Agronomía Mesoamericana <p>Agronomía Mesoamericana journal is a continued publication with shutdowns in January, May and September. Edited in the Universidad de Costa Rica, its objective is to disseminate scientific information in Spanish or English language, through the publication of articles, short communications, technical notes and literature reviews, related with food and agriculture sciences from anywhere in the world, emphasized in tropical and subtropical zones, especially from Mesoamerica and the Caribbean.&nbsp;</p> <p>&nbsp;</p> <p><strong>URL OAI-PMH</strong>&nbsp;<a href=""></a></p> en-US <p><strong>1. Proposed policy for open access journals</strong></p> <p>Authors who publish in this journal accept the following conditions:</p> <p><br>a. Authors retain the copyright and assign to the journal the right to the first publication, with the work registered under the attribution, non-commercial and no-derivative license from Creative Commons, which allows third parties to use what has been published as long as they mention the authorship of the work and upon first publication in this journal, the work may not be used for commercial purposes and the publications may not be used to remix, transform or create another work.</p> <p>b. Authors may enter into additional independent contractual arrangements for the non-exclusive distribution of the version of the article published in this journal (e.g., including it in an institutional repository or publishing it in a book) provided that they clearly indicate that the work was first published in this journal.</p> <p>&nbsp;</p> <p>c. Authors are permitted and encouraged to publish their work on the Internet (e.g. on institutional or personal pages) before and during the review and publication process, as it may lead to productive exchanges and faster and wider dissemination of published work (see <a href="">The Effect of Open Access</a>).</p> (Nancy León Ulate) (Ing. Nancy León Ulate) Wed, 19 Jan 2022 15:26:11 -0600 OJS 60 Morphometric subpopulations study of white-tailed deer (Odocoileus virginianus peruvianus) epididymal spermatozoa <p><strong><span class="CharOverride-2">Introduction.&nbsp;</span></strong>The study of the sperm morphometry of the white-tailed deer (<em><span class="CharOverride-6">Odocoileus virginianus peruvianus</span></em>) allows to characterize the sperm cells of this species for conservation purposes.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To determine the sperm subpopulations according to the morphometry of the epididymal spermatozoa of the white-tailed deer, using a CASA-Morph system.&nbsp;<strong><span class="CharOverride-2">Materials and methods.&nbsp;</span></strong>The study was carried out in the second semester 2016, at the Universidad Nacional San Antonio Abad del Cusco, Peru. In semen samples obtained from the caudal end of the epididymis of two deer (two and four teeth), it was determined based on the CASA-Morph system, Integrated Semen Analysis System (ISAS<span class="CharOverride-4">®</span>v1): the length, width, area, perimeter, ellipticity, elongation, regularity, and roughness of the sperm head were determined, also, the width, area, distance, and midpiece insertion angle of the sperm. Principal components analysis (PCA) was performed and the non-hierarchical k-means model was applied to determine the optimal number of clusters.&nbsp;<span class="CharOverride-2"><strong>Results.</strong>&nbsp;</span>The morphometric variables were distributed in five PCAs: ellipticity, size, circularity, midpiece insertion angle, which explained 81.24 % of the total variance. The Cluster analysis determined four subpopulations (SP), SP1 grouped large, elongated cells with high elongation and ellipticity (21.76 %), SP2 composed of small and thin spermatozoa both in the head and in the midpiece (37.7 %). The SP3 was related to the presence of elongated cells with high values of midpiece width, ellipticity, and elongation (17.7 %), and SP4 grouped spermatozoa with intermediate size of the head and the midpiece (22.84 %).<strong>&nbsp;<span class="CharOverride-2">Conclusion.&nbsp;</span></strong>The determination of four sperm subpopulations in white-tailed deer semen can be the basis of assisted reproduction programs for this species.</p> Hernán Cucho, Gregorio Nina, Aydee Meza, Ruth Ccalta, César Ordóñez, Anthony Valverde Abarca ##submission.copyrightStatement## Fri, 21 Jan 2022 00:00:00 -0600 Effect of induction moment on Bradyrhizobium-soybean (Glycine max) interaction <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;Legume nodulation is regulated by the exchange of molecular signals between the plant and rhizobia. The bacterial nodulation genes are activated by flavonoids present in root exudates. As a result of this activation, the Nod factors are synthesized, which in turn participate in the morphogenesis and function of the nodules. It is then possible to regulate the induction of Nod factors and other signals related to the nodulation process, during the inoculants production.<span class="CharOverride-2"><strong>&nbsp;Objective.</strong>&nbsp;</span>To determine if the moment to induce the nodulation genes in&nbsp;<span class="CharOverride-6"><em>Bradyrhizobium</em>&nbsp;</span>inoculants affects the synthesis of compounds related to the nodulation process and its interaction with soybean plants.&nbsp;<strong><span class="CharOverride-2">Materials and methods.</span></strong>&nbsp;The research was developed in Rizobacter S.A., Argentina and Fyteko S.A. laboratories, Belgium, and in a plant growth chamber of the first one, during May-June of 2017. Two&nbsp;<span class="CharOverride-6"><em>Bradyrhizobium</em>&nbsp;</span>strains were induced with daidzein in three moments. The signals produced by the strains and the biological effect in soybean plants were studied.&nbsp;<strong><span class="CharOverride-2">Results.</span></strong>&nbsp;Differences were detected in the molecules produced by the bacteria, but it did not affect the growing and plants nodulation related to the different moments of induction.<strong>&nbsp;</strong><span class="CharOverride-2"><strong>Conclusion</strong>.</span>&nbsp;The metabolites excreted by&nbsp;<span class="CharOverride-6"><em>Bradyrhizobium</em>&nbsp;</span>changed with strain and induction moment, although the latter did not affect nodulation or soybean plants growth.</p> Maria Caridad Nápoles-García, Daimy Costales-Menéndez, Ionel Hernández-Forte, Reneé Pérez-Pérez, Guilleaume Wegria, Juan Carlos Cabrera-Pino ##submission.copyrightStatement## Fri, 21 Jan 2022 00:00:00 -0600 Mineral profile of imported pet food in Costa Rica <p><strong><span class="CharOverride-2">Introduction</span>.</strong> The mineral content in pet food is not always displayed on the label. It is important to know this information in order to assess the nutritional contribution of the food.<strong>&nbsp;<span class="CharOverride-2">Objective.&nbsp;</span></strong>To determine the content of Ca, P, K, Na, Mg, S, Cu, I, Fe, Mn, and Zn in 34 imported foods for dogs, cats, rabbits, hamsters, ornamental fish, and turtles, and to compare the results with the recommendations found in the literature.&nbsp;<strong><span class="CharOverride-2">Materials and methods.&nbsp;</span></strong>During the months of August and December of 2018, ten samples were collected of dog and cat food, five for ornamental fishes, four for turtles, three for hamsters, and two for rabbits. These were acquired directly at different points of sale in the Greater Metropolitan Area, San Jose, Costa Rica. The samples were analyzed at the Animal Nutrition Research Center of the Universidad de Costa Rica. The minerals Ca, P, K, Mg, S, Cu, I, Fe, Mn, and Zn were quantified based on the methodology recommended by the Association of Official Analytical Chemists. The average content per feed group according to the animal species, standard deviation, maximum and minimum values were calculated compared with the nutritional recommendations for minerals found in the literature.&nbsp;<strong><span class="CharOverride-2">Results.&nbsp;</span></strong>The foods studied met, on average, the mineral requirements for pets. Imbalances in Ca, P, and Mg content in the turtle foods, high iodine contents in dog foods, and unbalanced mineral relations were observed.&nbsp;<span class="CharOverride-2"><strong>Conclusions.</strong>&nbsp;</span>A database was generated with average values and their dispersion in eleven minerals in 34 samples of commercial foods for seven companion animals in Costa Rica. Little information was available regarding the recommended upper limits and requirements in species such as hamsters, ornamental fish or turtles.</p> André Cedeño-López, Rodolfo WingChing-Jones ##submission.copyrightStatement## Wed, 19 Jan 2022 00:00:00 -0600 Effect of Morus alba on the flavonoids content and bromatological profile of goat milk <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;Mulberry (<em><span class="CharOverride-5">Morus alba</span></em>), a plant native to China, is used as a fodder on some farms. Its high protein content stimulates milk production in cattle; however, it is not known whether its flavonoids can be incorporated into goat milk.<span class="CharOverride-2">&nbsp;<strong>Objective.</strong></span>&nbsp;To evaluate the effect of a diet enriched with mulberry-enriched, on flavonoids concentration and bromatological parameters of milk from stabled alpine goats.&nbsp;<span class="CharOverride-2"><strong>Materials and methods.</strong>&nbsp;</span>The experiment was carried out in 2019, with goats from a particular farm located in Veracruz, Mexico. Two groups were formed (A with the treatment and B control) with five Alpine breed goats each, with similar characteristics (stall feeding, three calving, without mastitis, morning and evening hand milking). Group A received forage without mulberry before and after treatment (days 1-10 and 21-31, respectively), and a modified forage diet with mulberry (days 11-20; group B was fed forage without mulberry on all 31 days of experimentation. Additionally, the flavonoid content in mulberry and every three days in milk samples were analyzed, in addition to the bromatological content of protein, fat, lactose, non-fat solids, and density.&nbsp;<strong><span class="CharOverride-2">Results.</span></strong>&nbsp;During the mulberry-modified diet, the flavonoid concentration reached a maximum of 53.45 mg mL<sup><span class="CharOverride-4">-1</span></sup>&nbsp;EQ in group A at day 20, it decreased gradually during the post-treatment period; however, it maintained 20 % more flavonoids than the control group. A significant increase in protein content was also observed in group A, with no significant difference in the other bromatological parameters of the milk between the two groups.&nbsp;<strong><span class="CharOverride-2">Conclusions.</span>&nbsp;</strong>The diets modified with mulberry favored the incorporation of flavonoids and the increase of protein in goat milk, without modifying the other bromatological parameters.</p> Oscar Carmona-Hernández, Carmen Bulbarela-Sampieri, Micloth López-Del-Castillo-Lozano, José Armando Lozada-García ##submission.copyrightStatement## Thu, 16 Dec 2021 15:03:30 -0600 Rhizobia increases the germination of Coffea arabica and Coffea canephora seeds. Second evidence in Cuba <p><strong><span class="CharOverride-2">Introduction.</span>&nbsp;</strong>The slow and asynchronous germination of coffee seeds affects the obtaining of seedling and increases production costs. The application of plant growth promoting rhizobacteria (PGPRs) has shown to be an alternative to this problem.&nbsp;<strong><span class="CharOverride-2">Objective.&nbsp;</span></strong>To evaluate the effect of rhizobia inoculation on the germination of two coffee cultivars under controlled and productive conditions.&nbsp;<strong><span class="CharOverride-2">Materials and methods.&nbsp;</span></strong>During January and February 2020, two experiments were carried out at the Universidad de Oriente, Cuba, using ten rhizobia strains from legumes and grasses, and two coffee cultivars of economic importance in Cuba:&nbsp;<em><span class="CharOverride-5">Coffea arabica</span></em>&nbsp;Isla 5-15 and&nbsp;<span class="CharOverride-5"><em>Coffea canephora</em>&nbsp;</span>Pierre ex Froehner Robusta cultivars. The experiments were conducted, one under controlled conditions, where seed germination was evaluated in Petri dishes, and the other one using pre-germination beds. In both experiments, a completely randomized design was used and an analysis of variance was performed.&nbsp;<strong><span class="CharOverride-2">Results.</span></strong>&nbsp;Under controlled conditions, the inoculation of strains Rpr11, Rpr2, 1-2, ICA8001, and Can3 increased germination percentage, germination energy, germination index, germination speed index, and vigor index. In the pre-germination beds, the inoculants based on the Rpr2 and Rpr11 strains produced the highest percentages of emergence and germination energy.&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>The Rhizobium strains Rpr2 and Rpr11 increased seed germination of two varieties of coffee.</p> Sucleidi Nápoles-Vinent, Silfredo Milanés-Riquene, Ionel Hernández-Forte, Belkis Morales-Mena, María Caridad Nápoles-Garcias ##submission.copyrightStatement## Thu, 16 Dec 2021 14:17:09 -0600 Physicochemical and sensory characteristics of flavored milks made with goat and bovine milk <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;Goat’s milk is a product of high nutritional and nutraceutical value, around which there is no established culture of consumption in several countries, so its use in the development of new products is promising.&nbsp;<strong><span class="CharOverride-2">Objective.&nbsp;</span></strong>To define the effect of different proportions of goat and bovine milk on the physicochemical and sensory properties of flavored milks.<span class="CharOverride-2">&nbsp;<strong>Materials and methods.</strong>&nbsp;</span>At the National Center of Food Science and Technology of the Universidad de Costa Rica, during 2021, flavored milks of three different flavors were formulated with five inclusion levels of goat and bovine milk (0 %, 25 %, 50 %, 75 %, 100 %). These milks were evaluated for pH, total acidity, instrumental color (parameters L *, b *, and a *), and viscosity, as well as the overall taste by means of a panel with 110 judges.<span class="CharOverride-2">&nbsp;<strong>Results.&nbsp;</strong></span>As the proportion of goat milk increased, a decrease in pH and an increase in acidity were recorded in a lot of samples, as well as an increase in the viscosity of the chocolate milks. The color in each formulation showed no differences in the parameters a * and b * and L * when varying the proportions of milk. Sensory analysis generated three clusters of panelists (15.5 %, 48.1 %, and 36.4 %).&nbsp;<strong><span class="CharOverride-2">Conclusions.&nbsp;</span></strong>Strawberry flavored milk with a 50 % cow’s milk / goat’s milk ratio presented the best combination of physicochemical and sensory parameters.</p> Luis Miguel Barquero-Saldarriaga, Alejandro Chacón-Villalobos ##submission.copyrightStatement## Thu, 16 Dec 2021 10:45:47 -0600 Microbiological and physicochemical quality and flavor of hen eggs produced under grazing or conventional systems <p><strong><span class="CharOverride-2">Introduction.</span>&nbsp;</strong>The hen egg (<em><span class="CharOverride-5">Gallus gallus domesticus</span></em>) is a nutritious food in the diet of millions of people. Its worldwide production is obtained from conventional caging systems although alternative grazing systems are also used.<strong>&nbsp;</strong><span class="CharOverride-2"><strong>Objective.</strong>&nbsp;</span>To compare the microbiological and physicochemical quality and flavor of eggs produced under conventional or alternative grazing systems in Costa Rica.&nbsp;<strong><span class="CharOverride-2">Materials and methods.&nbsp;</span></strong>This research was performed in Alajuela, Costa Rica, from October 2016 to May 2017. Environmental surfaces and eggs of Isa Brown hens were sampled on farms from both systems and total coliform,&nbsp;<em><span class="CharOverride-5">Escherichia coli</span></em>, yeast and molds counts and absence/presence of&nbsp;<em><span class="CharOverride-5">Salmonella</span></em>&nbsp;sp. were determined. Also, physicochemical parameters (Haugh units, yolk index, pH, yolk color, and shell hardness) were measured and a discrimination sensory test with consumers was performed.&nbsp;<strong><span class="CharOverride-2">Results.&nbsp;</span></strong>The grazing production system had surfaces in contact with the eggs with total coliform and&nbsp;<span class="CharOverride-5"><em>E. coli</em>&nbsp;</span>counts significantly higher than those determined for the surfaces of the conventional system. Eggs from grazing hens had total coliform counts (3,2 log<span class="CharOverride-6">10&nbsp;</span>UFC egg<sup><span class="CharOverride-3">-1</span></sup>) significantly higher than conventional eggs (2,3 log<span class="CharOverride-6">10</span>&nbsp;UFC egg<sup><span class="CharOverride-3">-1</span></sup>).&nbsp;<em><span class="CharOverride-5">Salmonella</span></em>&nbsp;sp. was present in 8 % of the grazing eggs samples (incidence not significantly different from 0) and absent in the conventional eggs. A difference was found for the color of the yolk, (darker in conventional eggs). Also, there was a significant difference in the taste of both types of eggs.<span class="CharOverride-2">&nbsp;<strong>Conclusion.&nbsp;</strong></span>In general, microbiological and physicochemical quality and flavor of eggs produced under grazing system was different from the ones produced conventionally.</p> Marie Guier-Serrano, Gabriela Davidovich-Young, Eric Wong-González, Elba Cubero-Castillo ##submission.copyrightStatement## Thu, 16 Dec 2021 00:00:00 -0600 In vitro tolerance of Rubus spp. cultivars to mannitol-simulated drought stress <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;The characterization of hydric drought stress tolerant cultivars of&nbsp;<em><span class="CharOverride-5">Rubus</span>&nbsp;</em>spp. in experimental fields is complicated by the difficulty of controlling the external factors of the environment where they are installed.&nbsp;<span class="CharOverride-5">In vitro</span>&nbsp;stress induction is an efficient tool to study plant response mechanisms and is used in breeding programs for the selection of hydric drought stress tolerant genotypes.<span class="CharOverride-2">&nbsp;<strong>Objective.&nbsp;</strong></span>To evaluate the&nbsp;<span class="CharOverride-5"><em>in vitro</em>&nbsp;</span>morphological and physiological response of explants in three cultivars and the wild accession of&nbsp;<span class="CharOverride-5"><em>Rubus</em>&nbsp;</span>spp. under mannitol-simulated hydric drought stress conditions.&nbsp;<strong><span class="CharOverride-2">Materials and methods.&nbsp;</span></strong>The study was carried out in the Biology Laboratory of Universidad Nacional Toribio Rodríguez de Mendoza de Amazonas, Peru, during the year 2020. A completely randomized design with factorial arrangement (Factor A: four genotypes and Factor B: simulated water potentials with mannitol: 0, -0.2, -0.3, and -0.4 MPa) and four explants per experimental unit were used.&nbsp;<strong><span class="CharOverride-2">Results.&nbsp;</span></strong>The cultivars responded differently under mannitol-simulated hydric drought stress. The Navaho and Tupy cultivars registered higher tolerance.&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>The morphological and physiological traits related to the root length, the water content of the shoot, root and leaf allowed to identify&nbsp;<span class="CharOverride-5">Rubus</span>&nbsp;spp. cultivars tolerant to mannitol-simulated hydric drought stress in the vegetative phase.</p> Carlos Millones, Ernestina Vásquez ##submission.copyrightStatement## Tue, 14 Dec 2021 13:31:37 -0600 Grafts of orange (Citrus sinensis) and mandarin (Citrus reticulata) in production phase <p><strong><span class="CharOverride-2">Introduction.</span>&nbsp;</strong>In Venezuela, citrus is the fifth most important fruit crop, with a harvested area of 18,084 ha, and an average yield of 14.2 t ha<sup><span class="CharOverride-4">-1</span></sup>, below world production. Despite this, there is little information on the physiology and agronomy of the grafting of the most commonly used citrus cultivars in the country, as part of a strategy to select the best combinations (graft/rootstock) and the most limiting seasons for crop production.&nbsp;<strong><span class="CharOverride-2">Objective.&nbsp;</span></strong>To evaluate agronomic and physiological levels of five citrus cultivars during the period 2013-2015.&nbsp;<strong><span class="CharOverride-2">Materials and methods.</span>&nbsp;</strong>A trial was carried out on citrus plants sown between the period of January 2013 and August 2015 at the National Center for Agricultural Research, Maracay, Venezuela, in three replications under a completely randomized design, to evaluate variables associated with gas exchange and crop phenology in five cultivars of the most important citrus fruits of Venezuela.<span class="CharOverride-2">&nbsp;<strong>Results.&nbsp;</strong></span>1) Citrus trees showed partial opening of the stomata due to high temperature and drought without causing decrease in photosynthetic rate. 2) The plants with the highest average values in the gas exchange variables in the graft (Cleopatra and Volk) and in the rootstock (Dancy during the driest periods and Valencia in the wettest periods) caused the Cleopatra-Dancy, Cleopatra-Valencia, Volk-Valencia, and Volk-Dancy combinations to achieve the highest photosynthetic yield during all evaluation periods. 3) The budding phenological stage in citrus plants were the most important sink sources for the net photosynthetic assimilation rates.&nbsp;<strong><span class="CharOverride-2">Conclusions.&nbsp;</span></strong>The cultivar Cleopatra-Dancy had the most stable behavior for variables associated with gas exchange and Volk-Dancy for producing in drier seasons.</p> Mercedes Pérez-Macias, Enio Soto, Rommel Igor León-Pacheco, Guastavo Adolfo Rodríguez-Yzquierdo, Edwin Andrés Villagrán-Munar ##submission.copyrightStatement## Tue, 14 Dec 2021 11:08:28 -0600 Composting for the reduction of bird droppings (Gallus gallus domesticus) <p><strong><span class="CharOverride-2">Introduction.</span>&nbsp;</strong>The growth of the population and the consumption of protein sources such as chicken meat, have maximized the generation of poultry waste (chicken manure), this leads to the development of efficient management alternatives for the conversion of this waste into by-products such as organic fertilizers. Numerous investigations conclude the remarkable effect of compost obtained from poultry waste on the development and growth of crops, which provide high content of essential nutrients as an amendment in agroecological agriculture, within the circular economy and the sustainable development of production.&nbsp;<strong><span class="CharOverride-2">Objective.&nbsp;</span></strong>To carry out a review on the management plans of waste from the poultry sector through composting for use in agriculture in the region of Cordoba Veracruz Mexico.&nbsp;<strong><span class="CharOverride-2">Development.</span>&nbsp;</strong>The study was carried out between January and June 2020, through an exhaustive bibliographic search and the analysis of local experiences in the production of organic fertilizers with farmers. In this review and with the field work, the results established that in the region it is possible to obtain various types of compost with the incorporation of poultry waste, and the technologies of compost, vermicompost, and bocashi production individually or in a mixture with other regional by-products such as those derived from the sugar industry, coffee, livestock, etc. Nutrients such as nitrogen of 2.08-2.34 %, phosphorus 4.01-4.27 %, potassium 2.37-4.56 %, calcium 10.36-12.93, and magnesium 0.90-1.16 % are obtained and available for use.&nbsp;<span class="CharOverride-2"><strong>Conclusion.</strong>&nbsp;</span>Poultry by-products have a great potential to generate reutilization alternatives through rural application technologies without significant investment and waste management strategies.</p> Verónica Rosas-Martínez, Noé Aguilar-Rivera ##submission.copyrightStatement## Thu, 09 Dec 2021 00:00:00 -0600 Physical methods to reduce the inoculum of Sclerotium cepivorum in purple garlic seed (Allium sativum L.) <p><strong><span class="CharOverride-2">Introduction.&nbsp;</span></strong>In Colombia, garlic production is affected by pathogens, mainly&nbsp;<em><span class="CharOverride-5">Sclerotium cepivorum</span></em>, which is disseminated by planting material. It is necessary to establish low-cost technologies to control this pathogen.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To evaluate two thermotherapy methods, dry heat thermotherapy and water immersion thermotherapy, to reduce the presence of&nbsp;<em><span class="CharOverride-5">S. cepivorum</span></em>&nbsp;in garlic seed and its effect on agronomic characteristics of plants emerged from treated bulbs.&nbsp;<span class="CharOverride-2"><strong>Materials and methods.</strong>&nbsp;</span>This work was carried out at the Tibaitata Research Center of Corporacion Colombiana de Investigacion Agropecuaria (AGROSAVIA), located in Cundinamarca, Colombia, during the first semester of 2019. Nine treatments were evaluated; five in dry heat thermotherapy: 35 ºC for 12 h, 35 ºC for 129,6 h, 50 ºC for 48 min, 5 ºC for 20 days, 38 °C for 1 h; two in hot water immersion thermotherapy:48 °C for 30 min, 50 °C for 20 min, and two controls: chemical disinfection (tebuconazol) and room temperature (20 ºC for 20 days) in a randomized complete block design. Sprouting of bulbs and growth of garlic plants after applying thermotherapy to the seed and viability of&nbsp;<span class="CharOverride-5"><em>S. cepivorum</em></span><em>&nbsp;</em>sclerotia were evaluated.&nbsp;<span class="CharOverride-2">Results.</span>&nbsp;Seed storage at 5 ºC for 20 days accelerated its sprouting, reached a 80 % germination after five days, increased leaf number and biomass accumulation. Sclerotia germination was between 33 and 67 %; the treatment that presented the lowest incidence was 35 ºC for 129,6 h (33 %).&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>Dry heat thermotherapy treatment at 35 °C for 129,6 h showed potential in reduction of&nbsp;<span class="CharOverride-5">S. cepivorum&nbsp;</span>inoculum in garlic seeds.</p> Magda Rocío Gómez-Marroquín, Diana Marcela Torres-Jiménez, Ginna Natalia Cruz-Castiblanco, Anngie Katherine Hernández-Guzmán, Sadao Kobayashi, Andrea del Pilar Villarreal ##submission.copyrightStatement## Mon, 06 Dec 2021 00:00:00 -0600 Gypsum and potassium application to acid soils for maize (Zea mays L.) production in La Frailesca, Chiapas, Mexico <p><strong><span class="CharOverride-4">Introduction.</span>&nbsp;</strong>Maize (<em><span class="CharOverride-5">Zea mays</span></em>&nbsp;L.) production in La Frailesca region, Mexico, is limited by sandy soils, low in potassium (K), and with acidic arable layers and subsoils. There is information on the management of lime but not on amendments that could be used for subsoil acidity — such as gypsum — nor on the interactions between amendments for soil acidity and K fertilization.&nbsp;<strong><span class="CharOverride-4">Objective.</span>&nbsp;</strong>To evaluate the effects of K and gypsum on maize and on previously limed soils.&nbsp;<strong><span class="CharOverride-4">Materials and methods.</span>&nbsp;</strong>The evaluations were conducted in farmers’ fields in La Frailesca region, Chiapas (Mexico) in 2016 and 2017. Four gypsum rates (0, 1.25, 2.5 and 5 t ha<sup><span class="CharOverride-3">-1</span></sup>) and four K rates (0, 60, 90, and 120 kg ha<sup><span class="CharOverride-3">-1</span></sup>&nbsp;as K<sub><span class="CharOverride-6">2</span></sub>O) were factorially combined in a randomized block design, with three replicates. In both years, before the beginning of the experiments, dolomitic lime was applied to the experimental area following standard practices. Responses of crop yield, soil exchangeable K, Ca, Mg, and Al, and soil pH were obtained.<span class="CharOverride-4">&nbsp;<strong>Results.</strong>&nbsp;</span>Maize yields increased with gypsum (stabilizing at 1.25-3.0 t ha<sup><span class="CharOverride-3">-1</span></sup>), and K (stabilizing at 70-120 kg ha<sup><span class="CharOverride-3">-1</span></sup>&nbsp;of K<sup><span class="CharOverride-6">2</span></sup>O) applications. In soils, K application increased exchangeable K content, while gypsum increased exchangeable Ca content and pH, and decreased exchangeable Al content. Liming increased pH<span class="CharOverride-6">Ca</span>&nbsp;and exchangeable Ca and Mg contents, and lowered the exchangeable Al content in the top 7.5 cm of soil.<strong>&nbsp;</strong><span class="CharOverride-4"><strong>Conclusion.&nbsp;</strong></span>Soils with exchangeable K (≤0.3 cmol<span class="CharOverride-6">c</span>&nbsp;kg<sup><span class="CharOverride-3">-1</span></sup>) were responsive to K fertilization. The positive effects on yields from gypsum were probably linked to a greater Ca supply in the top 7.5 cm. These results are encouraging about the benefits of the combined application of dolomitic lime, gypsum, and K, but longer evaluations are needed to properly determine the effects of gypsum on subsoil acidity.</p> Armando Tasistro, Robertony Camas-Gómez, Ivan Ortiz-Monasterio ##submission.copyrightStatement## Thu, 25 Nov 2021 00:00:00 -0600 Productive behavior and phenotypic stability of Hordeum vulgare L. in Colombia <p><strong><span class="CharOverride-2">Introduction.</span>&nbsp;</strong>The incorporation of 40 thousand hectares of barley (<em><span class="CharOverride-5">Hordeum vulgare</span></em>&nbsp;L.) for the beer industry in Colombia, with a projected production of 80 thousand t yr<span class="CharOverride-4">-1</span>&nbsp;in the period 2016 to 2026, will allow to reduce imports by 60 %. However, meeting this goal requires high-yielding, high-quality barley varieties.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To identify a barley variety with stable grain yield and higher than 2.6 t ha<sup><span class="CharOverride-4">-1</span></sup>&nbsp;associated with tolerance to tipping, lower severity to yellow rust on the leaf and ear, and physical quality of the grain for the brewing industry.&nbsp;<strong><span class="CharOverride-2">Materials and methods.&nbsp;</span></strong>Between 2016 and 2017, an agronomic evaluation trial was carried out in the Colombian Andean region, in a randomized complete block design, with eight two-row barley varieties introduced to Colombia. The physiological maturity, tipping, severity to&nbsp;<span class="CharOverride-5"><em>Puccinia striiformis</em></span>&nbsp;f. sp&nbsp;<span class="CharOverride-5">hordei</span>&nbsp;in the leaf and ear, grain yield, and hectoliter weight were determined.<strong>&nbsp;<span class="CharOverride-2">Results.&nbsp;</span></strong>The Madi and S5 varieties with grain yields of 2.89 and 2.61 t ha<sup><span class="CharOverride-4">-1</span></sup>, respectively, were 24 and 16 % higher than Metcalfe and 19 and 11 % higher than Maltera 5. Both varieties showed broad phenotypic stability, tolerance to tipping, lower severity of leaf and ear rust, and a hectoliter weight suitable for the brewing industry.&nbsp;<span class="CharOverride-2"><strong>Conclusion.</strong>&nbsp;</span>The production characteristics, phenotypic stability, and physical quality of the grain of Madi and S5 varieties make them commercial candidates for the brewing industry and for recommendation in the Cundiboyacense highlands of Colombia, after validation with a semi-commercial trial.</p> Luis Fernando Campuzano-Duque, Diego Fernando Avendaño-Avendaño, Nadia Yurani Luque-Sanabria ##submission.copyrightStatement## Thu, 25 Nov 2021 00:00:00 -0600 Transplanting and the addition of boron in sweet corn (Zea mays L. group saccharate) production <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;Low seedbed temperatures at the planting and the direct sowing method can reduce the sweet corn germination. Transplanting may offer optimum environmental conditions for seed germination, early crop maturity, and increase sweet corn (<span class="CharOverride-5"><em>Zea mays</em>&nbsp;</span>L. group saccharata) productivity. Boron deficiency depresses sweet corn yield through male sterility.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To evaluate the effect of transplanting and the addition of boron in sweet corn production.&nbsp;<strong><span class="CharOverride-2">Materials and methods.</span></strong>&nbsp;A field experiment was conducted from March 19 to June 20, 2020 at the Research Station of Horticulture Department and Landscape Gardening Architecture, University of Diyala, Baqubah, Iraq. Direct sowing and transplanting, and foliar application of boron at 0, 50, or 75 mg L<sup><span class="CharOverride-4">-1</span></sup>&nbsp;was evaluated to determine effects on the yield, the yield components, and water use efficiency of sweet corn cultivars: Roi Soleal, Seker misir, and Succar.<span class="CharOverride-2">&nbsp;<strong>Results.</strong></span><strong>&nbsp;</strong>The cv. Seker Misir matured faster (57.5 days), had wider ears (4.53 cm), more kernel rows (16.0), the highest kernel yield (6.00 t ha<sup><span class="CharOverride-4">-1</span></sup>), and a higher water use efficiency (WUE) (2.85 kg m<sup><span class="CharOverride-4">-3</span></sup>). The cv. Succar had the longest ears (18.48 cm) and the heaviest fresh ears (251 g). Transplanting hastened the time to maturity (54.18 days), and produced the longest ears (17.91 cm), widest ears (4.52 cm), most kernel rows (15.96), heaviest fresh ears (229 g), the highest kernel yield (5.56 t ha<sup><span class="CharOverride-4">-1</span></sup>), and the highest WUE (2.64 kg m<span class="CharOverride-4">-3</span>). The 50 mg L<sup><span class="CharOverride-4">-1</span></sup>&nbsp;fertilizer treatment produced the longest ears (17.61 cm), widest ears (4.58 cm), more kernel rows (16.61), the highest kernel yield (5.64 t ha<span class="CharOverride-4">-1</span>), and the highest WUE (2.68 kg m<sup><span class="CharOverride-4">-3</span></sup>). The least time to maturity (57.72 days) and heaviest fresh ears (232 g) occurred with 75 mg L<sup><span class="CharOverride-4">-1</span>&nbsp;</sup>of boron fertilizer.&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>The use of 50 mg L<sup><span class="CharOverride-4">-1</span></sup>&nbsp;boron, as a foliar fertilizer, appears to be, next to the transplanting method, suitable for the cultivation of sweet corn plants to increase productivity and WUE.</p> Aziz Mahdi Al-Shammari, Ghassan Jaafar Hamdi, Solieman Daowd Najm Abdullah ##submission.copyrightStatement## Fri, 19 Nov 2021 00:00:00 -0600 Performance and silage inclusion of oat forage (Avena sativa L.) AV25 in diets for dairy cattle (Bos primigenius Taurus) <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;The use of forage oat silage (<em><span class="CharOverride-9">Avena sativa</span></em>&nbsp;L.) in dairy cattle in times of feed deficit, allows mitigating biomass losses due to drought in the Colombian high tropics.<span class="CharOverride-2">&nbsp;<strong>Objectives.</strong>&nbsp;</span>1) To determine the dry matter yield (DMY) of five forage oat genotypes and the phenotypic stability and the bromatological quality of their silage, and 2) to evaluate the inclusion of the AV25-T genotype silage in diets for dairy cattle.&nbsp;<span class="CharOverride-2"><strong>Materials and methods.</strong>&nbsp;</span>In the Colombian high tropics two experiments were performed: 1) agronomic evaluation test (October 2017 and February 2018) in a randomized complete block design with five genotypes, eight locations, and four replicates; dry matter yield (DMY) and protein, neutral detergent fiber (NDF) and total digestible nutrients (TDN) contents in silage were determined, and 2) animal response study (January 2018) with the inclusion of the AV25-T genotype in diets, in a simple crossover design with two factors: animal (5) and diets (3); the diets were: D1: only meadow; D2: 35 % AV25-T silage + grazing, and D3: 65 % AV25-T silage + grazing. Milk yield, protein, fat, total solids, were determined in the milk, and weight change was determined in the animals.&nbsp;<span class="CharOverride-2"><strong>Results.</strong>&nbsp;</span>AV25-T presented adaptation with the highest DMY. The inclusion of AV25-T silage in the animal diet showed a significant change in animal weight (0.1 and 0.25 kg with D2 and D3), milk yield (27.2 - 29.7 L/cow/day with D3 and D2), and the fat content (3.2 - 3.9 % with D3 and D2), without detriment in protein and total solids.<strong><span class="CharOverride-2">&nbsp;Conclusion.&nbsp;</span></strong>The use of AV25-T forage oats in silage allowed increases in animal weight, milk yield, and fat content in Holstein dairy cows without affecting protein and total solids in milk.</p> Luis Fernando Campuzano-Duque, Edwin Castro-Rincón, Javier Castillo-Sierra, Daniel Torres-Cuesta, David Nieto-Sierra, Paola Portillo-López ##submission.copyrightStatement## Wed, 10 Nov 2021 00:00:00 -0600 In vitro ruminal degradation of Tithonia diversifolia <p><strong><span class="CharOverride-2">Introduction.</span>&nbsp;</strong>The Mocache canton (Ecuador) is a humid tropical zone, with a dry season of six months, which affects the availability and quality of forage, a situation that reduces the productive and reproductive capacity of ruminants.&nbsp;<span class="CharOverride-2"><strong>Objective.</strong>&nbsp;</span>To evaluate the apparent<span class="CharOverride-7">&nbsp;in vitro</span>&nbsp;ruminal degradation parameters of dry matter (DMD), organic matter (OMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD) in&nbsp;<span class="CharOverride-7">Tithonia diversifolia</span>&nbsp;harvested at four different cutting ages during the dry season.<strong> Materials and methods.</strong> The research was carried out at the “La María” Experimental Farm of the Universidad Tecnica Estatal de Quevedo, Ecuador, between August and October 2017. Four rumen fistulated bulls were used. A complete randomized design (CRD) was used. The treatments were:&nbsp;<em><span class="CharOverride-7">Tithonia diversifolia</span></em>&nbsp;at 30 days of cutting (T1),&nbsp;<em><span class="CharOverride-7">Tithonia diversifolia</span></em>&nbsp;at 45 days of cutting (T2),&nbsp;<em><span class="CharOverride-7">Tithonia diversifolia</span></em>&nbsp;at 60 days of cutting (T3), and&nbsp;<em><span class="CharOverride-7">Tithonia diversifolia</span></em>&nbsp;at 75 days of cutting (T4). The incubation times were: 3, 6, 12, 24, 48, and 72 hours with four replicates per treatment. The variables evaluated were: DMD, OMD, NFDD, and AFDD.&nbsp;<span class="CharOverride-2"><strong>Results.</strong>&nbsp;</span>The ruminal degradation parameters showed statistical differences between treatments (p&lt;0.05), with T1 the best DMD, OMD, NDFD, and ADFD were obtained with 36.66, 35.44, 43.16, and 41.55 %, respectively).&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>The highest DMD, OMD, NDFD, and ADFD parameters were associated with the cutting ages and the structural components of the bromatological composition. The cutting age at 30 days in&nbsp;<span class="CharOverride-7">Tithonia diversifolia</span>&nbsp;influenced the potential and the effective nutrients degradation. As the cutting ages increased, the ruminal degradation parameters decreased.</p> Gary Alex Meza-Bone, Carlos Javier Meza-Bone, Juan Humberto Avellaneda-Cevallo, Luis Alverto Godoy-Montiel, Marcos Antonio Barros-Rodríguez, Fernando Jines-Fernández ##submission.copyrightStatement## Wed, 03 Nov 2021 00:00:00 -0600 Germination and growth of Leonia glycycarpa in Arosemena Tola, Napo, Ecuador <p><span class="CharOverride-2"><strong>Introduction.</strong>&nbsp;</span>The loss of wild plants species generates the need to evaluate their germination and growth characteristics in different environments in the Amazon region.&nbsp;<span class="CharOverride-2"><strong>Objective.</strong>&nbsp;</span>To evaluate the ex-situ germination and growth of&nbsp;<em><span class="CharOverride-6">Leonia glycycarpa</span></em>&nbsp;under conditions of primary forest soil use and coverage of intervened areas at the Amazonian Research, Postgraduate, and Conservation Center in Arosemena Tola, Napo, Ecuador.&nbsp;<span class="CharOverride-2"><strong>Materials and methods.</strong>&nbsp;</span>The study was developed in two phases between 2018-2020, the first, of&nbsp;<span class="CharOverride-6">ex-situ</span>&nbsp;germination in the greenhouse, where days until emergence and growth in tray were recorded, and the second of pre-transplant growth in field, in primary forest soil use and coverage of the intervened zone (<em><span class="CharOverride-6">Inga</span></em>&nbsp;sp. woodland and melatomatacea woodland). The height of the plant, stem diameter, and number of leaves up to 360 days and environmental variables such as air temperature, luminosity, and soil nutrients were recorded. Growth curves were established for plant height and stem diameter. A correlation analysis was carried out between the growth measures and the environmental and edaphic variables.&nbsp;<strong><span class="CharOverride-2">Results.</span></strong>&nbsp;In the first phase, an average of 33.5 days to emergence was obtained with 76 % of plants emerged at 45 days, reaching an average of 10.7 cm in height and 3.02 mm in diameter. In the field growth, the plants located in the intervened zone reached greater development and the linear and quadratic models prevailed in plant height and linear in stem diameter. Significant correlations were found between nutrient content and temperature and growth variables.&nbsp;<span class="CharOverride-2"><strong>Conclusion.</strong>&nbsp;</span><em><span class="CharOverride-6">L. glycycarpa</span></em>&nbsp;could be propagated under greenhouse conditions. Environmental and edaphic factors influenced growth in height, diameter and number of leaves, having greater growth cover in the intervened zone.</p> Ricardo Vinicio Abril-Saltos, Carolina Yasmin Villarroel-Gancino, Diego Mauricio Ramos-Criollo, Briyiidt Maryeli Pillco-Herrera, Jonny David Quishpe-López, Katherine Pamela López-Adriano ##submission.copyrightStatement## Wed, 03 Nov 2021 00:00:00 -0600 In vitro multiplication of yellow dragon fruit (Hylocereus megalanthus) from seedlings obtained in vitro <p><span class="CharOverride-2"><strong>Introduction.</strong>&nbsp;</span>The nutritional properties, antioxidant capacity, and commercial value of the yellow dragon fruit are attractive for its sowing; therefore, it is necessary to study technological improvements for its propagation.&nbsp;<span class="CharOverride-2"><strong>Objective.</strong>&nbsp;</span>To evaluate the feasibility of in vitro establishment and multiplication of yellow dragon fruit, with the use as explants of seedlings from the in vitro germination and various hormonal sources.&nbsp;<strong><span class="CharOverride-2">Materials and methods.</span></strong>&nbsp;The experiment was developed in the Plant Physiology and Biotechnology Laboratory of the Universidad Nacional Toribio Rodriguez de Mendoza, Peru, between February and June 2020. Four treatments were evaluated for germination [control: sterile water (3 mL), E1: MS (50 %), sucrose (30 g L<sup><span class="CharOverride-4">-1</span></sup>), agar (6 g L<sup><span class="CharOverride-4">-1</span></sup>), E2: AG<span class="CharOverride-7">3</span>&nbsp;(250 mg L<sup><span class="CharOverride-4">-1</span></sup>), E3: MS (100 %), sucrose (30 g L<sup><span class="CharOverride-4">-1</span></sup>), agar (6 g L<sup><span class="CharOverride-4">-1</span></sup>), AG<span class="CharOverride-7">3</span>&nbsp;(250 mg L<sup><span class="CharOverride-4">-1</span></sup>)] and multiplication [control: MS (100 %), sucrose (30 g L<sup><span class="CharOverride-4">-1</span></sup>), agar (7 g L<sup><span class="CharOverride-4">-1</span></sup>), M1: MS (100 %), sucrose (30 g L<sup><span class="CharOverride-4">-1</span></sup>), agar (7 g L<sup><span class="CharOverride-4">-1</span></sup>), coconut water (10 ml L<sup><span class="CharOverride-4">-1</span></sup>), M2: MS (100 %), sucrose (30 g L<span class="CharOverride-4">-1</span>), agar (7 g L<sup><span class="CharOverride-4">-1</span></sup>), coconut water (20 ml L<sup><span class="CharOverride-4">-1</span></sup>), activated carbon (2 g L<sup><span class="CharOverride-4">-1</span></sup>), M3: MS (100 %), sucrose (30 g L<sup><span class="CharOverride-4">-1</span></sup>), agar (7 g L<sup><span class="CharOverride-4">-1</span></sup>), BAP (0.10 mg L<sup><span class="CharOverride-4">-1</span></sup>), ANA (3 mg L<sup><span class="CharOverride-4">-1</span></sup>)]. The evaluated variables were: germination (%), number and length of shoots and roots, callus formation (%), rooting (%), and the number of areoles.&nbsp;<span class="CharOverride-2"><strong>Results.</strong>&nbsp;</span>The best germination (100 %) was obtained in the E1 medium, with more than three roots and two shoots per seedling (2,64 cm). The M2 medium generated the best multiplication, with 82.5 % rooting, 1.66 cm shoots and 1.86 areoles, and less presence of callus tissue (60 %).&nbsp;<span class="CharOverride-2"><strong>Conclusion.</strong>&nbsp;</span>The micropropagation of yellow dragon fruit was achieved by using seedlings obtained<em>&nbsp;<span class="CharOverride-6">in vitro</span></em>&nbsp;as an explant source.</p> Gerardo Mállap-Detquizán, Nuri C. Vilca-Valqui, Jegnes Benjamín Meléndez-Mori, Eyner Huaman-Huaman, Manuel Oliva ##submission.copyrightStatement## Wed, 03 Nov 2021 00:00:00 -0600 Effect on wheat (Triticum aestivum) yield of the yellow rust caused by Puccinia striiformis f. sp. tritici and its effect on yield <p><span class="CharOverride-2"><strong>Introduction.</strong>&nbsp;</span>In recent years, yellow rust caused by&nbsp;<em><span class="CharOverride-6">Puccinia striiformis</span>&nbsp;</em>was the most prevalent disease in wheat (<em><span class="CharOverride-6">Triticum aestivum</span></em>), in the north of the province of Buenos Aires, Argentina.<strong>&nbsp;<span class="CharOverride-2">Objective.</span>&nbsp;</strong>To evaluate the progress of yellow rust in wheat cultivars, with and without foliar fungicide application and its effect on yield and its components.&nbsp;<span class="CharOverride-2"><strong>Materials and methods.</strong>&nbsp;</span>This study was carried out during two consecutive years (2017 and 2018) in the town of Junín, Buenos Aires, Argentina, on nineteen wheat cultivars, with and without foliar fungicide application. The damages of yellow rust on yield and industrial quality were quantified. Likewise, the evolution of the disease was evaluated using the area under the disease intensity progress curve (ABCPIE). The ABCPIE was associated with the yield, its components, and hectoliter weight.&nbsp;<span class="CharOverride-2"><strong>Results.</strong>&nbsp;</span>Of all the variables analyzed, the ABCPIE had a significant interaction (p&lt;0.05) between the foliar fungicide application and the cultivar used. The cultivars Lapacho, Minerva, MS 415, and SY 211 were resistant to yellow rust. The cultivar most susceptible to the disease was Algarrobo. The application of foliar fungicide, with low levels of the disease, significantly reduced its evolution, as reflected from the area under the disease intensity progress curve.&nbsp;<span class="CharOverride-2"><strong>Conclusion.</strong>&nbsp;</span>The evolution over time of the yellow rust caused by&nbsp;<span class="CharOverride-6">P. striiformis&nbsp;</span>depended on the genetic behavior of the cultivar and the application of foliar fungicide. The cultivars that had the highest yields, lowest ABCPIE, and highest hectoliter weight were: Lapacho, SY 11, BIO 1006, and Minerva.</p> Miguel Lavilla ##submission.copyrightStatement## Tue, 26 Oct 2021 00:00:00 -0600 Chitosan applied in the treatment of wastewater from palm oil production <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;The use of biopolymers in effluents treatment allows to control the environmental impact associated with agroindustrial wastewater discharge.&nbsp;<span class="CharOverride-2"><strong>Objective.</strong>&nbsp;</span>To evaluate the effectiveness of chitosan as a natural coagulant in the treatment of palm oil production effluents.<span class="CharOverride-2">&nbsp;<strong>Materials and methods.&nbsp;</strong></span>The following parameters were determined: Chemical Oxygen Demand (COD), total suspended solids (TSS) and volatile solids (TVS), turbidity and fats and oils (GYA) in wastewater associated with palm oil production from the municipality of Agustín Codazzi in the department of Cesar (Colombia), by the jar test assay. Chitosan was applied in doses of: 100, 200, 300, 400, and 0 mg L<sup><span class="CharOverride-3">-1</span></sup>&nbsp;at three pH levels 4, 5, and 6 of the water. A completely randomized, two-way, fixed effects experimental was implemented. A multivariate analysis of the physical-chemical parameters of industrial effluent was used for data analysis. The study was conducted in 2012.&nbsp;<strong><span class="CharOverride-2">Results.</span>&nbsp;</strong>Chitosan allowed a reduction of more than 87 % turbidity, COD, TSS, TVS and fats and oils in all coagulant doses. While the control (0 mg L<sup><span class="CharOverride-3">-1</span></sup>) was statistically different (p&lt;0.05) to all the treatments. In the multivariate analysis of the data, the principal component 1 (PC1) explained 79.3 % of the total variance of the variables.&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>Doses of 100, 200, 300, and 400 mg L<sup><span class="CharOverride-3">-1</span></sup>&nbsp;of chitosan evaluated as a natural coagulant in water treatment, decreased the concentration of pollutants in effluents associated with palm oil production.</p> Dalia Milena Rodríguez-Jiménez, Esteban Burbano-Erazo, Yim James Díaz-Rodríguez ##submission.copyrightStatement## Tue, 19 Oct 2021 00:00:00 -0600 Diagrammatic scale for assessment the severity of Cercospora leaf blight on soybean (Glycine max) leaflets <p><strong><span class="CharOverride-2">Introduction.&nbsp;</span></strong>Cercospora leaf blight (CLB) caused by&nbsp;<em><span class="CharOverride-5">Cercospora kikuchii</span>&nbsp;</em>is an endemic soybean crop disease in Argentina.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To develop and validate a scale to quantify the severity of CLB in leaflets of soybean (<em><span class="CharOverride-5">Glycine max</span></em>) for the evaluation of foliar fungicides and cultivar trials.&nbsp;<span class="CharOverride-2"><strong>Materials and methods</strong>.&nbsp;</span>A diagrammatic scale to assess the severity of CLB on soybean leaflets (<span class="CharOverride-5"><em>Glycine ma</em>x</span>) was developed. The scale was based on the evaluation of 50 leaflets. The different severity levels of the leaflets were determined according to Weber-Fechner’s stimulus-response law. The proposed scale included severity levels of 1, 4.5, 17.5, 50, 82.2, 95, and 99 %. The validation of the scale was performed by 23 raters (3 experienced and 20 inexperienced) who assessed the severity of CLB on 50 leaflets with and without the use of the scale.<span class="CharOverride-2">&nbsp;<strong>Results.&nbsp;</strong></span>The results from the three experienced raters were more precise than those obtained by the inexperienced raters. The scale improved the visual interpretation to assess the severity of CLB for the inexperienced raters, who obtained estimated severity values close to the actual severity values. When the inexperienced raters used the proposed scale to estimate the severity of CLB on leaflets, they were accurate having determination coefficients (R2) between 0.74 and 0.91. According to the absolute errors, the greatest deviation was observed between -2.49 and 2.46. However, these deviations were not significantly different from the population average. To speed the process of cultivar evaluations we also propose the use of scales based on grades.&nbsp;<strong><span class="CharOverride-2">Conclusions.</span></strong>&nbsp;The proposed scale to assess the severity of CLB on leaflets can be used for the assessment of foliar fungicide trials and soybean cultivars. The scale showed specificity for assessing the severity of Cercospora leaf blight (CFB) in soybean leaflets.</p> Miguel Lavilla, Antonio Ivancovich, Antonio Díaz-Paleo ##submission.copyrightStatement## Mon, 11 Oct 2021 00:00:00 -0600 Water hyacinth (Eichhornia crassipes): A review <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;The water lily (<em><span class="CharOverride-5">Eichhornia crassipes</span></em>) is a free-floating hydrophytic plant of the Pontederiaceae family. It is one of the aquatic plants with the best reproduction and growth rate, so it spreads and forms mats that constrict submerged and floating native plants, reduces the entry of light into bodies of water and decreases the dissolved oxygen in the water.<strong>&nbsp;<span class="CharOverride-2">Objective.&nbsp;</span></strong>To carry out a comprehensive review of the water lily that allows the scientific community a better understanding of an invasive species, as well as the effects it causes on the ecosystem.&nbsp;<strong><span class="CharOverride-2">Development.&nbsp;</span></strong>The invasive capacity of this plant endangers various ecosystems, as it takes advantage of nutrient-rich waters. In addition, the dense floating colonies cause the oxygen content to drop to zero below its mantle, causing damage to the ecosystems.&nbsp;<strong><span class="CharOverride-2">Conclusions.</span>&nbsp;</strong>The water lily is one of the most invasive aquatic plants in the world, causing ecological and socio-economic effects. This plant has been used as a phytoremediator, in the removal of organophosphates, which indicates that it can be used to clean sewage. Furthermore, it can be used in the production of ethanol, paper, compost, biogas, human food, animal fodder, fiber, and in the extraction of volatile fatty acids.</p> Jessica Wendolin Rodríguez-Lara, Francisco Cervantes-Ortiz, Gerónimo Arambula-Villa, Luis Antonio Mariscal-Amaro, Cesar Leobardo Aguirre-Mancilla, Enrique Andrio-Enríquez ##submission.copyrightStatement## Mon, 04 Oct 2021 00:00:00 -0600 Effect of pruning on the Capsicum annum L. yield under two environments <p><strong><span class="CharOverride-2">Introduction.&nbsp;</span></strong>Pruning the stems of bell pepper has been recommended to improve light interception, increase fruit set, and the quality of fruits.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To evaluate the effect of pruning on yield components of two pepper hybrids established in two environments: open field and protected field under roof with plastic and natural ventilation.&nbsp;<span class="CharOverride-2"><strong>Materials and methods.</strong>&nbsp;</span>Two trials were conducted at the La Selva Research Center of the Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA), Rionegro, Antioquia, Colombia. Two pepper hybrids of block type were evaluated in two environments: open field (in the 2013-2014 cycle) and protected field under plastic cover (in the 2013-2014, 2014-2015 cycles), and three formation pruning treatments: two stems, three stems, and no pruning. For the first experiment, a randomized complete block design with six treatments (two hybrids and three pruning systems) and five replicates was used. For the second, the same treatments were established only under the protected environment, in a randomized complete block design.&nbsp;<strong><span class="CharOverride-2">Results.&nbsp;</span></strong>Statistical differences were found for total yield in the unpruned system in both trials. In the protected field–2013 the hybrids achieved an average yield of 36.7 t ha<sup><span class="CharOverride-5">-1</span></sup>, the unpruned system was the highest yielding (49.7 t ha<sup><span class="CharOverride-5">-1</span></sup>). In the open field the yield was 23.6 t ha<sup><span class="CharOverride-5">-1</span></sup>. The total yields obtained under the protected field-2014 (36.2 t ha<sup><span class="CharOverride-5">-1</span></sup>), equaled that obtained in 2013, and statistically exceeded those of the open field.&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>Unpruned plants showed the best yields in both trials. Differences between environments, hybrids, and their interaction were present in some variables. Further studies should be carried out to determine if the protected environment is suitable for the development of the hybrids.</p> Luz Fanny Orozco-Orozco, Jaime Lozano-Fernandez ##submission.copyrightStatement## Mon, 04 Oct 2021 00:00:00 -0600 Control of cacao (Theobroma cacao) diseases in Santo Domingo de los Tsachilas, Ecuador <p><strong><span class="CharOverride-11">Introduction.</span></strong>&nbsp;Ecuador occupies the fourth place in cocoa exports with 293,487 tons per year, produced on 559,617 hectares. However, its yield per hectare is low mainly due to the presence of pathogens that affect the pods<strong>.<span class="CharOverride-11">&nbsp;Objective.</span></strong>&nbsp;To evaluates different methods of control of pathogens of the&nbsp;<span class="CharOverride-5">Theobroma cacao&nbsp;</span>cv ‘CCN-51’ pod.<span class="CharOverride-11">&nbsp;<strong>Materials and methods.</strong></span><strong>&nbsp;</strong>The work was carried out in Luz de America, Santo Domingo de los Tsachilas, Ecuador, between 2016 and 2017. The treatments were the result of the combination of cultural practices + two fungicides (Chlorothalonil and Pyraclostrobin) + one biofungicide Serenade® (<em><span class="CharOverride-5">Bacillus subtilis</span></em>&nbsp;QST713), with and without fertilizers. In total, 16 treatments were evaluated with 3 replicates or blocks, installed in a commercial cocoa plantation cv ‘CCN-51’ and under a Randomized Complete Block Design (RCBD).&nbsp;<strong><span class="CharOverride-11">Results.</span>&nbsp;</strong>The use of fungicides (chemical and biological), decreased the incidence of moniliasis (<em><span class="CharOverride-5">Moniliophthora roreri</span></em>), black pod rot (<span class="CharOverride-5"><em>Phytophthora</em>&nbsp;</span>spp.), and cherelle wilt; but the application of fertilizers did not increase the effectiveness of these products. Treatment with only cultural practices did not decrease the final incidence of moniliasis, nor of brown rot, in contrast, the final incidence of cherelle wilt increased. The number of pods and the yield were not directly related and the highest yield of fermented and dry cocoa, corresponded to T9 [Cultural labors + Serenade® (0.2 kg ha<sup><span class="CharOverride-10">-1</span></sup>) (every 15 days) + Fertilizer (0.3 kg ha<sup><span class="CharOverride-10">-1</span></sup>) + Fertilizer (1 kg plant<sup><span class="CharOverride-10">-1</span></sup>)], a treatment that also had the highest net income per hectare.&nbsp;<strong><span class="CharOverride-11">Conclusion.&nbsp;</span></strong>Chemical and biological control can manage cocoa pods pathogens. The integration of both control methods allowed the cocoa producer to obtain greater income.</p> Vicente Anzules-Toala, Elvis Pazmiño-Bonilla, Leonel Alvarado-Huamán, Ricardo Borjas-Ventura, Viviana Castro-Cepero, Alberto Julca-Otiniano ##submission.copyrightStatement## Tue, 21 Sep 2021 00:00:00 -0600 Chemical properties of the oil of five genotypes of Jatropha curcas L., in Colombia <p><strong><span class="CharOverride-2">Introduction.</span></strong><span class="CharOverride-5"><strong>&nbsp;</strong><em>Jatropha curcas</em></span>&nbsp;L. (JC) is a multipurpose species with biological, pharmacological, and industrial applications. Its oil is recognized by the dominant composition of oleic-linoleic fatty acids that make it suitable as biofuel in internal combustion engines, without making major changes to the engine design.&nbsp;<strong><span class="CharOverride-2">Objective.</span></strong>&nbsp;To identify in the oil of five JC genotypes in Colombia the cetane, peroxide, iodine, the acidity value, the calorific value indixes and to verify if they comply with standards for biodiesel production.&nbsp;<strong><span class="CharOverride-2">Materials and methods.</span></strong>&nbsp;An experiment was carried out in Espinal, Colombia, in a randomized complete block design with five treatments and three repetitions. The treatments consisted of five JC genotypes. The fruit from the fifth harvest in 2015 was used. Five fatty acids (oleic, linoleic, linolenic, palmitic, and stearic) and five chemical properties (cetane index, acidity, peroxide, iodine, and calorific value) were determined from the oil.&nbsp;<strong><span class="CharOverride-2">Results.</span></strong>&nbsp;The oil from the five JC genotypes evaluated in Colombia presented a lipid profile with a predominance of monounsaturated (oleic C18: 1) and polyunsaturated (linoleic C18: 2) fatty acids. The JC genotypes evaluated in Colombia presented a low cetane, peroxide, and iodine indexes, low acidity, and high calorific value.&nbsp;<strong><span class="CharOverride-2">Conclusions.&nbsp;</span></strong>The properties of cetane and iodine indexes, of the genotypes evaluated complied with the specifications of the American Society for Testing and Materials (ASTM) and the European Norm for biofuel production, so they are classified as appropriate raw material for biofuel production.</p> Luis Fernando Campuzano-Duque, Fernando Cardeño-López ##submission.copyrightStatement## Fri, 17 Sep 2021 00:00:00 -0600 Carcass characterization of the slaughtered sheep in a meat processing plant in Córdoba, Colombia <p><strong><span class="CharOverride-2">Introduction.</span></strong>&nbsp;In Colombia, sheep are a promising species for meat production; however, reports on the characteristics of the carcass at a commercial level in the region are unknown.&nbsp;<strong><span class="CharOverride-2">Objective.</span>&nbsp;</strong>To diagnose the carcass quality of the sheep slaughtered in a meat processing plant in the Department of Cordoba, Colombia.&nbsp;<strong><span class="CharOverride-2">Materials and methods.</span></strong>&nbsp;From May 2017 to July 2018, variables were recorded in 883 sheep (phenotype, live weight, and sex) and their carcasses (weights, conformation and fatness, intrathoracic hemorrhages, morphometry, and pH at 24 h). A sampling was carried out on four groups of carcasses from castrated (C) and whole (E) animals, with three slaughter weights (lights: CL=±23.8 kg and EL= 23.9 kg; medium: CM=±27.7 kg; heavy: EP=36.2 kg) in an unbalanced design, to evaluate carcass and tissue composition of the shoulder.&nbsp;<strong><span class="CharOverride-2">Results.&nbsp;</span></strong>The hot carcass weight (PCC), carcass yield (RCC), and compactness index were 11.11 kg; 41.49 %, and 0.19. The carcasses showed normal to poor muscular conformation (87.7 %) and very low-fat cover (68.7 %). Males accounted for 84.3 % of the carcasses, with a PCC of 10.86±0.09 kg and a RCC of 41.51±0.1 %. Females, mostly older than one year (66.90 %), had significantly higher PCC 12.47±0.22 kg, but similar RCC than males. Intrathoracic hemorrhages occurred in 10.9% of the carcasses; pH24 in males and females were 5.84±0.01 and 5.94±0.03, respectively. The CL, CM, EL, and EP of carcasses presented, respectively, 63.66, 61.74, 62.17, and 64.80 % of muscle (p&lt;0.05), 7.20, 11.56, 6.48, and 6.80 % of total fat (p&lt;0.001), and 21.35, 19.66, 23.45, and 21.07 % of bone (p&lt;0.001).&nbsp;<strong><span class="CharOverride-2">Conclusion.&nbsp;</span></strong>The sheep presented low slaughter weight, with heterogeneous carcasses, with normal to poor muscular conformation, low compactness index, and very lean.</p> <p>&nbsp;</p> Lorena Angélica Aguayo-Ulloa, Clara Viviana Rua-Bustamante, Emiro Andrés Suárez-Paternina, Leyla Ríos-de-Álvarez ##submission.copyrightStatement## Sun, 12 Sep 2021 00:00:00 -0600