By having an extensive territory and suitable climate conditions, South America is one of the most important agricultural regions in the world, providing different kinds of vegetable products to different regions of the world. However, such favorable conditions for plant production also allow the development of several pests, increasing production costs. Among them, whiteflies (Hemiptera: Aleyrodidae) stand out for their potential for infesting several crops and for being resistant to insecticides, having high rates of reproduction and dispersal, besides their efficient activity as virus vectors. Currently, the most important species occurring in South America are Bemisia afer, Trialeurodes vaporariorum, and the cryptic species Middle East-Asia Minor 1, Mediterranean, and New World, from Bemisia tabaci complex. In this review, a series of studies performed in South America were compiled in an attempt to unify the advances that have been developed in whitefly management in this continent. At first, a background of the current whitefly distribution in South American countries as well as factors affecting them are shown, followed by a background of the whitefly transmitted viruses in South America, addressing their location and association with whiteflies in each country. Afterwards, a series of management strategies are proposed to be implemented in South American fields, including cultural practices and biological and chemical control, finalizing with a section containing future perspectives and directions for further research.

Changes in consumer expectations have led to increasing demand for novel plant protection strategies, in order to reduce the application of chemical products, reduce the occurrence of new pests and the impact that all these actions generate in the environment. In recent years there have been numerous investigations related to biological control and the use of microorganisms as new control strategies. As part of integrated disease management, antagonistic microorganisms have been investigated lately and presented great interest. Such microorganisms can be applied in conventional and in organic farming as biological control agents (BCA). Many of these microorganisms are present in the microbial ecology generating interactive associations between surrounding microorganisms. For these reasons, it has become necessary to search new natural antimicrobial agents as alternatives to synthetic and chemical products. It has been discovered that there are microorganisms, particularly yeasts, that have antagonistic activity and different mechanisms of action, indicating that they could be interesting candidates for the development of BCA. Here, we evaluate the antagonist effect of four endophytic yeast, Cryptococcus antarcticus, Aureobasidium pullulans, Cryptococcus terrestris and Cryptococcus oeirensis over the growth of Botrytis cinerea, Monilinia laxa, Penicillium expansum and Geotrichum candidum in in vitro assays (inhibition zone diameter assay and confrontation assay).The results revealed that the four yeast strains evaluated showed antagonistic activity against the phytopathogens tested, suggesting that these yeasts produce compounds capable of inhibiting the growth of fungi and, depending on the assay, the evaluated antagonist-yeasts have differential biocontrolling-effect against the postharvest pathogens tested.

Potato mop-top virus (PMTV) is an important pathogen of potato (Solanum tuberosum L.), occurring in Northern Europe, North and South America, and Asia, that significantly reduces potato production (Santala et al., 2010). PMTV is transmitted by spores of Spongospora subterranea f. sp. subterranea (Sss), the causal agent of powdery scab of potato (Jones and Harrison, 1969). During the summer season of 2012, native potato (S. tuberosum L. ssp. tuberosum) leaves showing virus-like symptoms were collected on several points within the Chiloé Archipelago (Chiloé Province, in the south of Chile), one of the centers of origin and diversity of cultivated potatoes (Montaldo, 1984). The presence and identity of viruses in the samples were determined through next generation high throughput sequencing (Solexa-Illumina) followed by assembly of viral small RNAs (vsRNAs) to reference plant virus genomes. The plant material used for the construction of the sRNA library corresponded to pools of symptomatic leaves sampled in the Archipelago. This analysis revealed that PMTV was infecting native potatoes in Chiloé, since the assembled contigs covered a 77.3, 76.8 and 68.0% of PMTV RNA1 (Reference sequence: NC_003723.1), RNA2 (Reference sequence: NC_003725.1) and RNA3 (Reference sequence: NC_003724.1), respectively. Subsequently, three farms growing native potatoes (local varieties Michuñe negra, Michuñe roja and Clavela lisa) with symptoms associated with PMTV infections were identified in Puqueldón (Lemuy Island, Chiloé Province ) during the summers of 2013 and 2014. Disease symptoms observed included stunting of stems, shortening of internodes, and mosaic patterns (V-shaped) on leaves, but necrotic symptoms on the surface or the flesh of tubers were not observed. To detect PMTV,total nucleic acid was extracted from three symptomatic plants each year and tested by reverse transcription (RT)-PCR using two sets of primers. In all samples analyzed, primer set C819/H360, targeting the coat protein (CP) gene in RNA3, yielded an amplicon of 460 bp (Xu et al., 2004). Primer set pmtF4/pmtR4 amplified a fragment of 417 bp from the second gene of the triple gene block (TGB2) in RNA2 (Xu et al., 2004). PCR products were directly sequenced (GenBank Accession Nos. KT267163 and KT267164). BLAST analysis showed that the amplicons were 99 to 100% identical to most of the CP or TGB2 sequences from several PMTV isolates from Europe and the United States. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA, Bioreba AG) on the same symptomatic potato leaf samples confirmed the presence of the virus in all cases. To our knowledge this is the first report of PMTV in Chile. However, the powdery scab pathogen, Sss, is widespread in the potato production areas near Chiloé Province. These results provide important and cautionary information to be considered by programs managing seed tuber production and plant quarantine for potato pathogens in Chile.

Ficus benjamina, commonly known as ficus or weeping fig, is an ornamental tree from Southeast Asia in the Moraceae family. It is an evergreen species grown as an interior plant worldwide, prized for its glossy green leaves, gray stem, and multiple branches. F. benjamina can be pruned and kept as a small shrub when grown indoors, with most commercially available cultivars in the ornamental industry derived from sports and propagated cuttings (Chen et al., 2010). In October 2022, symptoms indicative of alfalfa mosaic virus (AMV) infection, such as intense bright yellow spots, mottling and chlorosis were observed in leaves of F. benjamina growing in office environments in Santiago, Chile (supplementary Fig.1). Seven symptomatic and three asymptomatic plants were sampled and traced back to the same plant nursery, and only leaf tissue samples from the symptomatic plants tested positive for the presence of the AMV using enzyme-linked immunosorbent assay (ELISA) (Agdia Inc., Elkhart, IN). These results were verified using reverse transcription (RT)-PCR with specific primers AMV-F and AMV-R, targeting a region of the AMV CP gene (Xu and Nie, 2006). AMV was detected in all symptomatic leaf samples, producing 351-bp amplicons in the RT-PCR assay for all samples that were positive to AMV by ELISA. No amplification product was observed when seronegative samples or non-template control was used as templates in the RT-PCR assays. Three RT-PCR amplicons were directly sequenced in both directions. BLAST analysis of these sequences showed 100% nucleotide sequence identity to an AMV isolate previously reported (GenBank Accession No. KX458469), confirming the detection of AMV in F. benjamina. This pathogen causes disease in several species, including ornamentals plant such as Viburnum tinus L. (Peña et al., 2011), peony (Belardi and Rubies, 2003), phlox (Holcomb et al., 2006), and weeds such as Cayratia japonica (Thunb.) Gagnep, Justicia procumbens L. and Veronica persica Poir. (Gao et al., 2020). F. benjamina is among the most popular ornamental indoor plants in Chile, so nurseries should ensure AMV-free plants to restrict disease incidence and prevent the spread of this virus. However, Chile lacks specific regulations for ornamental nurseries, making adherence to pest and disease recommendations voluntary, and only imported plant material requires a sanitary certificate.

Bacteriophage-based products are gaining attention as effective tools to reduce harmful germs in food and combat antimicrobial resistance throughout the food production process. However, in South America, their use is still limited because of complicated regulations and inconsistent evidence requirements. This review aims to (i) explore the current scientific and technological landscape of using bacteriophages in South American food systems, (ii) identify main regulatory challenges that impact their classification, approval, and use, and (iii) highlight the need for consistent international guidelines, especially from Codex Alimentarius, to help safely and effectively incorporate phage-based products in food. Research on phage-based products is growing, but it is not consistent across different regions. There are more patents and advancements in biotechnology, but they are limited to certain areas. Although progress is being made, the regulatory frameworks are still unclear, especially when it comes to how these products are classified, labeled, and monitored for safety. To address these gaps, risk-based guidelines are needed. These should define product categories and claims, set safety standards, and include rules for tracking products and monitoring them after they hit the market. Creating a new Codex Alimentarius project on phage-based products could help establish global guidelines that promote safe use, reduce uncertainty in regulations, and improve trade in food markets around the world.

During the 2020 through 2024 growing seasons, pepper fruits exhibiting symptoms typically associated with spotted wilt were observed in the Arica y Parinacota region of northern Chile. As this region is a key winter supplier of vegetables to southern Chile, the present study aimed to identify and characterize orthotospoviruses infecting local pepper crops. Species-specific and generic primers targeting orthotospoviruses were used in RT-PCR assays for virus identification, and thrips vectors were characterized both morphologically and by PCR using ITS- and MtCOI-specific primers. Tomato spotted wilt virus (TSWV; Orthotospovirus tomatomaculae ) and the putative new orthotospovirus, pepper necrotic spot virus (PNSV), were detected in samples collected from four production fields in Arica y Parinacota. Among the known orthotospovirus vectors, only Frankliniella occidentalis was identified at sampled sites. While TSWV is already endemic in Chile, this represents the first report of PNSV in the country. Given that PNSV has been previously reported in Peru, the geographic proximity of Arica y Parinacota raises concern about its continued southward spread into Chile. This finding underscores the need for further epidemiological studies of PNSV and the development of strategies to mitigate its dissemination within the country.