2900 kg ha-1) and oil production (> 550 L ha-1). In Las Cruces (LC), at higher latitude, low temperatures present beginning in April coincided with the reproductive stage, affecting yield which was no more than 129 kg ha-1; thus this zone is not recommendable for chia cultivation. This study also determined an 11.8 h day length threshold for the beginning of flowering; when plants are exposed to shorter days flower initiation is more precocious, but when day length is not adequate plants only begin to flower when they have accumulated 600-700 °C d.]]>

This study aimed to characterize the in vitro antioxidant and antibacterial properties of oregano (Origanum vulgare) essential oil, as well as its chemical composition. To our best knowledge, there are few studies on oregano grown in the arid Andes region, but none on the metabolites produced and their bioactivity. This work identified fifty metabolites by Gas Chromatography–Mass Spectrometry (GC-MS)—monoterpene hydrocarbons, oxygenated monoterpenes, phenolic monoterpenes, sesquiterpene hydrocarbons, and oxygenated sesquiterpenes—present in the essential oil of oregano collected in the Atacama Desert. The main components of essential oregano oil were thymol (15.9%), Z-sabinene hydrate (13.4%), γ-terpinene (10.6%), p-cymene (8.6%), linalyl acetate (7.2%), sabinene (6.5%), and carvacrol methyl ether (5.6%). The antibacterial tests showed that the pathogenic bacteria Staphylococcus aureus and Salmonella enterica and the phytopathogenic bacteria Erwinia rhapontici and Xanthomonas campestris were the most susceptible to oregano oil, with the lowest concentrations of oil necessary to inhibit their bacterial growth. Moreover, oregano oil showed antibacterial activity against bacteria associated with food poisoning. In conclusion, O. vulgare from the arid Andean region possesses an important antibacterial activity with a high potential in the food industry and agriculture.

The Lamiaceae family is an important source of species among medicinal plants highly valued for their biological properties and numerous uses in folk medicine. Origanum is one of the main genera that belong to this family. The purpose of the study was to determine the phenolic composition of the Origanum vulgare extract and evaluate the antimicrobial, antioxidant, and inhibitory activities of this species that grows in the Andean region of the Atacama Desert. High-performance liquid chromatography was performed to determine the main phenols. Rosmarinic acid was identified as the predominant phenolic compound in this species (76.01 mg/100 g DW), followed by protocatechuic acid, which to our knowledge, no previous study reported similar concentrations in O. vulgare. The oregano extract exhibited a content of total phenolic (3948 mg GAE/100 g DW) and total flavonoid (593 mg QE/100 g DW) with a higher DPPH antioxidant activity (IC50 = 40.58 µg/mL), compared to the same species grown under other conditions. Furthermore, it was found to inhibit α-glucosidase activity with an IC50 value (7.11 mg/mL) lower than acarbose (129.32 mg/mL). Pseudomonas syringae and Pantoea agglomerans (both MIC 0.313 mg/mL and MBC 1.25 mg/mL) were the bacteria most susceptible to oregano extract with the lowest concentration necessary to inhibit bacterial growth. These results open the door for the potential use of this plant to manage chronic diseases, and they expand the knowledge of the species cultivated in arid environmental conditions.

N. Lara, L. Figueroa, F. Carvajal, Y. Zapata, C. Urbina, and H. Escobar. 2013. Quantitative differentiation between soil organic carbon and biochar carbon in Aridisol. Cien. Inv. Agr. 40(2): 387-395. To understand the effect of biochar, identify its presence and quantify its stability in soil, it is necessary to differentiate between the two main sources of carbon. These sources are resident soil organic matter and biochar, which is produced by burning organic matter under low oxygen concentration in a process known as pyrolysis. The present study employs solid-liquid extraction with an alkaline solution, the efficiency of which was improved by a reflux system and quantification using the modified Walkley-Black method, to distinguish the two carbon sources in samples of arid soils from the area surrounding the city of Arica, XV region of Chile. The mean annual precipitation of this area is less than 0.4 mm, and its soils are characterized by high salinity, low organic matter content, high porosity and low bulk density. The values for total extracted organic carbon obtained using this method were very similar to those for the resident soil organic carbon, indicating that the technique extracts mostly resident soil organic carbon and not biochar carbon. Biochar carbon represented less than 6% of the total organic carbon extracted by the method. The results demonstrate that this method can quantitatively differentiate between resident total organic carbon and applied biochar carbon. The method thus represents a valuable alternative to the use of an elemental analyzer.

La Physalis peruviana, es un cultivo andino con una amplia distribución en América del Sur, encontrándose también en casi todos los sectores altos de los trópicos y en varias partes de los subtrópicos. En Chile, sólo se tiene registro del cultivo en el sur del país, no encontrándose ningún registro para esta especie en los Andes del extremo norte del país. Este estudio evaluó la adaptación del cultivo Physalis peruviana a las condiciones edafológicas actuales de las localidades andinas del norte de Chile. La caracterización de aguas y suelos de las zonas estudiadas cumplen con los parámetros de cultivo para esta especie. Además, se estableció un manejo agronómico según el piso ecológico, con el fin de rescatar un cultivo andino olvidado por décadas en este sector.