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Essential oils as pepper seeds treatment for Colletotrichum gloeosporioides control

Daniele Maria do Nascimento: São Paulo State University

<div><em>Colletotrichum gloeosporioides</em> is one of the most important pathogens in the pepper crop. This fungus can be transmitted by seeds, which represent a way of this pathogen dissemination. Seeds treatment is recommended for this disease management. Aiming to reduce the use of chemical products in this crop, the action of eight essential oils (rosemary, citronella, clove, copaiba, eucalyptus, mint, basil and tea tree) on <em>C. gloeosporioides</em> was investigated. The in vitro activity of the essential oils on the fungus was evaluated by adding 0.25%, 0.50% and 0.75% of each essential oil to the potato-dextrose-agar medium (BDA). Then, a fungal mycelial disk was transferred to the center of each plate, incubated at 22°C and 12 hours photoperiod. Mycelial growth and sporulation were evaluated. Clove, citronella, eucalyptus, mint and basil essential oils, regardless of the concentration, totally inhibited the pathogen development. After the first experiment, the effect of these five essential oils on the sanitary and physiological quality of pepper seeds infected by <em>C. gloeosporioides</em> was investigated. For seeds treatment, the concentration of 0.25% of each essential oil was adopted. Sanitary quality, germination, seedling length, emergence of seedlings, emergence speed index and dry mass were evaluated. The essential oil of clove was efficient in reducing <em>C. gloeosporioides</em> incidence in the seeds, with no damages for their physiological quality.</div>