Title: EFFICIENCY OF SOME LOCAL PLANTS ESSENTIAL OIL AGAINST SEEDBORNE AND SEED TRANSMITED FUNGI OF RICE KA
1EFFICIENCY OF SOME LOCAL PLANTS ESSENTIAL OIL
AGAINST SEED-BORNE AND SEED TRANSMITED FUNGI OF
RICEKABORE K.B1. KOÏTA E1. OUEDRAOGO I1.
et NEBIE R2. (1) Institut de lEnvironnement et
de Recherches Agricoles (INERA)(2) Institut de
Recherche en Sciences Appliquées et
Technologies Département Substances
Naturelles (IRSAT) Burkina Faso
2HEADLINES
- Introduction
- Objectives
- Materials and Methods
- Results
- Discussion
- Conclusions and Perspectives
- Aknowledgement
3INTRODUCTION
- Importance of rice as food crop
- Biotic Constraints to production
- Seed-borne fungi as major mean of rice diseases
transmission and dissemination. - Increasing dependance of rice roduction upon the
use of conventionnal pesticides. - Negative impact on Environment and health
- Need in research of alternate biopesticides
- Research Hypotheses Some traditionnal local
plant species used as medical substances could
have fungicide properties (Kaboré et al.,2002)
4OBJECTIVES
- OVERALL OBJECTIVE
- Identify local plant species with bio pesticides
properties that can be used in agriculture. - SPECIFIC OBJECTIVES
- Identify local plant species with essential oil
presenting fongicide properties - Determine efficient level of application of
essential oil for rice seed treatment against
fungal mycoflor.
5MATERIAL AND METHODS (contd)
- local plants species used for study
- Cymbopogon citratus (D.C.) Stapf. Common french
name citronnelle (Poaceae ) - Cymbopogon giganteus Chiov ( Poaceae )
- Lippia multiflora Moldenke, (Verbenaceae) Common
french name thé de Gambie - Ocimum basilicum L, (Lamiaceae).
6MATERIAL AND METHODES
- Rice variety used IR6623275-5-12
- Seed-borne fungi and their contamination level
() - Bipolaris oryzae 28,5
- Curvularia oryzae 11,5
- Curvularia lunata 13,5
- Fusarium moniliforme 48,5
- Phoma sorghina 19,5
7Cymbopogon citratus
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10MATERIAL AND METHODS (contd)
- Essential oil was extracted by hydrodistillation
with a Clevenger apparatus from fresh leaves
collected from the different species during rainy
season 2004. - Essential oil of Ocimum basilicum L., Cymbopogon
citratus (DC) Stapf, Cymbopogon giganteus Chiov.
et Lippia multiflora Moldenke was used at the
concentration of 1 1,5 et 2 corresponding
respectively to 10 ml, 15 ml et 20 ml per litre
of media ( PDA)
11MATERIAL AND METHODS (contd)
- The conventionnal control for cereal seed
treatment fungicide was Calthio DS ( 20 of
Lindane and 25 of Thiram. This product was
incorporated into the media (2,5 g per litre of
PDA media) - Seed treatment
- Seed health testing by the blotter method
- Four replicates of 50 seed (25 seeds per Petri
dish) were soaked for 20 to 24 hours in essential
oil emulsion (1, 1,5 and 2) - Incubation à 22C
12MATERIAL AND METHODS (contd)
- Radial growth measurement of the fungi
- Essential oils were incorporated into the PDA
media at the concentration of 1, 1,5 and 2. - Petri disheswere incubated at 28C under
alternate cycles of 12h of NUV light and 12h
of darkness. - Measurement of radial growth (cm) after 3, 5 , 7
and 10 days of incubation (perpendicular
diametre Method). - Experimental design Split plot with oils as
main factor and concentrations as secondary
factor.
13MATERIAL AND METHODS (contd)
- Efficiency of extracts (Greche et Hajjaji,
2000) - E() 100DMT-DMH/ DMT
- where DMT represents the mean diametre of the
control (non treated) and DMH the mean diametre
of the treatment with essential oil. - Data were analysed for ANOVA with STATVIEW/SAS
software and the means were separated by the
Student- Newman- Keuls test
14RESULTS
15ANOVA
- ANOVA indicated significant différencies between
the traetments for the test of radial growth of
the fungi as well as the test of seed germination
- No significant difference was observed between
the tested concentrations
16Efficiency of essential oils
- All the four tested essential oils inhibited the
radial growth of the fungi Bipolaris oryzae,
Curvularia lunata Fusarium moniliforme and Phoma
sorghina. - When considering the different concentrations,
these oils reduced significantly the incidence of
the four seed-borne fungal species as compared to
the controls.
17 a b c d e Pétri
dishes presenting efficiency of C. Citratus
essential oil against Curvularia
lunata (aconcentration 1, bconcentration 1,5
, cconcentration 2 , dnon treated control ,
e control calthio).
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19Global seed contamination following treatment
with essential oil
20Incidence of Seed borne fungi after seed
treatment with essential oil (B. oryzae, C.
lunata, F. moniliforme et P. sorghina
21DISCUSSION
- Essential oil of C. citratus, C. giganteus, L.
multiflora and O. basilicum reduced significantly
the incidence of seed contamination by the fungi
and inhibited the radial growth of fungal
colonies as compared to the different controls. - The presence of citral in the essential oil of
C. citratus (Djibo., 2000), and also the presence
of oxygenous components like linalol and eugénol
in essential oil of O. basilicum (Nébié et al.,
2002) could explain antifungic properties of
these two plant species.
22DISCUSSION (Contd)
- These results are comparable to those of Dongma
(2002) who evaluated in vito the antifungic
activity of essential oil of Citrus limon and
Citrus latifolia against the inciting fungus of
citrus phaeoramulariosis (Phaeoramularia
angolensis). - Concerning the seed germination test by the
blotter method, essential oils of C. citratus and
C. giganteus were highly efficient against the
fungi but were slightly phytotoxic. Dabiret
(2004) came to the same conclusion that essential
of the genus Cymbopogon has a negative effect on
seed germination.
23CONCLUSIONS
- Essential oils of C. citratus, C. giganteus, L.
multiflora and O. basilicum have antifongic
properties. - For the firts time, efficency of L. multiflora
oil in improving the germination capacity of rice
seed under laboratory conditions was
demonstrated. - Essential oil of Lippia did not exhibited any
phytotoxic effect at the tested concentrations as
compared to oils of Cymbopogon, and Ocimum
moreover it reduced by up to 28,81 the
incidence of seed-borne and seed-transmitted
fungi.
24PERSPECTIVES
- The tested concentrations of some essential oils
used in this study should be lowered because of
the observed phytotoxicity they produced on the
seed germination tested by the blotter method..
25AKNOWLEDGEMENTWe like to thank Adama OUATTARA
and Raphaël SANOU for their technical
contribution to the realization of the present
work .
26Thank you for your attention
ASANTE SANA