Potential Application of Propolis Extracts to Control the Growth of Stemphylium vesicarium in “Rocha” Pear

Abstract

Stemphylium vesicarium (Wallr.) E. G. Simmons is the pathogen responsible of brown spot disease in pear and has become one of the main concerns for European pear producers. In Portugal, S. vesicarium is responsible for significant yield reduction and economic losses in “Rocha” pear (Pyrus communis L. cv Rocha) production. Considering the antimicrobial potential of propolis, the high incidence of brown spot in pears and the emergence of fungicides resistance in S. vesicarium, this study aimed to evaluate the potential of Portuguese propolis as an alternative strategy to control brown spot disease in “Rocha” pear. In vitro assays showed that propolis extracts were able to inhibit up to 90% the S. vesicarium mycelial growth. In vivo assays in artificially wounded and inoculated “Rocha” pears showed that, compared to the control, the disease incidence decreased up to 25% and the lesions diameter up to 57%, in fruits treated with propolis. Moreover, propolis seems to be more efficient in reducing the disease incidence when applied after pathogen inoculation (curative assay) than when applied before pathogen inoculation (prophylactic assay). Thus, the results suggest that propolis extracts have potential to be applied as part of an integrated approach for the control of brown spot of pear.

Tackling Food Insecurity in Cabo Verde Islands: The Nutritional, Agricultural and Environmental Values of the Legume Species

“…Total phenolic compounds were determined according to Loebler et al [31]. Briefly, water (6.0 mL), leaf ethanolic extract (100 µL) and undiluted Folin-Ciocalteu reagent (500 µL) were mixed in a 10.0 volumetric flask.…”

Impact of Portuguese propolis on keratinocyte proliferation, migration and ROS protection: Significance for applications in skin products

“…Extracts EP4 and EP5 were prepared using propolis from the central region of Portugal (Caramulo) and extract EPM1 was prepared using a mixture of propolis from the central and northern region of Portugal. Propolis extracts were prepared according to the procedure described by Loebler et al [18] Briefly, a representative sample of crude propolis was extracted (1:10, w/v) with 96% ethanol (extracts EP4 and EP5) or 70% ethanol (extract EPM1) in an ultrasonic bath (Sonorex‐SK‐100) during 20 min and kept in the dark for 24 h, at room temperature (20 to 22°C). The resulting suspensions were filtered, and the procedure was repeated with the part trapped in the filter.…”

“…The total phenolic content of propolis extracts was determined using the Folin–Ciocalteu method according to Loebler et al [18]. Results were expressed as milligram gallic acid equivalents (GAE) per gram of dry extract.…”

Biochemical Composition of Propolis and Its Efficacy in Maintaining Postharvest Storability of Fresh Fruits and Vegetables

“…E. G., which is the cause of brown spot disease in pear fruits. Researchers noted that the propolis extracts provides 90% reduction in the mycelial growth in in vitro studies and up to 57% in in vitro studies [66].…”

“…Edible film with 10%, 20%, and 30% EEP (70% ethanol) n/a n/a n/a n/a n/a n/a n/a n/a n/a + [64] Pear Spraying with 30.0 mg/mL or 6.0 mg/mL EEP (70% ethanol) n/a n/a n/a n/a n/a n/a n/a n/a n/a + [66] Apple Dipping in 1.5% and 2.5% EEP (70% ethyl alcohol and aqueous extract) nu n/a nu nu n/a n/a n/a n/a nu n/a [77] Pomegranate juice 1 drop of EEP (1 : 10 in 70% ethanol) per 250 ml of juice n/a n/a + + + n/a + n/a n/a + [62] WL: weight loss; CI: chilling injury; SSC: soluble solids concentration; TA: titratable acidity; VC: vitamin C (ascorbic acid); TPC: total phenolic content; AA: antioxidant activity; F: firmness (textural quality); S: sensory or visual acceptability; DI: decay incidence; n/a: no data available; +: positive influence; −: negative influence; nu: neuter effect.…”