Sanitary and physiological quality of corn seeds (Zea mays) treated with essential oil emulsion

Resumo

The aim of the present studies were to evaluate the effects of treatments with essential oil emulsion on the sanitary and physiological quality of creole corn seeds. In the studies were evaluated the essential oils of neem (Azadirachta indica), citronella (Cymbopogon nardus), lemon balm (Cymbopogon citratus), melissa (Melissa officinalis L.), and the combinations neem-citronella, neem-lemon balm, neem-melissa, citronella-lemon balm, citronella-melissa and lemon balm-melissa. The tests carried out were germination, length of seedlings (aerial part and root), dry mass and pathology for Fusarium sp and Aspergillus sp, in seeds of creole corn produced without the use of synthetic pesticides. The studies were carried out in vitro and consisted of the preparation of water emulsion, 5,000 ppm of essential oil and 1% of triton X100 and direct application on the seeds of creole corn, following the protocol of Rules of Seed Analysis (RSA). The results showed a significant decrease in the occurrence of fungi Fusarium sp and Aspergillus sp with treatment with essential oils of citronella, lemon balm and melissa, while the oil of neither reduced the occurrence of Fusarium sp, but increased the occurrence of Aspergillus sp in almost four times. All binary combinations of essential oils reduced the occurrence of both fungi. On the other hand, the physiological quality was strongly affected by the death of creole corn seeds, except for the treatment with lemon balm essential oil. Therefore, these studies allow to affirm that essential oils can be efficient in the control of pathogens, however they can kill the seeds of creole corn.