EVALUACIÓN DE EMERGENCIA DEL MAIZ CRIOLLO CON DISTINTOS PORCENTAJES DE HUMEDAD

ResumenLa investigación se llevó a cabo durante el ciclo primavera-verano 2017, en el Tecnológico Nacional de México Instituto Tecnológico Roque (ITR), en el estado de Guanajuato, México, ubicado a una altitud de entre 1700 a 1800 metros sobre el nivel del mar. El propósito del experimento es evaluar la humedad adecuada y eficiente requerida por la semilla de maíz criollo para obtener un índice tasa de emergencia.En el manejo de un cultivo es de gran importancia que el productor considere la fecha de siembra, la densidad de siembra, la fertilización, así como la disponibilidad de agua de un suelo y su textura, la profundidad de siembra y evaluar cuantitativamente la humedad disponible en el suelo de cultivo.Palabra(s) Clave(s): emergencia, índice, maíz criollo, tasa AbstractThe research was carried out during the spring-summer 2017 cycle, in the Roque technological institute, in the state of Guanajuato, Mexico located at an altitude of 1700 to 1800 meters above sea level. The purpose of the experiment is to evaluate the adequate and efficient humidity required by the native corn seed to obtain a high rate of emergence.In the management of a crop it is of great importance that the producer consider the date of sowing, the density of sowing, the fertilization, as well as the availability of water of a soil and its texture, the depth of sowing and quantitative evaluation of the available humidity on the growing soil.Keywords: emergency, index, maize, rate

Physico-chemical and antiadhesive properties of poly(Lactic acid)/grapevine cane extract films against food pathogenic microorganisms

The aim of this study was evaluation of the physico-chemical properties and adhesion of microorganisms on poly(lactic acid) (PLA)-based films loaded with grapevine cane extract (5–15 wt%). The films were processed in a compression molding machine and characterized by mechanical, thermal, water vapor barrier and microbiological tests. The best physical-chemical properties for PLA film containing 10 wt% of extract were obtained. The addition of 10 wt% of extract into PLA films led to decrease of tensile strength for 52% and increase in elongation at break for 30%. The water vapor barrier of this film formulation was enhanced for 55%. All films showed thermal stability up to 300◦C. The low release of the active compounds from films negatively influenced their antimicrobial and antifungal activity. Botrytis cinerea growth inhibition onto PLA containing extracts (PLA-E) films was in the range between 15 and 35%. On the other side, PLA/extract films exhibited the antiadhesive properties against Pseudomonas aeruginosa, Pectobacterium carotovorum, Saccharomyces pastorianus, and Listeria monocytogenes, which could imply their potential to be used as sustainable food packaging materials for preventing microbial contamination of food. © 2020 by the authors. Licensee MDPI, Basel, Switzerland