solid and liquid residues produced during milking. Objective. To determine the quantity and characteristics of residues generated by Jersey cattle during milking activities. Materials and methods. The study was conducted at the dairy unit of the Atlantic Campus of the University of Costa Rica, with a stocking rate of 6 AU/ha and Jersey cows with an average live weight of 396.6 kg per animal. Between May 2022 and May 2023, 39 samplings were carried out to quantify manure generation and the volume of wash water produced in the waiting area after each milking. Moisture, pH, and electrical conductivity were analyzed in manure, while chemical oxygen demand (COD), total suspended solids (TSS), and fecal coliforms were determined in wash water. Data were analyzed using descriptive statistics and Pearson correlation analysis. Results. Average manure production was 2.7 kg per animal, and water consumption reached 686.5 L per day. The effluent showed a high pollutant load, with COD (1931.7 mg/L) and TSS (6951.6 mg/L) levels exceeding the maximum permissible discharge limits by more than fourfold and thirtyfold, respectively. The microbiological load (1.7 × 108 CFU/100 mL) indicated a critical sanitary risk. Conclusions. Milking activities generated residues with high pollutant potential, which limits the direct reuse of wash water and highlights the need to implement management and treatment strategies to reduce environmental risk and promote residue valorization.
Copyright (c) 2026 Carlos A. Sánchez-Romero, Saúl Brenes-Gamboa (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Predictive value of soil exchangeable potassium in mycorrhiza-inoculated banana under organic-mineral fertilization in Cuban Cambisols
Introduction. Banana is a multi-cycle crop, with a high potassium (K) demand, and soil K analysis guides fertilization. Mycorrhizal inoculation reduces fertilizer K needs, yet soil-based K recommendations for inoculated systems remain undefined. Objective. To establish a soil potassium threshold for guiding fertilization in arbuscular mycorrhizal fungi (AMF)-inoculated banana crops under organic mineral fertilization. Materials and methods. Two experiments were conducted in Santo Domingo, Cuba, on Eutric Cambisols using the FHIA-18 cultivar. Both followed a randomized block design with four replicates. The first evaluated five organic-mineral fertilization (OMF) doses, with or without Rhizoglomus irregulare inoculation across mother plant and first ratoon cycles, and included measurements of yield, mycorrhizal indicators, foliar NPK concentrations, and soil fertility. The second, conducted across three crop cycles, involved combinations of OMF doses, Canavalia ensiformis as green manure, AMF inoculation, and mineral fertilization. In this experiment, only information about soil fertility and relative yield was used. Statistical analyses included ANOVA, while critical thresholds were identified using Cate-Nelson successive partitioning. Results. Banana yield increased with OMF dose, and AMF inoculation reduced the OMF requirement by 25 %, associated with higher colonization and improved K uptake. Soil exchangeable K allowed the establishment of soil K-based fertilization thresholds. Inoculation reduced the critical soil K thresholds relative to non-inoculated banana, which reflects enhanced mycorrhizal K acquisition efficiency. The canavalia reduced OMF requirements in inoculated banana but did not alter the soil K index, which remained consistent across inoculated treatments regardless of fertilizer sources. The index functioned as a sufficiency index for K fertilization. Conclusions. The soil K-based index established for AMF-inoculated banana defines the soil K threshold and provides a practical tool for assessing K fertilization sufficiency and guiding input adjustments under the tested edaphic conditions.
Copyright (c) 2026 Ramon Rivera, Jaime Enrique Simó González (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Water demand of black pepper (Piper nigrum L.) determined by NDVI
Introduction. Water scarcity compromises agricultural productivity and requires precise management tools. Normalized Difference Vegetation Index (NDVI) emerges as an effective alternative for estimating crop coefficient and monitoring crop water needs. Objective. To estimate the water demand of black pepper (Piper nigrum L.) during the flowering phase in the Northeast region of Pará, by means of satellite images to obtain the NDVI and, from it, the estimation of the crop coefficient. Materials and methods. The study was conducted from 2016 to 2018 in the Avelinos community, Santa Luzia do Pará, Brazil, in an area cultivated with black pepper that was 1, 2, and 3 years old. Coordinates were obtained by GPS and Landsat 8 images were used to calculate NDVI. The crop coefficient (Kc) was estimated using the SAFER algorithm based on NDVI, and the crop evapotranspiration (ETc) was calculated by multiplying Kc by the reference evapotranspiration. Results. In areas with 1 and 2 years of cultivation, Kc ranged from 0.22 to 1.00, while in the area with 3 years of cultivation, values ranged from 0.11 to 0.33, which indicates low vegetative vigor and water stress. The estimated water demand for the flowering phase was 2.50, 2.62, and 1.30 L m² day-1 for areas with 1, 2, and 3 years of cultivation, respectively. Conclusions. NDVI-based estimates effectively captured crop water requirements and vegetative vigor across different cultivation ages, revealing that the oldest area exhibits lower water demand coupled with elevated water stress. Given the absence of stage-specific values for black pepper, these estimated parameters provide a fundamental basis for refining irrigation management in Northeastern Pará.
Raimunda Eliane Nascimento do Nascimento
Copyright (c) 2026 Lailson da Silva Freitas, Felix Lélis da Silva, Raimunda Eliane Nascimento do Nascimento, Élvis da Silva Alves, Maryjane Diniz Araújo Gomes (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Plant-parasitic nematodes in potato crops of Cartago, Costa Rica: variation by altitude and soil
Introduction. Plant-parasitic nematodes (PPN) are a major problem for potato production. Updated information on PPN affecting potato (Solanum tuberosum) in Costa Rica is limited. Objective. To characterize the population genera of PPN in Cartago, with a focus on variations across different altitudes and soil properties. Materials and methods. Between 2015 and 2017, forty-five potato fields from northern Cartago, Costa Rica, were sampled and categorized by altitude: low (1600Ð2100 meters above sea level [m a.s.l.]), medium (2101Ð2600 m a.s.l.), and high (2601Ð3100 m a.s.l.). Composite soil and root samples were collected per field in a zigzag pattern for nematode analysis and soil characterization. Additional soil samples were collected for cyst quantification. Nematodes were extracted using centrifuge sugar-flotation for genus/family identification and the Fenwick method for cyst quantification. Abundance, frequency, and diversity (Hill’s N1 index) were compared across altitudes and sample types. Non-parametric tests (Kruskal-Wallis, Chi-square) and multivariate analyses (PCA, Spearman correlation) evaluated patterns and associations. Results. Thirteen genera/families were identified. Pratylenchus predominated in soil and roots, Meloidogyne showed the highest average density, and Globodera was more abundant at higher altitudes. In addition, nematode genera were associated with soil properties, and the presence of M. incognita and M. hapla was molecularly confirmed. Conclusions. Altitude and soil properties influenced the distribution of PPN in potato fields of Cartago.
Copyright (c) 2026 Rebeca Sandoval-Ruiz, Lorena Flores-Chaves, Danny A. Humphreys-Pereira (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Fungi associated with sorghum seeds and persistence of Fusarium after surface disinfestation
Introduction. The distinction between superficial colonization and internal infection by Fusarium spp. in sorghum (Sorghum spp.) seeds is limited when using conventional diagnostic methods, hindering the interpretation of inoculum localization. Objective. To characterize the fungal community associated with commercial sorghum seeds and to evaluate the persistence of Fusarium spp. after surface disinfestation as an indicator of the likely localization of the inoculum. Materials and methods. The study was conducted at the Estación Experimental Agropecuaria Paraná of the Instituto Nacional de Tecnología Agropecuaria, Oro Verde, Entre Ríos, Argentina, between November 2024 and November 2025. Seeds from thirty commercial hybrids were evaluated using a blotter test without surface disinfestation (200 seeds per hybrid). Fungal genera were identified, and their incidence (%) was recorded. Based on Fusarium spp. incidence, twelve sentinel hybrids were selected and subjected to a blotter test with surface disinfestation (2 % NaOCl for 2 min; 100 seeds per hybrid) to assess pathogen persistence. The analysis was descriptive, based on the comparison of incidence before and after treatment. Results. Sixteen fungal genera were identified, with Alternaria, Fusarium, and Cladosporium as the most prevalent. Fusarium spp. showed variation among hybrids, with an incidence range of 0-78 % in the evaluation without disinfestation. In sentinel hybrids, surface disinfestation resulted in variable reductions, with high values in some hybrids, suggesting the removal of mainly superficial inoculum, whereas in others pathogen persistence was observed after treatment. Conclusion. The combination of blotter test and surface disinfestation allowed the characterization of fungi associated with commercial sorghum seeds and the analysis of Fusarium spp. persistence in relation to its likely localization within the seed. Differential patterns among hybrids allowed the interpretation of inoculum origin and highlighted the usefulness of the method for seed health evaluation and preventive management.
Copyright (c) 2026 Pablo Daniel Velazquez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Genetic diversity analysis of Indonesian soybean genotypes based on morphological characteristics and SSR markers
Introduction. Soybean is an important crop due to its high protein and oil content. Yellow-seeded varieties are preferred for the production of food products. Analyzing genetic diversity is a crucial step in selecting parental lines for breeding programs. Objective. To analyze the genetic diversity of Indonesian soybean genotypes using morphological characteristics and simple sequence repeat (SSR) markers. Materials and methods. Field evaluations were conducted in Bogor, Indonesia, from March to June 2023. Morphological data were analyzed using principal component analysis (PCA) and principal coordinate analysis (PCoA). Subsequently, the genotypes were analyzed using 14 SSR markers. Results. PCA revealed that PC1-PC4 explained 72.63 % of total genetic variation. SSR marker analysis demonstrated excellent characteristics such as a high number of alleles and favorable PIC values. Genotypes were grouped into two clusters with a clear genetic distinction. Four genotype pairs exhibited high genetic diversity with favorable morphological traits related to yield and its components. These genotype pairs represent potential parental candidates for soybean breeding programs. Conclusions. Morphological and SSR marker characterizations clearly differentiated Indonesian soybean genotypes and identified genotype pairs with high genetic diversity that were suitable as parental candidates for breeding purposes. Both data analyses provided complementary information, resulting in a more comprehensive assessment of genetic diversity.
Copyright (c) 2026 I Made Tasma, Rosliana Purwaning Dyah, Kunto Wibisono, Habib Rijzaani, Muhamad Ace Suhendar (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Agronomic characteristics of maralfalfa (Pennisetum sp.) seedlings according to sowing and harvesting density
Introduction. Maralfalfa (Pennisetum sp.) stands out for its forage productivity in tropical regions; however, technical evidence regarding its management for propagule production is insufficient. The quality of asexual seed is subject to agronomic factors that determine stem robustness and physiological maturity. Objective. To evaluate the effect of planting density and the number of harvests on the yield and morphometric characteristics of maralfalfa as a seed nursery. Materials and methods. The study was conducted in Huaral, Peru (2018-2019), using a completely randomized design with a 3 × 2 factorial arrangement. Three planting densities (0.50, 0.75, and 1.00 m between plants; 0.80 m between rows) and two harvests (120 days post-planting and 90 days post-cut) were evaluated. Fresh biomass yield (FBY), plant height (PH), stem weight (SW), number of tillers per plant (NTP), stem diameter (SD), and number of stem nodes (NSN) were quantified. Results. No significant interaction between factors was detected (p > 0.05). FBY, SW, and NTP were significantly higher (p < 0.05) in the second harvest, with increases of 45 % (1.45 vs. 1.00 kg/plant), 29 % (564.31 vs. 437.30 g), and 10 % (3.79 vs. 3.45 tillers), respectively. The largest SD was obtained with a density of 1.00 m (3.97 cm; p < 0.05), while a density of 0.50 m produced plants with higher PH (3.80 m; p < 0.05) and NSN (15 nodes; p < 0.05). Conclusions. The second harvest optimized yield and tillering due to the consolidation of the root system. For propagule production, the 1.00 m spacing favored robustness, as reflected in stem diameter, whereas the 0.50 m spacing maximized node availability per unit area, allowing differentiated management according to the objective of the seedbed.
Copyright (c) 2026 Felix Esteban Airahuacho Bautista, Renzo Arturo Paredes Villarreal , Yaneline Nilda Hidalgo-Vasquez , Oscar Enrique Arbañil Huaman, Rufino Maximo Maguiña-Maza (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0