Este estudio estima la demanda de alimentos en los hogares mexicanos utilizando datos de la Encuesta Nacional de Ingresos y Gastos de los Hogares 2022. Para abordar la alta proporción de hogares con gasto cero en diversas categorías de alimentos, se aplica un sistema de ecuaciones censuradas. Las estimaciones se llevaron a cabo con una submuestra del 10% de los hogares que residen en localidades con más de 15,000 habitantes. Factores sociodemográficos como región, tamaño del hogar, edad, sexo y educación influyen significativamente en el consumo. Al ignorar la censura, el modelo QUAIDS sobreestima las elasticidades del gasto y subestima las elasticidades precio. Los resultados destacan la importancia de emplear modelos censurados en el análisis de políticas alimentarias.

Antecedentes y Objetivos: El género Agave ha sido poco estudiado a nivel ecológico en Hispaniola y en la región del Caribe. Se han documentado aspectos de su hábitat, pero no se ha profundizado en ese tipo de investigaciones. Los objetivos de este estudio fueron describir el hábitat de Agave en el Parque Nacional Sierra de Bahoruco, República Dominicana, determinar las variables ambientales que influyen en su crecimiento y en su variación morfológica, y registrar la fenología de sus especies. Métodos: Durante agosto y diciembre de 2023 se visitaron 12 localidades donde se registraron 24 variables ambientales. Se consideraron 46 variables morfológicas y se midieron 36 individuos en campo, complementando la información fenológica con especímenes de herbario. Se hicieron Análisis de Componentes Principales (ACP), Correlación de Spearman, pruebas de Kruskal-Wallis y de Dunn-Bonferroni y Coeficiente de Jaccard. Resultados clave: Los parámetros ambientales que influyeron sobre los caracteres morfológicos fueron la temperatura del bulbo húmedo, el calcio, la temperatura máxima, el cobre, el hierro, la iluminancia, el potasio, la pendiente, la elevación, el magnesio, la precipitación, el nitrógeno, la temperatura mínima, la humedad relativa y el manganeso. Los caracteres afectados fueron, por mayor a menor número de variables ambientales: la longitud de la hoja, la forma de la hoja, el color de los dientes en el ápice, el color de la espina, la forma del fruto, la forma de los dientes, la longitud del escapo floral, la uniformidad en el tamaño de los dientes, el ancho del escapo floral, la cantidad de dientes, la altura de la planta, la inserción del filamento y el ancho del filamento. La vegetación predominante fue el bosque de Pinus occidentalis. Conclusiones: Parte de la variación morfológica de los individuos de Agave en el Parque Nacional Sierra de Bahoruco es influenciada por variables ambientales.

There are currently multiple risks in Mexico’s agricultural sector, so it is critical to have concise and accurate information on the main mitigating factors faced by producers in order to contribute to the creation of risk management instruments that meet their needs. In this work, the unit of analysis was established on the basis of a census of 6852 small farmers (those with less than five hectares of sown area). Using a stratified sampling of 317 producers in the states of Tabasco, Guerrero, and Chiapas, risk management was analyzed in their production units. The sampling, with a precision level of 5 % and a reliability of 95 %, allowed obtaining representative results for the target population. Through a descriptive analysis, the profile of the producers was identified, detecting the main risks they face and the strategies they use to mitigate them. Frequency graphs were used to visualize the distribution of the variables analyzed. To evaluate the relationship between risk management and risk perception, chi-square and Cramér’s V contingency tests were applied. This study revealed a statistically significant relationship among 9 out of 13 risks analyzed and the risk management. In only six cases, the strength of association is moderate. This suggests that different tools exist to mitigate various hazards (natural disasters, pests and diseases, input prices, etc.), but their effectiveness varies by type. In the face of an adverse situation, producers often resort to strategies such as reducing food at home, using savings, and relying on government support. This study provides specific data on the specific conditions and challenges of these regions, enriching the general knowledge on family farming in Mexico.

Several adverse biotic and abiotic factors occur during the development of tomato (Solanum lycopersicum L.), reducing yield and fruit quality. This study evaluated the Alternaria foliar severity and subsequently the tolerance to Ca deficiency in 90 tomato (Solanum lycopersicum L.) genotypes, including 89 advanced S4 lines and one commercial control. The influence of Alternaria on yield and its components as average fruit weight, and total number offruits per plant was studied using a randomized complete block design with three replicates and four plants per replicate. After plant pathology analysis, Alternaria lycopersici was identified as the pathogen responsible for Ca deficiency and yield loss. Despite of the pressure of A. lycopersici and Ca deficiency, 14 advanced lines showed a yield like that exhibited by the commercial check 'El Cid'. Among 89 S4 lines, five tomato lines were resistant to A. lycopersici infection (+/- 0% leaf severity), while 52 lines showed moderate resistance (<= 25% leaf severity). A total of 24 advanced lines with no symptoms of blossom end rot due to Ca deficiency were identified. Additionally, two outstanding genotypes (48 and 49) from the source LOR95xC were selected for their high total fruit weight per plant and natural resistance to A. lycopersici. These lines showed no Ca deficiency, so they can be used as open-pollination varieties to improve the program's elite materials. Finally, susceptible lines to A. lycopersici showed Ca absorption capacity decreases in fruit (26.15 mu g g(-1)) and individual fruit weight (59.91 g). In contrast, resistant lines had values of 162.33 mu g g(-1), and an individual fruit weight of 107.11 g. This suggests that the lower the resistance to A. lycopersici in advanced lines, the more fruits with blossom end rot and lower average fruit weight due to calcium deficiency in the plant.

Barley in Mexico is an important crop for the brewing industry and animal feed. The physical and physiological quality and vigor of a batch of seed cv. Brennus was evaluated. The seed was divided by size (small and large) with a 2.5 mm sieve and subjected to different conditioning (aging and non-aging). The study variables were seed purity (SP), thousand seed weight (P1000S), volumetric weight (PV), moisture content (H), germination percentage, emergence speed, plumule length, dry matter in the plumule and seedling vigor index. The analysis of variance was performed under a completely randomized experimental design with factorial arrangement and four replications. Means were compared using Tukey's test (P < 0.05). The lot presented 98% SP, 1.8% inert material and 0.2% other seeds, P1000S was 42 g, PV 68 kg hL-1 and H was 7%. There were statistical differences (P < 0.05) between seed size, seed conditioning and interaction of both factors for most variables. Small and large unaged seeds showed similarity in germination, emergence speed, plumule length and seedling vigor index. The aging treatment had a negative effect on these variables regardless of size; however, the most extensive damage was seen on the large seeds. The seed lot has poor physical and physiological quality and vigor.

Las políticas públicas de extensionismo rural, son vistas a nivel internacional como factor determinante para acelerar la innovación agrícola e incidir en la reducción de la pobreza rural. Por ello, cobra relevancia la eva­luación de sus resultados. El objetivo de la investigación, fue evaluar el mejoramiento en los ingresos de los beneficiarios 2014-2015 de la política de extensión rural en México. Datos a nivel de predio desagregados por grupos de beneficiarios y no beneficiarios, fueron utilizados para evaluar los resultados con base en una variable explicativa de ingreso. Se utilizó una base de datos con una población estadística de 1,083 productores, de los cuales, 58.5% fueron beneficiarios y el resto no beneficiarios. Se ajustaron dos modelos de regresión para comparar resultados. El modelo de regresión lineal múltiple con base en mínimos cuadrados ordinarios, se ajustó en un primer momento y posteriormente, otro modelo no lineal tipo generalizado aditivo con variable dependiente tipo Pareto, adicionalmente, se utilizó un modelo de árboles de regresión aditivos bayesianos, para comprobar el efecto de la política sobre el ingreso de los beneficiarios. Los resultados exhiben que el modelo generalizado aditivo con una distribución Pareto y una función liga de identidad, fue el mejor modelo según el criterio de información de Akaike. En los modelos ajustados, se demostró que ser beneficiario de la política de extensión rural, tiene un efecto positivo sobre el ingreso de los productores. Esto implica que la política evaluada, mejoró el ingreso entre sus beneficiarios.

Abstract: Germination is influenced by several factors, among them pH. Two experiments were conducted to determine the effect of imbibition-water pH on the water absorption curve of chincuya seeds and germination. The results were contrasted to the known effect of gibberellic acid imbibition. In the first year of fruit collection and evaluation, imbibition curves were constructed per treatment. The seeds of this evaluation were divided into two lots: the first at the initial moisture content (39.9 %) and the second at the moisture content of 34.1 % after three days of drying in the laboratory. The seeds were imbibed for 84 h in distilled water at three pH levels (5, 7, and 9) and kept in a water bath at 30 °C. In the second year of collection and evaluation, the pH treatments were repeated, and an imbibition treatment with gibberellic acid at 350 mg L-1 (pH 3.9) was added. A control treatment contained distilled water at pH 6.1. For both years, treated seeds were incubated on paper towels and placed under controlled conditions at a 12-hour photoperiod and alternating day and night temperatures (30 °C:25 °C). The three imbibition curves showed similar behavior and no statistical significance. Seeds with a higher moisture content did not gain weight after imbibition. The imbibition curves increased constantly in the seeds at 34.1 % moisture, and weight gain reached almost 46 % with the pH 9 treatment. However, there were no statistical differences among treatments. The highest rate of water absorption occurred in the first six hours in the open-air, dehydrated seeds, and after 72 hours, the weight of the seeds did not increase. Average daily germination kinetics indicated a slow and poor germination process. Gibberellic acid significantly promoted germination, causing 43 % germination. The absolute control reached 5.7 %, while the rest of the treatments did not promote germination.

DIRECT-type optimisation algorithms recursively explore the domain of an objective function by means of a hierarchical partition. In this context, a regression tree can be estimated with the exploration data and be used to quickly reach the optimum. This regression tree allows to apply Bayesian optimisation techniques instead of the poorly adaptive rules applied within the original DIRECT algorithm. Although based on a probabilistic framework, this approach can perform a deterministic search, a remarkable attribute of DIRECT-type algorithms. This method based on a machine learning algorithm and Bayesian inference is compared with several R libraries for optimisation, including the original DIRECT algorithm and three representative evolutionary algorithms. For a collection of well-known benchmark functions, the proposal is statistically more reliable and robust than DIRECT with respect of dimensionality, but not enough to beat the evolutionary alternatives.

En el sur de Veracruz, México, una región conocida por su clima tropical y su vasta biodiversidad, los ganaderos enfrentan desafíos significativos que amenazan la viabilidad de sus operaciones.

Barley in Mexico is an important crop for the brewing industry and animal feed. The physical and physiological quality and vigor of a batch of seed cv. Brennus was evaluated. The seed was divided by size (small and large) with a 2.5 mm sieve and subjected to different conditioning (aging and non-aging). The study variables were seed purity (SP), thousand seed weight (P1000S), volumetric weight (PV), moisture content (H), germination percentage, emergence speed, plumule length, dry matter in the plumule and seedling vigor index. The analysis of variance was performed under a completely randomized experimental design with factorial arrangement and four replications. Means were compared using Tukey's test (P < 0.05). The lot presented 98% SP, 1.8% inert material and 0.2% other seeds, P1000S was 42 g, PV 68 kg hL(-1) and H was 7%. There were statistical differences (P < 0.05) between seed size, seed conditioning and interaction of both factors for most variables. Small and large unaged seeds showed similarity in germination, emergence speed, plumule length and seedling vigor index. The aging treatment had a negative effect on these variables regardless of size; however, the most extensive damage was seen on the large seeds. The seed lot has poor physical and physiological quality and vigor.

Objective: To evaluate the growth of Chetumal grass (Urochloa humidicola CIAT 679), in order to determine the optimal moment for the first harvest. Design/Methodology/Approach: A completely randomized experimental block design, with measurements repeated over time, and three repetitions was used. Morphological composition (MC), growth rate (GR), plant height (PH), intercepted radiation (IR), leaf:stem ratio (L:S), leaf:no-leaf ratio (L:NL), and aerial biomass (AB) —as well as leaf biomass (LB), stem biomass (SB), dead material (DM), net growth (NG), and total biomass (TB)— were evaluated every fifteen days, except for the two first samplings, which were carried out on a monthly basis. Data were analyzed using the GLM procedure of the SAS software and Tukey’s mean comparison test (α£0.05). Results: The morphological composition (MC) of the Chetumal grass was statistically different (p<0.05), during the different growth ages. The maximum accumulation of total biomass (TB) (13,324 kg DM ha-1), leaf biomass (LB) (2,569 kg DM ha-1), and growth rate (GR) (99 kg DM ha-1 d-1) was reached at 135 DAS. On that day, the prairie reached a 68 cm plant height (PH) and 100% intercepted radiation (IR). The L:S ratio decreased from 1.62 to 0.31, while L:NL ratio changed from 1.62 to 0.22. Study Limitations/Implications: The Brachiaria humidicola cv. Chetumal grass reached its highest potential during the rainy season. Findings/Conclusions: The first cut of the Urochloa humidicola cv. Chetumal grass can be carried out at 135 DAS, when the highest accumulation of total biomass (TB), leaf biomass (LB), and growth rate (GR) is recorded.

Despite ample knowledge of the effect of warm-dry storage on breaking dormancy in chincuya (Annona purpurea Moc. & Sessé ex Dunal) seeds, this paper investigates an important new aspect of this process—the applicability of seed treatment with gibberellic acid and its influence on seed viability and fatty acid profile. Chincuya is an underutilized, tropical wild species native to Mexico, with potential as a biopesticide. The impact of warm-dry storage and gibberellic acid treatment on seed viability and germination was determined to improve that knowledge further. Also, the content and kinetics of fatty acids in chincuya seeds were profiled during warm-dry storage. Seed treatments included storage time (0, 3, 6, 9, and 12 months), seed imbibition for 72 h in gibberellic acid at 350 mg L−1, and distilled water imbibition for 72 h for the control treatment. Seed viability was determined using the TTZ classic test. Imbibed seeds were germinated on paper towels and incubated at 30 °C during the day and 25 °C at night in a 12:12 h dark/light photoperiod. The lipid profile was obtained by gas chromatography. During the storage treatment, seeds stayed in darkness at 25 ± 3 °C. Results showed that high viability remained up to month 9 in storage when it significantly decreased. Freshly harvested seeds germinated at a statistically significantly lower rate (26.1%) than six-month-old seeds (65.6%). The profile of fatty acids breaks down as palmitic acid (33.41%), stearic acid (7.72%), and arachidic acid (1.30%), for a total of 42.44% of saturated fatty acids. The detected unsaturated fatty acids (52.15%) were palmitoleic acid (1.52%), oleic acid (43.37%), and linoleic acid (7.24%). No significant changes were detected in fatty acid content; however, the highest fatty acid content (92.84%) occurred with the highest germination rate. Regression analysis showed significant content changes: palmitoleic and palmitic acids increased while oleic acid decreased during dry storage. Arachidic acid showed a slight downward trend. Also, fatty acid content significantly differed between intact seeds (unstored and unincubated) and latent seeds (unstored, incubated, and ungerminated). The total fatty acids content for latent seeds was significantly lower. These results show that Annona purpurea seeds present morphophysiological dormancy. Also, we document the highest germination rate reported (65.6%) and report the presence of arachidic and palmitoleic acids in chincuya seeds.

La contaminación por ozono (O3) troposférico en concentra- ciones elevadas afecta la salud de los árboles. En este estudio se analizaron las concentraciones de O3 y su efecto en la vitalidad de árboles en la zona metropolitana de la ciudad de Guadalajara. Se utilizaron datos de la red de monitoreo de la calidad del aire de Jalisco y registros de la fluorescencia de clorofila de Fraxinus uhdei, Eucalyptus camaldulensis, y Casuarina equiseti- folia. Se ajustó el modelo de valores extremos generalizado para estimar la distribución del O3 e identificar las zonas de mayor concentración.Se realizó un análisis de varianza para determinar diferencias en la condición de vitalidad causadas por la concentración de O3. Las regiones con mayor concentración de O3 se localizaron en Zapopan, Tlaquepaque, y en el noreste de Guadalajara. No se observó efecto significativo de las zonas con mayores concentraciones de O3 sobre la vitalidad del arbolado.

Las pruebas de recuperación de gases son necesarias cuando se emplea la técnica de cámara de respiración para medir los gases de efecto invernadero exhalados por animales domésticos. Se obtuvo un conjunto de datos de 98 mediciones individuales de producción de metano y dióxidos de carbono de ganado alojado en dos cámaras de respiración para evaluar la recolección y repetibilidad de las mediciones realizadas. Se realizó un análisis de varianza para evaluar si existían diferencias estadísticamente significativas entre cámaras y entre animales. Los resultados mostraron las ocurrencias de variaciones en la produccion de metano entre las camaras.Estas variaciones pueden deberse muy probablemente a la fuga de aire de las cámaras oa las incertidumbres en los conductos de muestra de aire y las mediciones de flujo.

Lipoic acid (LA) reduces oxidative stress and stimulates the immune system. However, data on its use in ruminants is limited. The objective of this study was to determine the effects of LA supplementation on free radical production, rumen variables, and feed digestibility in sheep fed high-grain diets. Nine rumen-cannulated Suffolk sheep were randomly assigned to three treatments: control (LA0 ), no LA inclusion; supplementation of 10 (LA10) mg LA kg-1 body weight (BW); and supplementation of 20 (LA20) mg LA kg-1 BW. In situ (ISDMD) and in vitro (IVDMD) degradation of dry matter and ruminal variables were evaluated. Total bacteria (TB), cellulolytic bacteria (CB), and protozoa (P) were also determined. Thiobarbituric acid reactive substances (TBARS) were evaluated in blood samples at the beginning and end of each experimental period. The ruminal variables and IVADDM were analyzed using a PROC GLM model with a repeated 3 × 3 latin square design, while means were compared using pairwise Tukey tests. LA supplementation did not affect (p 0.05) the ruminal variables under study. LA modified (p 0.05) ISDMD at 4 h in LA10, while no differences were found in terms of IVDMD among the treatments. The LA dose of 10 mg kg-1 BW increased CB (p 0.05) and decreased TB (p 0.05). TBARS differed (p 0.01) among the treatments and evaluation periods and were higher (p 0.05) 15 d after administration. In conclusion, LA supplementation in sheep had an antioxidant effect, reducing oxidative stress 15 d after administration, with slight differences in the ruminal variables evaluated.

En México, más de 75% de las especies de cactáceas están sometidas a presión antropogénica y destrucción de su hábitat, como es el caso de Ferocactus pilosus, por lo que es importante aumentar el conocimiento para su recuperación in situ. El objetivo del estudio fue determinar la manera en que el ambiente semiárido del Altiplano de Tamaulipas tiende a limitar la distribución de cinco poblaciones de F. pilosus y promueve cambios morfológicos que operan en frutos y semillas. El dendrograma definió la similitud entre poblaciones II, III y IV de la biznaga, debido a diferencias en pedregosidad y ligera condición de humedad por el tipo de clima y la elevación. El análisis Manova y Tukey demostraron la existencia de diferencias significativas en número de semillas (NS) y peso de semillas (PS) de biznaga. El NS fue estadísticamente igual entre las poblaciones II (674 ±191), III (657 ±221) y IV (643 ±246), mientras que en las mismas poblaciones PS fue 0.92 ±0.27, 0.9 ±0.3 y 0.88 ±0.34 mg, respectivamente. Las poblaciones II, III y IV de la biznaga cabuchera, aprovecharon mejor las condiciones ambientales del Altiplano de Tamaulipas prevalecientes en 2013 y 2014, lo que provocó una variación importante de NS y PS en las mismas poblaciones de F. pilosus y el rechazo parcial de la hipótesis.

The study analyzed the dynamics of grazing in sheep production associated with agricultural crops based on the social, productive, market, income, and environmental dimensions in the temperate region of Puebla and Tlaxcala, Mexico. The use of grazing, topography, climate, crops and type of vegetation in the production systems and data on the family, means of production, market and income were recorded with interviews applied to 256 sheep producers. Data were analyzed with descriptive statistics and response surface linear regression models and multilevel models, with the SAS statistical package. Five crop and sheep associations were defined as results. The response surface linear regression models, fitted for grazing percentage, had differences in the slopes estimated (P<0.05) for producer experience, schooling, days of work spent on sheep, value of facilities and flock size. The multilevel analysis showed that 19 % of the variance in grazing time (hours) was explained by the variables of crop and sheep associations (level 2) and the rest by production units (level 1). Multilevel models associated grazing time with income (P<0.01), percentage of lamb sales (P<0.01), schooling (P<0.05), days of work spent on sheep (P<0.05), flock size P<0.05) and grazing percentage (P<0.001). The study allowed the classification of agroecosystems and the identification of the most appropriate profile of producer for sheep production in the socioecological and economic context in the temperate region of Puebla and Tlaxcala, Mexico.

- The objective of this work was to determine the nutritional content and the degradability of the dry matter and protein of fruits of Chloroleucon mangense and Acacia cochliacantha and of a 1:1 mixture of both, offered as supplements to Rambouillet sheep. In situ ruminal degradation was evaluated in three adult rams, fitted with a rumen cannula, with different incubation times of 0, 6, 12, 24, 48, and 72 hours. Protein intestinal degradability was quantified with a three-step procedure: in situ ruminal incubation, in vitro enzymatic digestion, and abomasal-intestinal digestion. The fruits of C. mangense and A. cochliacantha contain 21 and 12% crude protein, 47 and 56% neutral detergent fiber, 31 and 43% acid detergent fiber, and 0.9 and 6.0% condensed tannins, respectively. The fruits of C. mangense showed a higher nutritional value and a higher dry matter and crude protein degradability (p<0.05) than those of A. cochliacantha and the 1:1 mixture. The amount of protein that reaches the small intestine is higher for the 1:1, which is an indicative that its tannin concentration is enough to increase the bypass protein that can be absorbed in the small intestine.

Ancho (width) chile peppers have economic, social, culinary and cultural importance in Mexico and worldwide. This chile type considers divergent subtypes that altogether have not been analysed and therefore their morphological diversity has not been systematically described. The objectives were to describe the morphological diversity of ancho pepper landraces from Mexico, to identify groups of similarity and to define the traits with the higher contribution to the total variation. Eighty-six landraces of ancho chile peppers (red, ‘mulatos’, ‘miahuatecos’, ‘cristalinos’ and ‘huacle’), collected in six states of Mexico, and two commercial controls were evaluated in two localities, in a simple randomized complete block experimental design. We recorded 76 morphological traits. Statistical analysis included a combined ANOVA, Pearson's correlation coefficient, discriminant analysis, principal components and clusters. The morphological diversity in ancho chile peppers was mainly made up of fruit width, fruit wall thickness, stem diameter, corolla length, seed weight per fruit, plant height, stem length and pubescence. We defined four groups, which made it possible to differentiate ancho chile peppers of Puebla and the huacle chile pepper of Oaxaca from populations collected in the north and ‘Bajío’ (midland) parts of Mexico. Ancho chile peppers of Mexico showed wide morphological differences according to the type of chile pepper and seed collection regions. The traits that contributed the greatest morphological diversity were fruit width, fruit wall thickness, stem diameter, corolla length, seed weight per fruit, plant height, stem length and pubescence.

Abstract In Mexico, Annona purpurea Moc. &Sessé ex Dunal, chincuya is found in mountains and family gardens. It is used as food (fruits), traditional medicine (leaves, stems, roots, seeds, bark), wood in construction, papermaking, carpentry, rope making, and as fuel. There is not enough information on the seed, nor on germination management, which is scarce, prolonged and erratic. Considering that the morphophysiological dormancy is the probable cause, it was necessary, within a broader project, to start with the characterization of the seed and determine the effect of dry warm storage (DWS) on it. The perimeter and length of the embryos increased due to the increase in length of the cotyledons and the hypocotil root axis, while the middle hypocotyl area decreased, forming an acinturated embryo. These data indicate that the embryos of chincuya are underdeveloped since they grew and modified their shape, due to the effect of DWS, until the 6th month. This development of the embryo within the seed during dry warm storage confirms the presence of morphological dormancy. This is the first report of embryo growth and characterization of chincuya seeds.