BIOCONTROL
Use of biological methods
to control plant diseases
and pests
.
HARMFUL EFFECTS OF
PESTICIDES AND INSECTICIDES
Highly toxic and extremely
harmful.
Strong pollutant- pollute
environment (air, water, soil)
fruits , vegetables, crop
plants etc.
BIOCONTROL MEASURESADVANTAGES
Biocontrol measures, greatly
reduce our dependence on
toxic chemicals and pesticides.
BIOLOGICALCONTROL:
EXAMPLES
1. Aphids are predated by ladybird.
2.Mosquitoes are predated by dragon fly.
Bt-PLANTS
Biotechnologists introduced Bt toxin genes from Bacillus
thuringiensis into plants, and such plants are pests
resistant.
Eg: Bt-cotton
3.Caterpillars are killed by Bacillus
thuringiensis
Plants treated with
Trichoderma(a
free living fungus)
can resist many
plant pathogens.
 Baculoviruses are
pathogens of insects and
arthropods.
 They belongs to the genusnucleopolyhedrovirus.
 They are species specific.
Microbes as
Biofertilizers
• Bio fertilizers are
organisms that enrich
the nutrient quality of
the soil.
Examples:
1. Rhizobium- fixes atmospheric
Nitrogen in root nodules of
leguminous plants.
2.Azospirillum & Azotobacter are free
living Nitrogen fixing bacteria
3.Mycorrhiza(fungal growth on roots of some
plants)
Myccorhiza attached roots can:
Absorbs phosphorus from the soil
and passes it.
Show resistance to rootpathogens.
Tolerance to salinity and drought.
Overall increase in plant growth.
Cyanobacteria-
free living Nitrogen fixing
bacteriae widely available in aquatic and
terrestrial environment
Examples:
OSCILLATORIA
ANABAENA
NOSTOC
Nowadays many bio fertilizers are
commercially available in our
markets which the farmers can
purchase and use .
CONCLUSION :
It is right time to go back to
organic cultivation and use of
bio pesticides and biofertilizers
which only will save us from the
octopus grip of highly toxic
pollutants.