Use of three essential oils as seed treatments against seed-borne fungi of rice (Oryza sativa L.).

Abstract

Abstract: Three essential oils (EOS) extracted from Cymbopogon citratus, Ocimum gratissimum and Thymus vulgaris, were tested for their ability to control seed-borne infection and seed to seedling transmission of Alternaria padwickii, Bipolaris oryzae and Fusarium moniliforme in naturally infected seeds. Seven rice cultivars were tested and the EOs applied as slurry controlled the seed infection at a range of 48 % to 100%. The treatment also reduced the seed to seedling transmission of the referred fungi at a range of 76 % to 95%. The vigour of rice seedlings raised from the treated seeds was better compared to that of seedlings from the untreated seeds. The three Eos also increased the germination capacity of the treated seeds with 5 to 13%. On-farm evaluation is presently in progress in Cameroon. Key words: Essential oils Rice Seed-borne fungi Seed treatments INTRODUCTION (Fusarium moniliforme) and stackburn disease Rice (Oryza sativa L.) is the third important cereal known to decrease the germination of rice seeds [8, 9]. To crop in the world after wheat and maize, with an annual this effect, Agarwal et al. [4] and De Waard et al. [2], production of 576 million tonnes (with 90 % in Asia, 5 % in suggested disease management through seed treatments America and 3 % in Africa) that should be increased by as an integral component of rice crop production to avoid