Canker and dryness of branches of avocado tree (Persea americana): characterization of the pathogen, spatial distribution and control

• Grant number: 22/02694-9
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2022
• End date: December 31, 2024
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Ivan Herman Fischer
• Grantee: Ivan Herman Fischer
• Host Institution: APTA Regional. Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil
• Associated researchers: Ana Carolina Firmino ; Bruno Henrique Leite Gonçalves ; Juliana Cristina Sodario Cruz ; Lilian Amorim ; Rosemary Marques de Almeida Bertani
• Associated scholarship(s): 23/07007-2 - Identification and molecular, morphological and cultural characterization of Botryosphaeriaceae/Diaporthaceae isolates from avocado tree, BP.TT; 22/09932-2 - Pathogenicity of Botryosphaeriaceae/Diaporthaceae isolates from avocado, reaction of avocado varieties and branch cankers control with phosphites, BP.TT

Abstract

Branch canker and dieback of avocado has been a serious problem for avocado producing regions, and its etiology, epidemiology and management are still a challenge. Given the lack of information about this pathosystem in Brazil, the objective was to characterize the occurrence of branch canker and dieback in 15 avocado orchards, preferably in the State of São Paulo, evaluating the spatial pattern of the disease in the orchards; to determine the pathogenicity of Botryosphaeriaceae/Diaporthaceae isolates in avocado seedlings and fruits; identify and characterize pathogenic Botryosphaeriaceae species based on morphological, cultural and molecular characteristics; evaluate the behavior of avocado varieties (Hass, Quintal, Breda, Fortuna, Geada and Margarida) in relation to the pathogens to be found and evaluate the effectiveness of fungicides (azoxystrobin, difenoconazole, flutriafol, copper hydroxide, mancozeb, cuprous oxide, oxychloride of copper, thiabendazole and thiophanate-methyl) and phosphites (Ca, Cu, K, Mg, Mn and Zn) in vitro and in the preventive control of the disease. The experiments of detection and characterization of the causal agent, of pathogenicity of the isolates of Botryosphaeriacea/Diaporthaceae in fruits and of in vitro sensitivity to fungicides and phosphites will be carried out in the laboratory; the experiments of pathogenicity of the isolates of the pathogens in seedlings, of reaction of avocado varieties to branch canker and preventive control of the disease will be carried out in a greenhouse and the evaluation of the spatial distribution of diseased trees, through the index of dispersion and modified Taylor's law in orchards. (AU)