Studies on the role of aromatic shrubs in the inhibition of adjacent vegetation.

Kotoulas V., Panagopoulos G., Skouras V., Economou G. and Karamanos J.A.

Laboratory of Agronomy, Faculty of Crop Science, Agricultural University of Athens.

THE STATE OF THE ART

The biodiversity of aromatic flora in Greece

Typical constituent element of Mediterranean ecosystem

Origanum hirtum Origanum onites

THE STATE OF THE ART

Coridothymus capitatus Satureja thymbra

THE STATE OF THE ART

THE STATE OF THE ART

The classic uses - herbs - medicins - essential oils

"Let food be thy medicine and medicine be thy food" Hippocrates, the Father of Medicine

(460-377 B.C.)

THE STATE OF THE ART

The novel uses (industrial use)

- pharmaceutics- cosmetics, - agriculture - antimicrobial

- animal production

• agriculture - antimicrobial - animal production

THE STATE OF THE ART

QUESTION ?

Inhibitory effect on weeds ?

HYPOTHESIS

The inhibitory effect has been stated on oregano

Observation in situ

SCOPE To study the inhibitory effect of all the

“origanum” species indigenous of Greek ecosystems and Mediterranean in general

The longterm aim their effective use in terms of weed

control

APPROACHING THE SCOPE………..

Objectives

In situ assesement of inhibitory effect

In vitro biotests of their phytotoxicity

CASE STUDY

Islands of the north-eastern Aegean sea Ikaria and Fournoi

4 aromatic speciesa. Origanum onitesb. Origanum hirtumc. Coridothymus capitatusd. Satureja thymbra

METHODOLOGY

I. Study of adjacent vegetation during surveys in localized aromatic habitats.

Plot area: 15 m2 (5m x 3m)Richness: Number of the species Coverage: (the vertical projection of plant

canopy on the ground) Importance value: frequency + coverage (Wikum

and Shanholtzer, 1978)

METHODOLOGYII. Biotests a. Avena radicle Determination of 50%

inhibition in radicle elongation

b. Spirodela polyrhiza chlorosis

Determination of 50% Lethal Dose (LD 50%)

Doses: (ml of herbal distillate/ml of dilution)1 (A)0.5 (A/2)0.25 (A/4)0.125 (A/8)0.062 (A/16)0.031 (A/32)0.015 (A/64)0.008 (A/128)

Doses: (ml of herbal distillate/ml of dilution)1 (A)0.5 (A/2)0.25 (A/4)0.125 (A/8)0.063 (A/16)

Dose respone of herbal distillates

RESULTS

Richness

Origanumonites

OriganumHirtum

Thymus capitatus

Satureja thymbra

Origanum onites 1 1 1Origanum hirtum 1 0 1Thymus capitatus 1 0 1Satureja thymbra 1 1 1Ditrichia viscose 1 1 1 1Ruta graveolens 1 0 0 1

Euphorbia cyparissias

1 0 0 0

Lupinus angustifolius

0 0 1 1

Pteridium aquilinum

1 1 1 0

Arbutus unedo 1 1 1 1Erica manipuliflora 1 1 1 1

Rubus fruticosis 1 1 0 0Hypericum perforatum

1 0 1 1

Vitex agnus-castus 1 0 0 0Salvia officinalis 1 1 1 1Lavandula vera 1 1 1 1

Spartium junceum 1 1 1 1Sarcopoterium

spinosum1 1 1 1

Helichrysum angustifolium

1 0 1 1

Cistus parviflorus 1 1 1 1Quercus coccifera 1 0 1 1

Avena barbata 1 1 1 1Oryzopsis miliacea 1 1 1 1Hordeum murinum 1 1 1 1Silybum marianum 1 0 1 0Pistacia lentiscus 0 0 1 0Chrysanthemum

coronarium1 0 1 1

Vicia sativa 0 0 0 1

Total 24 15 21 21

RESULTS

IMPORTANCE VALUE

Sarcopoterium spinosum Salvia officinalis Lavandula vera

Satureja thymbraSpartium junceum

Ditrichia viscose Hypericum perforatum

Hordeum murinumChrysanthemum coronarium

Erica manipulifloraEuphorbia cyparissias

Quercus coccifera

0 5 10 15 20 25 30 35 40 45 50

Relative Frequency %Relative Cover %

Importance Value

a. Origanum onites

RESULTS

IMPORTANCE VALUE

b. Origanum hirtum

Cistus parviflorus Spartium junceum

Pteridium aquilinum Rubus fruticosis

Satureja thymbraSarcopoterium spinosum

Ditrichia viscose Erica manipuliflora

Salvia officinalis Oryzopsis miliaceaHordeum murinum

Origanum onites Arbutus unedo

Lavandula vera Avena barbata

0 5 10 15 20 25 30 35 40 45 50

Relative Frequency %Relative Cover %

Importance Value

RESULTS

IMPORTANCE VALUE

c. Coridothymus capitatus

Sarcopoterium spinosum

Salvia officinalis

Origanum onites

Avena barbata

Cistus parviflorus

Silybum marianum

Hordeum murinum

Pistacia lentiscus

Quercus coccifera

Lupinus angustifolius

Chrysanthemum coronarium

0 10 20 30 40 50

Relative Frequency %

Relative Cover %

Importance Value

RESULTS

IMPORTANCE VALUE

d. Satureja thymbra

Sarcopoterium spinosum Thymus capitatus

Origanum onites Ditrichia viscose

Helichrysum angustifolium Salvia officinalis

Hordeum murinumChrysanthemum coronarium

Vicia sativaRuta graveolens

Quercus coccifera

0 5 10 15 20 25 30 35 40 45 50

Relative Frequency %Relative Cover %

Importance Value

DOSE RESPONSE ANALYSISAverage radicle length of oat (cm)

Herbal distillate Ca (ml/ml)

O. onites S. thymbra O. hirtum C. capitatus

Control 11,07 (0)b 11,07 (0) 11,07 (0) 11,07 (0)0,008 7,09 (36) 9,14 (17) 9,54 (14) 7,04 (36)0,016 8,62 (22) 8,36 (24) 6,59 (40) 8,98 (19)0,031 6,23 (44) 8,30 (25) 1,79 (84) 6,85 (38)0,062 0 (100) 0,55 (95) 0,25 (98) 1,61 (85)0,125 0 (100) 0 (100) 0 (100) 0 (100)0,25 0 (100) 0 (100) 0 (100) 0 (100)0,5 0 (100) 0 (100) 0 (100) 0 (100)1 0 (100) 0 (100) 0 (100) 0 (100)

ld50c 0,18 (ab)d 0,22 (c) 0,16 (a) 0,20 (bc)

a Concentration (ml/ml), b numbers in parentheses indicate percent inhibition, concentration of the allelopathic components to cause 50% inhibition of radicle growth as determined by probit analysis. d Means with the same letter are not significantly different (LSD, P < 0.05).

DOSE RESPONSE ANALYSISResponse of Spirodella polyrhiza to herbal distillates

Leaf chlorosisb

Herbal distillate Ca (ml/ml) O. onites S.thymbra O. hirtum C. capitatus

Control 1 1 1 10,062 4 4 6 40,125 6 5 8 70,25 7 6 8 80,5 7 7 9 81 8 8 9 9

ld50 0,33 0,37 0,16 0,27a Concentration (ml/ml), b the European Weed Research Society classification scale of phytotoxicity (1: no symptoms, 9: heavy damage to total kill).

OVERVIEW CONCLUSIONS

In situ observations

Lower richness in O. hirtum

Lower importance value in O. onites

Biotests

O. hirtun showed the higher inhibitory effect

OVERVIEW CONCLUSIONS

CONVERSATION

S. thymbra

O. onites

C. capitatus

O.hirtum

0 20 40 60 80 100 120

carvacrolγ-terpineneortho-cymenecaryophylleneterpinene-4-olδ-careneβ-myrceneborneol

Chemical composition of ethereal oil

Arom

atic

shr

ubs

KEY MESSAGES

The identification of the effective constituent

The future effective use

The effective application on farm for

weed control

THANK YOU FOR YOUR ATTENTION!!!