Control of papaya fruits anthracnose by essential oil of Ricinus communis

ABSTRACT

The aim of this work was to investigate the potential of castor oil for the control of papaya diseases caused by the fungus Colletotrichum gloeosporioides and the bacterium Pseudomonas caricapapayae. The treatment with 1% castor oil did not significantly affect the fungal growth. The effectiveness of castor oil for the control of anthracnose was shown when 5% and 10% (v/v) were used in the assays resulting in reduced mycelial growth. Fungal sporulation was strongly inhibited at 10% (v/v) concentration of essential oil. The studies with the fresh fruits treated with 5% (v/v) castor oil in aqueous emulsions resulted in effective reduction of pathogen spread in these fruits. No lesion was found in the fruits treated with oil, when compared to the control fruits. Castor oil showed no effect against the P. caricapapayae when tested in vitro. These results suggested the potential use of the castor bean essential oil and its fatty acids constituents for the control of anthracnose in papaya fruits.