Biopesticides Class Teacher Dr Riffat Siddique Assistant Professor
Biopesticides • Class Teacher Dr. Riffat Siddique Assistant Professor (BPS-19) Department of Botany Lahore College for Women University, Lahore Pakistan. • Course Description » Course Title: PLANT BIOTECHNOLOGY » Course code: Maj/Bot-416 » Credit hours: 4 (3+1) • Class » Course : » Major: BS IV, 8 th Semester Botany
Biopesticides § Bio means involving life or living organisms. § A pest is any animal or plant detrimental to humans or human concerns. The term is particularly used for creatures that damage crops, livestock and forestry, or cause a nuisance to people § Pesticide includes substance or mixture of substances intended for preventing, destroying or controlling any pest. § Biopesticide is a formulation made from naturally occurring substances that controls pests by non toxic mechanisms and in ecofriendly manner. § Biopesticides may be derived from animals (e. g. nematodes), plants (Chrysanthemum, Azadirachta) and micro-organisms (e. g. Bacillus thuringiensis, Trichoderma, nucleopolyhedrosis virus), and include living organisms (natural enemies) etc. § However, biopesticides are generally less toxic to the user and are non-target organisms, making them desirable and sustainable tools for disease management. § Source: https: //www. slideshare. net/ruchirani 022/biopesticides-86535479 § https: //www. slideshare. net/santoshpathak 817/biopesticides-50835900
Need For Biopesticides § Proper pest management is important factor for healthy and high yielding crop to fulfill the food demand for increasing population. • Proper pest management is important factor § Chemical pesticides have accelerated land, air and water contamination. for healthy and high yielding crop to fulfill the food demand for increasing population. • Chemical pesticides have accelerated land, air § They have been the main cause of insect resistance as well as adverse impacts on and water contamination. • They have been natural enemies and humans. the main cause of insect resistance as well as adverse impacts on natural enemies and humans.
Advatages of Biopesticides § Inherently less harmful and less environmental load, § Designed to affect only one specific pest or, in some cases, a few target organisms, § Often effective in very small quantities and often decompose quickly, thereby resulting in lower exposures and largely avoiding the pollution problems. § When used as a component of Integrated Pest Management (IPM) programs, biopesticides can contribute greatly. Difficult for insects to develop resistance to these pesticides § Safe to natural enemies and higher organisms. § Biodegradable : Rapid degradation of the active ingredient make it more acceptable. § Cheaper, renewable, can be handled safely. § Often have other uses like household insect repellents or are plants with medicinal properties. § Most are compatible with insecticides and microbial agents. § There is great demand for residue free cotton garments, fruits, vegetables and beverages, large scale utilization of botanical pesticides will certainly help us in meeting international standards of quality and safety in these products.
Disadvatages of Biopesticides § Slow effect. § Lack persistence and wide spectrum activity. § Rapidly degraded by UV light so residual action is slow. § Effective dose is higher i. e. 30 ml/10 L especially in neem. § Seasonal availability of plant products indicates the need for their storage. § Not easily available everywhere. § Poor water solubility and are generally not systemic in nature. § All products applied followed by growers have not been scientifically verified.
Types Of Biopesticides • • • 1. Microbial pesticides 2. Plant-incorporated-protectants (PIPs) 3. Biochemical pesticides 4. Botanical pesticides 5. Biotic agents (parasitoids and predators)
1. Microbial Pesticides • Microbial pesticides are composed of microscopic living organisms (viruses, bacteria, fungi, protozoa, or nematodes) or toxin produced by these organisms • Applied as conventional insecticidal sprays, dusts, or granules. • Their greatest strength is their specificity as most are essentially nontoxic and non pathogenic to animals and humans. • Microbial pesticides includes insecticides, fungicides, herbicides and growth regulators of microbial origin.
Some of the important microbial pesticides A. Bacillus thuringiensis • Discovered in Japan in early 20 th century and first become a commercial product in France in 1938. • Control pests like American bollworm in cotton and stem borers in rice. Fig: Bacillus thuringiensis • When ingested by pest larvae, Bt releases toxins which damage the mid gut of the pest, eventually killing it. • Main sources for the production of Bt preparations are the strains of the subspecies kurstaki, galeriae and dendrolimus.
B. Agrobacterium radiobacter (Agrocin) • Agrobacterium radiobacter is used to treat roots during transplanting, that checks crown gall. • Crown gall is a disease in peaches, grapevine, roses and various plants caused by soil borne pathogen Agrobacterium tumefaciensm. • The effective strains of A. radiobacter posses two important features: üThey are able to colonize host roots to a higher population density. üThey produce an antibiotic, agrocin, that is toxic to A. tumefaciens.
C. Pseudomonas fluorescens (Phenazine) • This bacteria is used to control damping off caused by Pythium sp. , Rhizoctonia solani, Gaeumannomyces graminis. • It has ability to grow quickly in the rhizosphere. Fig: Pseudomonas D. Trichoderma is a fungicide effective against soil born diseases such as root rot. • This is also used against Necteia galligena, that causes silver leaf disease of fruit trees by entering through pruning wounds. Fig. spores of Trichoderma
E. Metarizium anisopliae • It infects spittlegbugs, rhinoceros beetles. F. Beauveria bassiana • Controls Colorado potato beetle. G. Verticillum lecanii: Fig: Metarhizium anisopliae • Controls aphids and whiteflies. H. Nomuraea riley: • Controls soybean caterpillars. I. Baculoviruses(Bvs) • Control lepidopterous and hymenopterous pests. • Rod shaped, circular double stranded super coiled DNA. Fig: Beauveria
2. Plant-Incorporated-Protectants (PIPs) • PLANT – INCORPORATED PROTECTANTS (PIPs) work as • Pesticidal substances that plants produce from genetic material that has been added to the plant. • Eg: scientists can take the gene for the Bt pesticidal protein and introduce the gene into the plant's own genetic material. Then the plant, instead of the Bt bacterium, manufactures the substance that destroys the pest. • As the pest feed on such plants they will eventually die
3. Biochemical pesticides • They are naturally occurring substance to control pest by non-toxic mechanisms. • Biochemical pesticides include substances as insect sex pheromones, that interfere with mating that attract insect pest to traps. • The synthetic attractants- are used in one of four ways: i. As a lure in traps used to monitor pest populations; ii. As a lure in traps designed to “trap out” a pest population; iii. As a broadcast signal intended to disrupt insect mating iv. As an attractant in a bait containing an insecticide
4. Botanical Pesticides • These are naturally occurring plant material that may be crude preparation of the plant parts ground to produce a dust or powder that can be used in full strength or dilute form in a carrier such as clay, talc or diatomaceous earth. • Several plant based insecticides as nicotinoids, natural pyrethrins, rotenoids, neem products etc are used. • Neem tops the list of 2, 400 plant species that are reported to have pesticidal properties and is regarded as the most reliable source of eco-friendly biopesticidal property. • Neem products are effective against more than 350 species of arthropods, 12 species of nematodes, 15 species of fungi, three viruses, two species of snails and one crustacean species. • Azadirachtin, a tetranortritarpinoid, is a major active ingredient disrupt the metamorphosis of insects, effects the reproductive and digestive procees of pest. • Neem Seed Kernel Extract (NSKE) was found most effective in reducing the larval
Continue--- • Over 195 species of insects are affected by neem extracts and insects that have become resistant to synthetic pesticides are also controlled with these extracts. • Neem bio-pesticides are systemic in nature and provide long term protection to plants against pests. • Pollinator insects, bees and other useful organisms are not affected by neem based pesticides
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Important Botanical Pesticides Fig: Neem oil Fig: Rotenone Fig: Tobacco suspension
5. Biotic agents/Natural enemies Predators • They consume several to many prey over the course of their development, they are free living and they are usually as big as or bigger than their prey. • lady beetles, rove beetles, many ground beetles, lacewings, true bugs such as Podisus and Orius, syrphid fly larvae, mantids, spiders, and mites such as Phytoseiulus and Amblyseius. Fig: lady bird beetle Fig: Lacewings
Parasitoids • Parasitoids are almost the same size as their hosts, and their development always kills the host insect. • An adult parasitoid deposits one or more eggs into or onto the body of a host insect or somewhere in the host’s habitat. • The larva that hatches from each egg feeds internally or externally on the host’s tissues and body fluids, consuming it slowly. • Later in development, the host dies and the parasitoid pupates inside or outside of the host’s body. • Bathyplectes, trichogramma, encarsia, muscidifurax etc. Fig: Trichogramma
Conclusion • Biopesticides are typically microbial biological pest control that are applied in a manner similar to chemical pesticides. • Available in different formulations • Also used to control soil borne and seed borne fungal pathogens • Disadvantages of them are, high specificity, slow speed of action and their requirement of suitable condition for their survival. • Eventhough, biopesticides are best for controlling the pests of agriculture then the chemicals • Therefore there should be more works on production on biopesticides and encourage people to use biopesticides to control the pests.
Future Prospective • Ecological studies on dynamics of diseases in insect populations are necessary. • Efforts should be made to minimize the loss of infectivity of certain pathogens due to photoinactiavtion. • Extension work needs to be geared up among the farming community to make them aware about the use and benefits of biopesticides. • Biotechnological approaches could be useful for obtaining bioactive products on large scale.
References: • https: //www. slideshare. n et/Sai. Appala/biopesticides • https: //www. slideshare. n et/ANJANAPRASAD 11/ biopesticides-83197928 • https: //www. slideshare. n et/santoshpathak 817/bio pesticides-50835900 • https: //www. slideshare. n et/ruchirani 022/biopestic ides-86535479
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