Inoculum reduction of Aphelenchoides besseyi in Brachiaria brizantha seeds treated with essential oils

Essencial oils were tested to control Aphelenchoides besseyi in Brachiaria brizantha cv. 'Marandu' seeds. Seeds naturally infested with A. besseyi were treated with essential oils of mustard (Brassica nigra), cinnamon (Cinnamomum zeylanicum), verbena (Lippia citriodora) and Bioprotector(R) (a commercial product based on formulation of plant extracts and essential oils), in concentrations of 0.5% and 1.0%. The effects of the same treatments after direct application on juveniles nematodes were evaluated in vitro. All treatments were less effective to control the nematode in the seeds (in vivo) comparing to the in vitro test. The treatments did not eradicate the nematode from the seeds. However, the essential oils of cinnamon and verbena (in both concentrations), mustard (1.0%), as well as Bioprotector(R) (1.0%), reduced the seed population of A. besseyi. Mustard oil (1.0%) stood out for its nematicide action with no effect on seed germination.