Eugenol, Isoeugenol, Thymol, Carvacrol, and Ester Derivatives as an Ecofriendly Option to Control Glomerella Leaf Spot and Bitter Rot on Apple
Renan R. Schorr,
Meira J. Ballesteros Garcia,
Debora Petermann,
Rafaele R. Moreira,
Beatriz H. L. N. Sales Maia,
Francisco A. Marques,
Louise L. May-De Mio
Affiliations
Renan R. Schorr
Laboratório de Ecologia Química e Síntese de Produtos Naturais (LECOSIN), Departamento de Química, Universidade Federal do Paraná (UFPR), Av. Cel. Francisco H. dos Santos, 100 Jardim das Américas, Curitiba 81531-980, Brazil
Meira J. Ballesteros Garcia
Laboratório de Ecologia Química e Síntese de Produtos Naturais (LECOSIN), Departamento de Química, Universidade Federal do Paraná (UFPR), Av. Cel. Francisco H. dos Santos, 100 Jardim das Américas, Curitiba 81531-980, Brazil
Debora Petermann
Laboratório de Epidemiologia para Manejo Integrado de Doenças de Plantas (LEMID), Departamento de Fitotecnia e Fitossanidade, Universidade Federal do Paraná, Rua dos Funcionários, 1540, Curitiba 80035-050, Brazil
Rafaele R. Moreira
Laboratório de Epidemiologia para Manejo Integrado de Doenças de Plantas (LEMID), Departamento de Fitotecnia e Fitossanidade, Universidade Federal do Paraná, Rua dos Funcionários, 1540, Curitiba 80035-050, Brazil
Beatriz H. L. N. Sales Maia
Laboratório de Ecologia Química e Síntese de Produtos Naturais (LECOSIN), Departamento de Química, Universidade Federal do Paraná (UFPR), Av. Cel. Francisco H. dos Santos, 100 Jardim das Américas, Curitiba 81531-980, Brazil
Francisco A. Marques
Laboratório de Ecologia Química e Síntese de Produtos Naturais (LECOSIN), Departamento de Química, Universidade Federal do Paraná (UFPR), Av. Cel. Francisco H. dos Santos, 100 Jardim das Américas, Curitiba 81531-980, Brazil
Louise L. May-De Mio
Laboratório de Epidemiologia para Manejo Integrado de Doenças de Plantas (LEMID), Departamento de Fitotecnia e Fitossanidade, Universidade Federal do Paraná, Rua dos Funcionários, 1540, Curitiba 80035-050, Brazil
Glomerella leaf spot (GLS) and bitter rot (BR) are severe diseases of apple. Colletotrichum nymphaeae and Colletotrichum chrysophillum are the main species in Brazil. To control GLS and BR in Brazilian apple orchards, mancozeb and thiophanate-methyl fungicides are still used despite reported Colletotrichum resistance to these active ingredients. In addition, mancozeb has been banned from apple-importing countries and it has been a great challenge for apple producers to find products for its replacement that are eco-friendly. So, this study aimed to search for alternatives to control the diseases. We assessed the antifungal activity of eugenol, isoeugenol, thymol, carvacrol, and some of their ester derivatives. The best products to inhibit the pathogen in in vitro assays were thymol, thymol butyrate, and carvacrol, completely inhibiting mycelial growth at 125 mg L−1 and conidial germination at 100 mg L−1. In detached apple fruit, eugenol, eugenyl acetate, carvacryl acetate, and thymol butyrate, significantly reduced BR symptoms caused by Colletotrichum species with some variation between experiments and species, decreasing the risk of BR with the time compared to control. In detached leaves, all tested compounds significantly reduced the risk of development of GLS symptoms with disease control varying from 30 to 100%. The compounds tested are promising alternatives to replace fungicides to control bitter rot and Glomerella leaf spot on apple culture and should be tested for field conditions.