3rd Africa Rice Congress Theme 3: Rice processing and marketing Mini symposium: improving rice processing technologies in Africa Author: Togola et. al.

1. Effectiveness of Eucalyptus camaldulensis and
Cymbopogon citratus essential oils in protecting
rice stocks from Sitophilus oryzae and Sitotroga
cerealella.
A. Togola, P.A. Seck, F.E. Nwilene, I.A. Glitho et D. Chougourou

2. OUTLINE
Introduction
Material & methods
Results
Conclusion

3. INTRODUCTION

Rice production
• Rice is a staple food for
millions of people in Africa
•
Since 2008 its cropping area
and production have increased
in West Africa (FAOSTAT, 2011)
•
Unlike the pass , rice is more
and more stored for seeds,
consumption and trade

4. INTRODUCTION
 Storage issues
• Rodents, insects, fungus, abiotic
factors, etc.
• Quantitative losses due to
insects reach 5% and 30% in 4
and 6 month of storage.
• Qualitative losses : physical,
culinary and nutritional
• Economic losses: leading to the
decrease in income of the actors
of rice sector

5. INTRODUCTION
The objective of this study is:
To develop alternative technologies (to
chemical methods) for an effective integrated
protection of stored rice against insects pests.

6. MATERIAL & METHODS
Animal material:
Sitophilus oryzae
(Coleoptera: Curculionidae)
Larve
Adulte
Sitotroga cerealella
(Lepidoptera: Gelechiidae)
Larve
Adulte

7. Plant material:
Eucalyptus camaldulensis
(Myrtaceae)
Cymbopogon citratus
(Poaceae)
Essential oil
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8. • Impregnation of gunny bags
(sacs en jute)
Alcohol
Eucalyptus camaldulensis
3%, 4%, 5%, untreated check,
Check with alcohol alone
Cymbopogon citratus
3%, 4%, 5% , untreated
check, Check with alcohol
alone
Replication: 4
• Infestation method in impregnated gunny bags
20
20
Paddy rice: 100g
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9. • Treatment of cotton bags (sacs en cretonne)
Cymbopogon + cotton bag ( dose : 0.25ml/bag)
Eucalyptus + cotton bag ( dose : 0.25ml/bag)
Eucalyptus + Cymbopogon + cotton bag
Cymbopogon + cotton bag + plastic film
Eucalyptus + cotton bag + plastic film
Eucalyptus + Cymbopogon + cotton bag + plastic film
Check with cotton bag + plastic film
Check with cotton bag alone
Rep 4
• Infestation method in cotton bags
20
20
Paddy rice: 100g
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10. Data collected at 90 days after treatment:
• Population of emerged adults
• Percentage of weight loss (%)
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11. RESULTS
Table 1: Effect of essential oils on Sitophilus oryzae and Sitotroga
cerealella population emerged in stored paddy rice inside gunny bags (Sac
s en jute)
Treatments
Emerged
population of
S. oryzae
Emerged population
of
S. cerealella
Untreated check
51.0 ± 6.2a
345.7 ± 24,9a
Check with alcohol alone
C. citratus 3 %
48.1 ± 3.4a
51.5 ± 8.4a
329.6 ± 21,5a
113.2 ± 9,0b
C. citratus 4 %
C. citratus 5 %
E. camaldulensis 3 %
E. camaldulensis 4 %
E. camaldulensis 5 %
37.2 ± 3.4a
21.2 ± 2.6b
20.2 ± 2.0b
15.2 ± 2.6b
9.5 ± 3.1b
98.5 ± 8,8b
88.7 ± 4,0b
263.7 ± 20,4a
280.0 ± 19,4a
266.5 ± 32,4a
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12. Weight losses of paddy rice (%)
10
a
a
8
6
4
b
c
d
2
0
Figure 1: weight losses recorded 90 days after storage in ganny bags
impregnated withCymbopogon citratus

13. Table 2: Impact of cotton bags treatment on paddy rice weight losses
(Sacs en cretonne).
Traitements
Check with cotton bag alone
Pertes pondérales
Enregistrées (%)
8,69b
Check with cotton bag + plastic film
4,78ab
Cymbopogon + cotton bag
Eucalyptus + cotton bag
Eucalyptus + Cymbopogon + cotton bag
Cymbopogon + cotton bag + plastic film
Eucalyptus + cotton bag+ plastic film
Eucalyptus + Cymbopogon + cotton bag + PF
3,53ab
3,88ab
4,79ab
3,14ab
3,76ab
1,83a

14. CONCLUSION
The use of the essential oils of C. citratus and E.
camalsulensis appeared to be a promising method for
protecting stored rice against S. cerealella and S. oryzae.
However, the method needs some improvement in order to
make the technology cheaper for a large access by end
users.
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15. Thank you for your kind attention