Banca de DEFESA: SARAH JANE ALEXANDRE MEDEIROS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : SARAH JANE ALEXANDRE MEDEIROS
DATE: 07/04/2025
TIME: 08:30
LOCAL: Sala do PPGPA
TITLE:

POTENTIAL OF ESSENTIAL OILS FROM SEMI-ARID PLANTS IN CONTROLLING Sclerotinia sclerotiorum IN BEAN CROP (Phaseolus vulgaris L.)

KEY WORDS:

Biological control; sustainable agriculture; Croton sp.

PAGES: 55
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUMMARY:

Common bean (Phaseolus vulgaris L.), a global dietary staple and critical source of proteins
and minerals, faces significant yield losses due to pathogens such as Sclerotinia sclerotiorum,
the causal agent of white mold, a disease capable of decimating up to 70% of productivity. In
Brazil, the world’s tenth-largest producer, conventional control relies on synthetic fungicides,
linked to environmental risks, fungal resistance, and market restrictions. In this context, the

search for sustainable alternatives, coupled with the biotechnological potential of the semi-
arid flora—particularly the Caatinga Biome—has emerged as a priority strategy. This study

investigated essential oils from Croton campestris (velame) and Schinus terebinthifolia
(aroeira-rosa), native plants adapted to extreme conditions, for controlling S. sclerotiorum in
common beans. In vitro assays revealed complete inhibition of mycelial growth for 216 hours
(velame) and 168 hours (aroeira) using 2% formulations of both essential oils. In vivo, velame
oil (2%) reduced leaf lesion area to 138 mm2 (vs. 548 mm2 in chemical control) and increased
root biomass by 91% (fresh) and 156% (dry) in infected plants. Enzymatic analyses showed
maximum activity of 0.46 μmol·min−1·g−1 (ascorbate peroxidase) and 0.12 μmol·min−1·mg−1
(catalase), indicating a robust antioxidant response. Chromatography identified α-pinene
(15.32%), limonene (12.15%), and β-myrcene (14.1%) as key bioactive compounds in
velame, correlated with fungal suppression. We conclude that velame essential oil at ≥2%
concentrations combine direct antifungal action (100% inhibition in vitro) with systemic
resistance induction, outperforming chemical control (Procymidone) and reducing lesions by
75%. These results highlight the potential of species from the Brazilian semi-arid regions,
such as the Caatinga Biome, to develop bioproducts aligned with sustainable agriculture,
directly impacting food security in semi-arid regions.

COMMITTEE MEMBERS:
Interna - EDILMA PEREIRA GONCALVES
Externa à Instituição - JAMILLY ALVES DE BARROS - UFAPE
Presidente - KEDMA MARIA SILVA PINTO