Studies on chemical constituents and antifungal activity of leaf essentialoil of Lippia alba (Mill)

The leaf volatile oil of Lippia alba (Mill) has been analysed by GC and CC- MS. Fifty components have been identified accounting for about 90% of the t otal oil. The major constituent is geranial (15.57%) followed by a unresolv able mixture of myrthenol and myrthenal (9.89%), neral (9.44%), geraniol (7 .36%), 2,6-octadien-1-ol, 3,7-dimethyl acetate (6.87%), 1-octene-3-ol (4.66 %),6-methyl-5-hepten-2-one (4.60%), caryophyllene oxide (4.52%), beta -cary ophyllene (3.09%),citronellol (2.63%), linalool (2.20%), 3-pinene-2-ol (2.1 9%), beta -myrcene (1.49%), farnesol (1.35%) and spathulenol. It was also f ound that oil vapours possessed strong antifungal activity against sugarcan e pathogens. The oil was highly effective in controlling teleutospore germi nation of Ustilago scitaminea and conidial germination of Colletotrichum fa lcatum and Curvularia lunata at 3 x 10(3) mul/L concentration. The oil also proved superior in comparison to commercial fungicides in controlling plan t pathogenic fungi.