Mexico has dominated the international mango trade having high yields and excellent fruit quality. The use of soil, plant and environmental sensors can monitor plant hydric status and optimize water application. Linear resistance dendrometers were developed and installed in a high-density 8-year old commercial mango orchard during two seasons; 10 in 2019 and 40 in 2020. Stem diameter fluctuations were acquired every 10 minutes to obtain maximum diameter (MXD), minimum diameter (MND), morning slope (MS) and afternoon slope (AS). Mango stem response during flowering, fruit-fall and fruit-growth was analyzed after applying daily irrigation (DI) or reduced deficit irrigation (RDI). Yield was similar for both treatments, but water use efficiency was higher with deficit irrigation. A new variable known as negative integral (NI) was obtained from the dendrometer signature after adding all the values between 8:00 and 18:00. NI provided a stem shrinkage magnitude, peaks attributed to transpiration and slopes showing flow transport to and from the trunk. NI presented a high correlation of 0.85 against T7 during the flowering stage for RDI-1. If NI crossed zero, a severe stress was present; a high AS present in the evening, indicates nutrient solution provided to fruits. Fruit yield depends on panicle number and fruit-drop during the first production stages, being RDI-1 more efficient in retaining fruits.
Soursop fruit (Anonna muricata L.) can be marketed fresh or processed due to its excellent sensory characteristics and pulp yields; it is, however, highly perishable and suffers from chilling injury (CI) when stored below 15 °C. In this study, symptoms of CI were evaluated in soursops ripened at 25 °C after a period of storage at 9 or 14 °C for 4 or 8 d (control fruit was stored at 25 ± 2 °C and 60 % RH for 8 d). While soursops stored at 14 °C behaved similarly to controls in all variables measured, color and firmness did not develop normally in those refrigerated at 9 °C, and the activity of polyphenol oxidase (PPO, an enzyme involved in the browning of damaged tissues) declined; however, the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD, another enzyme involved in tissue browning) all increased. In addition, soursops stored for 8 d at 9 °C suffered from substantial decreases in respiration, ethylene production, electrolyte leakage (EL), and the content of flavonoids, whereas total phenolics rose considerably. CI was therefore induced at 9 °C, and several of the aforementioned physical and chemical alterations are good indicators of this physiopathy in fruit of A. muricata L.
The genus Stenocereus includes species native to the American continent that grow from the southern of United States to Central America. Stenocereus spp. is a columnar cactus that produce ovoid-globose fruits of showy colors and with deciduous thorns. The objective of the work was to review the state of the genus Stenocereus in terms of the origin and distribution of species, the edaphoclimatic characteristics, propagation, cultivation, harvest, morphological characteristics of fruits, their post-harvest behavior, phytochemical composition, and uses. The species with the greatest economic importance due to the value of their fruits are S. queretaroensis, S. pruinosus, S. stellatus, S. griseus, and S. thurberi. Plants of the Stenocereus genus can grow under unfavorable conditions in arid and semi-arid zones, due to their low water and nutrient requirements. The fruit production occurs between April and September, depending on the species. Fruits are mainly consumed fresh, but postharvest life is short, which has motivated the transformation into various products. The high content of betalains and phenolic compounds in fruits has fostered a growing interest in conducting research related to the identification of these compounds and their bioactivity. The productivity of arid and semi-arid regions can be improved with the cultivation of Stenocereus species.
The objective was to determine the hematological parameters associated with physiological stages, type of lambing, age, and susceptibility in ewes infected with gastrointestinal nematodes (GIN). Forty-six Pelibuey ewes of 1.5–4 years of age and naturally infected with GIN were sampled during pregnancy and lactation. Fecal nematode egg counts (FECs) were determined and blood samples obtained to determine the hematocrit (HCT), peripheral eosinophil count (PEC), total plasma protein (TPP), and immunoglobulin A level (IgA) in plasma. Hematological variables were measured in a MEDONIC analyzer. The variables were analyzed using mixed models with the SAS software. The FEC showed higher values (P < 0.01) in early lactation (1,053 ± 2,064 eggs per gram of feces, EPG) compared with early and middle pregnancy (50 ± 199 and 171 ± 302 EPG). At middle pregnancy, most erythrogram components showed high values (HCT 33.8 ± 4.5%; red blood cell count (RBC) 9.2 ± 1.2 × 10⁹/mL; mean cell volume (MCV) 36.9 ± 5.5 fL; hemoglobin (HGB) 11.6 ± 1.1 g/dL), whereas at late pregnancy and during lactation, the values decreased. The lowest values were recorded in late lactation (HCT 25.7 ± 5.0%; RBC 8.2 ± 1.9 × 10⁹/mL; MCV 31.6 ± 7.9 fL; HGB 10.0 ± 1.7 g/dL). White blood cell counts gradually decreased during pregnancy and lactation, with the lowest values in late lactation (10.5 ± 2.8 cells 10⁶/mL). In the immune response, the PEC (0.91 ± 0.39 cells 10⁶/mL) and IgA (14.4 ± 14.9%) increased in late lactation. It was concluded that is necessary to consider the physiological state and age, litter size, and natural resistance of the ewes to conduct control activities against GIN.
Tomatillo (Physalis ixocarpa Brot. ex Horm.) is widely grown in Mexico with non-certified seed.Little research has been done on seed drying and physiology. Seed drying is a fundamental process in production technology, and the temperature used can affect its quality. This study aimed to evaluate the effect of different drying temperatures on the physical and physiological quality of seeds of four varieties (Tecozautla 04, Diamante, Gema and Manzano Tepetlixpa) in three storage periods. Seeds of each variety were dried in an oven until reaching constant weight at different temperatures: ambient, 30, 35, 40, 45, 50, 55 and 60 °C; subsequently, they were stored under ambient laboratory conditions for 0, 2 and 4 months. The experimental unit was 5 g of seeds. The study was carried out under a completely randomized experimental design with four replications. Physiological quality was evaluated with standard germination tests, and with the vigor test the germination speed index, total seedling length and seedling dry weight were determined. Seed quality was affected by temperature. When drying from 30 to 35 °C, the seeds expressed their maximum physiological quality, and above 45 °C their quality decreased. Tecozautla 04 had the greatest vigor, whereas Diamante had the least vigor and was the most sensitive to damage during the drying process. After two months of storage, the seeds showed the best physiological quality.
The coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville), is one of the main coffee pests (Coffea spp.) in the Neotropical region. This moth species develops exclusively on leaves of Coffea plants. In this study, we investigated the oviposition preference and performance of L. coffeella in environmentally stressed Coffea arabica L. plants. These plants were exposed to three independent treatments: (a) shade levels (0%, 50%, and 100%), (b) water availability (constant and intermittent irrigation), and (c) the application of phytohormones (salicylic acid, SA; or methyl jasmonate, MeJA). Groups of leaves from these treatments were exposed to individual L. coffeella-mated females, and the number of eggs laid per leaf and the performance in terms of the duration of the immature stages and survival of L. coffeella was recorded. Our results showed that oviposition preference was indistinct among the evaluated treatments. However, leaf miner larvae developed faster under 50% shade level, whereas survival was lower in plants under 100% shade level. Individuals reared on plants under 100% shade level showed slower larval development and smaller adult size. Constant plant irrigation decreased the L. coffeella survival. The application of MeJA delayed larval development, while the application of SA increased adult size. Our results suggest that plant environmental stress should be considered when studying the performance of specialist insect herbivores.
In Mexico, the genetic evaluations in Zebu breeds began in 2011 and there are no studies about the genetic progress achieved. Thus, this research aimed to quantify and analyse the genetic progress for growth traits in the Mexican Zebu beef cattle populations Nellore, Sardo Negro, Gyr, Indubrasil, and Guzerat. The genetic trends were obtained through weighted regression (by the number of animals) of estimated breeding values for direct birth weight, direct and maternal weaning weight, yearling weight, and weight at 540 days of age, on the year of birth. Genetic trends were also estimated by the four selection paths, groups of herds, and weighted averages of the sires' breeding values. The results showed genetic gain as expected of genetic improvement. Nellore presented the highest positive gains for all the traits, and Gyr had the smallest gains among the breeds. Guzerat showed contrary trends for weights until weaning, and had more favourable trends for weights after weaning than the other breeds. The genetic gains obtained for the growth traits reflected the strong influence of the selection made via the maternal paths. The results between weighted and unweighted average breeding values indicate no effective strategy for disseminating genetic material with high breeding values. The genetic gains obtained in the whole populations were due to the main groups of herds. Thus, to achieve further genetic progress, it is necessary to design a cooperative breeding program with a strategy for disseminating that genetic material. HIGHLIGHTS The evaluated populations are developed in the context of tropical livestock, with specific selection criteria and objectives. Genetic trends assess the direction and magnitude of genetic change. The results in the genetic trends show the consequences of the genetic improvement schemes carried out by the breeders. For breeders, it is important to evaluate and monitor genetic improvement schemes, and where appropriate, adjust, or redefine selection criteria and objectives.
Tomato (Solanum lycopersicum L.) is a vegetable with worldwide importance. Its wild or close related species are reservoirs of genes with potential use for the generation of varieties tolerant or resistant to specific biotic and abiotic factors. The objective was to determine the geographic distribution, ecological descriptors, and patterns of diversity and adaptation of 1296 accessions of native tomato from Mexico. An environmental information system was created with 21 climatic variables with a 1 km2 spatial resolution. Using multivariate techniques (Principal Component Analysis, PCA; Cluster Analysis, CA) and Geographic Information Systems (GIS), the most relevant variables for accession distribution were identified, as well as the groups formed according to the environmental similarity among these. PCA determined that with the first three PCs (Principal Components), it is possible to explain 84.1% of the total variation. The most relevant information corresponded to seasonal variables of temperature and precipitation. CA revealed five statistically significant clusters. Ecological descriptors were determined and described by classifying accessions in Physiographic Provinces. Temperate climates were the most frequent among tomato accessions. Finally, the potential distribution was determined with the Maxent model with 10 replicates by cross-validation, identifying areas with a high probability of tomato presence. These results constitute a reliable source of useful information for planning accession sites collection and identifying accessions that are vulnerable or susceptible to conservation programs.
There is promising evidence that public food procurement from family farming (PFPF) can serve as a powerful policy instrument in transitions towards more sustainable food systems. Despite the evidence around PFPF, there is lack of systemic and actor-oriented approaches analysing the relational and interactional dynamics among the multiple and diverse sets of actors in PFPF programs. In this paper, we address this gap by presenting an integrative framework that brings together food systems research, innovation studies and social network analysis, to assess the role of actor networks in PFPF. To illustrate the usefulness of the framework, we present the case of public procurement from family farming in Uruguay. We show how the framework has potential to: highlight the composition and diversity of networks of actors in PFPF; unravel individual and network barriers faced by actors in food systems; and, identify how interactions and (intermediary and brokerage) roles of network actors stimulate innovation or block the changes that are needed for PFPF to catalyse the transition towards sustainable food systems.
Phosphite [H2PO3⁻ or HPO3² (Phi)], an analog of phosphate [H2PO4⁻ or HPO4⁻² (Pi)], is gaining relevance as an inorganic biostimulant in agriculture, enhancing the growth, production, and productivity of various crop plants, while promoting better performance in species established in challenging environments. In nature, plants do not have the molecular machinery to metabolize Phi, and thus Phi cannot be used as a conventional source of P for plant nutrition approaches. As a plant biostimulant, it is effective especially when there is sufficient Pi in the growth medium. Furthermore, doses and rates of application adequately scheduled demands of crop plants are crucial factors to ensure efficient biostimulant effects. Ultimately, the final response of plants will depend on a series of interacting factors such as the genotype, the environment, the agricultural practices, and the sources of Phi utilized. Herein, we outline the most recent and salient studies on the impact of Phi as a biostimulant in agriculture and discuss the perspectives of its use.
Methionine is an essential amino acid that contributes to protein formation, fetal development, and milk synthesis. Thus, we hypothesized that a supplementation with Optimethione® during the last third of gestation in female goats will increase the maternal body live weight, the milk yield and milk composition and the offspring weight and body mass index at birth and postnatal performance. We fed (n = 30) or not (n = 30) herbal methionine Optimethione® to pregnant mul-tiparous Alpine goats from gestational day 100 until delivery. We evaluated the productive var-iables from the dams and offspring. Maternal intake of herbal methionine Optimethione® dur-ing pregnancy did not increase the live weight or increase the milk yield and composition. However, the tested offspring variables were influenced by the maternal intake of herbal me-thionine Optimethione® during gestation by improving the birth weight, body mass index, and postnatal growth pattern. An increase in birth weight would be expected to increase neonatal survival up to weaning. Moreover, a relative fatness is required for reproductive success; thus, offspring that are born heavier and bigger can display a faster postnatal growth and accelerate the onset of puberty and increase reproductive success.
Forests experience disturbances, such as fire, that affect their functioning, structure, and species composition. The objective of this work was to compare the species diversity and forest structure at sites affected by different degrees of fire severity, 9 years after a forest fire event. We used the differenced Normalized Burn Ratio (dNBR) index. Vegetation was sampled in three severity levels: high (HS), moderate (MS), and low (LS) and included the unburned (U) level as control. In addition, we calculated the species richness (S), the Shannon index (H), and the Evenness Index (E). The structural diversity of tree diameters and heights was measured applying the indices H, E, and the coefficient of variation (CV). The differences in the indices calculated across the fire severity levels were determined through analyses of variance (ANOVA) and Tukey’s multiple comparison tests. The results showed no significant differences (p � 0.05) in the species diversity indices between fire severity levels. The structural diversity of tree diameters and heights was lower at the HS level. dNBR was negatively related to structural diversity; thus, it is concluded that HS tends to reduce structural variability in terms of diameter, height, and age. These results provide a baseline to understand how fire can modify forest structure and species diversity.
Assessing adaptive capacity to climate change is a complex task since it is a multidimen-sional component. There has been considerable discrepancy between the dimensions or elements that compose it. This study aimed to analyze the relevant dimensions and indicators that allow estimation of the adaptive capacity to climate change and to propose a set of indicators that will enable their application to assessment at the level of agricultural producers. A systematic review of scientific literature on evaluating or measuring adaptive capacity to climate change was carried out. Subsequently , the indicators were analyzed and selected through a coincidence analysis and were calibrated through a multicriteria evaluation with relevant actors in the southern Mexico, state of Chia-pas. In total, 329 indicators were identified and analyzed. As a result, 19 indicators were selected and then grouped into six dimensions: economic resources, human resources, infrastructure for production and marketing, institutionality, social capital, and natural resources. These represent the 14 specific dimensions with the greatest potential to contribute to the estimation of adaptive capacity to climate change. The dimensions and indicators can be applied to assess the adaptive capacity of farmers in Mexico at a national or regional scale and specifically by producer types.
Introducción. El cambio climático puede alterar las reservas de carbono (C) almacenado en los sistemas agroforestales con café. Objetivo. Simular las reservas de C en la biomasa aérea (ABOC) y suelo (COS) a una proyección de cincuenta años bajo la línea base y con escenarios de cambio climático en sistemas agroforestales con café, mediante el modelo CO2Fix. Materiales y métodos. En el año 2020, se estableció la línea base de C total (ABOC + COS) en veinticinco parcelas de café orgánico de la Sociedad Catuaí Amarillo S. de S.S, Chocamán, Veracruz, México. Las parcelas se clasificaron en tres diseños agroforestales: D1 (árboles de sombra-café en laderas), D2 (árboles de sombra-café-plátano en laderas) y D3 (árboles de sombra-café-plátano en el valle). Se utilizó el modelo CO2Fix para simular las reservas de C total a una proyección de cincuenta años bajo la línea base y con escenarios de cambio climático en los tres diseños agroforestales con café. Resultados. El C total en la línea base fue de 124,59, 107,43 y 102,320 t ha-1, para D1, D2 y D3, respectivamente. Se presentaron disminuciones entre 0,77 y 8,75 t ha-1 en las reservas de C total bajo escenarios de cambio climático en los tres diseños agroforestales evaluados. No hubo diferencias estadísticamente significativas entre los diseños agroforestales en la línea base y bajo escenarios de cambio climático. Aunque se constataron variaciones, las reservas de C total se mantuvieron a lo largo del tiempo. La cohorte de árboles fue la principal fuente de almacenaje del C total. Conclusión. Fue posible simular, en una proyección de cincuenta años, las reservas de carbono en la biomasa aérea y suelo en la línea base, bajo los diferentes escenarios de cambio climático, mediante el uso del modelo CO2Fix, en sistemas agroforestales con café de la Sociedad Catuaí Amarillo S. de S.S.
En este artículo se analiza de qué manera las políticas públicas productivas repercuten en la transformación de hábitos y valores de la población campesina en los últimos 13 años (2008-2021). El estudio se encuentra basado en datos cualitativos de un estudio de caso compuesto por familias tseltales de las comunidades de Sibactel y El Pach, en el municipio de Tenejapa y la comunidad de Chilolja en San Juan Cancuc, Chiapas. Los resultados indican que las políticas públicas dependen de la interdependencia entre diferentes actores, mismos que enfrentan una serie de obstáculos como las prácticas de corrupción, conflictos de intereses, individualismo, oportunismo político y abuso de poder. Situación que ha dejado a su paso un incremento de asimetrías en la práctica de valores socio-culturales, en la economía campesina y las practica de habilidades productivas. Una vía para hacer frente a esta situación es crear un programa de política pública diferenciada para agricultores familiares con enfoque agroecológico. En conclusión, los programas de política pública y las estrategias de reproducción social campesina son dos categorías determinantes en la continuidad de la reproducción campesina, además de que motivan las diferentes formas de pensar, de actuar y de organizarse de los campesinos.
The potential effect of intravenous administration of glutamate on the ovarian activity and the LH secretion pattern, considering the anestrous yearling goat as an animal model, were assessed. In late April, yearling goats (n = 20) were randomly assigned to either (1) Glutamate supplemented (GLUT; n = 10, Live Weight (LW) = 29.6 ± 1.02 kg, Body Condition (BCS) = 3.4 ± 0.2 units; i.v. supplemented with 7 mg GLUT kg−1 LW) or (2) Non-supplemented (CONT; n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2 units; i.v. saline). The oats were estrus-synchronized; blood sampling (6 h × 15 min) was carried out for LH quantification. Response variables included pulsatility (PULSE), time to first pulse (TTFP), amplitude (AMPL), nadir (NAD), and area under the curve (AUC) of LH. Ovaries were ultra-sonographically scanned to assess ovulation rate (OR), number of antral follicles (AF), and total ovarian activity (TOA = OR + AF). LH-PULSE was quantified with the Munro algorithm; significant treatment x time interactions were evaluated across time. The variables LW and BCS did not differ (p > 0.05) between the experimental groups. Nevertheless, OR (1.77 vs. 0.87 ± 0.20 units), TOA (4.11 vs. 1.87 ± 0.47 units) and LH-PULSE (5.0 vs. 2.2 pulses 6 h-1) favored (p < 0.05) to the GLUT group. Our results reveal that targeted glutamate supplementation, the main central nervous system neurotransmitter, arose as an interesting strategy to enhance the hypothalamic–hypophyseal–ovarian response considering the anestrous-yearling goat as an animal model, with thought-provoking while promising translational applications.
In recent years, Opuntia ficus-indica (L.) Mill. (OF) has emerged as a species that has a growing role in the area of agro-energy for their use as substrate in anaerobic digestion for the production of biogas and methane. In order to improve Biochemical Methane Potential (BMP), the objective of this study was to evaluate the influence of different feedstock ratios of cladodes in co-digestion with cow manure (CM) (OF:CM, 0:100 to 95:5) to determine the best co-digestion condition that improves BMP. Two co-digestion systems had BMP statistically significantly higher than the mono-digestion system, with improvements in the range of 80–92%. No statistical differences were found among the tested co-digestion treatments. These results demonstrate that the co-digestion of and CM biomass enhanced methane production through anaerobic digestion, with important implications for bioenergy production.
Non-timber forest products (NTFPs) are essential for community development, but their enormous demand has posed a serious threat to trees growing in their natural habitat. Copal resin is one of these products, which has a great deal of religious and ceremonial significance in Mexico and around the world. Resin extraction from a tree depends on its morphological and physiological characteristics, as well as its physical and sanitary condition. In this study, a methodology was proposed for determining the yield and health status of Copal trees, and a random forest (RF) model was developed to explain their resin production based on their morphological and condition characteristics. The experiment was conducted in the Agua Escondida watershed in Puebla, Mexico. With the training data, the average accuracy of the model was 99%, with a Kappa index of 98%, which is considered an excellent level of agreement beyond chance, and with the validation data, the average accuracy was 71% and 47%, which is considered a good level of agreement beyond chance. Tree condition was the most important factor affecting resin production in Copal trees, followed by stem diameter (33 and 38 cm), height (2 and 2.5 m), and diameter of secondary branches (from 8 to 15, 22 and 32 cm).
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