Revista de la Facultad de Agronomía de la Universidad del Zulia <p>The Journal of the Faculty of Agronomy, Universidad del Zulia is a publication of the Agronomic Research Institute of the Faculty of Agronomy, Universidad del Zulia, published since 1968 and is supported by the Universidad del Zulia, in order to disseminate the results of researchers Venezuelans and other parts of the world, related to the agricultural field. The Rev. Fac. Agron. (LUZ) publishes four issues per year, i. e., every three months, under continuous publication format (rolling pass). , with original and unpublished scientific articles, technical notes, review articles, quick communications, extensive summaries of congresses and scientific meetings related to the agricultural area for the consideration of the Editorial Committee. The journal publishes research products of high scientific quality and promotes the exchange of publications and scientific activity at the agricultural level, in the areas of Plant Production, Animal Production, Food Technology and Socioeconomics. The topics included in these areas are: agrosystem management, environment, agricultural biotechnology, meat science, milk science, rural development, agricultural economics, agricultural entomology, fertilizers, post-harvest physiology, plant physiology, physiology and animal reproduction, pastures and forages, animal and plant genetics and improvement, weeds, animal nutrition, plant pathology, agri-food safety, agri-food systems and soils.</p> Universidad del Zulia en-US Revista de la Facultad de Agronomía de la Universidad del Zulia 0378-7818 Fluctuation of main insect pests and diseases in cañihua (Chenopodium pallidicaule Aellen) of the Peruvian Andean Altiplano <p>The Andean crop germplasm bank, of the Camacani Experimental Center of the Universidad Nacional del Altiplano de Puno, has around 400 accessions of cañahua (<em>Chenopodium pallidicaule</em> Aellen), and 27 of them have been agronomically characterized. Given the importance of this crop for the inhabitants of highlands of the Peruvian Andes, the objective of this research was to assess the population fluctuation of insect pests and the severity of diseases in the mentioned accessions, along with three commercial varieties. The evaluations were carried out in three phases of the crop development, including the grain yield. It was found that the accessions and varieties of cañahua were tolerant to the attack of most pests and diseases. The most important pest was <em>Eurysacca quinoae</em> Povolny, especially in the accession 03-21-26 and the Ramis variety, in which up to 5.5 and 4.5 larvae were found per plant, respectively; however, the pest did not exceed the economic threshold of 6 larvae per plant during the phenological phases. In regards to diseases, it was confirmed that <em>Peronospora </em>sp. (mildew) is the main pathology that occurred during the agricultural season. Accessions 03-21-03 and 03-21-24 were not affected by the disease, while accessions 03-21-267, 03-21-218, 03-21-124, 03-21-26 and 03-21-64 were the most affected, showing the highest severity and area under the disease progress curve.&nbsp; When evaluating one season, the accessions and varieties of cañihua showed resistance to insect-pests and diseases, without appreciably decrease of their grain yields.</p> Betsabe Leon Ttacca Rosario Bravo Portocarrero Joven Llanos Nina Alicia Leon Tacca Wenceslao Medina Espinoza Copyright (c) 2022 Betsabe Leon Ttacca, Rosario Bravo Portocarrero, Joven Marino Llanos Nina, Alicia Leon Tacca, Wenceslao T. Medina Espinoza 2022-03-21 2022-03-21 39 2 e223923 e223923 Population fluctuation of Anastrepha spp. in Creole mango in four locations in Vinces, Ecuador <p>Among species in the genus <em>Anastrepha </em>we find several key pests belonging to fruit crops of quarantine importance established by importing countries. The knowledge of population fluctuation of these pests, in certain areas is a starting point for designing control strategies. The population fluctuation of fruit flies was evaluated in four localities of the Vinces country, Los Ríos province (La Americana, Santa Martha, Primavera and Pavana). For this purpose, we used McPhail traps with hydrolyzed protein bait, and placed three traps per site into trees that are recognized hosts of fruit flies. Traps were reviewed weekly, and fly.trap<sup>‐</sup><sup>1</sup>.day<sup>‐</sup><sup>1</sup> (FTD) index was determined, outcomes were correlated with climatic variables. Results show that population peaked in December, FTD was 5,94, temperature was 27,40°C and relative humidity 78%. We found a positive moderate correlation between the captured insects and the temperature expressed in °C, with a correlative value r = 0,61 and a negative correlation with relative humidity (r = ‐0.64). <em>Anastrepha fraterculus </em>(Wiedemann) was the most conspicuous with 3111 specimens, 1055 were found in La Americana, the location with the highest infestation.</p> Jorge Meza Alexander Rodríguez Edwin Mendoza Copyright (c) 2022 Jorge Javier Meza Aguila, Alexander Regulo Rodríguez Berrio, Edwin Amado Mendoza Hidalgo 2022-03-31 2022-03-31 39 2 e223925 e223925 Design, installation and calibration of a block of lysimeters to adjust the crop coefficient <p>The efficient management of water resources using techniques that improve it uses, based on knowledge of evapotranspiration are key elements for crop production. Amongst main techniques for water management, the use of drainage lysimeter installed in the field below vegetable fields may be used to quantify the amount of water needed. The aim of this work is to design, install and calibrate a set of lysimeters for adjusting crop coefficient (Kc). In the calibration of the lysimeters, it was obtained that to induce drainage in lysimeters from one to five, an over-irrigation of 25% of the field capacity was needed, while the rest needed 50%. With lysimeters built the physical characteristic of soil could be simulated in this study.</p> Juan León Vicente Parra Robinson Peña Juan Silva Daniel Román Francisco Salazar Copyright (c) 2022 Juan Eduardo León Ruíz, Vicente Javier Parra León, Robinson Fabricio Peña Murillo, Juan Sebastián Silva Orozco, Daniel Arturo Román Robalino, Francisco Gabriel Salazar Badillo 2022-04-18 2022-04-18 39 2 e223926 e223926 Physical-chemical characterization of local maize from Chiapas, Mexico <p>The physical-chemical quality of maize has become important for the food industry, so it is a condition for the selection of any local cultivar or improved varieties. The physical-chemical quality of local maize from La Sepultura Biosphere Reserve (REBISE), Chiapas, was characterized, to demonstrate that the maize diversity in the reserve presents potential for the flour and tortilla industry in Mexico. Collections of eighteen local maize populations associated with different races and two commercial hybrid materials were evaluated. Nineteen variables were characterized using multivariate techniques of Factor Analysis and Clusters. By reduction of data, six components were extracted. Typology of maize varieties merged into four groups: Group I) Of high projection in the components of &nbsp;breaking strength (Fu Rup RE, 300.25 gf) and pericarp dissolution (pericarp, 5.39 %; retained pericarp, 47.91 %); Group II) also high scoring in breaking strength and its persistence (Fu Rup RE, 277.25 gf), but low scoring for grain consistence and protein yield (flotation index &nbsp;24.50); weight of 100 grains 33.31 g, (grain proteins 9.94 %); Group III) presented greater projection in the component of grain density, and moisture of the nixtamal and the dough (hectoliter weight 73.5 kg<sup>-hl</sup>, elongation 13.60 mm, dough moisture 57.95 %, Fu Rup RE, 220.83 gf); Group IV) showed lower projection in nixtamal moisture (44.48 %) and dough,&nbsp;so as elasticity of the tortillas (12.94 mm). The physical-chemical variables contributed to identify cultivar groups on the quality of the grain.</p> Francisco Guevara-Hernández Manuel Hernández-Ramos Manuel La O-Arias René Pinto-Ruíz Luis Rodríguez-Larramendi Deb Raj Aryal Copyright (c) 2022 Francisco Guevara-Hernández, Manuel Antonio Hernández-Ramos, Manuel Alejandro La O-Arias, René Pinto-Ruíz, Luis Alfredo Rodríguez-Larramendi, Deb Raj Aryal 2022-03-21 2022-03-21 39 2 e223924 e223924 Physico-chemical quality of fish products marketed in Colombia <p>The nutritional characteristics of fish products have positioned them as one of the fastest growing food categories worldwide. Additionally, for developing innovative foods, it is crucial to understand the physico-chemical properties of commercial products and to be familiar with the food industry regulations that determine the criteria and specifications for new developments. For this purpose, frequency questionnaires were applied to fish products marketed in the retail sector. Additionally, processed products were selected for analytical determinations of moisture, NaCl content, and water activity. The results showed that 80% of the products are marketed in large supermarkets with 20% in local markets. It was also observed that 79% of the products are of national origin. The highest salt contents on a dry basis (~48%) were determined on smoked salmon and salted-smoked herring samples, while tilapia patties showed the lowest NaCl values on a dry basis ~6%. Within the Colombian market, products with a high degree of processing are imported and they contain higher salt contents. The national product offers low processing levels, being mainly frozen fillets. This opens the possibility for the development of innovative products using local raw materials.</p> Silvia Carrera Nelson Gutiérrez Joel Girón Copyright (c) 2022 Silvia Carrera, Nelson Gutiérrez Guzmán, Joel Girón Hernández 2022-04-18 2022-04-18 39 2 e223927 e223927 Dynamics of carbon storage in forage systems in a livestock farm in Concepción, Paraguay <p>Although the capacity of plants to store carbon is known, obtaining information about the sequestration potential in the soil and in herbaceous, shrubby and tree biomass in land use systems is essential, even more in landscapes dominated by livestock. The objective was to study the dynamics of carbon storage in three different forage systems in a livestock farm in Concepción, Paraguay. For this, the carbon level was estimated at different soil depths (0-20, 20-40 and 40-60 cm) and in the herbaceous/shrub biomass in three systems (<em>Brachiaria brizantha cv Marandú, Panicum maximum cv Colonial and Leucaena leucocephala</em> consortium with <em>colonial</em>), with an interval of 30 days between the three measurement moments. The results generated from the biomass indicated that the system constituted by the colonial forage consortium with <em>L. leucocephala</em>, presented the highest level of carbon (3.73 t.ha<sup>-1</sup>), showing a significant difference in relation to the <em>B. brizantha</em> (2.12 t.ha<sup>-1</sup>; p&lt;0.05). On the other hand, the initial period showed higher carbon concentration (4.55 t.ha<sup>-1</sup>; p&lt;0.05). Likewise, a higher content was found at a depth of 0-20 cm (20.26 t.ha<sup>-1</sup>; p&lt;0.05)<strong>. </strong>These results were obtained in a winter process. In this regard, it is important to mention that forage shrubs in systems with pastures constitute a fundamental nutritional resource in winter, in this sense it is recommended to use improved and consortium pasture systems, to increase carbon storage, achieve stable and productive systems, in correspondence with its potentialities.</p> Roberto Martínez-López Olga Niz Maura Díaz-Lezcano Liz Centurión Copyright (c) 2022 Roberto Martínez-López, Olga Niz, Maura Isabel Díaz-Lezcano y Liz Mariela Centurión 2022-04-21 2022-04-21 39 2 e223928 e223928