Cinnamomum cassia essential oil and (E)-cinnamaldehyde as control agents of anthracnose on common bean seeds

Amongst the fungi that cause damage to common bean (Phaseolus vulgaris) and are disseminated by seeds, Colletotrichum lindemuthianum stands out. This fungus causes anthracnose in common bean plants. The use of natural compounds, for example essential oils (EO), is a viable and safer option than chemicals to manage this disease. According to the results of the in vitro assay, we observed complete inhibition of the growth of C. lindemuthianum with the use of Cinnamomum cassia EO and its major component (E)-cinnamaldehyde, presenting MIC of 125 µg/ml, whilst the commercial fungicide presented MIC of 30.6 µg/ml. In addition in vivo assay, where seeds naturally infected with C. lindemuthianum were treated with the EO and the substance in a solution with commercial soybean oil, we observed reducing the incidence of anthracnose over the days evaluated, as well as for the commercial fungicide used (thiophanate-methyl). In addition, the treatments did not affect germination and initial seed vigour. This is the first study to demonstrate the efficacy of Ci. cassia essential oil and (E)-cinnamaldehyde on the control of C. lindemuthianum through the treatment of common bean seeds.