Banca de QUALIFICAÇÃO: CLEIA DA SILVA LIMA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : CLEIA DA SILVA LIMA
DATA : 20/07/2026
HORA: 13:30
LOCAL: Unemat de Tangará da Serra
TÍTULO:

POTENTIAL AND COSTS OF BIOAGENTS IN THE CONTROL OF FUSARIUM WILT IN PINEAPPLE

PALAVRAS-CHAVES:

Fusariosis; Fusarium spp.; pineapple; biocontrol; Trichoderma; Bacillus; agricultural sustainability

PÁGINAS: 77
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

Pineapple fusariosis, primarily caused by Fusarium guttiforme, represents one of the main obstacles to crop productivity in Brazil, resulting in significant losses and compromising fruit quality. Given the limitations of chemical control, particularly regarding environmental impacts, health risks, and the selection of resistant pathogens, this dissertation aimed to evaluate the potential of biocontrol agents, with emphasis on the genera Trichoderma and Bacillus, in managing fusariosis, as well as to analyze their technical and economic viability compared to conventional methods. The study was structured in three complementary approaches: (i) in vitro assessment of the efficacy of bioagents on the growth and sporulation of Fusarium spp. isolates; (ii) analysis of the aggressiveness of different pathogen isolates in pineapple seedlings and fruits, linked to the response to biological control; and (iii) comparative analysis of the costs involved in the use of bioagents versus chemical control. The theoretical framework was based on concepts of phytopathology, integrated disease management, and biotechnology applied to agriculture, highlighting microbial antagonism mechanisms such as competition, antibiosis, and induction of resistance. Experiments were conducted in a completely randomized design, with different treatments involving Trichoderma spp., Bacillus spp. isolates and their combinations, as well as chemical control. Isolates of Fusarium spp. from different regions were used, morphologically characterized, and evaluated for conidia production and mycelial growth. Analyses included measurements of growth inhibition, sporulation quantification, and pathogenicity tests under controlled conditions. Data were subjected to analysis of variance and mean comparison using the Sisvar software. Results revealed high variability among Fusarium spp. isolates, both in morphological characteristics and aggressiveness, indicating the complexity of the pathosystem. Among the agents evaluated, Trichoderma spp. stood out as the most efficient biocontrol agent, promoting significant inhibition of mycelial growth and reduction in pathogen sporulation. In contrast, Bacillus spp. isolates showed variable performance, with low efficacy in some cases and even stimulation of sporulation in others, underscoring the need for careful selection of these microorganisms. Agent combinations demonstrated, in some cases, additive effects. Although chemical control exhibited superior efficacy, bioagents showed relevant potential as sustainable alternatives, especially when integrated into management strategies. Economic analysis indicated that the use of biological agents can be competitive in the long term, considering reduced environmental impacts and the sustainability of the production system. It can be concluded that the use of Trichoderma spp. represents a promising strategy for managing pineapple fusariosis. However, it is recommended that results be validated under field conditions to consolidate their practical applicability and expand their adoption in tropical fruit production.

MEMBROS DA BANCA:
Interna - 138379001 - DEJANIA VIEIRA DE ARAUJO
Interno - 118802007 - HILTON MARCELO DE LIMA SOUZA
Externa ao Programa - 40773001 - DAYANE CASTRO SILVA