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
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Establishment of new drought-tolerant varieties of Cenchrus purpureus
Introduction. Drought can reduce grain production by up to 50 % and drastically reduce the biomass of pastures and forages used for animal feed. Objective. To evaluate the establishment of ten new varieties of Cenchrus purpureus that are tolerant to drought under conditions of intense seasonal drought in Cauto Valley, Cuba. Materials and methods. The present study used a randomized block design with four replicates to evaluate ten new varieties of Cenchrus purpureus (CT-600, CT-601, CT-602, CT-603, CT-604, CT-605, CT-606, CT-607, CT-608 and CT-609) on Fluvisol soil in an area of intense seasonal drought in Cuba, from November 2019 to May 2020. The variety CT-115 was used as a control. At the time of sprouting, soil moisture, plant height, leaf area, biomass yield, and leaf-to-stem ratio were monitored and calculated. Results. During the first 12 days after planting, varieties CT-608, CT-607, CT-609, CT-600, CT-115, and CT-603 showed a higher percentage of sprouting (p ≤ 0.05), a response maintained at 19 days. The varieties CT-603 and CT-608 reached the highest sprouting capacity, exceeding 60 % in 29 days, followed by CT-600 and CT-609 with more than 50 %, and then CT-607 with 44 % (p ≤ 0.05). The remaining varieties, including the control, exhibited slower sprouting, with values ranging from 20 to 40 % by that period. Conclusions. At the establishment cut, no significant differences were found between varieties in height, growth, leaf area, and dry matter (DM) yield; however, biomass structure indicators varied, with only CT-604 surpassing the control in leaf-to-stem ratio (2.1 vs. 1.5) and leaf percentage (67.4 vs. 57.8 %). The new varieties demonstrated the capacity to establish under the conditions evaluated.
Copyright (c) 2026 Jorge Valentín Wright-Ramírez, José Leonardo Ledea Rodríguez, Dalibia Díaz-Fonseca, Rafael Herrera-García, Ramón Crucito Arias-Pérez, José Alfredo Guevara-Franco (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Yield and quality of five BMR sorghum varieties in the dry tropics of Costa Rica
Introduction. Sorghum (Sorghum bicolor L. Moench) is a C4 grass recognized for its high productivity and tolerance to heat and drought stress, widely used in animal feeding. The incorporation of the Brown Midrib (BMR) gene enhances its forage value by reducing fiber content and increasing digestibility. Objective. To evaluate the productive performance and bromatological quality of five BMR sorghum varieties in order to identify those with the greatest potential for use in cattle feeding. Materials and methods. The study was conducted at the Enrique Jiménez Núñez Experimental Station (Cañas, Guanacaste, Costa Rica) during the 2020 rainy season and the 2021 dry season (under irrigation). A randomized complete block design with four replications was used. Treatments included five BMR lines (0916, 0919, 0925, 0929, and 0936), derived from crosses between BMR materials from Texas (USA) and Central American germplasm. Forage Black Sorghum (Sorghum almum) was used as the control. Agronomic traits and nutritional quality of fresh and ensiled forage were evaluated. Results. Although the BMR varieties showed lower biomass production and shorter crop cycles than the control, they exhibited superior nutritional quality in both seasons. Conclusions. BMR sorghum varieties had lower biomass yield than Forage Black Sorghum but showed nutritional advantages, supporting their potential as a strategic forage alternative in cattle production systems of the Costa Rican dry tropics.
Copyright (c) 2026 José Roberto Camacho-Montero, José Pablo Jiménez-Castro, Josselyne Aguilar-López, William Sánchez-Ledezma, Nevio Bonilla-Morales (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Epidemiological factors linked to fruit soft rot in banana renovated plantations
Introduction. Fruit Soft Rot (FSR) constitutes a relevant phytosanitary problem in banana production, particularly in renewed plantations. The limited updated information on climatic variables and associated epidemiological factors constrains the design of effective management strategies. Objective. To evaluate the contribution of climatic variables, insect vectors, cultural practices, and soil splash to the dissemination of FSR in renewed banana plantations. Materials and methods. The frequency of FSR, climatic variables, and bagging per hectare were analyzed between 2013 and 2016 in three renewed plantations of the Huetar Caribe Region of Costa Rica (Río Frío, Valle de la Estrella, and Guápiles), considering three stages of fruit development. Predictive models were developed from variables with the highest explanatory capacity regarding the epidemiological behavior of the disease, and the most robust model was selected for validation. Additionally, the potential effect of de-flowering, vector activity (Drosophila spp.), and soil splash was evaluated in Río Frío. Results. Accumulated precipitation and relative humidity showed the greatest explanatory capacity for FSR incidence during inflorescence emergence and fruit bagging. Among seven developed models, Model 2 was the most appropriate for estimating FSR as a function of accumulated precipitation and precipitation hours. De-flowering, fly activity, and soil splash, in the presence of D. chrysanthemi, increased disease frequency in healthy bunches. Conclusions. The disease is favored by climatic conditions during inflorescence emergence and bagging; de-flowering generates entry wounds for D. chrysanthemi; Drosophila spp. disperse D. chrysanthemi; and soil splash transports inoculum to the inflorescence. Model 2 predicted FSR trends and constitutes a tool for integrated management.
Copyright (c) 2026 Jose Pablo Vargas-Fernández, Amy Wang-Wong, Miguel Muñoz-Fonseca, Edgar Valverde-Araya (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Identification of halotolerant bacteria isolated from soils of the Ciénaga de Zapata
Introduction. Halotolerant bacteria improve plant adaptability to high salt concentrations in soils, making it essential to study isolates inhabiting vulnerable agroecosystems. Objective. To identify halotolerant bacteria isolated from soils of Ciénaga de Zapata, Cuba, and to characterize them as plant growthÐpromoting bacteria in plants tolerant to high salinity levels. Materials and methods. The research was conducted in the laboratories of the Instituto de Investigaciones Fundamentales en Agricultura Tropical Alejandro de Humboldt, Cuba, and the Centro Nacional de Recursos Genéticos, Mexico. Five isolates capable of tolerating 200 mM NaCl were selected and phylogenetically identified through 16S rRNA gene sequencing. Laboratory experiments were performed under a completely randomized design, with the five isolates as treatments. Nitrogen fixation, phosphate solubilization, and the production of ammonium, siderophores, indolic compounds, and lytic enzymes were evaluated as response variables. Plant assays were conducted between June and November 2023 under a randomized block design with six treatments (five bacterial strains and an uninoculated control), with three replicates, assessing plant growth and salinity tolerance indicators. Data were subjected to one-way analysis of variance and Duncan’s test at 5% significance. Results. The isolates belonged to the genera Bacillus and Cupriavidus. All fixed atmospheric nitrogen and solubilized calcium phosphate; four produced siderophores; two generated ammonium; two solubilized potassium; two synthesized indolic compounds and lytic enzymes; and one solubilized aluminum. In plant assays, strains CZ1 and CZ6 stood out, showing significant differences compared to the other strains and the control. Conclusions. The isolated halotolerant bacteria possess traits that support their use as microbial inoculants in saline environments.
Copyright (c) 2026 Marisel Ortega-García, Yoania Ríos-Rocafull, Alfredo Socorro-García, Lily Xochil Zelaya-Molina, Ismael Fernando Chávez-Díaz, Maria Caridad Napoles Garcia (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Genetic parameters of growth in a dairy goat herd under semi-intensive management in tropical environment
Introduction. The estimation of genetic parameters for growth in goats makes it possible to identify the contribution of additive direct and maternal effects at different stages of development, which is essential for designing more efficient selection strategies. Objective. To estimate growth genetic parameters in a dairy goat herd using random regression models. Materials and methods. The study was conducted at the experimental herd of the Universidad Nacional, Heredia, Costa Rica. A total of 6 127 body weight records from birth to 30 months of age were analyzed, these were collected between 2008 and 2024, from 388 females and 108 males of Saanen and Saanen×Toggenburg breeds. A mixed random regression model was fitted, including fixed effects: contemporary group, breed type, sex, parity, type of birth, and age; and random effects: direct additive genetic (h²d), maternal genetic (h²m), and permanent environmental (ap) effects, modeled using Legendre polynomials. Results. The value of h²d ranged from 0,01 (month 2, SE 0,01) to 0,17 (month 11, SE 0,08), the h²m ranged from 0,02 (month 2, SE 0,01) to 0,25 (month 1, SE 0,07), and the pe value increased progressively from 0,03 (month 1, SE 0,20) to 0.67 (month 30, SE 0,08). Genetic correlations (direct and maternal) and permanent environmental correlations were mostly positive and of moderate magnitude (>0.60), with higher values (>0.80) between adjacent ages. Direct breeding values for body weight ranged from −2,33 and 1,80 kg (month 3) and from −3,90 to 3,20 kg (month 12). Conclusions. The use of random regression models allowed the estimation of genetic parameters for growth while accounting for both animal and maternal effects at different stages. This approach facilitates more accurate selection of replacements and guides breeding strategies to obtain more productive and efficient animals.
Copyright (c) 2026 Jorge A. Campos-Alfaro, Bernardo Vargas-Leitón, Andrés H. Alpízar-Naranjo (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Performance and silage inclusion of oat forage (Avena sativa L.) AV25 in diets for dairy cattle (Bos primigenius Taurus)
Introduction. The use of forage oat silage (Avena sativa L.) in dairy cattle in times of feed deficit, allows mitigating biomass losses due to drought in the Colombian high tropics. Objectives. 1) To determine the dry matter yield (DMY) of five forage oat genotypes and the phenotypic stability and the bromatological quality of their silage, and 2) to evaluate the inclusion of the AV25-T genotype silage in diets for dairy cattle. Materials and methods. In the Colombian high tropics two experiments were performed: 1) agronomic evaluation test (October 2017 and February 2018) in a randomized complete block design with five genotypes, eight locations, and four replicates; dry matter yield (DMY) and protein, neutral detergent fiber (NDF) and total digestible nutrients (TDN) contents in silage were determined, and 2) animal response study (January 2018) with the inclusion of the AV25-T genotype in diets, in a simple crossover design with two factors: animal (5) and diets (3); the diets were: D1: only meadow; D2: 35 % AV25-T silage + grazing, and D3: 65 % AV25-T silage + grazing. Milk yield, protein, fat, total solids, were determined in the milk, and weight change was determined in the animals. Results. AV25-T presented adaptation with the highest DMY. The inclusion of AV25-T silage in the animal diet showed a significant change in animal weight (0.1 and 0.25 kg with D2 and D3), milk yield (27.2 - 29.7 L/cow/day with D3 and D2), and the fat content (3.2 - 3.9 % with D3 and D2), without detriment in protein and total solids. Conclusion. The use of AV25-T forage oats in silage allowed increases in animal weight, milk yield, and fat content in Holstein dairy cows without affecting protein and total solids in milk.
Copyright (c) 2022 Luis Fernando Campuzano-Duque, Edwin Castro-Rincón, Javier Castillo-Sierra, Daniel Torres-Cuesta, David Nieto-Sierra, Paola Portillo-López (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Water hyacinth (Eichhornia crassipes): A review
Introduction. The water lily (Eichhornia crassipes) is a free-floating hydrophytic plant of the Pontederiaceae family. It is one of the aquatic plants with the best reproduction and growth rate, so it spreads and forms mats that constrict submerged and floating native plants, reduces the entry of light into bodies of water and decreases the dissolved oxygen in the water. Objective. To carry out a comprehensive review of the water lily that allows the scientific community a better understanding of an invasive species, as well as the effects it causes on the ecosystem. Development. The invasive capacity of this plant endangers various ecosystems, as it takes advantage of nutrient-rich waters. In addition, the dense floating colonies cause the oxygen content to drop to zero below its mantle, causing damage to the ecosystems. Conclusions. The water lily is one of the most invasive aquatic plants in the world, causing ecological and socio-economic effects. This plant has been used as a phytoremediator, in the removal of organophosphates, which indicates that it can be used to clean sewage. Furthermore, it can be used in the production of ethanol, paper, compost, biogas, human food, animal fodder, fiber, and in the extraction of volatile fatty acids.
Copyright (c) 2022 Jessica W. Rodríguez-Lara, Francisco Cervantes-Ortiz, Gerónimo Arámbula-Villa, Luis A. Mariscal-Amaro, César L. Aguirre-Mancilla, Enrique Andrio-Enríquez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Carcass characterization of the slaughtered sheep in a meat processing plant in Córdoba, Colombia
Introduction. In Colombia, sheep are a promising species for meat production; however, reports on the characteristics of the carcass at a commercial level in the region are unknown. Objective. To diagnose the carcass quality of the sheep slaughtered in a meat processing plant in the Department of Cordoba, Colombia. Materials and methods. From May 2017 to July 2018, variables were recorded in 883 sheep (phenotype, live weight, and sex) and their carcasses (weights, conformation and fatness, intrathoracic hemorrhages, morphometry, and pH at 24 h). A sampling was carried out on four groups of carcasses from castrated (C) and whole (E) animals, with three slaughter weights (lights: CL=±23.8 kg and EL= 23.9 kg; medium: CM=±27.7 kg; heavy: EP=36.2 kg) in an unbalanced design, to evaluate carcass and tissue composition of the shoulder. Results. The hot carcass weight (PCC), carcass yield (RCC), and compactness index were 11.11 kg; 41.49 %, and 0.19. The carcasses showed normal to poor muscular conformation (87.7 %) and very low-fat cover (68.7 %). Males accounted for 84.3 % of the carcasses, with a PCC of 10.86±0.09 kg and a RCC of 41.51±0.1 %. Females, mostly older than one year (66.90 %), had significantly higher PCC 12.47±0.22 kg, but similar RCC than males. Intrathoracic hemorrhages occurred in 10.9% of the carcasses; pH24 in males and females were 5.84±0.01 and 5.94±0.03, respectively. The CL, CM, EL, and EP of carcasses presented, respectively, 63.66, 61.74, 62.17, and 64.80 % of muscle (p<0.05), 7.20, 11.56, 6.48, and 6.80 % of total fat (p<0.001), and 21.35, 19.66, 23.45, and 21.07 % of bone (p<0.001). Conclusion. The sheep presented low slaughter weight, with heterogeneous carcasses, with normal to poor muscular conformation, low compactness index, and very lean.
Copyright (c) 2022 Lorena Angélica Aguayo-Ulloa, Clara Viviana Rua-Bustamante, Emiro Andres Suárez-Paternina, Leyla Ríos-de-Álvarez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Productive behavior and phenotypic stability of Hordeum vulgare L. in Colombia
Introduction. The incorporation of 40 thousand hectares of barley (Hordeum vulgare L.) for the beer industry in Colombia, with a projected production of 80 thousand t yr-1 in the period 2016 to 2026, will allow to reduce imports by 60 %. However, meeting this goal requires high-yielding, high-quality barley varieties. Objective. To identify a barley variety with stable grain yield and higher than 2.6 t ha-1 associated with tolerance to tipping, lower severity to yellow rust on the leaf and ear, and physical quality of the grain for the brewing industry. Materials and methods. Between 2016 and 2017, an agronomic evaluation trial was carried out in the Colombian Andean region, in a randomized complete block design, with eight two-row barley varieties introduced to Colombia. The physiological maturity, tipping, severity to Puccinia striiformis f. sp hordei in the leaf and ear, grain yield, and hectoliter weight were determined. Results. The Madi and S5 varieties with grain yields of 2.89 and 2.61 t ha-1, respectively, were 24 and 16 % higher than Metcalfe and 19 and 11 % higher than Maltera 5. Both varieties showed broad phenotypic stability, tolerance to tipping, lower severity of leaf and ear rust, and a hectoliter weight suitable for the brewing industry. Conclusion. The production characteristics, phenotypic stability, and physical quality of the grain of Madi and S5 varieties make them commercial candidates for the brewing industry and for recommendation in the Cundiboyacense highlands of Colombia, after validation with a semi-commercial trial.
Copyright (c) 2022 Luis Fernando Campuzano-Duque, Diego Fernando Avendaño-Avendaño, Nadia Yurani Luque-Sanabria (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Composting for the reduction of bird droppings (Gallus gallus domesticus)
Introduction. The growth of the population and the consumption of protein sources such as chicken meat, have maximized the generation of poultry waste (chicken manure), this leads to the development of efficient management alternatives for the conversion of this waste into by-products such as organic fertilizers. Numerous investigations conclude the remarkable effect of compost obtained from poultry waste on the development and growth of crops, which provide high content of essential nutrients as an amendment in agroecological agriculture, within the circular economy and the sustainable development of production. Objective. To carry out a review on the management plans of waste from the poultry sector through composting for use in agriculture in the region of Cordoba Veracruz Mexico. Development. The study was carried out between January and June 2020, through an exhaustive bibliographic search and the analysis of local experiences in the production of organic fertilizers with farmers. In this review and with the field work, the results established that in the region it is possible to obtain various types of compost with the incorporation of poultry waste, and the technologies of compost, vermicompost, and bocashi production individually or in a mixture with other regional by-products such as those derived from the sugar industry, coffee, livestock, etc. Nutrients such as nitrogen of 2.08-2.34 %, phosphorus 4.01-4.27 %, potassium 2.37-4.56 %, calcium 10.36-12.93, and magnesium 0.90-1.16 % are obtained and available for use. Conclusion. Poultry by-products have a great potential to generate reutilization alternatives through rural application technologies without significant investment and waste management strategies.
Copyright (c) 2022 Verónica Rosas-Martínez, Noé Aguilar-Rivera (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Chemical properties of the oil of five genotypes of Jatropha curcas L., in Colombia
Introduction. Jatropha curcas L. (JC) is a multipurpose species with biological, pharmacological, and industrial applications. Its oil is recognized by the dominant composition of oleic-linoleic fatty acids that make it suitable as biofuel in internal combustion engines, without making major changes to the engine design. Objective. To identify in the oil of five JC genotypes in Colombia the cetane, peroxide, iodine, the acidity value, the calorific value indixes and to verify if they comply with standards for biodiesel production. Materials and methods. An experiment was carried out in Espinal, Colombia, in a randomized complete block design with five treatments and three repetitions. The treatments consisted of five JC genotypes. The fruit from the fifth harvest in 2015 was used. Five fatty acids (oleic, linoleic, linolenic, palmitic, and stearic) and five chemical properties (cetane index, acidity, peroxide, iodine, and calorific value) were determined from the oil. Results. The oil from the five JC genotypes evaluated in Colombia presented a lipid profile with a predominance of monounsaturated (oleic C18: 1) and polyunsaturated (linoleic C18: 2) fatty acids. The JC genotypes evaluated in Colombia presented a low cetane, peroxide, and iodine indexes, low acidity, and high calorific value. Conclusions. The properties of cetane and iodine indexes, of the genotypes evaluated complied with the specifications of the American Society for Testing and Materials (ASTM) and the European Norm for biofuel production, so they are classified as appropriate raw material for biofuel production.
Copyright (c) 2022 Luis Fernando Campuzano-Duque, Fernando Cardeño-López (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
In vitro multiplication of yellow dragon fruit (Hylocereus megalanthus) from seedlings obtained in vitro
Introduction. The nutritional properties, antioxidant capacity, and commercial value of the yellow dragon fruit are attractive for its sowing; therefore, it is necessary to study technological improvements for its propagation. Objective. To evaluate the feasibility of in vitro establishment and multiplication of yellow dragon fruit, with the use as explants of seedlings from the in vitro germination and various hormonal sources. Materials and methods. The experiment was developed in the Plant Physiology and Biotechnology Laboratory of the Universidad Nacional Toribio Rodriguez de Mendoza, Peru, between February and June 2020. Four treatments were evaluated for germination [control: sterile water (3 ml), E1: MS (50 %), sucrose (30 g L-1), agar (6 g L-1), E2: AG3 (250 mg L-1), E3: MS (100 %), sucrose (30 g L-1), agar (6 g L-1), AG3 (250 mg L-1)] and multiplication [control: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), M1: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), coconut water (10 ml L-1), M2: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), coconut water (20 ml L-1), activated carbon (2 g L-1), M3: MS (100 %), sucrose (30 g L-1), agar (7 g L-1), BAP (0.10 mg L-1), ANA (3 mg L-1)]. The evaluated variables were: germination (%), number and length of shoots and roots, callus formation (%), rooting (%), and the number of areoles. Results. The best germination (100 %) was obtained in the E1 medium, with more than three roots and two shoots per seedling (2,64 cm). The M2 medium generated the best multiplication, with 82.5 % rooting, 1.66 cm shoots and 1.86 areoles, and less presence of callus tissue (60 %). Conclusion. The micropropagation of yellow dragon fruit was achieved by using seedlings obtained in vitro as an explant source.
Copyright (c) 2022 Gerardo Mállap-Detquizán, Nuri C. Vilca-Valqui, Jegnes Benjamín Meléndez-Mori, Eyner Huaman-Huaman, Manuel Oliva (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Effect of Morus alba on the flavonoids content and bromatological profile of goat milk
Introduction. Mulberry (Morus alba), a plant native to China, is used as a fodder on some farms. Its high protein content stimulates milk production in cattle; however, it is not known whether its flavonoids can be incorporated into goat milk. Objective. To evaluate the effect of a diet enriched with mulberry-enriched, on flavonoids concentration and bromatological parameters of milk from stabled alpine goats. Materials and methods. The experiment was carried out in 2019, with goats from a particular farm located in Veracruz, Mexico. Two groups were formed (A with the treatment and B control) with five Alpine breed goats each, with similar characteristics (stall feeding, three calving, without mastitis, morning and evening hand milking). Group A received forage without mulberry before and after treatment (days 1-10 and 21-31, respectively), and a modified forage diet with mulberry (days 11-20; group B was fed forage without mulberry on all 31 days of experimentation. Additionally, the flavonoid content in mulberry and every three days in milk samples were analyzed, in addition to the bromatological content of protein, fat, lactose, non-fat solids, and density. Results. During the mulberry-modified diet, the flavonoid concentration reached a maximum of 53.45 mg mL-1 EQ in group A at day 20, it decreased gradually during the post-treatment period; however, it maintained 20 % more flavonoids than the control group. A significant increase in protein content was also observed in group A, with no significant difference in the other bromatological parameters of the milk between the two groups. Conclusions. The diets modified with mulberry favored the incorporation of flavonoids and the increase of protein in goat milk, without modifying the other bromatological parameters.
Copyright (c) 2022 Julio César García-Valadez, Oscar Carmona-Hernández, Carmen Bulbarela-Sampieri, Micloth López-Del-Castillo-Lozano, Ana María Aguirre Martínez, José Armando Lozada-García (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
In vitro ruminal degradation of Tithonia diversifolia
Introduction. The Mocache canton (Ecuador) is a humid tropical zone, with a dry season of six months, which affects the availability and quality of forage, a situation that reduces the productive and reproductive capacity of ruminants. Objective. To evaluate the apparent in vitro ruminal degradation parameters of dry matter (DMD), organic matter (OMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD) in Tithonia diversifolia harvested at four different cutting ages during the dry season. Materials and methods. The research was carried out at the “La María” Experimental Farm of the Universidad Tecnica Estatal de Quevedo, Ecuador, between August and October 2017. Four rumen fistulated bulls were used. A complete randomized design (CRD) was used. The treatments were: Tithonia diversifolia at 30 days of cutting (T1), Tithonia diversifolia at 45 days of cutting (T2), Tithonia diversifolia at 60 days of cutting (T3), and Tithonia diversifolia at 75 days of cutting (T4). The incubation times were: 3, 6, 12, 24, 48, and 72 hours with four replicates per treatment. The variables evaluated were: DMD, OMD, NFDD, and AFDD. Results. The ruminal degradation parameters showed statistical differences between treatments (p<0.05), with T1 the best DMD, OMD, NDFD, and ADFD were obtained with 36.66, 35.44, 43.16, and 41.55 %, respectively). Conclusion. The highest DMD, OMD, NDFD, and ADFD parameters were associated with the cutting ages and the structural components of the bromatological composition. The cutting age at 30 days in Tithonia diversifolia influenced the potential and the effective nutrients degradation. As the cutting ages increased, the ruminal degradation parameters decreased.
Copyright (c) 2022 Gary Alex Meza-Bone, Carlos Javier Meza-Bone, Juan Humberto Avellaneda-Cevallos, Luis Alberto Godoy-Montiel, Marcos Antonio Barros-Rodríguez, Fernando Jines-Fernández (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Physical methods to reduce the inoculum of Sclerotium cepivorum in purple garlic seed (Allium sativum L.)
Introduction. In Colombia, garlic production is affected by pathogens, mainly Sclerotium cepivorum, which is disseminated by planting material. It is necessary to establish low-cost technologies to control this pathogen. Objective. To evaluate two thermotherapy methods, dry heat thermotherapy and water immersion thermotherapy, to reduce the presence of S. cepivorum in garlic seed and its effect on agronomic characteristics of plants emerged from treated bulbs. Materials and methods. This work was carried out at the Tibaitata Research Center of Corporacion Colombiana de Investigacion Agropecuaria (AGROSAVIA), located in Cundinamarca, Colombia, during the first semester of 2019. Nine treatments were evaluated; five in dry heat thermotherapy: 35 ºC for 12 h, 35 ºC for 129,6 h, 50 ºC for 48 min, 5 ºC for 20 days, 38 °C for 1 h; two in hot water immersion thermotherapy:48 °C for 30 min, 50 °C for 20 min, and two controls: chemical disinfection (tebuconazol) and room temperature (20 ºC for 20 days) in a randomized complete block design. Sprouting of bulbs and growth of garlic plants after applying thermotherapy to the seed and viability of S. cepivorum sclerotia were evaluated. Results. Seed storage at 5 ºC for 20 days accelerated its sprouting, reached a 80 % germination after five days, increased leaf number and biomass accumulation. Sclerotia germination was between 33 and 67 %; the treatment that presented the lowest incidence was 35 ºC for 129,6 h (33 %). Conclusion. Dry heat thermotherapy treatment at 35 °C for 129,6 h showed potential in reduction of S. cepivorum inoculum in garlic seeds.
Copyright (c) 2022 Magda Rocío Gómez-Marroquín, Diana Marcela Torres-Jiménez, Ginna Natalia Cruz-Castiblanco, Anngie Katherine Hernández-Guzmán, Sadao Kobayashi, Andrea del Pilar Villarreal-Navarrete (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Effect of pruning on the Capsicum annum L. yield under two environments
Introduction. Pruning the stems of bell pepper has been recommended to improve light interception, increase fruit set, and the quality of fruits. Objective. To evaluate the effect of pruning on yield components of two pepper hybrids established in two environments: open field and protected field under roof with plastic and natural ventilation. Materials and methods. Two trials were conducted at the La Selva Research Center of the Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), Rionegro, Antioquia, Colombia. Two pepper hybrids of block type were evaluated in two environments: open field (in the 2013-2014 cycle) and protected field under plastic cover (in the 2013-2014, 2014-2015 cycles), and three formation pruning treatments: two stems, three stems, and no pruning. For the first experiment, a randomized complete block design with six treatments (two hybrids and three pruning systems) and five replicates was used. For the second, the same treatments were established only under the protected environment, in a randomized complete block design. Results. Statistical differences were found for total yield in the unpruned system in both trials. In the protected field–2013 the hybrids achieved an average yield of 36.7 t ha-1, the unpruned system was the highest yielding (49.7 t ha-1). In the open field the yield was 23.6 t ha-1. The total yields obtained under the protected field-2014 (36.2 t ha-1), equaled that obtained in 2013, and statistically exceeded those of the open field. Conclusion. Unpruned plants showed the best yields in both trials. Differences between environments, hybrids, and their interaction were present in some variables. Further studies should be carried out to determine if the protected environment is suitable for the development of the hybrids.
Copyright (c) 2022 Luz Fanny Orozco-Orozco, Jaime Lozano-Fernández (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Diagrammatic scale for assessment the severity of Cercospora leaf blight on soybean (Glycine max) leaflets
Introduction. Cercospora leaf blight (CLB) caused by Cercospora kikuchii is an endemic soybean crop disease in Argentina. Objective. To develop and validate a scale to quantify the severity of CLB in leaflets of soybean (Glycine max) for the evaluation of foliar fungicides and cultivar trials. Materials and methods. A diagrammatic scale to assess the severity of CLB on soybean leaflets (Glycine max) was developed. The scale was based on the evaluation of 50 leaflets. The different severity levels of the leaflets were determined according to Weber-Fechner’s stimulus-response law. The proposed scale included severity levels of 1, 4.5, 17.5, 50, 82.2, 95, and 99 %. The validation of the scale was performed by 23 raters (3 experienced and 20 inexperienced) who assessed the severity of CLB on 50 leaflets with and without the use of the scale. Results. The results from the three experienced raters were more precise than those obtained by the inexperienced raters. The scale improved the visual interpretation to assess the severity of CLB for the inexperienced raters, who obtained estimated severity values close to the actual severity values. When the inexperienced raters used the proposed scale to estimate the severity of CLB on leaflets, they were accurate having determination coefficients (R2) between 0.74 and 0.91. According to the absolute errors, the greatest deviation was observed between -2.49 and 2.46. However, these deviations were not significantly different from the population average. To speed the process of cultivar evaluations we also propose the use of scales based on grades. Conclusions. The proposed scale to assess the severity of CLB on leaflets can be used for the assessment of foliar fungicide trials and soybean cultivars. The scale showed specificity for assessing the severity of Cercospora leaf blight (CFB) in soybean leaflets.
Copyright (c) 2022 Miguel Lavilla, Antonio Ivancovich, Antonio Díaz-Paleo (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Transplanting and the addition of boron in sweet corn (Zea mays L. group saccharate) production
Introduction. Low seedbed temperatures at the planting and the direct sowing method can reduce the sweet corn germination. Transplanting may offer optimum environmental conditions for seed germination, early crop maturity, and increase sweet corn (Zea mays L. group saccharata) productivity. Boron deficiency depresses sweet corn yield through male sterility. Objective. To evaluate the effect of transplanting and the addition of boron in sweet corn production. Materials and methods. A field experiment was conducted from March 19 to June 20, 2020 at the Research Station of Horticulture Department and Landscape Gardening Architecture, University of Diyala, Baqubah, Iraq. Direct sowing and transplanting, and foliar application of boron at 0, 50, or 75 mg L-1 was evaluated to determine effects on the yield, the yield components, and water use efficiency of sweet corn cultivars: Roi Soleal, Seker misir, and Succar. Results. The cv. Seker Misir matured faster (57.5 days), had wider ears (4.53 cm), more kernel rows (16.0), the highest kernel yield (6.00 t ha-1), and a higher water use efficiency (WUE) (2.85 kg m-3). The cv. Succar had the longest ears (18.48 cm) and the heaviest fresh ears (251 g). Transplanting hastened the time to maturity (54.18 days), and produced the longest ears (17.91 cm), widest ears (4.52 cm), most kernel rows (15.96), heaviest fresh ears (229 g), the highest kernel yield (5.56 t ha-1), and the highest WUE (2.64 kg m-3). The 50 mg L-1 fertilizer treatment produced the longest ears (17.61 cm), widest ears (4.58 cm), more kernel rows (16.61), the highest kernel yield (5.64 t ha-1), and the highest WUE (2.68 kg m-3). The least time to maturity (57.72 days) and heaviest fresh ears (232 g) occurred with 75 mg L-1 of boron fertilizer. Conclusion. The use of 50 mg L-1 boron, as a foliar fertilizer, appears to be, next to the transplanting method, suitable for the cultivation of sweet corn plants to increase productivity and WUE.
Copyright (c) 2022 Aziz Mahdi Abd Al-Shammari, Ghassan Jaafar Hamdi, Solieman Daowd Najm Abdullah (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Gypsum and potassium application to acid soils for maize (Zea mays L.) production in La Frailesca, Chiapas, Mexico
Introduction. Maize (Zea mays L.) production in La Frailesca region, Mexico, is limited by sandy soils, low in potassium (K), and with acidic arable layers and subsoils. There is information on the management of lime but not on amendments that could be used for subsoil acidity Ñ such as gypsum Ñ nor on the interactions between amendments for soil acidity and K fertilization. Objective. To evaluate the effects of K and gypsum on maize and on previously limed soils. Materials and methods. The evaluations were conducted in farmers’ fields in La Frailesca region, Chiapas (Mexico) in 2016 and 2017. Four gypsum rates (0, 1.25, 2.5 and 5 t ha-1) and four K rates (0, 60, 90, and 120 kg ha-1 as K2O) were factorially combined in a randomized block design, with three replicates. In both years, before the beginning of the experiments, dolomitic lime was applied to the experimental area following standard practices. Responses of crop yield, soil exchangeable K, Ca, Mg, and Al, and soil pH were obtained. Results. Maize yields increased with gypsum (stabilizing at 1.25-3.0 t ha-1), and K (stabilizing at 70-120 kg ha-1 of K2O) applications. In soils, K application increased exchangeable K content, while gypsum increased exchangeable Ca content and pH, and decreased exchangeable Al content. Liming increased pHCa and exchangeable Ca and Mg contents, and lowered the exchangeable Al content in the top 7.5 cm of soil. Conclusion. Soils with exchangeable K (²0.3 cmolc kg-1) were responsive to K fertilization. The positive effects on yields from gypsum were probably linked to a greater Ca supply in the top 7.5 cm. These results are encouraging about the benefits of the combined application of dolomitic lime, gypsum, and K, but longer evaluations are needed to properly determine the effects of gypsum on subsoil acidity.
Copyright (c) 2022 Armando Tasistro, Robertony Camas-Gómez, Iván Ortiz-Monasterio (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Effect on wheat (Triticum aestivum) yield of the yellow rust caused by Puccinia striiformis f. sp. tritici and its effect on yield
Introduction. In recent years, yellow rust caused by Puccinia striiformis was the most prevalent disease in wheat (Triticum aestivum), in the north of the province of Buenos Aires, Argentina. Objective. To evaluate the progress of yellow rust in wheat cultivars, with and without foliar fungicide application and its effect on yield and its components. Materials and methods. This study was carried out during two consecutive years (2017 and 2018) in the town of Junín, Buenos Aires, Argentina, on nineteen wheat cultivars, with and without foliar fungicide application. The damages of yellow rust on yield and industrial quality were quantified. Likewise, the evolution of the disease was evaluated using the area under the disease intensity progress curve (ABCPIE). The ABCPIE was associated with the yield, its components, and hectoliter weight. Results. Of all the variables analyzed, the ABCPIE had a significant interaction (p<0.05) between the foliar fungicide application and the cultivar used. The cultivars Lapacho, Minerva, MS 415, and SY 211 were resistant to yellow rust. The cultivar most susceptible to the disease was Algarrobo. The application of foliar fungicide, with low levels of the disease, significantly reduced its evolution, as reflected from the area under the disease intensity progress curve. Conclusion. The evolution over time of the yellow rust caused by P. striiformis depended on the genetic behavior of the cultivar and the application of foliar fungicide. The cultivars that had the highest yields, lowest ABCPIE, and highest hectoliter weight were: Lapacho, SY 11, BIO 1006, and Minerva.
Copyright (c) 2022 Miguel Lavilla (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Germination and growth of Leonia glycycarpa in Arosemena Tola, Napo, Ecuador
Introduction. The loss of wild plants species generates the need to evaluate their germination and growth characteristics in different environments in the Amazon region. Objective. To evaluate the ex-situ germination and growth of Leonia glycycarpa under conditions of primary forest soil use and coverage of intervened areas at the Amazonian Research, Postgraduate, and Conservation Center in Arosemena Tola, Napo, Ecuador. Materials and methods. The study was developed in two phases between 2018-2020, the first, of ex-situ germination in the greenhouse, where days until emergence and growth in tray were recorded, and the second of pre-transplant growth in field, in primary forest soil use and coverage of the intervened zone (Inga sp. woodland and melatomatacea woodland). The height of the plant, stem diameter, and number of leaves up to 360 days and environmental variables such as air temperature, luminosity, and soil nutrients were recorded. Growth curves were established for plant height and stem diameter. A correlation analysis was carried out between the growth measures and the environmental and edaphic variables. Results. In the first phase, an average of 33.5 days to emergence was obtained with 76 % of plants emerged at 45 days, reaching an average of 10.7 cm in height and 3.02 mm in diameter. In the field growth, the plants located in the intervened zone reached greater development and the linear and quadratic models prevailed in plant height and linear in stem diameter. Significant correlations were found between nutrient content and temperature and growth variables. Conclusion. L. glycycarpa could be propagated under greenhouse conditions. Environmental and edaphic factors influenced growth in height, diameter and number of leaves, having greater growth cover in the intervened zone.
Copyright (c) 2022 Ricardo Vinicio Abril-Saltos, Carolina Yasmin Villarroel-Gancino, Diego Mauricio Ramos-Criollo, Briyidt Maryeli Pillco-Herrera, Jonny David Quishpe-López, Katherine Pamela López-Adriano (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Chitosan applied in the treatment of wastewater from palm oil production
Introduction. The use of biopolymers in effluents treatment allows to control the environmental impact associated with agroindustrial wastewater discharge. Objective. To evaluate the effectiveness of chitosan as a natural coagulant in the treatment of palm oil production effluents. Materials and methods. The following parameters were determined: Chemical Oxygen Demand (COD), total suspended solids (TSS) and volatile solids (TVS), turbidity and fats and oils (GYA) in wastewater associated with palm oil production from the municipality of Agustín Codazzi in the department of Cesar (Colombia), by the jar test assay. Chitosan was applied in doses of: 100, 200, 300, 400, and 0 mg L-1 at three pH levels 4, 5, and 6 of the water. A completely randomized, two-way, fixed effects experimental was implemented. A multivariate analysis of the physical-chemical parameters of industrial effluent was used for data analysis. The study was conducted in 2012. Results. Chitosan allowed a reduction of more than 87 % turbidity, COD, TSS, TVS and fats and oils in all coagulant doses. While the control (0 mg L-1) was statistically different (p<0.05) to all the treatments. In the multivariate analysis of the data, the principal component 1 (PC1) explained 79.3 % of the total variance of the variables. Conclusion. Doses of 100, 200, 300, and 400 mg L-1 of chitosan evaluated as a natural coagulant in water treatment, decreased the concentration of pollutants in effluents associated with palm oil production.
Copyright (c) 2022 Dalia Milena Rodríguez-Jiménez, Yim James Rodríguez-Díaz, Esteban Burbano-Erazo (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
In vitro tolerance of Rubus spp. cultivars to mannitol-simulated drought stress
Introduction. The characterization of hydric drought stress tolerant cultivars of Rubus spp. in experimental fields is complicated by the difficulty of controlling the external factors of the environment where they are installed. In vitro stress induction is an efficient tool to study plant response mechanisms and is used in breeding programs for the selection of hydric drought stress tolerant genotypes. Objective. To evaluate the in vitro morphological and physiological response of explants in three cultivars and the wild accession of Rubus spp. under mannitol-simulated hydric drought stress conditions. Materials and methods. The study was carried out in the Biology Laboratory of Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, Peru, during the year 2020. A completely randomized design with factorial arrangement (Factor A: four genotypes and Factor B: simulated water potentials with mannitol: 0, -0.2, -0.3, and -0.4 MPa) and four explants per experimental unit were used. Results. The cultivars responded differently under mannitol-simulated hydric drought stress. The Navaho and Tupy cultivars registered higher tolerance. Conclusion. The morphological and physiological traits related to the root length, the water content of the shoot, root and leaf allowed to identify Rubus spp. cultivars tolerant to mannitol-simulated hydric drought stress in the vegetative phase.
Copyright (c) 2022 Carlos Millones, Ernestina Vásquez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Grafts of orange (Citrus sinensis) and mandarin (Citrus reticulata) in production phase
Introduction. In Venezuela, citrus is the fifth most important fruit crop, with a harvested area of 18,084 ha, and an average yield of 14.2 t ha-1, below world production. Despite this, there is little information on the physiology and agronomy of the grafting of the most commonly used citrus cultivars in the country, as part of a strategy to select the best combinations (graft/rootstock) and the most limiting seasons for crop production. Objective. To evaluate agronomic and physiological levels of five citrus cultivars during the period 2013-2015. Materials and methods. A trial was carried out on citrus plants sown between the period of January 2013 and August 2015 at the National Center for Agricultural Research, Maracay, Venezuela, in three replications under a completely randomized design, to evaluate variables associated with gas exchange and crop phenology in five cultivars of the most important citrus fruits of Venezuela. Results. 1) Citrus trees showed partial opening of the stomata due to high temperature and drought without causing decrease in photosynthetic rate. 2) The plants with the highest average values in the gas exchange variables in the graft (Cleopatra and Volk) and in the rootstock (Dancy during the driest periods and Valencia in the wettest periods) caused the Cleopatra-Dancy, Cleopatra-Valencia, Volk-Valencia, and Volk-Dancy combinations to achieve the highest photosynthetic yield during all evaluation periods. 3) The budding phenological stage in citrus plants were the most important sink sources for the net photosynthetic assimilation rates. Conclusions. The cultivar Cleopatra-Dancy had the most stable behavior for variables associated with gas exchange and Volk-Dancy for producing in drier seasons.
Copyright (c) 2022 Mercedes Pérez-Macias, Enio Soto, Rommel Igor León-Pacheco, Gustavo Adolfo Rodríguez-Yzquierdo, Edwin Andrés Villagrán-Munar (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Rhizobia increases the germination of Coffea arabica and Coffea canephora seeds. Second evidence in Cuba
Introduction. The slow and asynchronous germination of coffee seeds affects the obtaining of seedling and increases production costs. The application of plant growth promoting rhizobacteria (PGPRs) has shown to be an alternative to this problem. Objective. To evaluate the effect of rhizobia inoculation on the germination of two coffee cultivars under controlled and productive conditions. Materials and methods. During January and February 2020, two experiments were carried out at the Universidad de Oriente, Cuba, using ten rhizobia strains from legumes and grasses, and two coffee cultivars of economic importance in Cuba: Coffea arabica Isla 5-15 and Coffea canephora Pierre ex Froehner Robusta cultivars. The experiments were conducted, one under controlled conditions, where seed germination was evaluated in Petri dishes, and the other one using pre-germination beds. In both experiments, a completely randomized design was used and an analysis of variance was performed. Results. Under controlled conditions, the inoculation of strains Rpr11, Rpr2, 1-2, ICA8001, and Can3 increased germination percentage, germination energy, germination index, germination speed index, and vigor index. In the pre-germination beds, the inoculants based on the Rpr2 and Rpr11 strains produced the highest percentages of emergence and germination energy. Conclusion. The Rhizobium strains Rpr2 and Rpr11 increased seed germination of two varieties of coffee.
Copyright (c) 2022 Sucleidi Nápoles-Vinent, Silfredo Milanés-Riquene, Ionel Hernández-Forte, Belkis Morales-Mena, María Caridad Nápoles-Garcias (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Control of cacao (Theobroma cacao) diseases in Santo Domingo de los Tsachilas, Ecuador
Introduction. Ecuador occupies the fourth place in cocoa exports with 293,487 tons per year, produced on 559,617 hectares. However, its yield per hectare is low mainly due to the presence of pathogens that affect the pods. Objective. To evaluates different methods of control of pathogens of the Theobroma cacao cv ‘CCN-51’ pod. Materials and methods. The work was carried out in Luz de America, Santo Domingo de los Tsachilas, Ecuador, between 2016 and 2017. The treatments were the result of the combination of cultural practices + two fungicides (Chlorothalonil and Pyraclostrobin) + one biofungicide Serenade¨ (Bacillus subtilis QST713), with and without fertilizers. In total, 16 treatments were evaluated with 3 replicates or blocks, installed in a commercial cocoa plantation cv ‘CCN-51’ and under a Randomized Complete Block Design (RCBD). Results. The use of fungicides (chemical and biological), decreased the incidence of moniliasis (Moniliophthora roreri), black pod rot (Phytophthora spp.), and cherelle wilt; but the application of fertilizers did not increase the effectiveness of these products. Treatment with only cultural practices did not decrease the final incidence of moniliasis, nor of brown rot, in contrast, the final incidence of cherelle wilt increased. The number of pods and the yield were not directly related and the highest yield of fermented and dry cocoa, corresponded to T9 [Cultural labors + Serenade¨ (0.2 kg ha-1) (every 15 days) + Fertilizer (0.3 kg ha-1) + Fertilizer (1 kg plant-1)], a treatment that also had the highest net income per hectare. Conclusion. Chemical and biological control can manage cocoa pods pathogens. The integration of both control methods allowed the cocoa producer to obtain greater income.
Copyright (c) 2022 Vicente Anzules-Toala, Elvis Pazmiño-Bonilla, Leonel Alvarado-Huamán, Ricardo Borjas-Ventura, Viviana Castro-Cepero, Alberto Julca-Otiniano (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Multilocus identification of Colletotrichum species associated with papaya anthracnose
Introduction. Anthracnose caused by Colletotrichum spp., is the main postharvest disease of papaya worldwide. Molecular approaches have allowed the identification of new species of the genus associated with tropical fruits anthracnose in different countries. Objective. To identify, by morphological and molecular techniques, the Colletotrichum species associated with papaya anthracnose in Costa Rica. Materials and methods. During 2014 and 2015, 129 Colletotrichum spp. monosporic isolates were established from papaya fruits exhibiting anthracnose symptoms, collected in Parrita, San Carlos, and Guácimo, Costa Rica. All isolates were characterized by colony morphology and PCR with taxon- specific primers for the species C. gloeosporioides s.l., C. acutatum s.l., respectively, and with species-specific primers for C. magnum and C. truncatum. Species identification was confirmed by multilocus analysis, base on the partial sequence of the actin(ACT), β-tubulin (TUB2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and chitin synthase 1 (CHS) genes and the ITS region. The phylogenetic analysis was based on the criteria of Maximum Likelihood and Bayesian analysis. Results. Six species were identified, C. fructicola, C. tropicale, C. theobromicola of the C. gloeosporioides species complex, C. simmondsii of the C. acutatum species complex, C. truncatum, and C. magnum s.l., being the latter the dominant species. Temperatures above 18 ¡C allowed the development of five species, C. theobromicola, C. fructicola, C. tropicale, and C. magnum s.l., which showed accelerated growth, while C. simmondsii had slow growth. Conclusion. The multilocus analysis was able to identify species belonging to the C. gloeosporioides and C. acutatum complexes. This is the first report of C. fructicola, C. tropicale, C. theobromicola, and C. simmondsii associated with anthracnose of papaya fruits in Costa Rica.
Copyright (c) 2022 Catalina Ruiz-Campos, Gerardina Umaña-Rojas, Luis Gómez-Alpízar (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Microbiological and physicochemical quality and flavor of hen eggs produced under grazing or conventional systems
Introduction. The hen egg (Gallus gallus domesticus) is a nutritious food in the diet of millions of people. Its worldwide production is obtained from conventional caging systems although alternative grazing systems are also used. Objective. To compare the microbiological and physicochemical quality and flavor of eggs produced under conventional or alternative grazing systems in Costa Rica. Materials and methods. This research was performed in Alajuela, Costa Rica, from October 2016 to May 2017. Environmental surfaces and eggs of Isa Brown hens were sampled on farms from both systems and total coliform, Escherichia coli, yeast and molds counts and absence/presence of Salmonella sp. were determined. Also, physicochemical parameters (Haugh units, yolk index, pH, yolk color, and shell hardness) were measured and a discrimination sensory test with consumers was performed. Results. The grazing production system had surfaces in contact with the eggs with total coliform and E. coli counts significantly higher than those determined for the surfaces of the conventional system. Eggs from grazing hens had total coliform counts (3,2 log10 UFC egg-1) significantly higher than conventional eggs (2,3 log10 UFC egg-1). Salmonella sp. was present in 8 % of the grazing eggs samples (incidence not significantly different from 0) and absent in the conventional eggs. A difference was found for the color of the yolk, (darker in conventional eggs). Also, there was a significant difference in the taste of both types of eggs. Conclusion. In general, microbiological and physicochemical quality and flavor of eggs produced under grazing system was different from the ones produced conventionally.
Copyright (c) 2022 Marie Guier-Serrano, Gabriela Davidovich-Young, Eric Wong-González, Elba Cubero-Castillo (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Physicochemical and sensory characteristics of flavored milks made with goat and bovine milk
Introduction. Goat’s milk is a product of high nutritional and nutraceutical value, around which there is no established culture of consumption in several countries, so its use in the development of new products is promising. Objective. To define the effect of different proportions of goat and bovine milk on the physicochemical and sensory properties of flavored milks. Materials and methods. At the National Center of Food Science and Technology of the Universidad de Costa Rica, during 2021, flavored milks of three different flavors were formulated with five inclusion levels of goat and bovine milk (0 %, 25 %, 50 %, 75 %, 100 %). These milks were evaluated for pH, total acidity, instrumental color (parameters L *, b *, and a *), and viscosity, as well as the overall taste by means of a panel with 110 judges. Results. As the proportion of goat milk increased, a decrease in pH and an increase in acidity were recorded in a lot of samples, as well as an increase in the viscosity of the chocolate milks. The color in each formulation showed no differences in the parameters a * and b * and L * when varying the proportions of milk. Sensory analysis generated three clusters of panelists (15.5 %, 48.1 %, and 36.4 %). Conclusions. Strawberry flavored milk with a 50 % cow’s milk / goat’s milk ratio presented the best combination of physicochemical and sensory parameters.
Copyright (c) 2022 Luis Miguel Baquero-Saldarriaga, Alejandro Chacón-Villalobos (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0
Diversity and use of plant and animal species in backyards of Nunkiní, Campeche, Mexico
Introduction. In rural areas, backyard agricultural production satisfies part of the food needs of families, provides health benefits, and contributes to the conservation of the biological diversity of plants and animals. Objective. To quantify, using ecological indices, the diversity of plant and animal species present in the backyards of Nunkiní, Campeche, Mexico, and to analyze their main forms of use. Materials and methods. The information was obtained through a survey with directed sampling applied to the female heads of household units in the community of Nunkiní, Campeche, Mexico. Fieldwork was conducted between August and November 2023, during which 33 household units were visited. The survey included sections on family composition, backyard characteristics, an inventory of plants and animals, and the forms of use of both. The Shannon and Margalef indices were estimated to determine diversity and relative abundance. Results. The presence of 179 plant species and 20 animal species was recorded. Diversity and abundance were high for plant species (H’ = 4.243; Margalef = 23.3), whereas for animal species they were low (H’ = 1.204) or medium (Margalef = 2.60). Eight uses were identified for plant species and ten for animal species. Conclusions. In the sampled backyards, most of the diversity is composed of plant species, with predominance of those belonging to the Cactaceae family. Animal diversity represents 11.2 % of the total recorded species, most of which belong to the Phasianidae family. The main forms of use of the plant component were ornamental and food, whereas in the animal component their contribution to food and the generation of economic income stood out.
Copyright (c) 2025 Miguel Angel Magaña Magaña, Sandra Trinidad Atondo Cordova, Samuel Albores Moreno, Raúl Andrés Perezgrovas Garza, Ingrid Abril Valdivieso Pérez (Autor/a) https://creativecommons.org/licenses/by-nc-nd/4.0