Application of coatings formed by chitosan and Mentha essential oils to control anthracnose caused by Colletotrichum gloesporioides and C. brevisporum in papaya (Carica papaya L.) fruit.

This study investigated the efficacy of coatings formed by chitosan (Chi) and Mentha piperita L. (MPEO) or M. × villosa Huds (MVEO) essential oil to control the development of antrachnnose in papaya fruit caused by Colletotrichum gloeosporioides and C. brevisporum. Chi (2.5–10 mg/mL), MPEO and MVEO (0.15–1.25 μL/mL) alone effectively inhibited the growth of C. gloeosporioides and C. brevisporum isolates in laboratory media. Combinations of Chi (5 and 7.5 mg/mL) and MPEO or MVEO (0.15–1.25 mL/mL) inhibited the growth of Colletotrichum isolates and mostly presented additive or synergistic interactions. Development of anthracnose lesions caused by C. gloeosporioides and C. brevisporum isolates was reduced by coatings formed by Chi (5 mg/mL) and MPEO or MVEO (0.3–1.25 μL/mL) combinations during storage (10 days, 25 ± 0.5 °C). Decreases in anthracnose lesion development in papaya coated with Chi (5 mg/mL) and MPEO or MVEO (0.6 and 1.25 μL/mL) were similar or higher than those caused by a comercial fungicides formulation. The application of coatings formed by combinations of selected Chi and MPEO or MVEO concentrations could be considered an alternative strategy to control papaya anthracnose caused by C. gloeosporioides and C. brevisporum. • Chitosan (Chi) and Mentha essential oils (MEO) inhibited pathogenic Colletotrichum. • Chi + MEO had additive or synergistic effects on C. gloesporioides and C. brevisporum. • Chi-MEO coatings inhibited anthracnose lesion development in papaya over time. • Coatings were similarly or more effective than fungicides to control anthracnose. [ABSTRACT FROM AUTHOR]