Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Introduction. Real-time monitoring of water stress levels in crops is crucial to improve water use efficiency in agriculture. Objective. To determine the feasibility of using thermal images collected by an unmanned aerial vehicle(UAV) to detect water stress in cotton (Gossypium barbadense L.), Molinero extra-long variety. Materials andmethods. The study was conducted at the Irrigation Research Unit of the National Agrarian University La Molina, Lima, Peru, from November 2022 to May 2023. Forty-eight sampling units of 0.80 × 1.5 m were used with dripirrigation activated in response to physical signs of water stress in cotton. The crop water stress index (CWSI) wasmonitored through eight UAV flights equipped with a thermal camera, and the data were corrected using radiometer measurements. Stomatal conductance (gs) was measured using a porometer, and soil moisture (θ) with a sensor. In addition, tests were carried out in pots to cause plant death and induce maximum water stress. Results. A 0.96correlation was obtained for the thermal images. A potential 0.83 correlation between gs and CWSI was observed, along with a 0.88 between θ and CWSI, indicating an adequate representation of water stress variability with irrigation levels. Conclusions. The use of thermal images obtained via UAV allowed estimating a maximum CWSI of 0.39, optimizing irrigation timing and achieving water savings of 50 %. The CWSI proved to be a valuable tool for accurate irrigation scheduling, with potential to improve water use efficiency up to 2.27 kg/m3 in arid regions such as La Molina, Peru.

Introduction. Currently, food industry innovation results in the generation of thousands of tons of organic waste that negatively impacts environmental sustainability. Therefore, it is important to implement actions that contribute to waste reduction and utilize bioactive compounds effectively. Objective. To conduct a systematic literature review on the nutrients and bioactive compounds present in the main components of jackfruit (peel, pulp, and seed), to evaluate its potential incorporation into livestock feed. Development. A systematic review was conducted based on experimental articles retrieved from ScienceDirect, Wiley, Google Scholar, Scopus, and Springer Link databases. A specific search equation was employed for this purpose. Results demonstrated that different jackfruit components contain nutrients (proteins, carbohydrates, minerals) and bioactive compounds (polyphenols, flavonoids, polysaccharides, phenols, etc.) that have demonstrated positive effects when incorporated into livestock feed (broilers, sheep, and goats). Conclusions. The incorporation of jackfruit into animal feed promotes weight gain, improves digestibility, stimulates the immune system, and reduces feed production costs.

Introduction. Trialeurodes vaporariorum (Westwood) is considered one of the main pests affecting horticultural and ornamental crops, especially in greenhouses. Effective management of this pest requires the integration of various methods and techniques, including the use of botanical extracts. Objective. To evaluate the efficacy of botanical extracts derived from Jatropha curcas for the control of Trialeurodes vaporariorum under laboratory conditions. Materials and methods. The study was conducted in the Entomology Laboratory of the Crops Protection Research Center, Universidad de Costa Rica. An adaptation of the methodologies described by Liu and Stansly (1995) and Ibrahim and Mostafa (2018) was implemented to evaluate the efficacy, median lethal concentration (LC50), and median lethal time (LT50) of aqueous botanical extracts made from leaves, stems, and seeds of two J. curcas accessions at concentrations of 50, 100, 150, and 200 g/L on T. vaporariorum. Results. The lowest LC50 (1.52 g/L) and LT50 (61.01 hours) values, as well as the highest efficacy values (above 65 %), were achieved with leaf extracts with significant differences observed exclusively in the LT50 values. Concentration was the most important factor in efficacy estimation according to the Akaike information criterion, and efficacy increased by 0.15 % for each concentration unit. None of the evaluated extracts caused phytotoxicity in Solanum melongena L. plants. Conclusions. The leaf extracts are a promising alternative for the control of T. vaporariorum; however, it is necessary to determine the compounds in Jatropha leaves that induce mortality.

Introduction. Costa Rica ranks among the world’s leading producers and exporters of pineapple; however, production and post-harvest handling are hampered due to phytosanitary problems caused by fungi of the genus Fusarium. Objective. To determine the pathogenicity of different Fusarium species associated with the pineapple plant and fruit, and their frequency in the main production areas of Costa Rica. Materials and methods. The experiments were conducted at the University of Costa Rica, San Jose, from 2015 to 2019. Pathogenicity tests were carried out using inoculation with six Fusarium species in bracts, peduncles, and fruits of pineapple, and were verified using Koch’s postulates. Through the collection of 120 isolates, the frequency of Fusarium species in the production areas was established. Results. All Fusarium species caused damage to bracts. The largest lesions were caused by F. oxysporum. In fruit, internal lesions were observed in the pulp with F. ananatum, and a correlation between lesion size and the concentration of inoculated conidia was found. In the peduncle and pulp, lesion diameter varied among Fusarium species. In terms of species frequency, all Fusarium species were present in the Huetar Norte region, and F. ananatum was more abundant in all production regions, except the Brunca region. Conclusions. All the species analyzed were pathogenic in the pineapple crop, in bracts, peduncles, and fruit. F. oxysporum and F. ananatum caused the greatest lesions. The presence in all pineapple-growing regions, the pathogenic potential, and the production of mycotoxins determine the importance of taking precise measures to control and prevent the spread of species from this genus.

Introduction. Broiler production is an activity of increasing economic importance worldwide, but it entails a significant environmental impact. Objective. To assess the environmental impact of conventional broiler production chain systems. Materials and methods. The life cycle analysis (LCA) methodology was used following a “cradle to gate” approach. Base parameters were collected from a poultry farm located in San Ramón, Alajuela, Costa Rica, during the period January through December 2021. The LCA functional unit was defined as one metric ton of chicken meat (MT CM). Environmental impact categories were analyzed using the ReCiPe 2016 v.1.1 system, with characterization factors at the midpoint level under a hierarchical perspective. Results. The estimated environmental impacts, expressed in equivalent units per MT CM were as follows: global warming, 5208 kg CO2-eq; terrestrial acidification, 52.6 kg SO2-eq; marine eutrophication, 4.19 kg Neq; freshwater eutrophication, 2.47 kg P; land use, 5238 m2 crop year; water consumption, 3962 m3; terrestrial ecotoxicity, 1831 kg 1,4-DCB; marine ecotoxicity, 2.79 kg 1,4-DCB; freshwater ecotoxicity, 8.49 kg 1,4-DCB; human toxicity (carcinogenic), 1.13 kg 1,4-DCB; human toxicity (non-carcinogenic), 84.4 kg 1,4-DCB; fine particulate matter formation, 8.15 kg PM2.5; fossil resource depletion, 246.1 kg oil; ozone formation (ecosystem health), 10.8 kg NOx; ozone formation (human health), 10.7 kg NOx, and stratospheric ozone depletion, 0.043 kg CFC11. Conclusions. The processes contributing most significantly to the environmental impacts evaluated in this study were the production of feed, fertilizers, and fuels, along with farm waste management. The majority of the environmental impact attributable to the broiler production chain occurs outside of Costa Rica’s borders.

Introduction. Dose-response trials are used with the objective of selecting the efficient herbicide dose in weed management. Data analysis of these experiments has been criticized for the use of statistical models that do not fit the distribution of the response variable, failure to specify the original structure of the experimental design, and the preference for partial models instead of fitting a unique model. Nonlinear mixed models are presented as a more accurate alternative for analyzing these experiments. Objective. To determine the effective herbicide dose using three modeling strategies in dose-response trials. Materials and methods. Two independent experiments were conducted in greenhouses located in Tambor, Alajuela, Costa Rica, during 2012, where the fresh weight in grams (g) of a biotype of Paspalum paniculatum L. was quantified as a function of grams of acid equivalent (GAE) of an applied herbicide, under a randomized complete block design. A four-parameter logistic regression model was used as a basis, and three model variants were fitted. Using penalized information criteria (Akaike information criterion [AIC] and Bayesian information criterion [BIC]), the best-fitting model was chosen. Results. The strategy that considered the experiment and the block within each experiment as random effects proved to be the most accurate. This model estimated the confidence interval (95 %) for the mean effective dose of GAE between 335.12 and 384.32 g. Conclusions. Integrating information from independent experiments as random effects within a unique model generated more accurate estimates of glyphosate’s effective dose.

The Fabio Baudrit Moreno Agricultural Experiment Station (EEAFBM) is located in the district of San José de Alajuela, Alajuela, Costa Rica (10°00′26″N, 84°15′57″W, at 840 m a.s.l.). It is a unit attached to the Faculty of Agricultural Sciences at the University of Costa Rica (UCR), dedicated to carrying out multidisciplinary work in research, teaching, and social outreach, in line with the objectives established in the UCR Statute, and contributing to the agricultural development of the country. This document describes the acquisition of the EEAFBM lands, the pioneers in its establishment and evolution, the beginning of research and extension programs, the successful collaborative work with governmental and international institutions, as well as the support provided to the agricultural sector during the 20th century, which continues into the 21st century. In addition, it includes the scientific outreach methods of the Experimental Station. This review also pays tribute to agronomist Fabio Baudrit Moreno, as the driving force behind the acquisition, management, initial leadership, and launch of the first research and teaching activities at the EEAFBM

Introduction. The study of factors affecting the productive performance of dairy goats under tropical conditions is essential for optimal resource utilization. Objective. To quantify the impact of genetic and environmental factors affecting the productive performance of dairy goats under semi-intensive tropical conditions. Materials and methods. The research was conducted at the Finca Experimental Santa Lucía of the Universidad Nacional, Heredia, Costa Rica. The experimental period spanned from January 2007 to December 2023. A total of 15,686 daily milk yield records were analyzed from 191 dairy goats of Saanen (S) and Saanen×Toggenburg (S×T) breed types. A generalized linear mixed model was used to evaluate the effect of various predictor variables on daily milk yield, and standard lactation curves were fitted for different genetic and environmental conditions using the Wood function. Results. Highly significant effects (p < 0.001) were determined for parity number, year of kidding, lactation week, buck category, number of offspring, season, and month of kidding on milk yield. For primiparous goats of S and S×T breeds kidding in the rainy season, peak daily milk yields of 2.46 and 2.54 kg were estimated, reached at weeks 6.4 and 5.9, with persistencies at the end of lactation of 86 % and 84 %, respectively. Conclusions. Multiparous status and access to feed with higher nutritional content during the rainy season were factors associated with higher milk yield. Lactation curves revealed different patterns in milk production between primiparous and multiparous goats, as well as among different kidding seasons and breed types. The study provides valuable information for commercial validation and optimization of lactating goat management under semi-intensive tropical conditions.

Introduction. In Tamaulipas, Mexico, environmental conditions are suitable for nopal (Opuntia spp.) production; however, yields are lower than the national average. Objective. To characterize the nopal production system in the Huasteca Tamaulipeca region and identify the main issues that limit production. Materials and methods. A diagnosis of the nopal production system in the Huasteca Tamaulipeca region was conducted through 28 interviews with 65 questions, divided into three sections: a) producer identification, b) characterization of the family production unit, and c) technical-productive characterization and commercialization. Results. Producers’ ages ranged from 37 to 78 years, with an average schooling of 6.5 years. A total of 32 % of the producers do not receive technical assistance, 57.1 % work on land under the ejido system (communal land tenure), 82.1 % sell their products to intermediaries, and 100 % do not use agricultural machinery for their activities. Conclusions. Most nopal producers in the Huasteca Tamaulipeca region are older adults with experience in nopal cultivation. Nopal production in the region is carried out traditionally, under rainfed conditions, without infrastructure, and with little technical support. The main issues identified were low prices due to limited product demand and a lack of technical assistance for crop management.

Introduction. Dairy farms in Costa Rica have been classified into three production systems: specialized high-altitude, specialized lowland, and dual-purpose systems. However, this typification does not reflect their current complexity level, as there exists a wide variety of production systems based on sanitary, reproductive and feeding management practices. Objective. To characterize the dairy production systems in two representative livestock regions of Costa Rica and their technological adaptation capacities to climate change. Materials and methods. To determine the technical-productive, social, and economic characteristics of Costa Rican dairy farms located in the Chorotega and Huetar Norte regions, a designed and validated survey was applied. Data were collected between April and May 2021. A total of 143 farmers were interviewed, allowing for the evaluation of 193 variables. Subsequently, cluster analysis was performed, executing hierarchical cluster analysis, using Ward’s method. Results. Three clusters were obtained with farm management capacities: high, medium, and low, related to their climate change adaptation capacities. The first group comprised producers with higher education and farm management levels (high capacity), reflected in the adoption of more adaptation strategies. The farms of the second group (medium capacity), with lower technical management than the first group, and the third group of farms (low capacity), composed of producers with the lowest educational level, demonstrated a more limited technological management capacity. Conclusions. The livestock activity was characterized by three groups of producers with different climate change adaptation capacities.