Introduction to the Biopesticides.pptx

biopesticides

1. Introduction In agriculture to produce crops of best quality and quantity they are needed to be protected from phytopathogens. Generally chemical fertilizers are used that are very effective for pest control but their are long term effects are hazardous to humans, crops and environment. To overcome an alternative method of using bio-pesticides are used.

2. Bio-pesticides Bio - means biological agents pest – any living organism that affects the plant growth Pesticides – Mixture of substances used for preventing, destroying or controlling any pest. B io-pesticides – biological Substances or Organism that damages or kill pests by non-toxic mechanism. They are highly specific and do not harm to non targeted species. They are biodegradable and do not cause pollution No harmful residues remain in food, fodder and fibres.

3. Types of Bio pesticides

4. Microbial bio-pesticides – these are composed of microscopic living organisms or toxins produced by these organism.

5. Bacterial bio-pesticides Bacterial bio-pesticides are the most widely used and are cheaper than other modes of pest bio regulation. Many species of bacteria can infect different varieties of insects but those bacteria belongings to the genus bacillus are most widely used as pesticides Bacillus thuringiensis, has developed many molecular mechanisms to produce insecticidal toxins most of toxins are coded by several cry genes. Bacillus thuringiensis and cry proteins are efficient ,safe and sustainable alternatives to chemical pesticides for the control of insect pest because of their high specificity and their safety in the environment .

6. Mode of action of BT-toxin against lepidopteron

7. Fungal bio-pesticides Fungi specifically associated with insects are known as entomopathogenic fungi. .It is a form of microbial control .Hence virulence is caused by contact and action is through penetration. .they are effective against eggs, larvae , intermediate stages and adults of a variety of insects including grasshoppers, locusts , mosquitoes and oth ers Mode of infection – When spores of the fungus come in contact with cuticle of insects, they Germinate to form germ tube and penetrate directly throughout the cuticle. Fungus proliferates throughout the insect body, producing toxins and draining the insect of nutrients eventually killing it. Death caused by tissue damage and toxin produced by fungus.

8. Beauveria bassiana It Is an entomopathogenic fungi which causes white Muscardine disease in silkworm. It is being used as a biological insecticide to control a number of pests such as termites, thrips, whiteflies, aphids and different Beetles. Mode of action : The fungi usually attached to the external body surface of insects in the form of microscopic spores. Under favourable conditions these spores germinate grow as hyphae and colonise the insect cuticle. When the conidia land on an insect they secrete enzymes that eat through the cuticle and release beauvericin toxin The fungus replicates and feeds on the host, killing it In about 3 to 7 days depending on conditions. After the host dies the fungus continues to feed off it’s dead host covering it in a white powdery mold.

9. Viral bio-pesticides Baculovirus is the commonly used viral bio-pesticide They are extremely small and are composed of double stranded DNA. The genus Baculoviruses contains 3 subgroups 1. Nuclear Polyhedrosis viruses (NPVs) 2. granulosis viruses 3. Non occluded viruses They are so specific in their action that they infect and kill only one or a few species of caterpillars.

10. Mode of action of Baculovirus The virus act as a stomach poison. Larvae eat the infected foliage and the virus enters the midgut of the insect larvae

11. Plant – incorporated protectants PIPs pesticidal substances that plants produces from genetic material that has been added to the plant. e.g.: Scientist take the gene from the BT pesticidal protein and introduced the gene into plants own genetic material. then the plant instead of BT bacterium manufacture the substance that destroy the pest.

12. Biochemical pesticides Biochemical pesticides are naturally occurring substances that control pests by non toxic mechanism. E.g. – Insect sex pheromones and other compounds that prevent meeting. Different aromatized plant extract attracting pest to traps.

13. Advantages of bio pesticides over chemical pesticides

14. Advantages of bio pesticides Bio pesticides control pest in an eco friendly and non toxic manner they cost less harm to ecosystem as compared to chemical pesticide these offer the following advantages. Zero or little residual effect – Residues of microbial bio-pesticides produce no adverse effects on living being. To be used as a part of integrated pest management (IPM) Less chances to develop resistance by pests – Narrow range of action that contributes to specificity towards a particular insect pest

15. Biodegradable in nature. Effective in low concentration and provide pest control over generations. Non toxic nature along with non pathogenicity towards targets. these do not affect eco friendly insects such as pollinators and soil micro flora hence help in improving the plant growth and crop yield .

16. Reference Current status and advancement of Bio-pesticides : Microbial and botanical pesticides March 2016 in journal of Entomology and zoology studies by Muhammad Nawaz, juma Mabubu Research article on current status and recent Developments in Bio- pesticide use by Christos A.Damalas and spyridonD. Kouttrobas Kumar S(2012) Bio-pesticides : a need for food and environmental safety