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

Antecedentes. La caña de azúcar (Saccharum officinarum L.) es uno de los principales cultivos en México, tan solo, durante la zafra 2021-2022, se industrializaron 54.6 millones de toneladas de caña bruta molida, posicionándose como el sexto lugar en producción a nivel mundial. Sin embargo, durante el procesamiento se generan diversos productos y coproductos de los cuales se destaca el bagazo de caña, que en su mayoría se destina a la producción de energía eléctrica mediante combustión, convirtiendo cerca del 25 % de su peso en gases de efecto invernadero generando problemas ambientales. Por esta razón, es necesario diseñar procesos alineados a los ejes del desarrollo sustentable (ambiental, social y económico) para impulsar la valorización y diversificación. Objetivo. Determinar el efecto de dos pretratamientos sobre la sacarificación enzimática de bagazo de caña de azúcar para su posterior conversión a bioetanol. Metodología. Se realizó la producción de extractos enzimáticos por fermentación en estado sólido (FES) utilizando bagazo de caña como soporte-sustrato y cepas fúngicas autóctonas como inóculo. Para la sacarificación enzimática el bagazo de caña fue pretratado con peróxido de hidrógeno y microondas, para el pretratamiento con peróxido de hidrógeno se evaluaron las variables tiempo (1, 3 y 6 h), relación mL de peróxido por gramo de bagazo (16.6:1, 33.3:1 y 100:1), temperatura (26, 50 y 70°C) y concentración del peróxido (1, 3 y 5%); y para el pretratamiento con microondas se evaluaron las variables potencia de las microondas (p30, p50 y p80) y tiempo (5 y 10 min). Para la etapa de sacarificación enzimática fueron utilizados extractos enzimáticos producidos por FES y bagazo pretratado con peróxido de hidrógeno. Por último, los azúcares fermentables obtenidos de la sacarificación enzimática de bagazo de caña fueron empleados como única fuente de carbono en un sistema de fermentación alcohólica. Resultados. Los resultados de la FES mostraron la presencia de actividad celulasa (2 U/g) y xilanasa (61 U/g). Por otro lado, los resultados del pretratamiento de bagazo de caña con peróxido de hidrógeno indicaron que las mejores condiciones fueron 100 mL de peróxido de hidrogeno al 3% por cada gramo de bagazo de caña a 50°C, mientras que, las mejores condiciones del pretratamiento con microondas fueron 50p por 5 minutos. La sacarificación enzimática de bagazo de caña presento un rendimiento de azúcares reductores máximo cuando el bagazo de caña fue pretratado con peróxido de hidrógeno obteniendo 0.41 g/g. Por último, la concentración máxima de etanol (4.32 g/L) fue obtenida tras 48 horas de fermentación con Saccharomyces cerevisae comercial. Implicaciones. La agroindustria azucarera en México se limita a la producción de sacarosa y etanol siendo necesaria una diversificación productiva sustentable. Conclusiones. El aislamiento de cepas fúngicas autóctonas permitió la producción de celulasas y xilanasas por fermentación en medio sólido con especificidad adecuada para hidrolizar/ sacarificar bagazo de caña de azúcar pretratado y su posterior conversión a etanol. 

Background: Heavy metals are perceived as the most persistent and dangerous. Cu is essential for plants, in excess it causes detrimental effects on plants and human health. Plant growth promoting bacteria have been mainly used in agriculture to promote seed germination, plant vigor and growth, and improve crop yields. Objective: To analyse the effect of germination in two roselle varieties that were inoculated with extracellular plant growth-promoting rhizobacteria of the genus Pseudomonas and in seven solutions of copper sulphate pentahydrate. Methodology: Roselle seeds were germinated in copper sulphate solutions, the seeds were inoculated with bacterial suspensions of two strains of Pseudomonas M40 and M67, the germination percentages were determined and vigour tests were also carried out. Results: The effect of copper sulphate on germination was significant in the interaction between main factors, but no significance was found in the effect of the strains and their interaction with the varieties. In the vigour tests, significance was detected between factors of stem dry weight, root and stem length, and strains. Implications: The tolerance of the seeds to copper sulphate, to know if it has an effect of promoting germination or, on the contrary, inhibits it. Conclusion: copper sulphate has the effect of promoting the germination of roselle seeds. Jamaica has a potential effect of phytoremediation of metals in combination with the inoculation of rhizobacteria that promote plant growth.

Background. The Fan of Ibagué is one of the most important livestock and agricultural regions in the country, which faces a sustainability crisis and whose origins can be a critical point for understanding it. Objective. To understand the historical processes of settlement of the Ibague fan and the development of the rice and livestock industries in the region. Methodology. This historical perspective is constructed from agroecology, a transdisciplinary science that seeks to understand the multidimensional nature of current environmental problems. Qualitative analysis is thus relevant at this point since it provides means to analyze ecosystem transformations and the consequences derived from contemporary production practices. Oral testimonies by diverse actors (producers, members of institutions, traders, researchers in the region) were gathered through semi-structured interviews after field visits and later analyzed in the search for agricultural production milestones and their role in the ecological transformation of the region. The findings were contrasted with written sources and documentary records such as agricultural censuses, institutional files, and fieldwork evidence. Results. Four crucial events in the local agricultural development of the Ibagué Fan were reported: the extensive livestock farming around 1900, which lead to the consolidation of four generations of producers; the construction of irrigation channels which benefited large-scale rice production in the area by the mid-twentieth century; the combination of rice production, livestock farming and all its associated crops; and finally, the introduction of sustainable livestock farming projects. Implications. Historical analyzes show the need to know the perspective of the actors involved in the development of agriculture and livestock in the region over the years; these milestones are fundamental for the development of public policies that recognize the historical, social and geographical particularities. Conclusions. The history of the colonization of the Colombian territory from the seventeenth century was characterized by the introduction, adaptation, and expansion of the livestock farming culture, together with the populating of the territories near the plains of the Magdalena river, as it was the main connecting route in the region.

Background: The Yucatan Peninsula is covered mainly by semi-humid forests associated with karstic zones. These landscapes show high rates of endemism, and although they are resilient ecosystems, climatic variations place them as highly susceptible areas to climate change. Objective: To identify environmental and anthropogenic risk factors in the semi-humid forests of the Yucatan Peninsula, and to evaluate the vulnerability to climate change of 25 forest species with economic importance in this region. Methodology: A multi-criteria analysis was carried out to rank edaphic and climatic variables, changes in potential distribution due to climate change, species density and growing rate. These variables were integrated into a matrix and each variable was valued from 0 to 4, weighted between parameters, the higher the value, the greater the susceptibility. Four percent of the species were classified into the high-risk susceptibility and 84 % as medium risk and the rest as low. These species have a low density per hectare, have a restricted distribution, are slow growing and are over shallow soils. Implications: Species that can develop in a wide range of environmental conditions and have rapid growth rates were less susceptible to the risk factors analyzed here. Conclusions: The greatest risk factor was due to the effect of climate change, followed by the proximity to the Caribbean coast and the type of soil, which suggests that more conservation actions for forest species are needed, which will also ensure the provision of environmental services to human populations.

Background: Sows’ lifetime reproductive performance is a key component for farm productive efficiency and profitability.  Objective: To investigate associations between first parity wean-to-service interval (WSI) and sows’ lifetime reproductive performance traits. Methodology: Data were collected in a 3,900-sows farrow-to-finish farm in Yucatan, Mexico. Lifetime productivity records included parity number at culling (NCP), lifetime number piglets born alive (LNBA) from parity two until culling, lifetime non-productive days (LNPD) and length of productive life (LPL) for 4,175 sows. Association between WSI and sow lifetime productivity traits were analyzed using general linear models, including year and season at first service as categorical fixed effects and WSI as linear and quadratic predictor. Cut-off values for WSI were estimated using regression trees analysis. Results: WSI was negatively associated (P < 0.05) with LNBA and NCP, positively (P < .05) with LNPD and non-associated with LPL (P > 0.05). Cut-off values for WSI varied for each predicted variable: WSI > 5 days would translate into longer 13 more days of LPL, WSI < 7 days would increase LNBA by two extra pigs, WSI ≥ 9 days increase NCP by 0.2 parities and WSI <10 days would mean 24 fewer LNPD. Conclusions: Under the conditions of this study, shorter WSI were associated with improved lifetime productivity traits, confirming the importance of traits observed early in life as indicators of performance in subsequent parities.

Background: In studies of local maize diversity, conservation is often identified as a linear process, related to the limited analysis of the implications of technological change, especially improved commercial seed, on local maize potential and its conservation. This generates increasing socio-technical complexity Objective: To characterize the potential of local maize present in two ejidos of the Frailesca region of Chiapas, considering the farmers' knowledge about them and the configurations they adopt together with other maize in the context of technological change. Methodology: Using the snowball technique, peasant domestic production units that conserve local maize (LM) were identified and samples were collected. The ethnographic method was used to deepen the farmers' knowledge of the local varieties and the configurations they share with other maize. The characteristics of the ear and kernel of the collected LM were described. Results: In the selected peasant domestic production units farmers maintain 15 varieties of LM based on a broad knowledge of these varieties; the basis of the selection process, conservation and adaptation to the conditions where they preserve them. According to the parameters of grains and cobs the LM collected are concentrated in three groups and form non-linear configurations with improved maize and other local varieties, in correspondence with the homogenizing technological flow typical of the Frailesca region. Implications: This productive environment where the conservation of LM is developed makes evident the importance of an integrative approach to capture their growing socio-technical complexity. Conclusions: The LM potential evidenced permanence and morphological variability despite the homogenizing effect of technological change in the study area, where the socio-technical framework of LM conservation becomes more complex and the broad expert knowledge of farmers on the management of maize diversity acquires greater relevance. 

Background. Studies in temperate regions report the effect of lactation length (LL) and farrowing- service (IFS) and weaning-to-first service intervals (IWS) on the reproductive efficiency of sows in commercial farms. However, research about this topic under tropical conditions is scarce. Objective. To investigate the relationship of LL, IWS and IFS on subsequent number of piglets born alive (SPBA), and the effect of LL on number of parity per sow per year (NFY) and number of piglets born alive per sow per year (PBAY) in a commercial farm in the tropics of Mexico. Methodology. Data from 9663 litters were used. The statistical model for SPBA, NFY and PBAY included the fixed effects of farrowing year (2013, 2014), farrowing season (rainy, north and dry), farrowing number (1, 2, 3, 4, 5, 6), simple interaction of year by farrowing season, and the linear and quadratic effects of LL, IWS and IFS for SPBA, and the linear and quadratic effect of LL for NFY and PBAY. Results. The factors evaluated were significant for all variables of interest. Linear effect (P < 0.05) of LL, IWS and IFS was found only on SLNV. The predictive equation for SLNV was Y= 10.8551+0.02242*LLL+0.01515*IDS. The equation for SPBA with IFS was Y= 10.9939 + 0.01604*IFS. In addition, a negative linear and quadratic effect (P < 0.05) of LL on NFY, and a negative linear effect (P < 0.05) on SPBA were found. The predictive equation for NFY was Y= 2.7432-0.001689*LL-0.00032*LL2 and for PBAY was Y= 32.2414-0.1444*LL. Implications. The effect of LL, IWS and IFS on sow productivity is fundamental for decision making and adapting management, techniques and technologies to production systems. Conclusion. Under the conditions of the present study, increasing LL and IWS increased sow SPBA. However, increasing LL reduced NFY and PBAY.

Background: Soil cover with crop residues is an ancient tradition that is gaining momentum in conservation agriculture´s current trends. Objective: The objective of this research is to evaluate the effect of soil mulching with corn-mulberry on Spodoptera frugiperda management in corn Zea mays variety Tuson after imbibition in vinasse. Methodology: The first part of the experiment evaluates the effect on germination with seed previously soaked in vinasse in 1:15 ratio under controlled conditions for 30 min. The second part was developed in the Unidad Empresarial de Base “Antonio Maceo” Yara, Granma, Cuba under field conditions, which consisted of two treatments: (T1) corn-mulberry soil mulching 2 t ha-1 before planting and (T2) control group without cover. The percentage of maize plants were evaluated from 1 to 3 and from 4 to 5 degrees in damage at 30 days, in addition to agricultural yield at 150 days. Both experimental stages were performed in a randomized complete block design (RCBD). Results: The results showed that germination percentages increased by using 1:15 vinasse, whereas the corn-mulberry soil cover decreased S. frugiperda incidence at the same time and increased agricultural yields. Implications: Future studies should find an equilibrium point that guarantees the use of crop residuals as agroecological practices in soil protection and conservation, as well as in animal feed sources in places and season where natural forage is affected. Conclusion: Soil cover with corn-mulberry mulching from leaf waste before sowing decreases S. frugiperda incidence and corn yield increases. 

Antecedentes. Los bioestimulantes microbianos en plantas permiten mejorar la nutrición y calidad en los frutos de los cultivos. Los insecticidas a base de hongos entomopatógenos e insecticidas de última generación controlan plagas en hortalizas de forma efectiva. Objetivo. Evaluar tres bioestimulantes y tres insecticidas biorracionales en el cultivo de berenjena en condiciones protegidas de macrotúnel. Metodología. Los tratamientos bioestimulantes fueron: Genifix®, T22®, Mix® y testigo; para insecticidas fueron: Movento®, Beauveria bassiana, Isaria javanica y testigo. Se evaluaron en berenjena en condiciones de macrotúnel. Resultados. Se registró un efecto significativo de los bioestimulantes en el incremento del peso y dimensiones de frutos de berenjena, destacando el Genifix®, seguido del T22® y Mix®. El Movento® redujo más moscas blancas en comparación a B. bassiana e I. javanica. Implicaciones. Los productos evaluados pueden aplicarse en un manejo biorracional de berenjena, reduciendo el uso excesivo de fertilizantes e insecticidas sintéticos. Conclusiones. Se demostró el potencial de los bioestimulante Genifix®, T22® y Mix® para mejorar el desarrollo de frutos de berenjena, así como del insecticida Movento® para controlar la plaga Bemisia tabaci en berenjena. El bioinsecticida B. bassiana puede usarse de manera efectiva en un manejo integrado de la mosca blanca en berenjena.

Background: Heliconias are commercially important flowers due to its abundance of shapes, sizes, and colors. In Mexico, however, this ornamental crop is not considered in the statistical yearbook of agricultural production. In addition, there is no research regarding the context of tropical floriculture. Objective: To explore all scientific contributions related to the cultivation of heliconias. Methodology: A bibliographic search was conducted in Redalyc, SciELO, Scopus and Google Scholar with the key word “heliconia.” After cleansing the database of similar results, we generated a final compilation of 42 papers, which were then subject to an analysis of textual content by using Nvivo 12 Plus software to identify the contributions by means of the following categories of analysis: Production, post-harvesting, and commercialization. The species of heliconias were also identified. Results: The content analysis showed that 73.71% of all scientific contributions correspond to the production category, 12.5 % to post-harvesting, and 13.88% to commercialization. For each category, different topics which guide the contributions were identified. We found 43 species of heliconias that were used for research purposes in the three categories of analysis. Implications: The analysis was limited only to scientific contributions explored. An analysis that considered other sources of information could have strengthened this analytical exercise. Conclusion: The scientific contributions regarding the cultivation of heliconias are mainly oriented to the production category, which demonstrates that the focus is on the improvement of the production process. On the contrary, the contributions on post-harvesting and commercialization are incipient; therefore, it is important to address these topics in future research.