IN VITRO EFFECT ON PHYTOPATHOGENS OF ESSENTIAL OIL AND AQUEOUS CRUDE EXTRACT OF OCIMUM GRATISSIMUM HARVESTED IN THE FOUR SEASONS

ABSTRACT The present >work aimed to evaluate the effects of the essential oil and crude extract of wild basil (Ocimum gratissimum), harvested in different seasons, on the in vitro mycelia growth of Rhizoctonia solani, Sclerotium rolfsii, Phytophthora sp. and Alternaria alternata. To evaluate the effect of the essential oil, sterilized oil aliquots of 20 ?L, 40 ?L and 60 ?L were distributed on the surface of potato-dextroseagar (PDA). The aqueous crude extracts (ACE) were filtrated and incorporated in PDA at 1%, 5%, 10%, 15%, 20%, 25% and 50%. The results showed total inhibition of mycelial growth in the different aliquots of essential oil. The ACE collected from plants in autumn had better results; in this season the ACE at 5% was enough to provide 100% of mycelia growth inhibition of A. alternata and S. rolfsii.