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

Biodiesel production was studied through the transesterification of used edible vegetable oil, using a calcium oxide (CaO) catalyst derived from Crassostrea Virginica oyster shells. Which were calcined at 900 ° C for 2 hours and characterized by scanning electron microscopy (SEM-EDX), X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). The efficiency of conversion to methyl esters was evaluated using 2%, 3% and 4% of catalyst and they were analyzed by 1H NMR. The results showing that concentrations greater than 2% of CaO generate biodiesel conversions greater than 90%.

Objective: To quantify the direct and indirect damage caused by Diceroprocta bulgara in the cultivars of Persian lemon, Mexican with and without thorn, Colimex and Lise, in the Oaxaca Coast. Design/methodology/approach: The damage caused by D. bulgara was recorded their nests in each tree. In each plot, 15 trees were randomly selected to evaluate tree height, crown diameter, number of damaged vegetative growth flows, diameter of the first three flows, length of damage and oviposited eggs. In three planting densities of Lise and Colimex, the loss of fruit was estimated due to the indirect effect of the insect (kg ha-1). Results: The incidence of damage was from 79% (Mexican without spines) to 95% (Colimex). A slight correlation between tree size and damage was observed, larger trees showed a higher percentage of affected flows. The flow with the highest frequency of damage was the second (31.99%) and the first with the lowest (17.33%). The lowest number of eggs oviposited was 26 on the flow 1 in the Mexican lemon, and the maximum of 171 in the spineless one. The higher number of eggs was recorded in Persian lemon (371). A significant relationship was determined between the number of eggs with the length of damage and flow diameter (<0.05). The highest number of mummified fruits (15.6) was observed in Colimex (density 312 trees ha-1), estimating that up to 146 kg of fruit could be lost. Findings/conclusions: In the present work, the direct and indirect damage caused by the cicada D. bulgara was quantified for the first time, which represents a loss of fruit in productive trees. Studies on the biology of the insect are suggested for future integrated management plans.

Objective: develop a fast, practical and economical methodology for the determination of plants with HLB symptoms, by exploring the potential use of Sentinel-2 satellite images. Design/methodology/approach: Sentinel-2 images were used to perform a supervised classification to discriminate healthy Persian lime trees and trees with HLB molecularly verified by qPCR, as well as other land uses in the citrus growing area of Huimanguillo, Tabasco. Results: The results showed that in the green (560nm), red (665 nm) and near infrared (705 nm) band regions the spectral response of trees with HLB is higher than that of healthy trees. An area of 26.96 and 12 981 hectares of Persian lime affected and free of HLB was found, respectively, with an accuracy of 0.84 % and a Kappa coefficient of 0.83. Field verification corroborated three plantations in which plants with HLB were previously detected and are currently in production. Limitations on study/implications: The study was carried out in the period of less cloud cover, as this is a limiting factor for the analysis of the image since it can lead to inadequate tracking of the affected area. Findings/conclusions: The results showed that using Sentinel-2 satellite images, it is possible to differentiate Persian lemon plants affected by HLB from healthy plants.

Objective. Identify the use of traditional foods through the quantification of the main regional foods that are consumed and propose a dish of totonac good eating was proposed. Methodology. A semi-structured survey was used in 328 households in the municipality of Filomeno Mata, Veracruz, Mexico. The “Dietary Diversity Score at home” was used in addition to a section to obtain information on the regional foods they consume daily. Results. The families recognized a total of 35 products of plant and animal origin that are produced in the place. On average, each household interviewed included 7 of the foods reported in their daily diet. Limitations. To improve and apply the proposal of the well-eating dish, some important elements must be taken into account such as: age, sex, height, physical activity or physiological state, among other indications Conclusions. Registered foods are connected to the culture of the area and open a guideline for the generation of different strategies for the use of these resources, such as the Totonac plate of well-eating.

Objetive: Evaluate two heights (50 and 70 cm) and pruning frequencies (60 and 135 d) in Moringa oleifera and Leucaena leucocephala in a developing silvopastoral system. Desing/methodology/approach: Four treatments were established, T1: Moringa oleifera with pruning at 50 cm, T2: Moringa oleifera with pruning at 70 cm, T3: Leucaena leucocephala with pruning at 50 cm and T4: Leucaena leucocephala with pruning at 70 cm and pruning frequencies at the 60 and 135 d. The number of sprouts, diameter and length of the largest sprout, and biomass were recorded. The data were analyzed using a mixed model, analysis of variance and Tukey's tests. Results: The number of regrowths in L. leucocephala was higher than M. oleifera. The T2 had the highest behavior at 60 d, for L. leucocephala it was similar between pruning and frequencies. The diameter and length were greater for T2 at both frequencies, at 60 d for T3 and at 135 d for T4. Biomass was higher in M. oleífera than L. leucocephala, pruning at 70 cm was better than at 50 cm. Pruning at 135 days obtained higher biomass than at 60 days. T2 obtained higher biomass at 60 d, T1 and T4 at 135 d. Study limitations/implications: Forage species, frequencies and pruning heights determine the growth potential and amount of biomass available to the animals. Findings/conclusions:Leucaena leucocephala has better agronomic performance in response to pruning without influencing the height and frequency of pruning in a silvopastoral system.

Stevia rebaudiana Bertoni is a crop that meets the current demand for natural sweeteners, this demand requires a sustainable production of the crop, due to the inclusion of its steviol glycosides or active ingredients in the food and pharmaceutical sector. Modern agriculture involves the integrated use of widely proven natural resources such as arbuscular mycorrhizal fungi. These microorganisms perform a symbiotic association with 80% of terrestrial plants and provide multiple benefits. They are able to enhance the productivity of a crop both directly and indirectly through the translocation of mineral nutrients from the soil solution, especially phosphorus. As a sustainable production alternative for S. rebaudiana, they provide an improvement in nutritional status resulting in higher biomass production and glycoside concentration, fundamental parameters for yield. They stimulate plant resistance to biotic and abiotic stress factors and act as soil improvers. It should be noted that the mutualistic fungus-plant association is approximately 400 million years old, yet it is only in recent years that interest in this interaction has been awakened. Although arbuscular mycorrhizal fungi are an exploitable natural resource, the communities are threatened by biotic factors such as interaction with other microorganisms and abiotic factors involving poor agricultural practicesStevia rebaudiana Bertoni is a crop that meets the current demand for natural sweeteners, this demand requires a sustainable production of the crop, due to the inclusion of its steviol glycosides or active ingredients in the food and pharmaceutical sector. Modern agriculture involves the integrated use of widely proven natural resources such as arbuscular mycorrhizal fungi. These microorganisms perform a symbiotic association with 80% of terrestrial plants and provide multiple benefits. They are able to enhance the productivity of a crop both directly and indirectly through the translocation of mineral nutrients from the soil solution, especially phosphorus. As a sustainable production alternative for S. rebaudiana, they provide an improvement in nutritional status resulting in higher biomass production and glycoside concentration, fundamental parameters for yield. They stimulate plant resistance to biotic and abiotic stress factors and act as soil improvers. It should be noted that the mutualistic fungus-plant association is approximately 400 million years old, yet it is only in recent years that interest in this interaction has been awakened. Although arbuscular mycorrhizal fungi are an exploitable natural resource, the communities are threatened by biotic factors such as interaction with other microorganisms and abiotic factors involving poor agricultural practicesStevia rebaudiana Bertoni is a crop that meets the current demand for natural sweeteners, this demand requires a sustainable production of the crop, due to the inclusion of its steviol glycosides or active ingredients in the food and pharmaceutical sector. Modern agriculture involves the integrated use of widely proven natural resources such as arbuscular mycorrhizal fungi. These microorganisms perform a symbiotic association with 80% of terrestrial plants and provide multiple benefits. They are able to enhance the productivity of a crop both directly and indirectly through the translocation of mineral nutrients from the soil solution, especially phosphorus. As a sustainable production alternative for S. rebaudiana, they provide an improvement in nutritional status resulting in higher biomass production and glycoside concentration, fundamental parameters for yield. They stimulate plant resistance to biotic and abiotic stress factors and act as soil improvers. It should be noted that the mutualistic fungus-plant association is approximately 400 million years old, yet it is only in recent years that interest in this interaction has been awakened. Although arbuscular mycorrhizal fungi are an exploitable natural resource, the communities are threatened by biotic factors such as interaction with other microorganisms and abiotic factors involving poor agricultural practices.

Objective: The aim of this study was to test the survival of Macrobrachium tenellum in different confinement conditions with Dormitator latifrons. Design/methodology/approach: Using wild specimens acclimated to captive conditions of both species, three trials of different proportion were performed with treatments consisting in the presence/absence of food and shelters. Prawn/fish proportion for the assays were: 15/15 for T1, 15/3 for T2 and 10/3 for T3. In assays T1 and T2 juvenile prawns and fish were used, while in T3 post-larvae prawns and pre-juvenile fish were used. To test the survival with or without fed, it was schedule a four-day feeding ad libitum period, following by a two-day fed depravation period in all the assays. Results: In assays with juveniles of M. tenellum the survival rate was superior to 80% with or without shelter, when T1 showed 97-100% survival; meanwhile T3 presented a 56.67 % of survival, suggesting it’s necessary to use only juvenile prawns in co-culture systems. The use of shelters and fed deprivation had no significant effects on the survival of prawns. Limitations on study/implications: M. tenellum is an important aquatic resource for the central Mexican Pacific, region in which the D. latifrons is a representative native fish with a developing aquaculture. A polyculture or co-culture system with these species can accelerate the sustainability of both species productions. Findings/conclusions: The results suggest this polyculture system may be feasible, and longer duration culture are recommended.

Objective: To evaluate the germination, survival and growth of native trees of the Sonoran Desert, in a fertile agricultural soil and with irrigation, and protection against herbivory. Design / methodology / approach: The germination, survival, and growth of five tree species (Parkinsonia microphylla, Olneya tesota, Prosopis velutina, Guaiacum coulteri, and Parkinsonia florida) were evaluated, with and without drip irrigation, excluding herbivory, and carried out on agricultural land for six months. Results: It was found that the irrigated species O. tesota, P. velutina, had the highest germination percentage (?2 = 398.941, p <0.0001). Plant survival was above 62% (?2 = 21.196, p <0.0035), with the exception of G. coulteri and P. florida without irrigation, which presented zero survival. The highest height at 6 months was presented by P. florida (p <0.0001), while the lowest heights were the plants without irrigation and G. coulteri with irrigation. Canopy coverage at 6 months was higher for P. velutina, P. florida, and O. tesota (p <0.0001), while plants without irrigation and G. coulteri with irrigation had the lowest coverage. Limitations / implications: It is necessary to continue with agronomic studies, which allow the successful establishment of commercial forest plantations, which contribute to environmental problems. Findings / conclusions: It is feasible to establish by direct sowing, the five species of native plants studied, in agricultural soil and with drip irrigation.

Objective: To evaluate the effect of indole-3-acetic acid and type of rods in the vegetative propagation by cutting of the cuatomate and to describe the phenological stages, to increase production. Design/Methodology/Approach: A completely randomized design was used by means of a 22 factorial arrangement to estimate the effect of two concentrations of indole-3-acetic acid (1000 and 10000 ppm) and type of rods (secondary and tertiary) on the number of leaves and sprout of the plant. For propagation, 30 cm rods from secondary and tertiary branches of the cuatomate were used; with cuts at the ends, transversal and diagonal; parts that generate to the dossal and root, respectively. The data were analyzed by analysis of variance with the general linear models procedure. Results: Highly significant differences (p ? 0.01) were observed between the variables under study. Higher number of leaves and sprout (16.700 and 20.000, respectively) were observed in tertiary rods when inoculated with 1000 ppm of IAA. In the evaluation of the phenological stages, the first bud appeared at 30 days, the first leaf and flowers at 40 and 180 days after inoculation, respectively. Limitations on study/implications: In the transversal section, commercial candelilla wax was applied to prevent possible attacks by pathogens and it was ensured that the rods are completely covered with indole-3-acetic acid. Findings/conclusions: The use of indole-3-acetic acid in the vegetative propagation of the cuatomate would be an alternative to increase its production; promoting a sustainable activity for the Mixtec region of Puebla.

Objective: To evaluate the phytoremediation potential of two varieties of rice (Oriza sativa L.) with new and weathered hydrocarbons.Materials and Methods: The treatments were 150 mg kg-1 (control soil), 30,000; 60,000 and 90,000 mg kg-1 of new oil and 79,457 mg kg-1 of weathered oil 1 and 42,000 mg kg-1 of weathered oil 2, were established in a completely randomized design with a 6x3 factorial, with four replicates each. The variables evaluated were total bacterial populations (CFU colony forming units per gram of dry soil), free-living nitrogen-fixing bacteria (CFU), total fungi (CFU) and total dry biomass (g). Total bacteria and fungi were quantified at the beginning of the experiment at 90 and 145 days.