Banca de QUALIFICAÇÃO: Vitor Augusto Carvalho Baldo

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Vitor Augusto Carvalho Baldo
DATE: 01/02/2023
TIME: 08:00
LOCAL: Auditório do Instituto de Biologia
TITLE:

Chemical, biological and varietal control of asian rust (Phakopsora pachyrhizi). 2022. Thesis Project (Doctor in Phytopathology) - University of Brasilia, Brasília, DF.

KEY WORDS:

Glycine max; biologic control; genetic resistence; chemical control; Normalized Difference Vegetation Index.

PAGES: 97
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Fitopatologia
SUMMARY:

Soybean (Glycine max) is the main agricultural commodity in Brazil, where it currently surpasses the United States in cultivated area and productivity, becoming the world's largest producer of the oilseed. Since the mid-2000s, one of the main phytosanitary problems occurring in the crop is Asian rust, causing losses that can reach up to 90%. Rust is caused by the basidiomycete fungus Phakopsora pachyrhizi Syd. & Syd, and its anamorphic reproduction phase (uredinia and urediniospores) predominates in disease epidemics. FAS (Asian rust) initially manifests with dark green lesions, changing to brown-brown or reddish brown over time, where uredinia usually affect the abaxial faces. With the advancement of infections and infected leaf area, there is generalized yellowing and early leaf fall, which in turn generates anticipation of the cycle and damages to the full filling of the grains. In this work, the objective was to evaluate the management of Asian rust in terms of the association of chemical and biological fungicides and genetic resistance, due to the small number of studies involving the dynamics of interaction of the three factors. For these purposes, four field trials were installed on 17/12/2021 and 19/12/2022 (in progress) in the town of Rio Verde (GO), considering the main objective of comparing the resistant and susceptible cultivar in terms of the chemical fungicide application program and biological. The experimental design was in randomized blocks, with four replications. The area of the plots was 20 m2, with a useful area of 15 m2. The cultivars used were TMG 7063 Inox® (GM: 7.0; early cycle: 110 days; resistant to P. pachyrhizi) and Brasmax Foco IPRO® (maturation group: 7.2; early cycle: 108 days; susceptible to P. pachyrhizi). The chemical fungicides used were: Fox Xpro® [Trifloxystrobin/Strobilurin + Prothioconazole/Triazole + Bixafem/Carboxamide (150 + 175 + 125 g a.i. ha-1)], Cypress 400 EC® [Ciproconazole/Triazole + Difenoconazole/Triazole (150 + 250 g a.i. ha-1)], Aproach Prima® [Picoxystrobin/Strobilurin + Cyproconazole/Triazole (200 + 80 g a.i. ha-1)], Ativum® [Epoxiconazole/Triazole + Fluaxapiroxad/Carboxamide + Pyraclostrobin/Strobilurin (50 + 50 + 81 g a.i. ha-1)], Unizeb Gold® [Mancozeb/Dithiocarbamate (720g a.i. ha-1)], Bravonil 720® [Chlorothalonil/Isophthalonitrile (720 g a.i. ha-1)], Reconil® [Copper Oxychloride/ Cupric (588 g a.i. ha-1)] and Status® [(Copper/Cupric Oxychloride (588 g a.i. ha-1)]. The biological fungicides used were: Romeo SC® [Cerevisane/Microbiologico (100 g a.i. ha-1)] and Bio-Imune SC® [Bacillus subtilis BV02/Microbiológico (42 g a.i. ha-1)]. Chemical and biological fungicides were applied at four phenological stages of the crop, being positioned at 30, 45, 6 0 and 75 DAE (days after emergence). The variables measured were: disease severity, vigor analysis by reflectance (Green Seeker®), AACPD (Area Below the Disease Progress Curve), remote sensing with NDVI (Normalized Difference Vegetation Index, photographs using the eBee Ag® drone - Sensefly Duet M® lens), total plot productivity and thousand-grain mass (MMG). Rust was the main factor responsible for the variation in yield between treatments, generating comparative viability between them. The chemical fungicides used reduced the AACPD in relation to the control and consequently providing greater productivity. The decrease in the amount of chemical fungicide applications significantly interfered in the control of the disease, with a significant difference between cultivars. In general, the TMG 7063 Inox® variety showed lower severity scores compared to Brasmax FOCO®. In treatments with 1 and 2 applications of specific fungicides, the difference was minimal, with greater efficiency after 3 applications. The treatments with 4 isolated applications of the specific fungicide Fox Xpro® presented less control than the treatment with three applications of Fox Xpro® and two associated multisite. Among the multisite fungicides, Unizeb Gold® was the protective fungicide that presented the greatest control in association with the site-specific fungicides. Regarding treatments with biological fungicides, they alone did not show efficiency, having similar severities to the control and in some cases with worse severity scores. The preventive replacement of biologicals with chemicals increased the inoculum concentration for later applications, altering and making the management of FAS difficult. The late association of biologicals (third and fourth applications, carried out in 60 anda 75 DAE) with chemical fungicides did not present an increase in disease control.

BANKING MEMBERS:
Presidente - 2210861 - JOSE RICARDO PEIXOTO
Interna - 3117540 - THAIS RIBEIRO SANTIAGO
Externa ao Programa - 2858601 - MICHELLE SOUZA VILELA
Externo à Instituição - AILTON REIS - EMBRAPA
Externo à Instituição - CARLOS ALBERTO LOPES - EMBRAPA
Externo à Instituição - JADIR BORGES PINHEIRO - EMBRAPA