Ricardo Arturo Varela Pardo

Dr. Ricardo Arturo Varela Pardo

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Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 September 2025 in Crops
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RPRicardo Arturo Varela Pardo
Ricardo Arturo Varela Pardo
Gustavo CuraqueoGustavo Curaqueo
Gustavo Curaqueo
AFAlejandra Fuentes
Alejandra Fuentes
PDPaola Díaz
Paola Díaz
CLClaudia Lopez Lastra
Claudia Lopez Lastra
EWEduardo Roberto Wright
Eduardo Roberto Wright
The whitefly (Bemisia tabaci) (Hemiptera: Aleyrodidae) is a small phytophagous invertebrate of herbaceous plants, shrubs, trees, wild plants, and crops of economic importance. It generates substantial economic losses due to direct damage caused by sap sucking and virus transmission. This work presents referential images of the morphology of B. tabaci and one of its main biological controllers in southern South America, thus serving as a reference for other researchers. In addition, results are presented of studies carried out to evaluate the pathogenicity of two fungal isolates (previously selected in vitro against Sclerotinia sclerotiorum and Botrytis cinerea and plant growth promoters) identified as Metarhizium taii CEP-722 and Trichoderma afroharzianum CEP-754 in immature stages of B. tabaci in tomato plants (Solanum lycopersicum). The trials were conducted under controlled conditions in controlled chambers, ensuring optimal growth conditions for B. tabaci, after morphological prospection, collection, identification, and mass rearing of adults in entomological cages. The results indicate that M. taii CEP-722 caused approximately 30% mortality in the immature stages of B. tabaci, while T. afroharzianum CEP-754 did not increase mortality under the experimental conditions. This study provides new knowledge on the potential of M. taii as a biological control agent against B. tabaci, offering a promising alternative in integrated pest management strategies. The results with T. afroharzianum suggest that further methodologies or combinations should be explored to improve its efficacy.

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CBCarlos Eulogio Belezaca-Pinargote
Carlos Eulogio Belezaca-Pinargote
BPBélgica Cristina Intriago Pinargote
Bélgica Cristina Intriago Pinargote
BBBrithany Belezaca-Pinargote
Brithany Belezaca-Pinargote
ESEdison Solano-Apuntes
Edison Solano-Apuntes
RPRicardo Arturo Varela Pardo
Ricardo Arturo Varela Pardo
PDPaola Díaz
Paola Díaz
A newly emerging disease affecting Schizolobium parahyba (commonly known as pachaco), termed “decline and dieback,” has been reported in association with the fungal pathogens Fusarium sp. and Botryodiplodia sp. This study assessed the antagonistic potential of two Trichoderma sp. isolates (CEP-01 and CEP-02) against these phytopathogens under controlled laboratory conditions. The effects of three temperature regimes (5 ± 2 °C, 24 ± 2 °C, and 30 ± 2 °C) on the growth and inhibitory activity of two Trichoderma spp. isolates were evaluated using a completely randomized design. The first experiment included six treatments with five replicates, while the second comprised twelve treatments, also with five replicates. All assays were conducted on PDA medium. No fungal growth was observed at 5 ± 2 °C. However, at 24 ± 2 °C and 30 ± 2 °C, both isolates reached maximum growth within 72 h. At 24 ± 2 °C, both Trichoderma spp. isolates exhibited inhibitory activity against Fusarium sp. FE07 and FE08, with radial growth inhibition percentages (RGIP) ranging from 37.6% to 44.4% and 52,8% to 54.6%, respectively. When combined, the isolates achieved up to 60% inhibition against Fusarium sp., while Botryodiplodia sp. was inhibited by 40%. At 30 ± 2 °C, the antagonistic activity of Trichoderma sp. CEP-01 declined (25.6–32.4% RGIP), whereas Trichoderma sp. CEP-02 showed increased inhibition (60.3%–67.2%). The combination of isolates exhibited the highest inhibitory effect against Fusarium sp. FE07 and FE08 (68.4%–69.3%). Nonetheless, the inhibitory effect on Botryodiplodia sp. BIOT was reduced under elevated temperatures across all treatments. These findings reinforce the potential of Trichoderma spp. isolates as a viable and eco-friendly alternative for the biological control of pathogens affecting S. parahyba, contributing to more sustainable disease management practices. The observed inhibitory capacity of Trichoderma sp., especially under optimal temperature conditions, highlights its potential for application in integrated disease management programs, contributing to forest health and reducing reliance on chemical products.

28 May 2026 in Agronomy
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RPRicardo Arturo Varela Pardo
Ricardo Arturo Varela Pardo
PDPaola Díaz
Paola Díaz
RMROMINA GUADALUPE MANFRINO
ROMINA GUADALUPE MANFRINO
AGAlmendra Ignacia Jofré González
Almendra Ignacia Jofré González
AFAlejandra Fuentes
Alejandra Fuentes
Modern agriculture, heavily influenced by the Green Revolution, has increased productivity through the intensive use of external inputs and agrochemicals, but at the cost of growing environmental degradation, loss of biodiversity, pest resistance, and risks to human health. This production model has proven to be environmentally unsustainable in the face of current challenges, such as climate change, the increase in the world’s population, and the depletion of natural resources. In this context, agroecology emerges as an integrative scientific approach that promotes the transition from conventional agricultural systems to diversified, resilient, and functionally balanced agroecosystems, based on ecological principles and the progressive reduction of synthetic inputs. This review addresses the role of fungal microorganisms, with an emphasis on entomopathogenic fungi and fungi associated with the plant microbiome, as key tools in the sustainable management of biotic agricultural challenges. This paper addresses the biology and multifunctionality of entomopathogenic fungi, not only as biological control agents but also as crop growth promoters and phytopathogen suppressors. Taken together, the background information presented reinforces the potential of entomopathogenic fungi as strategic components in agroecological transition processes, contributing to productive sustainability, reduced agrochemical use, and the restoration of the ecological functionality of agroecosystems.

14 May 2026 in Horticulturae
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Journal Article
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RPRicardo Arturo Varela Pardo
Ricardo Arturo Varela Pardo
AGAlmendra Ignacia Jofré González
Almendra Ignacia Jofré González
PSPaz Soto
Paz Soto
AFAlejandra Fuentes
Alejandra Fuentes
DVDamián Vega
Damián Vega
ASAndrés Pérez San-Martín
Andrés Pérez San-Martín
The common pea (Pisum sativum L.) is widely cultivated due to its nutritional value and adaptability, though climate change and increasing food demand require improved agricultural strategies. The genus Metarhizium, an entomopathogenic fungus, has shown potential to enhance plant growth and physiology. This study aims to evaluate the effect of naturalized Metarhizium spp. isolates on agronomic parameters and root architecture of Pisum sativum seedlings under greenhouse conditions. Fungi were isolated from rhizosphere soils using Tenebrio molitor larvae. Six Metarhizium strains and a control (sterile distilled water) were tested, with eight replicates per treatment. After 36 days, growth parameters and chlorophyll content were measured at ambient temperatures between 12.1 ± 1.5 and 42.4 ± 2.4 °C. Significant differences were analyzed using Tukey’s HSD post hoc test (p < 0.05). Significant increases in shoot length were observed in strains MM23B and MM26B (13.2 ± 0.6 and 13.0 ± 1.1 cm). Stem diameter was higher in MM23B, G9C, and MM30D (3.1–3.2 mm). Chlorophyll content increased moderately, with MM29C reaching 296.7 ± 35.9 compared to 242.5 ± 22.8 µmol m−2 in the control. Shoot biomass was highest in G9C, MM23B, and MM26B (0.27–0.29 g) with higher shoot/root ratios in MM23B and MM26B (2.41 and 2.58). Root biomass showed no significant differences. However, root system architecture was modified, particularly in MM26B, which significantly increased root length (239.08 ± 34.22 cm) and area (20.70 ± 2.13 cm2), without changes in volume or diameter. Finally, naturalized Metarhizium spp. isolates demonstrated potential as plant growth-promoting fungi, improving physiological and morphological parameters in early P. sativum development.