The genus Blechnum has 13 species that are common plants, well-distributed in Chile. Here, we report a phytochemical analysis of B. chilense (Kaulf.) Mett., as well as the insecticidal effects of extracts of this plant. From the n-hexane fraction four phytoecdysones were isolated: ecdysone, ponasterone, shidasterone and 2-deoxycrustecdysone. A bioassay with Drosophila melanogaster larvae was used to evaluate insecticidal activity. The EtOAc and n-hexane fractions at 800 ppm caused 66.7 and 50.0% larval mortality, respectively. Treatments with both extracts at 800 ppm caused the greatest larval mortality, whereas treatments with 500 and 200 ppm induced premature pupation compared with the control and the highest adult mortality, probably due to interference with ecdysteroid metabolism and inhibition of ecdysis triggering hormone (ETH). The dead adult flies exhibited malformations.
This research aims to carry out a systematic review of the available literature about smart irrigation systems. It will be focused on systems using artificial intelligence techniques in urban and rural agriculture for soil crops to identify those that are currently being used or can be adapted to urban agriculture. To this end, a modified PRISMA 2020 method is applied, and three search equations are formulated. From those filters, and after a screening process, 170 articles are obtained. These articles are analyzed through VantagePoint, a text processing software. After this, they are taken through a detailed analysis phase in which 50 sources are selected as the most relevant to be read and analyzed by topic. Finally, the different phases of the analysis are used to draw conclusions that might be interesting for researchers working in this specific field or for the general public interested in rural and urban agriculture and its automation.
The objective of this work is to find the most prevalent elements that have positive effects on pollinator density and diversity in crop fields, as reported in the literature, through a systematic review. The search equations yielded 659 papers, from which 138 were filtered and finally 55 were selected by publication date, journal, Scimago Journal Rank, Scimago Quartiles, subject area, keywords, and relevance. These papers were subjected to an in-depth qualitative analysis and tabulated using VantagePoint 10.0, finding 30 terms that were considered relevant due to their recurrence in all papers. From these 30 terms, the 10 most mentioned practices were extracted and grouped into four broad categories: proximity to natural habitats (98), grassland management (82), floral resources (80) and organic farming (65). All the above agricultural management practices were found to have the potential to increase pollinator numbers and diversity in different contexts. From the results, further research is recommended to try to attract the attention of specific groups of pollinators, as it was also identified that each species has very specific requirements, and a configuration intended just for one species could cause other groups to leave the area.
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