7. Attack to Crops
Bacteria
Insects
Fungi
Viruses
Nematodes
Weeds
Food plants of the world are damaged by more than 10,000 species of insects, 30,000
species of weeds, 100,000 diseases (caused by fungi, viruses, bacteria and other microbes)
and 1000 species of nematodes (Hall, 1995; Dhaliwal et al., 2007)
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8. Estimation of crop losses caused by insect pests
to major agricultural crops in India
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Dhaliwal et al., 2010
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9. Role of Pesticides
Crop production without
pesticide is unimaginable
To ensure better production at harvest against
unpredictable losses caused by plant diseases & pests
To improve both quality & quantity of food
To decrease the extent of vector born & other
diseases in humans & animals
“Complete ban on agrochemicals use in agriculture might
result in 50% reduction in global food production and 4 to 5
times increase in food prices”
Nobel Laureate Norman Borlaug
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10. Risk Associated With Chemical Pesticides
Toxicity to plants
• Indiscriminate use leads to the Three sad R’s :
Toxicity to
Resistance, Resurgence and Residues mammals
Toxicity to aquatic creatures
• Elimination of Natural enemies of pests
Toxicity to beneficial organisms
• Upsetting the ecological balance
• Environmental degradation/Pollution
• Enters food chain and lead to Bio-Accumulation
and Bio-Magnification
As a result of The misuse and overuse of pesticides crop
losses have consistently shown an increasing trend (Dhaliwal
and Koul, 2010)
High persistence of residues
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11. New form of pesticide
Environmentally safe
Low residual toxicity
Host specific in action
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12. Active ingredient- Living organisms
Biopesticides are used to control pests, pathogens, and weeds by a variety
of means
Microbial biopesticides may include a pathogen or parasite that infects the
target
Alternatively, they might act as competitors or inducers of plant host
resistance
1st Biopesticide discovered in the year 1835
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13. Bio means involving life or living
organisms
Pesticide includes substance or mixture
of substances intended for preventing,
destroying or controlling any pest
Biopesticide refers introduction of any
living organism such as microorganism
including bacteria , fungi , nematodes
viruses, protozoa and parasitoids and
predators that controls pests by biological non-toxic means
e.g. Trichoderma sp., Bacillus thuringiensis, Beauveria etc.
All the living organisms, which are cultivated in the laboratory on large
scale & used and exploited experimentally for the control of harmful
organisms are called biopesticides
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14. Global biopesticides & synthetic pesticides market, 2003-2010
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15. Locked Horns:
Synthetic pesticides Vs. Bio-pesticides
Factors
Synthetic Pesticides
Bio-pesticides
Cost effectiveness
Cheap but increased
spraying cost
Costlier but reduced
number of applications
Persistence and residual
effect
High
Low
Knockdown effect
Immediate
Delayed
Handling and Bulkiness
Easy but danger and
Hazardous
Bulky : Carrier based
Easy : Liquid formulation
Pest resurgence
More
Less
Effect on Beneficial flora
More harmful
Less harmful
Target specificity
Mostly broad spectrum
Mostly host specific
Nature of control
Curative
Preventive
Shelf life
More
Less
The market share of bio-pesticide is only 2% as compared to synthetic pesticide
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(Source : agriculture Today. Nov. 2005)
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16. MICROBIAL PESTICIDE
Active ingredient : Microorganism (Fungi, bacteria, virus, nematode etc.)
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Woo et al., 2010
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17. MICROBIAL PESTICIDE
List of registered microbial products by CIB
Name of microbes
Type
Bacillus sp.
Bacteria
Trichoderma sp.
Fungi
Pseudomonas fluorescens
Bacteria
Gliocladium sp.
Fungi
Beauveria bassiana
Fungi
Verticillium lecanii
Fungi
Metarhizium anisopliae
Fungi
Nomuraea rileyi
Fungi
Nuclear Polyhedrosis Viruses
Virus
Granulosis Viruses
Virus
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Courtesy: http://www.cibrc.nic.in
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18. Characteristics
Storable
Economical
Easy to produce
Safe & acceptable
Convenient to apply
Virulent against target pest
Advantages
High degree of specificity
Compatible with chemical pesticides
Easy to apply & aid growth through out
No adverse effect on non-target organisms
Absence of residue build-up in the environment
Relatively cheaper by 50% as compared to chemical pesticides
(Narayanasamy, 1995)
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20. Entomopathogenic Fungi
Entomopathogenic fungi are fungi that can act as parasites of insects and
kill or seriously disable them
Mode of Action
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22. Beauveria
Beauveria bassiana most common
Habitat: Foliage
Insect Host: White flies, beetles & caterpillars (including Helicoverpa sp.)
Dose: 2 treatments made at 15-day intervals with 1.5 kg/ha concentrated product of
B. bassiana (3.0 × 109 conidia)
Treatment:
i) Foliar spray: 400-500 g in ½ bigha (5g/L of water)
ii) Soil drench: 250-500 g/3 bigha
Health impact: It causes granulosis disease in human ear
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Beauveria
bassiana
Cultures of B. bassiana
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Grasshoppers killed by B. bassiana
23. Metarhizium
Metarhizium anisopliae var. anisopliae & var. major
Habitat: Foliage
Insect host: Frog hoppers, beetles
Dose: Aerial treatment at 50 l/ha with 6 1011 to 1.2 1012 conidia/l of water
Conidia
Different cultures of M. anisopliae
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Cockroach killed by
M. anisopliae
23
24. Verticillium
Dose: 41
Verticillium (Cephalosporium) lecanii
Habitat: Glasshouse foliage
Insect host: Aphids, whiteflies & scales
107 active spores/g either undiluted or as a 10% concentration (diluted
with talc or water)
Conidia
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Cultures of Verticillium lecanii
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Whitefly scale infected
with V. lecanii
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25. Fungal Antagonists
Principal fungi: Gliocladium virens & Trichoderma sp.
Trichoderma sp. mainly T. harzianum & T. viride
Habitat: Soil
Effective against: damping-off & wilt
Parasitize Rhizoctonia & Sclerotium
Inhibit growth of Pythium, Phytophthora & Fusarium
T. harzianum
T. viride
Disease: T. harzianum causes green mold in cultivated button mushrooms & T.
viride causes green mold rot of onion
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26. Mode of action
Direct parasitism or lysis (lytic enzymes like chitinase, cellulase & glucanase) & death
of the pathogen
Direct toxic effects on the pathogen by antibiotic substances released by the
antagonist
Mycoparasitism by a Trichoderma
strain on the plant pathogen Pythium
Cultures of Trichoderma harzianum
Competition with pathogen for food
Indirect toxic effects on the pathogen by volatile substances released by the
metabolic activities of the antagonist
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27. The aim of investigations was to confirm the effect of Trichoderma
harzianum on Rhizoctonia solani and make a possibility for its usage in
tobacco production
T. harzianum was applied before and after sowing including a fungicide Top
M (0.1%)
At additional treatment with Trichoderma after use of fungicide, had a
better result than fungicide alone
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28. The influence of T. harzianum on intensity of disease attack
Natural inoculation
Artificial inoculation
The best results have shown by a variant with T. harzianum applied on a soil before
sowing and further application at certain intervals any time in a growing season of
tobacco seedlings
Additional treatment with T. harzianum after a fungicide Top M is advantageous to
the situation with a disease, so, it may be applied with this fungicide treatment
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29. Bacterial Antagonists
•
Pseudomonas sp. are gram negative, aerobic, rods that are inhabitants of wide
range of soil, water & plant surfaces
•
P. fluorescens recognized by fluorescent pigment called ‘pyoverdines’
•
Bio-control abilities of strains depend on aggressive root colonization, induction
of systemic resistance in the plant & production of diffusible or volatile
antifungal antibiotics
•
Antibiotics with bio-control properties include – phenazines, hydrogen cyanide,
2,4-diacetylphloroglucinol, pyoluteorin, pyrrolnitrin, lipopeptides etc.
Phenazin
pyoluteorin
Lipopeptide
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pyrrolnitrin
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Hydrogen cyanide
29
2,4-diacetylphloroglucinol
30. Mode of Action
Theories include • Induction of systemic resistance – resist attack by true pathogen
• Competition with other (pathogenic) soil microbes, e.g. siderophores
• Production of compounds (antibiotics) antagonistic to other soil microbes
Control of diseases
• Different strains of P. fluorescens extensively used in bioremediation of
various organic compounds & bio-controls of pathogens in agriculture
• P. fluorescens found effective in controlling fungal pathogens such as
wilt/root rot, Fusarium oxysporum f. sp. Cubense, Pythium sp., R. solani, R.
oryzae, S. rolfsii & bacterial pathogens like Xanthomonas citri & P.
solanacearum in field tests
• Bacterial preparations widely used in organic spice cultivation of southern
India
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31. Entomopathogenic Bacteria
Bacillus thuringiensis
• Bacillus thuringiensis (Bt), a Gram-positive, motile, rod shaped bacterium
produces a parasporal crystal composed of one or more proteins
• The strains of Bt characterized so far affect members of 3 insect orders:
Lepidoptera (butterflies and moths), Diptera (mosquitoes & biting flies), and
Coleoptera (beetles)
• EPA registered Bt products include
B.t. israelensis (Diptera)—frequently used for mosquitoes
B.t. kurstaki (Lepidoptera)—frequently used for gypsy moth, spruce
budworm, and many vegetable pests
B.t. sandiego and tenebrionis (Coleoptera)—frequently used for leaf
beetle, Colorado potato beetle
B.t. kurstaki is the most commonly used Bt formulation
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32. Mode of Action
Bacillus thuringiensis strains
produce crystalline proteins
(called δ-endotoxins)
Caterpillar consumes the Bt spore
(diagram 1) & crystalline toxintreated leaf
The Bt Treatments:
crystalline toxin (diamond shapes in
diagram 2) binds to gut wall receptors, and
Dose:
the caterpillar– 150 feeding for field crops.
i) 100 stops g/ bigha
ii) 150-200 g /bigha for orchards.
Within hours, the gut wall breaks down,
allowing spores (oval tube shapes) and normal
Method: The powder is first mixed with small quantity of
gut bacteria (circular shapes) to enter body
water to prepare a uniform suspension. Then the required
cavity, where the toxin dissolves
quantity of water is added and thoroughly mixed before spray.
The caterpillar dies in 24 to 48 hours from septicemia, as spores and gut
bacteria proliferate in its blood (diagram 3)
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33. Laboratory assays were done to evaluate the effect of Bacillus
thuringiensis, neem seed kernel extract (Azadirachta indica), Vitex
negundo leaf extract, & applied separately or together, on nutritional
indices of the rice leaf-folder Cnaphalocrocis medinalis
Bt biopesticide & other 2 botanical pesticide suppressed feeding and larval
growth and low concentrations affected the larval performance
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34. The combined effect of these resulted in a considerable decrease in
nutritional indices indicating strong deterrence
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(Nathan et al. ,2005)
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35. Human Health & Safety
• Bt is considered to be “practically nontoxic” to humans and other
vertebrates
• It can cause a “very slight irritation” if inhaled & can cause eye irritation
• Bt is not carcinogenic, mutagenic, or teratogenic
• Bt does not persist in the brains, lungs, or digestive systems of
animals, including humans
• Bt has been found in fecal samples of exposed greenhouse workers, no
gastrointestinal symptoms were associated with its presence
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36. Human Health & Safety …
• Bt appears to be a normal component in the feces of vegetableconsuming animals, where it apparently causes no problem
• Like the active bacterial ingredient, the inert ingredients in Bt
formulations have also been studied and modified for safety
• Granular and microcapsule formulations reduce the inhalation hazard
• Volatile agents associated with some Bt formulations do not appear to
constitute a significant health hazard.
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37. Environmental Impacts
• No danger has been found to aquatic communities accidentally
exposed to Bt or to non-target organisms including beneficial insects,
amphibians, fish, and mammals
• Few reports of Bt lethality upon non-target organisms, such as leaffeeding caterpillars
• Clay soils may bind the bacterial toxin, increasing its environmental
persistence and possible toxicity to non-target species
• Newer formulations employ preservatives, like sorbitol, that are safer
than the xylene used decades ago
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38. Phytonematode management through
bacteria
Bacteria
Genus/species
Target nematode
Mode of action
References
Parasitic
bacteria
Pasteuria penetrans,
P. thornei
Phytonematodes
Parasitism
Bekal et al.(2001),
Bird et al. (2003)
Opportunistic
bacteria
Brevibacillus
laterosporus,
Bacillus nematocida
Free living &
Phytonematodes
Parasitism
Niu et al. (2006),
Tian et al. (2007)
Rhizobacteria
Bacillus sp.,
Pseudomonas sp.
Meloidogyne sp.,
Heterodera sp.
Interfering with
recognition,
production of
toxin, nutrient
competition, plant
growth promotion
Marleny et al.
(2008),
Meyer (2003)
Crystal
forming
bacteria
Bacillus thuringiensis Trichostrongylus
(Cry 5,6,12,13,14,21) colubriformis,
Caenorhabditis
elegans
Cry proteins cause
damage to the
intestines of
nematodes
Kotze et al.(2005),
Wei et al. (2003)
Rhizo-bacterial &
endophytic
bacterial mode of
action
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Sturz et al. (2004),
Compant et al.
(2005)
Endophytic
bacteria
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Root knot
nematode,
Cyst nematode
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39. Nuclear polyhedrosis virus (NPV)
A) NPV (Helicoverpa): It is highly effective on H. armigera, pest of
cotton,gram, pea, pigeon pea, tomato, cabbage, ground nut, millets,
oilseeds & roses
A) NPV (Spodoptera): It is highly effective against S. litura caterpillar, pest
of cotton, gram, pigeon pea, cabbage, tomato, chillies & oilseeds
Treatments: Dose: 250 – 500 LE/ha
Method:
i) Shake the bottle properly and prepare a solution @ 1 ml/litre of water
ii) Spray the solution 2-3 times at 10-15 days interval
iii) Spray preferably in the evening and on young larval stages or on sighting of
egg laying
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40. Enhancing food security by the local production of
microbial bio-pesticides against insect crop pests:
African armyworms as a case study
2 types of application studied
A) Aerial spray of SpexNPV
B) Ground spray of SpexNPV & OP pesticide Diazinon
separately
SpexNPV = Spodoptera exempta Nucleo polyhedrovirus
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(Wilson et al., 2008)
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46. Parasitoids & Predators
Types of biocontrol agents
Names of biocontrol agents
Target species
PARASITOIDS
Trichogramma chilonis
Brinjal shoot and fruit
borer, shoot borers of
cotton, sugarcane, rice
T. brasiliensis and T.
pretiosum (egg
parasitoids)
tomato fruit borer
Cryptolaemus
montrouzieri
(Austrtralian ladybird
beetle)
several species of mealy
bugs and soft scales
Chrysoparla sp. (green
lacewing bug)
aphids, white flies
PREDATORS
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47. Few examples of bio-control
Muscodor albus strain QST 20799 acts as bio-fumigant & controls
bacteria and soil borne pest by releasing volatile toxin
Aspergillus flavus strain AF36 can act as bio-fungicide for cotton. Unlike
other strains it will not produce carcinogenic ‘Aflatoxin’
Pasteuria sp. acts as bio-nematicide & controls microscopic worms &
other nematodes that feed on plant roots
Cydia pomonella granulosis virus acts as bio-insecticide & controls
codling moth in fruits like apples & pears
Phytophthora palmivora acts as bio-herbicide & controls milkweed
(Asclepias sp.) in citrus orchards
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48. Path Ahead
More studies needed to determine the environmental effects on the fate
of bio-agents
New technologies such as micro encapsulation of bio-control agents may
be of high priority in enhancing their potential
Integration of bio-pesticides with botanical pesticides has a lot of
potential in pest management
Integration of bio-pesticides with chemical pesticides as part of Biointensive Integrated Pest Management (BIPM)
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49. Conclusion
Microbials such as bacteria, fungi, viruses are the major bio-pesticides being
studied mostly to develop alternatives to chemicals
The no. & growth rate of bio-pesticide showing an increasing marketing trend
in past few decades
Bio-pesticides are host specific & bio-degradable resulting in least persistency
of residual toxicity
Bio-pesticides саn mаkе vital contributions tο IPM & can greatly reduce
conventional pesticides, while crop yield remains high
Bio-pesticides having lesser health hazard provides an important alternative
in the search for an environmentally sound and equitable solution to the
problem of food security
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50. “Life is not living, but being in health.”
- Latin poet Martial
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