© Benaki Phytopathological Institute
Gitsopoulos
et al.
52
terferes with cell division by disrupting mi-
totic microtubules and cell plates while at
higher concentrations it inhibits cell elon-
gation by disrupting cortical microtubules.
Carvacrol has also been reported to exhib-
it potential for use in weed control (Azirak &
Karaman, 2008).
In the present study, the essential oil of
M. officinalis
, with citral as main constituent,
showed greater phytotoxicity on
L. rigidum
germination and root length of
Ph. brachys-
tachys
compared to
S. hortensis
essential oil,
with carvacrol being its main component.
The greater effect of
M. officinalis
essential
oil could be attributed to higher citral con-
centration (83%), as compared with carvac-
rol concentration (47%) in
S. hortensis
essen-
tial oil. Our findings come in agreement with
the results of Dudai
et al.
(2000) which re-
vealed that inhibition of wheat germination
was more pronounced by citral compared to
carvacrol. Apart from the higher activity of
M. officinalis
, different response of the two
grass weed species was evident, with the
Ph
.
brachystachys
germination more affected by
both essential oils. However, previous stud-
ies reported that whatever activity has been
found against a certain target species will
not necessarily be maintained against an-
other target species, even at the same fam-
ily or genus (Vokou
et al.,
2003). Summariz-
ing, the results of this study indicated that
both essential oils exhibited herbicidal ac-
tivity on both grass weed species, with the
essential oil of
M. officinalis
to be more active
and
Ph. brachystachys
to be more suscepti-
Table 1
.
Chemical composition of
Satureja hortensis
and
Melissa officinalis
essential oils
.
S. hortensis
essential
oil constituents
% yield
M. officinalis
essential
oil constituents
% yield
a
-thujene
2.10
2-hexenal
0.27
α
-pinene
1.90
1-octen-3-ol
0.59
β
-pinene
1.05
5-hepten-2one-6-methyl
1.10
β
-myrcene
3.20
β
-myrcene
0.17
a
-phellandrene
0.58
trans
b
-ocimene
0.13
a
-terpinene
5.16
linalool
0.59
p
-cymene
4.62
citronellal
0.32
sylvestrene
0.90
neral
36.10
γ
-terpinene
29.14
geranial
47.16
carvacrol
46.94
methylgeranate
0.31
β
-caryophyllene
1.29
geranyl acetate
2.98
b
-bisabolene
0.70
β
-caryophyllene
2.62
caryophyllene oxide
1.57
Table 2.
Effect of essential oil (% of control) of
Satureja hortensis
and
Melissa officinalis
on ger-
mination and root length of
Lollium rigidum
and
Phalaris brachystachis.
Essential oil
L. rigidum
Ph. brachystachys
germination
root length
germination
root length
% of control
S. hortensis
82
1
a
2
38 a
54 a
47a
M. officinalis
72 b
41 a
47 a
35 b
**P<0.05
NS
3
NS
***P<0.001
1
Data were arcsine square root transformed before statistical analyses, De-transformed data are presented.
2
Means within each column followed by the same letter are not significantly different at P = 5% level of
significance
3
NS= not significant
1,2,3,4,5 7,8,9,10,11,12,13,14,15,16,...43