REVISTA TERRA LATINOAMERICANA 2020-05-27T02:26:56+00:00 Dr. Bernardo Murillo Amador Open Journal Systems <h4><span style="float: right; color: #111111; font-family: 'helvetica neue',helvetica,arial,verdana,sans-serif; font-size: 14.4px; font-style: normal; font-variant: normal; letter-spacing: normal; line-height: 18.72px; text-align: justify; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; background-color: #ffffff;">ISSN Electrónico 2395 - 8030.</span></h4> Table of Contents 38-2 2020-04-17T17:35:20+00:00 Rosa María López Atilano 2020-04-17T13:32:16+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Editorial Committee 38-2 2020-04-21T18:36:27+00:00 Rosa María López Atilano 2020-04-17T04:11:29+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Index 38-2 2020-05-18T02:50:31+00:00 Rosa María Lopéz Atilano 2020-04-17T13:31:51+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Induction of flowering by girdling to advance the ‘Hass’ avocado harvest in Nayarit, Mexico 2020-05-27T02:26:49+00:00 Esperanza Sánchez-Hernández Gelacio Alejo-Santiago Juan Diego García-Paredes Rufo Sánchez-Hernández Circe Aidín Aburto-González Leobarda Guadalupe Ramírez-Guerrero Rosendo Balois-Morales <p>Among the difficulties of the ‘Hass’ avocado production in Nayarit are the low prices derived from seasonality of the harvest in the months ranging from September to November. The objective of our research was to identify the girdling date capable of advancing the flowering and thereby advancing the harvest season. Four girdling dates (treatments) were evaluated in ten replicates under a completely randomized experimental block design, generating the following treatments (T) during 2017: T1 = August 15, T2 = September 15, T3 = October 15, T4 = November 15 and T5 (without girdling). Each ring was 0.5 cm wide and disposed in 50% of the branches. The variables evaluated were the following: concentration of N, P, K, Ca and Mg in vegetative and flowering stages, days at the beginning of flowering, number of flower buds per m3 of canopy, days at the beginning of fruiting, panicle length, panicle thickness, fruit production per tree and dry matter of mesocarp. The analysis of variance showed significant differences for days at the beginning of flowering, days at the beginning of fruiting, panicle length, dry matter in mesocarp and fruit production. There were no differences in nutritional concentration at the phenological stages. We concluded that August 15 was the girdling date that advanced flowering by 52 days compared to T5, and allowed the harvest to be performed in May.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 JOURNAL TERRA LATINOAMERICANA Pollution by nitrates and phosphates from agricultural activity in the low basin of the Mayo river in the state of Sonora, Mexico 2020-05-27T02:26:42+00:00 Isaac Shamir Rojas-Rodríguez Manuel Arturo Coronado-García Segio Ramón Rossetti-López Félix Alfredo Beltrán-Morales <p>The pollution of water bodies within watersheds has gained relevance in the last decade. Agriculture is designated as the main anthropogenic activity that generates this pollution phenomenon. Specialized studies define this type of pollutants as “diffuse pollution” due to the way that they are distributed within the basins. Among the main substances reported from agriculture are nitrates and phosphates, as remnants of fertilization processes. The objective of our study was to characterize the contribution of nitrates and phosphates from agriculture in the Lower Basin of the Mayo River in the State of Sonora, Mexico, with the purpose of comparing the baseline scenarios and the pollution scenario derived from wheat agriculture in the region. In this research we hypothesize that the contribution of nitrates and phosphates from agriculture exceeds what is established in the baseline scenario. By applying the hydrological simulation model Soil and Water Assessment Tool (SWAT), we simulated the contributions of polluting substances within the basin under study for the period of 2000 to 2017. The descriptive study was performed by comparing means where, for all cases, the results of the agricultural simulation exceeded the parameters obtained in the baseline scenario. Significant differences were found for nitrate and nitrogen dioxide. The results show evidence of the fact that the agricultural activity within the hydrological basin under study generates an increase in the contributions of substances exceeding the estimated baseline scenario.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Vermicompost, synthetic auxins, and greenhouse production of gray squash Cucurbita pepo L. 2020-05-27T02:26:45+00:00 Felipe Ayala-Tafoya Guadalupe Alfonso López-Urquídez Juan Martín Parra-Delgado Jesús Enrique Retes-Manjarrez Carlos Alfonso López-Orona Moisés Gilberto Yáñez‑Juárez <p>Vermicomposts increase the availability and assimilation of nutrients and natural growth promoter substances. In addition, vermicomposts contribute to numerous physiological responses in plants, such as increased growth and yield. Our study was developed with the objective of comparing the effect of synthetic auxins and vermicomposts on the growth and yield of gray squash Cucurbita pepo L., cultured under greenhouse conditions. A randomized block design was used with the following five treatments: synthetic auxins -Amcotone®- applied to foliage (AUX); vermicopost -VioHache®- incorporated into the soil at 5 (DBV); 10 (DMV); and 15 Mg ha-1 (DAV); and a control treatment (TES). The results obtained showed that the synthetic auxins and all vermicompost doses promoted plant growth. The highest yields, 40.5 and 37.9 Mg ha-1, were obtained with DBV and DMV, respectively. The medium-sized gray squash (18.9 to 22.8 cm, 3.9 to 4.4 cm, and 101 to 225 g) was the most produced, with 58.6 to 74.5% of the total yield. The yield of medium gray squash obtained with synthetic auxins or vermicomposts increased from 26.9 (DMV) to 61.1% (DBV), compared with TES (17.5 Mg ha-1).</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Quitating capacity of the chitosan over the soluble arsenic in two fluvisols from an arid zone of Mexico 2020-05-27T02:26:51+00:00 Karla Janeth Martínez-Macías Miguel Ángel Segura-Castruita Jorge Arnaldo Orozco-Vidal Guillermo Hernández-Ordaz José Ernesto Frías-Ramírez <p>Chitosan in pearls and acidic pH (Q) has the ability to adsorb arsenic (As) from water. The Q could adsorb the As found in the soil solution. The objective of this research was to evaluate the chelating capacity of Q adjusted to acidic and neutral pH to decrease the concentration of soluble As in two Fluvisols. To carry out the experiment, Q was conditioned at two pH (5 and 7) with the addition of sulfuric acid and Q was left untreated for use as a control. Four treatments were tested (soils without Q, with untreated Q, with Q adjusted to pH 5 and with Q adjusted to pH 7). Each treatment was conducted in quadruplicate, making 16 experimental units for each soil. Each experimental unit consisted of 500 g of soil packed in a plastic bag, to which a phosphate fertilizer (200 mg kg‑1) was added and brought to field capacity, leaving it to stand for 48 h. Upon completion of the resting time, 0.063 g of Q of the corresponding treatment and its respective replicate were added to each bag, leaving them in incubation for 48 h at a temperature of 25 °C. The experimental design used was completely random. To the soils, the soluble As content was determined by an extraction with deionized water and the extracted was measured by the method of atomic absorption spectrophotometry with hydride generation. The data was subjected to an analysis of variance and a test of means (Tukey, P ≤ 0.05). The results showed that the chitosan adjusted with sulfuric acid at pH 5, (QpH5) adsorbed the greatest amount of soluble As (640%). Which represents an alternative for the recovery of soils contaminated with As.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Carbon dynamics in soil aggregates with different types of land uses in Monte Tláloc, State of Mexico 2020-05-27T02:26:38+00:00 Edgar Barrales-Brito Fernando Paz-Pellat Jorge Dionisio Etchevers-Barra Claudia Hidalgo-Moreno Alma Velázquez-Rodríguez <p>Changes in land use influence the carbon dynamics in ecosystems given these modify the soil structure and increase the mineralization rates of organic matter. In this study, we evaluated the effect of soil use, depth and size of aggregates on carbon (C) and soil respiration (CO2) content emitted by the mineralization of C in soils with different land uses (forestry, acahual, grassland and agricultural) in Mount Tláloc. Soil C was higher in forest ecosystems (over 100 g C kg-1 of soil) than in soils with agricultural, acahual and grassland use with 20, 30 and 50 g C kg-1 of soil, respectively. In sites with forest land use, mean weighted diameter values were larger than 1.5 mm and a greater percentage of macroaggregates (&gt;2 mm; &gt;25%) was found, which indicated a better soil structure in the first 30 cm depth with respect to the site with agricultural use, where microaggregates were predominant (&lt; 0.5 mm) with percentages higher than 50%, and a lower amount of C (less than 10 g C kg-1 of soil) was detected, as well as a higher amount of CO2 emitted by respiration (greater than 40 g CO2 kg-1 of soil). The soil structure stability influenced the dynamics of C, given that a better soil structure presented a higher content of C and a decrease of CO2 emissions of the soil.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Chemical and biological soil changes caused by Pteridium aquilinum (L.) Kuhn in areas of influence of the reserve of the biosphere of Calakmul, Campeche 2020-05-27T02:26:56+00:00 Carlos Valdez-Ramírez Samuel Israel Levy-Tacher Noé Samuel León-Martínez Darío Alejandro Navarrete-Gutiérrez Ángel Isauro Ortiz-Ceballos <p>The fern Pteridium aquilinum is one of the most important invasive species in the world. In Mexico, in the influence area of the Calakmul Biosphere Reserve (REBICA) this species invades and dominates agricultural and livestock land, which leads the peasants to look for new sites for their cultivation, to the detriment of the conserved areas. In this research, chemical and biological properties of soil were evaluated in areas invaded with bracken fern forests and in mature vegetation. Thus, 12 plots with three contrasting conditions, with four repetitions per condition were established: young helechal (HJ; 5-10 years old) and old helechal (HV, more than 25 years old) and mature vegetation (VM). Chemical components were evaluated in the soil: pH, organic matter (MO), organic carbon (CO), total nitrogen and available phosphorus Olsen (P), and biological component like: litter accumulation, rhizoms and macrofauna. In chemical components of the soil, significant differences were found in pH (F = 10.719, P ≤ 0.05) and P (F = 14.377, P ≤ 0.05) of HJ and HV in regard to VM. In biological attributes, it was encountered that the dry matter of litter and the dead rhizomes and its depth varied significantly (F = 5.53, P &lt; 0.05; T = 3.04, P &lt; 0.05; T = 2.57, P &lt; 0.05) between HJ and HV, respectively. Nevertheless, abundance of macrofauna was similar to the three conditions (HV, HJ y VM). In accordance with the edaphic variables studied, it was found that the condition HV is not degraded and even presents favorable conditions to carry out restoration/rehabilitation actions.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Potassium:calcium balance, relationship with vapor pressure deficit and photosynthetically active radiation in greenhouse tomato 2020-05-27T02:26:47+00:00 Ramiro Salas-Rivera Luis Alonso Valdez-Aguilar Daniela Alvarado-Camarillo Emilio Rascón-Alvarado Fidel Maximiano Peña-Ramos José Antonio González-Fuentes <p>Greenhouse tomato production requires technical knowledge such as the management of the nutrient solution and its interaction with environmental conditions. Imbalances between nutrients such as potassium (K) and calcium (Ca) can occur in the nutrient solution; Moreover, the flow of sap and nutrients translocation are affected by the vapor pressure deficit (VPD) and photosynthetically active radiation (PAR). The present study was carried out with the objective to determine the optimal balance of K and Ca depending on VPD and PAR prevailing during the development of the fruits of 10 clusters in tomato; the first five clusters were developed during the spring, while the clusters sixth to tenth during the summer. Plants were irrigated with solutions whose K:Ca balance was: 0.54, 0.64, 0.78, and 0.82. The balance did not affect fruit quality in spring, although in summer, balances 0.64 and 0.78 reduced soluble solids. In spring, fruit yield in each of the five clusters was influenced by the K:Ca balance as well as by the VPD; the clusters had a higher fruit production when the K:Ca balance was 0.64 and the VPD was 2.81 KPa. During the summer, the highest yield in fruits was in plants treated with a balance of 0.54 and the VPD was 2.50 or 2.74 KPa. The K:Ca balance during the spring correlated negatively with the VPD, however, in the summer, the correlation was positive. In spring, the K:Ca optimum balance should be 0.78-0.82 when PAR reached a maximum of 102‑142 μmol m-2 s-1, while extreme PAR levels should be accompanied by a reduction in the K:Ca balance.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Native Bacillus spp. strains as sustainable alternative in the yield of corn forage 2020-05-27T02:26:36+00:00 Martha Georgina Rodríguez-Hernández Miguel Ángel Gallegos-Robles Lucio Rodríguez-Sifuentes Manuel Fortis-Hernández J. Guadalupe Luna-Ortega Uriel González-Salas <p>The use of growth-promoting microorganisms has great benefits, which help to reduce the excessive use of fertilizers and pesticides used in agricultural production. The objectives were to isolate, characterize and evaluate in the field strains of the genus Bacillus spp., in the yield of forage corn. The study was conducted in the experimental field of the Faculty of Agriculture and Zootechnics of the Juarez University of the state of Durango in the Lagunera Region, located in northern Mexico, during 2018. Bacillus spp., strains were isolated and identified, from roots of Johnson grass (Sorghum halepense), corn (Zea mays) and sorghum (Sorghum bicolor), preselected according to the ability to fix nitrogen and characterized by sequencing of the 16S rDNA gene. Two strains of Bacillus amyloliquefaciens and three more of Bacillus subtilis were identified. Subsequently evaluated in the field during the spring-summer (S-S) and autumn-winter (A-W) cycles of the year 2018, in two corn hybrids (Galactic and AG 614). Inoculation with the strain Bacillus amyloliquefaciens favored a good result for the fresh weight of the plant, dry weight, stem diameter, number of ears per plant, fresh root weight and length of the root; while Bacillus subtilis, better in fresh root weight compared to the control. Regarding the leaf area and the percentage of crude protein, a significant difference was shown between the treatments, with results similar to chemical treatment. Finally, for root diameter, the most favorable result was presented in chemical treatment. The best results were found during the S-S cycle.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Optimal redesign of the pressurized network of section 01 of 001 irrigation district Pabellon de Arteaga, Aguascalientes 2020-05-27T02:26:40+00:00 Osvaldo Galván-Cano Adolfo Antenor Exebio-García <p>Water as resource is increasingly more restricted, agriculture is the sector with the highest water demand, thus, irrigation infrastructure that is able to optimize and supply water to the crops is needed. The purpose of our study was to redesign and optimize section 01 of the 001 (DR 001) irrigation district, Pabellon de Arteaga, Aguascalientes, for the network to fulfill the water requirements of crops with demand-based irrigation supply. The first Clément formula was applied for the hydraulic capacity of the network sections and linear programming to determine the optimal diameters of the pressurized network, minimizing the cost of the pipeline, which is one of the components with the highest budget in an irrigation system. The minimum and maximum speed, length of each section, minimum pressure at the nodes and a minimum flow rate of 20 L s‑1 were employed as restrictions. The results suggest important modifications with respect to the installation, currently, the sections of the network belong to class 5, and the redesign mostly assigned class 7. In addition, 10, 61% of the sections increased their diameter, with a minimum total cost of $ 6 968 266 in terms of polyvinyl chloride (PVC) pipe. Moreover, the restriction of the 4 pressure regulating valves (PRV) within section 01 was also removed for it to operate with the whole pressure of the entrance of the section.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Rhizospheric bacteria with potential benefits in agriculture 2020-05-27T02:26:53+00:00 Araceli Rodríguez-Sahagún Antonio Velasco-Jiménez Osvaldo Castellanos-Hernández Gustavo Acevedo-Hernández Rayn Clarenc Aarland <p>Rhizobacteria are a vast and diverse group of bacteria that live in the environs of the plant roots, which develop beneficial, neutral and even harmful relationships, although the latter to a lesser extent. The interactions between bacteria and plant roots rich in nutrients have played a decisive role in the adaptation and productivity of plants over time. Several studies show that rhizobacteria have improved the growth, the production and health of plants directly through mechanisms that include the assimilation of vital nutrients such as nitrogen and the facilitation of nutrients such as phosphorus, potassium, and phytostimulation through the production of various phytohormones; and indirectly affecting the growth of important phytopathogens, activating immunity in plants and lessen the problems caused by abiotic stress. Due to their metabolic diversity, rhizobacteria could positively contribute to the improvement of agricultural productivity and the solution of environmental problems caused by current agriculture. Different genera such as: Acidithiobacillus, Aminobacter, Arthrobacter, Azoarcus, Azospirillum, Azotobacter, Bacillus, Burkholderia, Clostridium, Enterobacter, Gluconoacetobacter, Pseudomonas, Serratia and Sphingomonas have demonstrated their enormous capacity to promote growth. This review provides a focus on the mechanisms by which rhizobacteria improve plant growth, their contribution to sustainable agriculture and their commercialization, a field that continues to grow steadily.</p> 2020-04-13T00:00:00+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Presentation of Special Volume No. 38-2 2020-05-18T02:56:08+00:00 Edgar Iván Sánchez-Bernal <p>“Investigaciones en Relación con Problemas Agrícolas, Pecuarios y Forestales en la Región Costa de Oaxaca”</p> 2020-05-18T02:56:08+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Growth of seedlings of Tabebuia rosea and Gliricidia sepium under hydrochloric salinity conditions 2020-05-27T02:26:34+00:00 Edgar Iván Sánchez-Bernal Héctor Manuel Ortega-Escobar Erika Nachele Muñoz-Hernández Álvaro Can-Chulim Verónica Ortega-Baranda Jorge Ochoa-Somuano <p>A greenhouse experiment was conducted with agrolite pots, irrigated with sodium chloride (NaCl) solutions at concentrations of 0, 1.28, 2.56, 3.84, 5.12, 6.40 and 7.68 g L-1. The objective of our study was to evaluate emergence, height, stem diameter, length of the root, number of leaves and accumulation of total biomass of seedlings of Tabebuia rosea and Gliricidia sepium from the low deciduous forest of Oaxaca, and to determine their tolerance to salt. Results indicate that the increase of saline level delayed emergence and decreased growth of both plant species. The control plants were significantly larger than those grown in the saline treatments (P = 0.05). The growth reduction was differential, since concentrations &gt; 6.40 g L-1 inhibited the emergence of Tabebuia rosea seedlings, whereas concentrations &gt; 5.12 g L-1 produced dwarf ism in the seedlings of Gliricidia sepium. Salinities &gt;&nbsp;1.28&nbsp;g&nbsp;L-1 produced burning of plant tissues and toxicity. In conclusion, Tabebuia rosea is less tolerant to hydrochloric salinity than Gliricidia sepium. The proposed regression model was consistent with the saline effect on decreasing the total dry weight of plants.</p> 2020-05-18T03:04:29+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Quality indicators physical chemistry of wastewater of state Oaxaca, Mexico 2020-05-27T02:26:32+00:00 Adriana Camacho-Ballesteros Héctor Manuel Ortega-Escobar Edgar Iván Sánchez-Bernal Álvaro Can-Chulim <p>The state of Oaxaca has an extensive and complex hydrological system due to its variation in regional and temporal availability. In addition, the human population and industrial growth have increased the discharge of wastewater, degrading its quality. The volume of wastewater that is allowed to be transferred into the channels of the State is 0.35 m3 s-1; however, there are illegal discharges that increase the ionic concentrations; these waters are used for agricultural irrigation from its source to its mouth. In order to quantitatively assess the parameters over ionic concentrations of wastewater to be applied in agricultural soils, 89 sampling stations were established in the summer of 2018 along the State. The water quality was classified according to its electrical conductivity (EC), sodium adsorption ratio (RAS), residual sodium carbonate (CSR), and concentration of boron and phosphorus. The coefficient of mg L-1 = af (EC) was a = 0.671, this value a corresponds to the type of water of SO4‑Cl‑HCO3 composition. The pH was 6.98-7.54-8.32; the EC fluctuated between 80 and 2550 µS cm-1 with an average value of 475 μS cm-1. The content of Na2CO3 is (-0.34) -0.74-8.10 mmolc L-1. The coefficient of the functional relationship μ (M L‑1) = af (EC) was a = 0.0117. The values of original, adjusted and corrected RAS were: RASor 0.27-1.82-11.54, RASaj 0.05-2.76-23.51 and RAScorr 0.18-1.87-12.66, respectively. To determine the potential danger of sodicity, PSI-RAS relationship values were calculated, resulting in RASor = 16.32, RASaj = 28.43, RAScorr = 17.63. In accordance with the physical-chemical parameters, the wastewaters from Oaxaca are sulphatic-hydrochloric-bicarbonated.</p> 2020-05-18T03:05:19+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Arboreal vegetation of deciduous lower rainforest in degraded litosol and eutric regosol soils 2020-05-27T02:26:30+00:00 Verónica Ortega-Baranda Edgar Iván Sánchez-Bernal Liliana Sánchez-Aragón María de los Ángeles Luis-Reyna Gabriel Ruvalcaba-Gómez <p>In Mexico, low deciduous forests (SBC) are disturbed by agricultural activities. Its regeneration causes the reestablishment of secondary arboreal vegetation with less plant cover and root rooted to the ground produce thermophilic and hydrophobic soils vulnerable to erosion, which prevents the regeneration of SBC. The structure, composition and diversity of the arboreal vegetation in two SBCn degraded lithosols and regosols were determined in two conservation areas located the first in the municipality of San Pedro Mixtepec (SBC-M) and the second in San Pedro Pochutla (SBC-P) of the coast of Oaxaca. In each area, four sampling units of 0.25 ha were established, divided into 25 squares of 100 m² each, in which arboreal individuals with a normal diameter &gt; 2.5 cm were measured. The composition of species, the vertical (height) and horizontal (diameter) structure, the Importance Value Index (IVI) and Forest Value (IVF) were determined. The registered wealth was evaluated by parametric and non-parametric estimators (Chao2), the Simpson indexes (1-Dp) modified by Pielou, Shannon-Weaver (H’), equity (JH’), dominance and similarity (IS). between SBC. Soil samples from the SBC-M were collected and physical-chemical characterization was carried out. The results indicate that the species richness between development conditions (SBC-M = 33; SBC-P = 47) had significant differences (P &lt; 0.05). The vertical structure was between 1 - 10 m and the horizontal one remained in the diameter class 5 (2.5 - 7.5 cm), for both conditions. The species with the highest IVI and IVF were: Ceiba parvifolia, Heliocarpus donnell smithii, Dalbergia congestiflora and Amphipterygium adstringens. The SBC-M and SBC-P had an index I-Dp = 0.911 and 0.919 for H’ = 2.73 and 3.00, in both JH’ = 0.78; the dominance was from 0.157 to 0.219. The similarity of species among forests was 60%.</p> 2020-05-18T03:05:42+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Greenhouse growth of Cayman and Cobra grasses under diverse NaCl salinity levels 2020-05-27T02:26:28+00:00 Edgar Iván Sánchez-Bernal Silvia Santos-Jerónimo Héctor Manuel Ortega-Escobar Serafín Jacobo López-Garrido Marco Antonio Camacho-Escobar <p>Saline soils affect the growth and yield of pastures and decrease the availability of forage for animal feed. Objective: To evaluate the emergence, growth and biomass production of the Cayman (BR/1752) and Cobra (BR/1794) grasses under salinity conditions induced by NaCl salt at seven levels of electrical conductivity (CE) of 0, 2, 4, 6, 10, 12 and 15 dS m-1. Methodology: In a greenhouse, experimental pots with agrolite were planted at a density of 25 seeds per pot, to evaluate emergence. Later a clear was performed to leave three plants per pot in a completely random design. Irrigation consisted of replacing the water lost through evaporation by supplying distilled water. The experiment covered a period of 60 days, during which the height of plants, diameter of stem, number of shoots, number of leaves, root length and biomass production were determined. The results indicate that increasing the concentration of NaCl for both pastures, differentially decreased the percentage of emergence, height of plants, stem diameter, the number of shoots and the number of leaves and consequently these reductions affected the biomass production of the plants. The degrowth was more pronounced in Cayman grass than in Cobra grass. Cultivars showed tolerance differences since in the Cayman grass biomass production was signif icantly affected (P = 0.05) at CE&nbsp;≥ 10 dS m-1, while in Cobra grass this decrease occurred at CE ≥ 12 dS m-1.</p> 2020-05-18T03:06:06+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Effect of incorporating arboreal vegetation to Cynodon nlemfuensis diets during in-vitro ruminal fermentation 2020-05-27T02:26:26+00:00 Narciso Ysac Ávila-Serrano Serafín Jacobo López-Garrido Mónica Marcela Galicia-Jiménez Guillermo de Jesús González-Crespo Marco Antonio Camacho-Escobar <p>Gramineae do not meet the needs of ruminants in the tropics, and their marked seasonal production causes disadvantages in animal production; in addition, high fiber levels and low protein content result in a higher production of greenhouse gases (GHG). For this reason, this study intended to supplement the diet by adding different foliage levels of tropical trees with the objective of evaluating the effect of incorporating 15, 30, and 45% of Moringa oleifera, Leucaena leucocephala or Guazuma ulmifolia on a diet based on Cynodon nlemfuensis grass during ruminal fermentation in vitro. The methodology consisted of ten treatments with different inclusion percentages of three different trees; the chemical composition, in vitro ruminal fermentation, dry matter degradation (IVDMD), pH, volatile fatty acid concentration (VFAs), biogas production and emission of methane (CH4) and carbon dioxide (CO2) were determined. Data were analyzed through a completely randomized design. The chemical composition of the diets showed differences (P &lt; 0.05) when tree foliage was added gradually to the diet; the IVDMD was different (P &lt; 0.05); pH of the treatments showed no differences (P &gt; 0.05); VFA concentration was different (P &lt; 0.05), the diet with 45% of Moringa oleifera had the best VFA concentration; however, the total biogas production and CH4 and CO2 concentrations were lower (P &lt; 0.05) in the diet with 45% Leucaena leucocephala. In conclusion, the addition of 45% of Leucaena leucochephala to the diet improved chemical composition without affecting the VFA concentration and producing less CH4 and CO2 (18 and 24%, respectively).</p> 2020-05-18T03:06:46+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA Description of the tree stratum in combination with rustic coffee in a medium subperennifolia rainforest, Jocotepec, Oaxaca 2020-05-27T02:26:24+00:00 Víctor Moreno-Guerrero Verónica Ortega-Baranda Edgar Iván Sánchez-Bernal Irma Gisela Nieto-Castañeda <p>Agroforestry systems (SAF) of coffee are considered areas that increase the biodiversity of species of both flora and fauna, are sources of economic income for the communities that work them, as well as multiple environmental services. In order to know the influence of coffee SAF management on the diversity of tree species, the composition, structure and diversity of the tree stratum in two rustica coffee plantations was described, under management conditions: active coffee (CA) and abandoned coffee plantation (CAb), in Jocotepec, region Coast of Oaxaca. In each driving condition four study units of 20 × 30 m (0.06 ha) were placed. All trees individuals from 1.30 m above the ground were registered with the normal diameter (DN) ≥ 2.5 cm, total height and canopy cover. Wealth, vertical, horizontal structure, Importance and Forest Value Indices (IVI and IVF) were evaluated; diversity with the Simpson Indices modified by Pielou (1-D) and Shannon-Weaver (H´) and equity (E), dominance (D) and Similarity. A wealth of 35 species was obtained for the CA and 31 in CAb; The main taxonomic families were Fabaceae, Lauraceae and Moraceae. In both driving conditions, the diameter category 5 (2.5 - 7.5 cm) exceeded the number of tree individuals, with a distribution of heights that revealed the existence of two vertical strata. The species that presented a high IVI and IVF in CA were: Cedrela odorata, Tabebuia rosea and Quercus crispifolia and for the CAb: Quercus sp., Ficus tecolutensis and Ocotea helicterifolia. Between CA and CAb there were no differences in the evaluated variables, 1-D, H´, E and D. The floristic similarity between conditions was 52%.</p> 2020-05-18T03:08:52+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA In vitro methane and carbon dioxide production of tropical grasses of the coast of Oaxaca, Mexico 2020-05-27T02:26:18+00:00 Marco Antonio Camacho-Escobar Mónica Marcela Galicia-Jiménez Edgar Ivan Sánchez-Bernal Narciso Ysac Ávila-Serrano Serafín Jacobo López-Garrido <p>Tropical grasses have different chemical composition; when they are fermented in rumen, they show different values in digestibility, volatile fatty acid concentration (VFA), and methane (CH4) and carbon dioxide (CO2) production. The objective of this study was to determine the chemical composition, characterize fermentation, and estimate CH4 and CO2 emissions in vitro in tropical grasses of Oaxaca. For the experiment, 0.5 g of dry matter of the grasses Cynodon nlemfuensis, Andropogon gayanus, Pennisetum purpureum cv. Taiwan Morado, Pennisetum purpureum cv. Maralfalfa and Panicum maximum were incubated with 45 mL of culture medium for anaerobic microorganisms and deposited in 100 mL glass vials with CO2 flow. The grasses were inoculated with 5 mL of rumen fluid and incubated at 39 °C for 72 h. Biogas production and microorganism population were determined at 6, 12, 24, 48, and 72 h. Volatile fatty acid (VFA) concentrations, pH and in vitro dry matter degradability (IVDMD) were determined at 72 h. CH4 and CO2 emissions were estimated at 24, 48, and 72 h. The response variables were evaluated by a completely randomized design with five replicates per treatment; the comparison of means was made with Tukey’s test. C. nlemfuensis had the highest (P &lt; 0.05) crude protein content. The cellulolytic bacterial population was lower (P &lt; 0.05) in Andropogon gayanus and Panicum maximum. Cynodon nlemfuensis, Andropogon gayanus and Pennisetum purpureum cv. Taiwan Morado had lower (P &lt; 0.05) acetate concentrations; Panicum maximum had higher (P &lt; 0.05) propionate concentration. Pennisetum purpureum cv. Maralfalfa showed the highest (P &lt; 0.05) IVDMD and produced the lowest (P &lt; 0.05) CH4 volumes; Cynodon nlemfuensis and Panicum maximum produced lower CO2 volumes.</p> 2020-05-18T03:19:15+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA The cause and potential solution to the Fusarium wilt disease in banana plants 2020-05-27T02:26:22+00:00 Ana Claudia Sánchez-Espinosa José Luis Villarruel-Ordaz Luis Maldonado-Bonilla <p>The Fusarium wilt disease of banana caused by the soil-borne fungal pathogen Fusarium oxysporum f. sp. cubense is currently considered the most prominent disease that threatens the global fruit production. Control of this pathogen is essential to guarantee the supply of banana fruits. The use of chemical pesticides is a common practice for its control; however, this causes contamination of soils, water and atmosphere, and also affects the human health. The knowledge of natural antagonists of Fusarium oxysporum f. sp. cubense is a reliable alternative to develop crop protection strategies. Concerning this, the genus Trichoderma comprises mycoparasitic species adapted to distinct environmental and soil conditions. The features of Trichoderma have enabled its use as an effective biological control agent, but this potential must be extended in order to prevent the economic losses caused by the Fusarium wilt. In this review we present essential information about two contrasting fungal inhabitants of the soil: a group of phytopathogens that produces deleterious consequences in banana plants and its potential antagonists that will provide novel methods of biological control.</p> 2020-05-18T03:13:25+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA The physico-chemical plant defenses and its effect on ruminant feeding 2020-05-27T02:26:20+00:00 Marco Antonio Camacho-Escobar Diego Arturo Ramos-Ramos Narciso Ysac Ávila-Serrano Edgar Iván Sánchez-Bernal Serafín Jacobo López-Garrido <p>Plants are consumed by various organisms, this situation puts their survival at risk, so they have developed defense mechanisms that prevent their intake. For example, anatomical adaptations, chemical defenses or secondary metabolites. These phytochemicals inhibit the attack of pathogens, cause contact irritation, affect the cutaneous, gastrointestinal, cardiac and nervous systems of herbivores or can cause death. Ruminants have mechanical, physiological and ethological adaptations to evade plant defenses: rejection, regulation and biotransformation. They developed anatomic-physiological adaptations to house microbial symbionts to degrade cellulose and plant toxins. Some secondary metabolites may have beneficial effects in food or animal medicine, but more study needed on the subject.</p> 2020-05-18T03:16:30+00:00 Copyright (c) 2020 REVISTA TERRA LATINOAMERICANA