Postharvest management of Heliconia psittacorum x H. spathocircinata cv. Tropics

Objetive:  Evaluate different techniques to prolong the postharvest life of  Heliconia psittacorum x H. spathocircinata cv. Tropics. Design/methodology/approach: Two experiments were carried out; in the first it was evaluated the effect of five pulse solutions [(T1 = control (water); T2 = Hydraflor® 100 (0.5 g L-1); T3 = Hydraflor® 100 (0.5 g L-1) + sucrose (5% w/v); T4 = salicylic acid (1mM) and T5 = salicylic acid (1mM) + sucrose (5% w / v)] prior to storage at 11 ° C and 85 % RH for 10 d. In the second experiment, a wax coating was applied to the heliconia bracts and then maintain at 13 °C and 84% RH for 10 d; after storage the stems were placed in water or salicylic acid solution (1 mM). The results were analyzed by a completely randomized design, 10 replicates were used per treatment, one stem was one experimental unit. An ANOVA and a means comparison test (Tukey, ?=0.05) were performed with the SAS version 9.4. Results: The anatomy of heliconia stems determines their vase life, since they have wide xylem vessels susceptible to cavitation, for which the absorption of water is limited, also and non-functional stomata in the bracts, which increase the loss of moisture from the tissue. The use of pulse solutions or preservatives has little effect in prolonging the life of heliconia stems. Therefore, the application of wax creates a physical barrier that maintains the turgor of the stems, reduces oxidation, maintaining the bracts quality and increased the total postharvest life for 6 d more than the control stems. Study limitations/implications: No limitations were found in this study Findings/conclusions: The postharvest life of heliconia is conditioned by the loss of turgor and low water absorption, which leads to an early wilting of the inflorescences. The application of pulse solutions or preservatives have little effect in prolonging the life of the vase, so the most suitable technique to preserve the quality of the stems is waxing

Antibacterial activity of the Calendula officinalis L. essential oil on Escherichia coli

In developing countries, the risk of getting sick from eating food contaminated with Escherichia coli is very high. As a consequence of the multidrug resistance of this bacterium, a therapeutic alternative has been sought in the plant kingdom. The Objective of this research was to evaluate the antibacterial effect of pot marigold (Calendula officinalis) essential oil (EO) on the growth of E. coli. Design/Methodology/Approach: The antibacterial activity was determined using a Kirby-Bauer disk diffusion susceptibility test. A 90 to 60% dilution of EO generated 24 to 22 mm halos. The EA was subjected to a GC/MS analysis. The results showed that cadinene (53.8%) was the main constituent, followed by germacrene (22.5%). The minimum inhibitory concentration was 7 μg mL-1. Findings/Conclusions: C. officinalis EO can be considered as an option in the treatment against this enterobacteria

Intercambio de gases y relaciones hídricas durante el retraso de la senescencia foliar de trigo (Triticum aestivum L.) por la citocinina bap

Se estudió el efecto de la citocinina 6-bencilaminopurina (BAP) en el intercambio de gases y relaciones hídricas de Triticum aestivum L. durante el retraso de la senescencia foliar en invernadero. Plántulas de 21 días después de la siembra (DDS) fueron asperjadas con BAP 0,1mM o agua (testigo) cada 3 días por 20 días. El retraso de senescencia foliar en las plantas tratadas con BAP fue monitoreado mediante cuantificación de clorofila y proteína soluble total. El intercambio de gases se estimó mediante conductancia estomática (gs) y tasa de fijación de CO2. Las relaciones hídricas se evaluaron midiendo el potencial de agua total (ΨA) y sus componentes, osmótico (Ψs) y de turgencia (Ψt), cada 5 días por 20 días. Las hojas con BAP mostraron mayor concentración de clorofila y proteína total que el control tras 26 DDS, diferencias que aumentaron con el tiempo y a los 41 DDS fueron 7 veces mayores que el control. La gs registró valores no significativamente diferentes al estado verde pre-senescente. Estas respuestas se asociaron con tasas mayores de fijación de CO2, con concentraciones cercanas a las hojas verdes pre-senescentes (6,2μmol·CO2·m-2·s-1). El ΨA se mantuvo constante bajo BAP y Ψs fue significativamente menor que en los testigos, favoreciendo la retención de solutos en el citoplasma de hojas con retraso de senescencia. El Ψt de las hojas tratadas fue mayor que su respectivo testigo de 31 a 41 DDS. Por tanto, la citocinina BAP promovió el mantenimiento de la tasa de fijación de CO2 y las relaciones hídricas durante el retraso de la senescencia foliar