Oregano from Socoroma (Atacama Desert) is characterized by its unique organoleptic properties and distinctive flavor and it is produced using ancestral pesticide-free agricultural practices performed by the Aymara communities. The cultivation in this zone is carried out under extreme conditions where the standard production of different crops is limited by several environmental factors, including aridity, high concentration of salts, and boron among others. However, oregano plants are associated with microorganisms that mitigate biotic and abiotic stresses present in this site. In this work, the S57 strain (member of the Pseudomonas genus that is closely related to Pseudomonas lini) was isolated from roots of oregano plants, which are grown in soils with high content of non-sodium salts and aluminum. This bacterium stimulates the growth of Micro-Tom tomato plants irrigated with saline-boric water. Moreover, it controls the growth of phytopathogenic fungi Fusarium oxysporum and Botrytis cinerea and the nematode Meloidogyne incognita under saline-boric conditions. Together with the high levels of bacterial biomass (~47 g/L), these results allow the establishment of the bases for developing a potential new agricultural bioproduct useful for arid and semiarid environments where commercial biological products show erratic behavior.

Stabilized organic amendments (SOA) from poultry are used in agriculture to improve the conditions of the soil. SOAs favor the growth of the crops and reduces the effect of soil-borne plant-pathogens. However, in northern Chile, there are no studies to support this observation, nor have the mechanisms involved in the beneficial effects observed in the field been established. This work aims to establish whether the promotion of growth and control of soil fungi in tomato observed in the field as a result of commercial SOA application can be attributed to different endospore-forming bacteria (EFB). The effect of commercial SOA on nutrient availability was determined. EFB isolated from a commercial product, and the application of bacterial isolates were compared with the commercial formulation of SOA, for plant growth promotion (PGP) and biocontrol of Fusarium oxysporum fsp. radicis-lycopersici (FORL). The local tomato cultivar Poncho Negro was used given its sensitivity to different nutritional alterations and FORL. A series of measurements of growth parameters were carried out in plants submitted to different mixtures of SOA treatments. Isolates were identified by biochemical tests and sequencing of the 16S rRNA gene. Eleven EFB were isolated from SOA, and some tests were performed to determine the PGP and biocontrol of FORL activities of each isolate. Notably, isolates BAC22 (Bacillusmegaterium), BAC21, and BAC23 (B. amyloliquefaciens/velezencis) were associated with PGP, highlighting the ability to produce indole-3-acetic acid, a trait that in many cases is key to explaining the effects of Bacillus spp.

The Aculops lycopersici (Tryon, 1917) (Acari: Eriophyidae) (= Tomato russet mite), was reported for the first time on tomato (Solanum lycopersicum L.) in Arica, Chile. Its damage was described and its geographic distribution was expanded.