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 , with original and unpublished scientific articles, technical notes, review articles, quick communications, extensive summaries of congresses and scientific meetings related to the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 Identification of regions associated to the late blight resistance and viruses in potato germplasm using molecular markers <p>The combination of traits of economic interest in new potato cultivars, such as resistance to late blight, viral diseases, and culinary quality are important to achieve their adoption by farmers. In the present work, molecular markers were used to identify regions associated to late blight, the viruses PVY and PLRV resistance, in 50 materials belonging to the National Institute of Agricultural Research (INIA-Venezuela): commercial cultivars, differentials of blight, advanced clones from CIP and hybrids from the Fundación PROINPA of Bolivia. DNA extraction was carried out from vitroplants and known microsatellite, SCAR and CAPS molecular markers were used. Among 96 to 26% of the accessions amplified regions of the QTL <em>tbr</em> of chromosome XII, associated with resistance to blight. Only the differential R9 and crc2/P8 from PROINPA amplified the <em>R1</em> gene region. Between 18 and 68% of the genotypes presented the regions associated with the PVY and PLRV resistance genes (<em>Ry<sub>adg</sub> </em>and <em>N</em> genes), respectively; only 10% amplified both regions; while in 24% these genes were not detected, among them are the commercial varieties Granola, Andinita and Cartayita. This study generated valuable information to support genebank curators and breeders in potato genetic improvement programs of this country.</p> Ariadne Vegas García Yanet Sandrea Rincón† Asia Zambrano† Lourdes González Martha Osorio Guillermo Trujillo Jorge Peralta Calle Copyright (c) 2022 Ariadne Vegas García, Yanet Sandrea Rincón, Asia Zambrano, Lourdes González, Martha Osorio, Guillermo Trujillo, Jorge Peralta Calle 2022-06-27 2022-06-27 39 3 e223935 e223935 FTIR-ATR for the identification of Psidium guajava plants infested with Meloidogyne enterolobii <p>The <em>Meloidogyne enterolobii</em> Yang and Eisenback nematode represents one of the most devastating pests in guava cultivation in Venezuela and the world. The diagnosis of this parasite requires specialized knowledge and very laborious procedures. The objective of this research was to identify the infrared spectra of guava plants, in the nursery phase, infested with <em>M. enterolobii</em> using Fourier-transform infrared spectroscopy coupled to attenuated total reflectance (FTIR-ATR). Leaves from healthy and infested plants were taken 60 days after nematode inoculation and&nbsp; analyzed in a FTIR-ATR spectrometer. The main spectral bands corresponding to the chemical compounds (lipids, proteins and carbohydrates) produced by plant metabolism as a result of nematode infestation were characterized. These results represent the starting point to determine the potential of this rapid and non-destructive technique for the early diagnosis of plants infested by the “guava root-knot nematode”.</p> Ana Casassa-Padrón Edgar Portillo Cesar González Copyright (c) 2022 Ana María Casassa-Padrón, Edgar Portillo and Cesar González 2022-08-03 2022-08-03 39 3 e223937 e223937 Induced mutagenesis in janeiro grass by ethyl-meta-sulfonate and its effect on spittlebug control <p>In this research, the median lethal dose (LD<sub>50</sub>) and resistance to spittlebug (<em>Mahanarva andigena</em>) were determined, using a mutagenizing agent ethyl meta-sulfonate (EMS) in Janeiro grass (<em>Eriochloa polystachya</em> Kunth) as a means to generate mutations. The study was carried out at the laboratory and greenhouse level, using a Complete Random Design (DCA) with ten treatments and three repetitions, which consisted of 5 doses of EMS (0.00%, 0.25%, 0.50%, 0.75% and 1.00%). for 2 impregnation times (24 and 48 hours). According to the results, the doses of ethyl meta-sulfonate (EMS) influenced the setting of the stolons of the janeiro grass, presenting a high rate of deflation in doses higher than 0.50%. Treatments with doses of 0.25% EMS at 48 hours achieved the best agronomic performance up to 95 days, where plant height had its best development with use close to that determined as DL<sub>50</sub> (0.32%). The janeiro grass impregnated with EMS presented slight damage caused by the spittle.</p> Juan Gómez Villalva Fernando Cobos Mora Edwin Hasang Moran Ana Eguiluz de la Barra Israel Cortez Herrera Copyright (c) 2022 Juan Gómez Villalva; Fernando Cobos Mora; Edwin Hasang Moran; Ana Luzmeira Eguiluz de la Barra and Isrrael Cortez Herrera 2022-08-03 2022-08-03 39 3 e223938 e223938 Drying effect by infrared radiation on sensory quality in special coffees (Coffea arabica) cup <p>The drying process of coffee (<em>Coffea arabica</em>) is important to achieve quality organoleptic characteristics. The objective of the study was to evaluate the effect of drying by means of an electromechanical system based on infrared on sensory quality in special coffees cup. For this, an electromechanical system was designed using infrared emitters that combines electromagnetic radiation with conventional convective heating. 75 coffee samples were collected at three (3) height levels. The samples underwent the traditional drying process and the electromechanical system, to later be evaluated by professional tasters under the SCAA (Specialty Coffee Association of America) scale. The samples dried with infrared at 12% humidity presented a cupping value of 82.93 for cup coffee with a smaller data dispersion than the traditional system that obtained 81.34, in addition the t-test of non-equivalent samples indicates that its value is significantly better (p&lt;0.05). We concluded that the electromechanical system with infrared drying increased the sensory quality of coffee compared to traditional drying.</p> Maricely Guevara-Sánchez Karen Guevara-Sánchez Neiser Quispe-Cubas Miguel Valles-Coral Jorge Navarro-Cabrera Lloy Pinedo Copyright (c) 2022 Maricely Guevara-Sánchez, Karen Elizabet Guevara-Sánchez, Neiser Quispe-Cubas, Miguel Angel Valles-Coral, Jorge Raul Navarro-Cabrera, Lloy Pinedo 2022-06-30 2022-06-30 39 3 e223936 e223936 Potential supply of lactic acid as a diversification alternative of the sugar agro-industry in Veracruz, Mexico <p>In Mexico, sugarcane (Saccharum spp.) is one of the most notable agrifood crops, due to the economic importance it represents, sucrose and ethanol are systematically produced from it. However, a modernization scheme is currently required through productive diversification, valorizing and taking advantage of the generated co-products. In this scheme, the production of lactic acid is proposed, which generates added value and has potential demand in different industries such as food and pharmaceuticals. Therefore, the objective of this research was to evaluate factors that determine potential supply of lactic acid, if it were produced using bagasse and molasses generated in 18 sugar mills located in four sugarcane regions in Veracruz, Mexico. Statistical methods of panel data analysis were applied by estimating five econometric models, using the factors that can determine such supply. Analysis results indicated that the four sugarcane regions have lactic acid production potential, highlighting the Papaloapan-Gulf (2.6 million t) and Cordoba-Gulf (1.6 million t) regions. Factors that influenced or determined supply were: harvest duration, lactic acid import price, the number of co-products and by-products, the harvested area and the average of schooling level. In conclusion, the sugar agroindustry in Veracruz has the potential to diversify its production through the co-production of lactic acid in the context of a deficit trade balance.</p> Jorge Castillo-Martínez Francisco Hernández-Rosas María Ríos-Corripio Elizabeth Varela-Santos Manuel Lizardi-Jiménez Ricardo Hernández-Martínez Copyright (c) 2022 Jorge Francisco Castillo-Martínez, Francisco Hernández-Rosas, María Antonieta Ríos-Corripio, Elizabeth del Carmen Varela-Santos, Manuel Alejandro Lizardi-Jiménez and Ricardo Hernández-Martínez 2022-08-04 2022-08-04 39 3 e223939 e223939