Sanitizante no manejo pós-colheita de spondias tuberosa arruda e óleos essenciais no controle in vitro de colletotrichum sp.

Abstract

The species Spondias tuberosa Arruda, known as umbuzeiro, is native to the Caatinga biome and has high socioeconomic and nutritional value. Rich in vitamin C, fiber, and antioxidant compounds, umbu fruit is widely used in the production of juices, pulps, ice creams, jams, sweets, and liqueurs. However, its fruits are highly perishable and susceptible to diseases, mainly of fungal origin, such as anthracnose, caused by Colletotrichum sp., which compromises fruit quality and reduces postharvest shelf life. In this context, the use of sanitizers and essential oils (EOs) emerges as a sustainable alternative with lower risk of contamination to the environment and humans. This study aimed to evaluate the effectiveness of different concentrations of Havoxil® in the postharvest management of S. tuberosa fruits and to determine the action of essential oils in the in vitro control of Colletotrichum sp. The fruits were immersed in concentrations of 0%, 1%, 2%, 3%, and 4% Havoxil®

diluted in sterile distilled water (SDW), in addition to the fungicide Thiabendazole®. The postharvest variables of treated fruits were firmness, weight loss, pH, soluble solids, acidity, and vitamin C during four days of storage. In the in vitro experiment, the EOs of citronella, lemongrass, clove leaves, palmarosa, patchouli, ginger, and Virginia cedar were tested at concentrations of 1%, and evaluated for inhibition of mycelial growth and sporulation of Colletotrichum sp., isolated from symptomatic fruits of S. tuberosa and cultivated in PDA medium. Fruits treated with different concentrations of Havoxil® showed significant changes during storage, especially at concentrations of 3% and 4%, which promoted an increase in soluble solids and vitamin C contents compared to the control, as well as greater preservation of firmness and reduction in pathogen incidence, mainly Colletotrichum sp. In the in vitro evaluation, all tested EOs demonstrated significant antifungal activity, with reduced mycelial growth and sporulation, with citronella, lemongrass, clove leaves, and palmarosa being the most effective. The observed effects are related to the presence of bioactive compounds capable of interfering with fungal structure and metabolism. The results highlight the potential of using Havoxil® and essential oils as sustainable alternatives for in vitro control of Colletotrichum and postharvest management of S. tuberosa fruits. Treatments with Havoxil® at concentrations of 3% and 4% promoted the absence of Colletotrichum sp., Fusarium sp., Nigrospora sp., and Pestalotiopsis sp. Havoxil® concentrations of 2%, 3%, and 4% provided preservation of vitamin C content at the end of the storage period. All essential oils tested in vitro showed high antifungal efficacy against Colletotrichum sp.