1. Allium sativum (Garlic): A Review of its
Biology and Potential in Biological
Control
Anna Katrina E. Cruz

2. • Introduction
• Garlic
• Biological Control
• Discussion
• Biology of Allium sativum
• Understanding Biological Control
• Potential of Allium sativum as a Biocontrol agent
• Conclusion and Recommendation
• Literatures Cited
Outline

3. •Objectives
• To describe the biology of Allium sativum
• Evaluate its potential as a biological control agent
Introduction

4. • Garlic
• Local name : Bawang
• Scientific name : Allium sativum
• Taxonomy
• Kingdom : Plantae
• Order : Asparagales
• Family : Alliaceae
• Genus : Allium
• Species : sativum
Introduction

5. • Description
• A perennial plant
• Grows as tall as 2-3 ft.
• Leaves - long and flat.
• Flowers -white
• Bulbs –consists of several
cloves
• Habitat
• Originated in Central Asia
• Grows best in a rich, sandy,
moist soil in sunny areas
Introduction

6. • Uses
• Medicinal -since the time of the ancient Egyptians
• Antibiotic
• reduces cholesterol, blood pressure & internal
blood clots
• may prevent stomach cancer
• Strengthen immune system in people with aids.
(Swerdlow, 2000)
• Ingredient in many dishes
• Ecological Pesticide
Introduction

7. • Biological control
• Method that made use of an organism to reduce
the population density of another organism.
• Includes the control of animals, weeds, and
diseases.
• Uses macrobial and microbial agents
(Bale etal., 2008)
Introduction

8. • Studies
• Potential of Allium sativum as a biocontrol agent
 Feasibility of Allium sativum as a pesticide
 Binding of Garlic (Allium sativum) leaf lectin to the gut
receptor of Homopteran pests is correlated to its insecticidal
activity
(Bandyopadhay and Das, 2001)
 Effects of garlic juice containing allicin on Phytophora infestans and
downy mildew of cucumber caused by Pseudoperonospora cubensis
( Portz et.al.,
n.d.)
 Antibacterial effect of Allium sativum and Ficus carica extracts on
tomato bacterial pathogens (Balestra et.al.,
2008)
 Antifungal activity of some extracts against some plant pathogenic
fungi (Aba-Alkhail,
2005)
 Garlic as a Biological control agent for Sorghum ergot
Discussion (Singh and Navi, 2000)

9. • Potential of Allium sativum as a biocontrol agent
Feasibility of Allium sativum as a pesticide
• Questions?
Is it comparable to commercial ones?
Is it feasible to be a good source of pesticide
Is it harmful to human beings?
• Mixture
Garlic, mineral oil, water, and liquid soap
• Specimen
Cockroaches
• Results
Cockroaches were found dead
Garlic is feasible in making pesticide
Does not give any harm to human & environment
Discussion

10. • Potential of Allium sativum as a biocontrol agent
 Binding of Garlic (Allium sativum) leaf lectin to the gut receptor of
Homopteran pests is correlated to its insecticidal activity
(Bandyopadhay and Das,
2001)
Purified Allium sativum leaf lectin
Insect pests
 Lypaphis erysimi (aphids)
 Dysdercus cingulatus (red cotton bug)
Methods
 Insect Bioassay
 Immunohistochemical analysis
 Western analysis
Findings
 Possibility of using garlic leaf lectin as a potent control agent to
engineer crop plants for insects resistance
Discussion

11. • Potential of Allium sativum as a biocontrol agent
 Effects of garlic juice containing allicin on Phytophthora infestans and
downy mildew of cucumber caused by Pseudoperonospora cubensis
( Portz et.al., n.d.)
 Allium sativum juice containing allicin
 Phytophthora infestans
 Pseudoperonospora cubensis
 Results
 Germination of sporangia & cysts & subsequent germ tube by
Phytophthora infestans were inhibited.
 Desease severity in P. infestans tomato seedlings was also reduced.
 Severity of cucumber downy mildew caused by P. cubensis was
reduced.
 Recommendation
 Potential for developing preparations from garlic for use in specialized
aspects in organic farming
Discussion

12. • Potential of Allium sativum as a biocontrol agent
 Antibacterial effect of Allium sativum and Ficus carica
extracts on tomato bacterial pathogens
(Balestra et.al., 2008)
Allium sativum & Ficus carica extracts
Tomato bacterial pathogens (under greenhouse & field
conditions)
In vitro & in vivo tests
Results
 Reduced disease incidence by 58% & 30%, disease severity
by 68% & 22%
 Effective disease control of up to 65% (A.sativum) & 38%
(F. carica)
 Useful in protecting plants against bacterial pathogens in
the greenhouse
Discussion

13. • Potential of Allium sativum as a biocontrol agent
 Antifungal activity of some extracts against some plant
pathogenic fungi
(Aba-Alkhail, 2005)
 In vitro tests, to determine the antifungal activity of 5 plants
 Plants were extracted w/ either cold distilled water or cold
ethanol
 2 culture filtrates of Trichoderma antagonistic fungi
 Fusarium oxysporum, F. lycopersici, Botrytis cinerea, &
Rhizoctonia solani
 Results
 Plants extracts especially those extracted w/ cold distilled
water had strong antifungal activity
 Antagonistic fungus T. harzianum was more efficent to
decrease growth of tested fungi
 Plant extracts could be used as a natural fungicide to control
pathogen fungi to reduce dependence on synthetic fungicides
Discussion

14. • Potential of Allium sativum as a biocontrol agent
 Garlic as a Biological control agent for Sorghum ergot
(Singh and Navi, 2000)
Crude garlic extract
Sorghum ergot
Results
 Crude garlic extract was the most effective in providing
complete inhibition of conidial germination
 Greenhouse conditions: Prophylactic spray containing 12% of
crude garlic extract gave 98-100% control.
 Field conditions: the spray gave about 90% ergot control
 Non-toxic to humans
 Extracts can be effectively used as an environment friendly
method for the control of this disease.
Discussion

15. • Results have shown distinct potential of Allium
sativum in controlling pests and some destructive
organisms in plants & crops.
• This review will aid farmers in managing their
crops & guide people in protecting our
agriculture.
• This may lead students, researchers, & scientists
in formulating a mixture made of plant extract
that can be used in preventing insect pests.
• This is a great alternative to costly insecticides.
Conclusion and Recommendation

16. • Aba-Alkhail A.A. Antifungal Acivity of Some Extracts Against Some Plant Pathogenic Fungi. 2005.
• Adejumo T.O. Crop protection strategies for major diseases of cocoa, coffee and cashew in Nigeria.
2004.
• Bandyopadhay S., Roy A., and Das S. Binding of garlic (Allium sativum) leaf lectin to the gut receptors
of homopteran pests is correlated to its insecticidal activity. 2001.
• Bale J.S., van Lenteren J.C., and Bigler F. Biological control and sustainable food production.
• Balestra G.M., Heydari A., Ceccarelli D., Ovidi E., and Quatrucci A. Antibacterial effect of Allium
sativum and Ficus carica extracts on tomato bacterial pathogens. 2008.
• Chaturvedi R. and Chaturvedi S. A review on different therapeutic uses and antimicrobial potential of
Garlic. n.d.
• Kalu I.G., Ofoegbu U., Eroegbusi J., Nwachukwu C.U. and Ibeh B. Larvicidal activities of ethanol
extract of Allium sativum (garlic bulb) against the filarial vector, Culex quinquefasciatus. 2010.
• Kamel A. and Saleh M. Recent studies on the chemistry and biological activities of the organosulfur
compounds of garlic (allium sativum). 2007.
• Lirio L.G., Hermano M.L., and Fontanilla M.Q. Note Antibacterial Activity of Medicinal Plants from
the Philippines. 1998.
• Portz D., Koch E., and Slusarenco A.J. Effects of Garlic (Allium sativum) juice containing allicin on
Phytophthora infestans and downy mildew of cucumber caused by Pseudoperonospora cubensis. n.d.
• Singh S.D. and Navi S.S. Garlic as a Biocontrol Agent for Sorghum Ergot. 2000.
• Swerdlow Joel L. Nature’s Medicine, Plants that Heal. 2000
Literatures cited

17. Thank you..