Qualidade fisiológica de sementes de tomate revestidas por nanoemulsão de óleo essencial no controle da fusariose

Abstract

Several crops intended for food production are susceptible to pest attacks and diseases. In case of tomato (Solanum lycopersicum L.), the fields are affected by many pathogens, especially Fusariosis, which is caused by Fusarium oxysporum f. sp. Lycopersici (FOL). The chemical treatment of seeds has caused the development of resistant variants, environmental pollution and risks to workers' health. Therefore, the use of essential oils extracted from plants is an alternative treatment. The aim of this work was to evaluate the effect of the coating starch-based, incorporated with nanoemulsion in thyme essential oil on the physiological potential of tomato seeds. Initially, the seeds of cultivars Ibiza and Napolitano were disinfested and subsequently inoculated with Fusarium oxysporum f. sp. Lycopersici. Eight treatments were defined for each cultivate: T1 (untreated tomato seeds - Control); T2 (seeds inoculated with F. oxysporum.); T3 (seeds inoculated and treated with 0 ppm thyme EO nanoemulsion); T4 (seeds inoculated and treated with nanoemulsion of Thyme EO 5,000ppm); T5 (seeds inoculated and treated with thyme EO nanoemulsion 10,000ppm); T6 (2 layers of incorporated coating with thyme EO nanoemulsion at 0 ppm); T7 (2 layers coating incorporated with thyme EO nanoemulsion at 5,000 ppm) and T8 (2 layers of coating incorporated with thyme EO nanoemulsion a 10,000ppm) which underwent to the following tests; water content, seed health, first counting, germination, emergence, emergence speed index, accelerated aging and image analysis. The experimental design was the completely randomized design (CRD), with 4 replications and Scott-Knott applied at 5% probability, and also a multivariate statistics through the analysis of the principal components (PCA). It was concluded that there was no phytotoxic effect of the oil essential in the germination of tomato seeds, with the exception of the use of two layers coating incorporated with thyme EO nanoemulsion at 10,000 ppm. Considering the cultivars Ibiza and Napolitano, the other treatments were efficient in control of fusariosis without affecting the quality of tomato seeds.