herbal pesticides

a small review on herbal pesticides

1. A Review On -- HERBAL PESTICIDES-- BY – DIPANKAR DUTTA B. Pharm 4 th year DEPARTMENT OF PHARMACEUTICAL SCIENCES ASSAM UNIVERSITY, SILCHAR

2. Definition of Pesticides Pesticides are chemical compounds that are used to kill pests, including insects, rodents, fungi and unwanted plants (weeds). Pesticides are used in public health to kill vectors of disease, such as mosquitoes, and in agriculture, to kill pests that damage crops. HERBAL PESTICIDES Herbal pesticides are derived or extracted from plant or herbs. They are having very much low side effect to the human body as well as the eco system in comparison to synthetic pesticides.

3. Significance of selecting Herbal pesticides :- Herbal pesticides are usually inherently less toxic than conventional pesticides. Herbal pesticides generally affect only the target pest and closely related organisms, in contrast to broad spectrum, conventional pesticides that may affect organisms as different as birds, insects and mammals. Herbal pesticides often are effective in very small quantities and often decompose quickly , resulting in lower exposures and largely avoiding the pollution problems caused by conventional pesticides. Herbal pesticides are environment friendly. Systematic don’t attack the host organism. Easily bio degradable and don’t possess any toxic effects. Do not having any dosage problems as their drugs tolerance limit is very high . May also be tried by mixing with one or more botanicals or the synthetic organic compounds (synergistic effect) and such combination may be more effective. Many synthetic pesticides are carcinogenic it may causes cancer, but herbal pesticides are relatively safe.

4. HERBL PESTICIDES SYNTHETIC PESTICIDES They don’t develop resistance to pesticides They accelerated the development of genetic resistance to pesticides They are selective They are not selective The ecosystem is less effected The ecosystem is very much effected No such harmful residues remains in food, fodder and fibers. Many harmful residues remains in food, fodder and fibers They are less stable They are more stable Narrow spectrum of activity Broad spectrum of activity Slow action; residues may not be accumulate Fast action; residues may be accumulate COMPARISON BETWEEN HERBAL AND SYNTHETIC PESTICIDES Benefit of Herbal pesticides:- Rapid degradation : This characteristic, although desirable in some respect, creates a need for precise timing or more frequent applications Toxicity: All toxins used in pests control pose some hazarded to the user and to the environment. Lack of test data: Data of effectiveness of long term (chronic) toxicity are unavailable for some botanicals and tolerances for some have not been properly established.

5. Pharmaceutical dosage forms of various Herbal pesticides:- They are processed into various forms – Preparation of crude plant material Plant extract Pure chemical isolated from the plant Generally Herbal pesticides are used in various dosage forms i.e. spray, paste, suspension, dust, emulsion & sometime they are marketed in the form of aerosols and gas propellants . For the application of the Herbal pesticides dosages forms small hand spray, small brush for use in home to large powder sprays for livestock’s and field crops. For vast area dispersal airplanes and helicopters are used. Essential of good Herbal pesticides:- It should be a high margin of safety for plants and animals casing a very little or no damage to the foliage or live stocks respectively. It should be safe. It should be easier to handle and easy for the applications. It should not show toxicity. It should not be inflammable or explosive.

6. EXAMPLES OF SOME HERBAL PESTICIDES

7. Neem ( Azadirachta Indica ) Family – MALINACEAE part used – leaf botanical description – India , Nepal , Pakistan , Chemical compounds - Azadirachtin , Nimbin , Nimbidin , Nimbidol , Quercitin , , , Asorbic acid, β - sitosterol , Some marketed Neem pesticides Nicotiana glauca (tobacco) Color: - Green or slightly brown Odor: - Characteristic to Nicotine Taste: - Bitter Size: - 60 – 80 cm. in length, 35 – 45 cm.in Shape: - Ovate, elliptic or lanceolate Chemical compounds piperidine type of alkaloid, nicotine . The other alkaloids are nor- nicotine and anabasine . Some marketed tobacco pesticides

8. Capsicum frutescens (chili ) Family – NIGHTSHADE Part used- fruit Botanical description – India , Bangladesh , Nepal Chemical compounds: capsaicinoids ( responsible for hotness ) & ascorbic acid, zinc, phosphorous, copper are also present in chili. Some marketed chilli pesticides Cymbopogon nardus (citronella ) Family :- CARDIOPTERIDASE Part used :- from leaf oil is extracted Botanical description – India , Bangladesh , Nepal Chemical compounds:- volatile oil , geraniol and citronellal Others constituents borneol , linalool, methyl eugenol . Recently it is found to have cadinene and elmicin . Some marketed citronella pesticides

9. Conclusion It is noticed by the farming community and agricultural scientist that amount of using pesticides is increasing day by day in the agriculture. But by the using of various unsafe synthetic pesticides it gives a very harmful effect on the human health and as well as the ecosystem. Today’s agriculture demands practice of modern techniques coupled with scientific management. This will help getting more yield of better quality resulting into better revenue and profit. So the entire world is now shifting towards natural crop protection i.e. for the use of herbal pesticides .

10. THANK YOU