Efficacy of Essential Oil Formulations in Rice Seed Treatment Against <i>Magnaporthe oryzae </i>B.C Couch, a Rice Blast Pathogen

Abstract

Rice is one of the most widely produced cereals in Burkina Faso. However, the fungi transmitted by rice seeds, <i>Oryza sativa</i> L, cause enormous production losses in rice fields. The aim of this study was to assess the efficacy of powdery formulations of essential oils against <i>Magnaporthe oryzae </i>in rice. Thus, rice seeds of the FKR64 variety were disinfected with 15% sodium hypochlorite for 10 minutes and soaked in the suspension of 10<sup>4</sup> conidia/ml for 24 hours. These contaminated rice seeds were coated into powdery formulations of essential oils of <i>L. multiflora,</i> <i>C. schoenanthus</i> and their combination at a dose of 10g/kg of seed. A contaminated control was used. The experimental set-up was a completely randomised block with four treatments in three replicates, one of which was an absolute control. These treatments were carried out on <i>L. multiflora </i>essential oil, <i>C. schoenanthus essential oil</i> and their combination at a proportion of 50%. The results showed that the essential oil of <i>L. multiflora</i> recorded the highest percentage emergence, average height and average number of tillers of the plants, with values of 97.33%, 47.67 cm and 7.89 tillers respectively. This same formulation recorded the lowest percentage of seedling melt and foliar incidence, at 1.33% and 11.67% respectively. These essential oil formulations can be recommended for seed treatment against <i>Magnaporthe oryzae</i>.