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Pesticides use in agriculture: benefits, risks and safety

  1. Speaker Krishna Gupta Ph.D. Scholar
  2. Introduction • Pesticides constitue an important component in agricultural development and protection of public health in developing countries. • Pesticides enhanced economic potential in terms of increased production of food and fiber, and amelioration of vector-borne diseases. • Pesticide use raises a number of environmental concerns, including human and animal health hazards, pollution of air, water and soil.
  3. Pesticides • Pesticide means any substance intended for preventing, destroying, attracting, repelling or controlling any pest including unwanted species of plants or animals during production, storage, transport, distribution and processing of food, agricultural commodities or animal feeds or which may be administered to the animals for the control of ectoparasites. (F AO, 1989).
  4. Historical Perspective of Pesticides • About 4000 years ago the first known pesticide was elemental sulfur. • In 15th century arsenic, mercury and lead were being applied to crops for kill the pests. • In17th century nicotine sulfate was extracted from tobacco leaves for use as an insecticide. • In 19th century introduction of two more natural pesticides, pyrethrum and rotenone. • In 1939, Paul Muller discovered that DDT was a very effective insecticide. 15th century 17th century 19th century
  5. Conti… • Pesticide use in India dates back to the year 1948 when DDT and BHC were imported for malaria and locust control. • In 1960 Rachel Carson wrote the best-selling book Silent Spring about biological magnification. • In 1960 triazine, 2,4-D and glyphosate herbicides were introduced. • In 1970 U.S. Environmental Protection Agency was established and amendments to the pesticide law in 1972 • In 1975 introduced organophosphates and carbamates pesticides.
  6. Production and usage of pesticides in India • The production of pesticides started in India in 1952 with the establishment of a plant for the production of BHC near Calcutta, and India is now the second largest manufacturer of pesticides in Asia after China and ranks twelfth globally (Mathur, 1999). • There has been a steady growth in the production of technical grade pesticides in India, from 5,000 metric tons in 1958 to 1,02,240 metric tons in 1998. • In 1996–97 the demand for pesticides in terms of value was estimated to be around Rs. 22 billion (USD 0.5 billion), which is about 2% of the total world market. Aktar et al., 2009
  7. Types of Pesticides and there Target Organism Types of pesticide Target organism/pest Insecticides Insects Fungicides Fungi Bactericides Bacteria Herbicides Weeds Rodenticides Rodents Acaricides Arachnids such as ticks and mites Moluscicides Mollusks Avicides Bird pests Nematicides Nematodes Algaecides Algae
  8. Insecticides • Definition: Insecticide may be defined as a substance or mixture of substances intended to kill, repel or otherwise prevent the insects. • Insecticides disrupt the nervous system, whereas others may damage their exoskeletons, repel them or control them by some other means. • They can also be packaged in various forms including sprays, dusts, gels, and baits. • Because of these factors, each insecticide can pose a different level of risk to non-target insects, people, pets and the environment. Ex.-Organophosphates, Carbamate and different newer insecticide.
  9. Fungicides • Fungicides are pesticides that kill or prevent the growth of fungi and their spores which damage plants, by causing rusts, mildews and blights. • They might also be used to control mold and mildew in other settings. • Fungicides work in a variety of ways, but most of them damage fungal cell membranes or interfere with energy production within fungal cells. • Ex.- Plantomycin, Cyprodinil, Iprodione and Metconazole etc.
  10. Herbicides • Herbicides kill unwanted plant, while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic mimics of natural plant hormones. • The most frequent application of herbicides occurs in row crop farming, where they are applied before or during planting to maximize crop productivity by minimizing other vegetation (weed). • Ex. Bromoxynil, Arylex, 2,4-D, triazine and glyphosate etc.
  11. Rodenticide • Rodenticides are pesticides that kill rodents, including mice and rats. • They are often formulated as baits with attractive substances like peanut butter or molasses. • Rodenticide baits can provide short-term control of rodent infestations. • People, pets, and wildlife are very similar to rodents, so they can also be poisoned by rodenticides. • Recent changes to rodenticide regulations limit the availability of more toxic baits for home use. • Ex.- Zinc phosphide, Warfarin, and Strychnine etc.
  12. Product wise use of pesticides (FY17)
  13. Use of pesticides in World and India for crops Source: Vision 2050 (NRCWS Perspective plan 2017)
  14. Globally pesticide consumption (Kg/ha) comparison (2017)
  15. Benefits • The benefits of pesticides include increased food production • Increased profits for farmers. • Management of pest. • Improve quality of food. • Due to the use of pesticides, it is possible to combat pests and produce larger quantities of food. • Pesticides also increase farm profits by helping the farmer save money on labor costs. • In addition to saving crops and livestock, pesticides have also had direct benefits to human health. • It is estimated that since 1945, the use of pesticides has prevented the deaths of around seven million people by killing pests that carry or transmit diseases. Catherine W. 2018
  16. Risks • The risk of a pesticide depends on two things, exposure (how much?) and toxicity (how poisonous?). • The exposure is the amount you get in or on your body, or the amount that is released into the environment. • The toxicity of a pesticide is measure of how poisonous it is to people or the environment.
  17. Risks of pesticides • Effect on human • Air pollution by pesticide • Water pollution by pesticide • Soil pollution by pesticide • Pesticide effect on plants • Pesticide effect on animals • Resistance development • Effect of pesticides on pollinators • Effect of pesticides on non-targets organism • Pesticide Biomagnifications
  18. Effect on Human • Annually there are dozens of million cases of pesticide poisonings worldwide (Richter, 2002). • Pesticide effects to human can be categorized as acute i.e those with quick felt effects e.g. nausea or chronic i.e those with long term felt effects such as the case of leukemia. • These are the most common health effects:- • Cancers • Depressions/neurological deficits • Diabetes • Respiratory diseases • Women specific disorders • General health/multiples diseases
  19. Pesticide effect on animals • Pesticides can eliminate some animals' essential food sources. • Residues can travel up the food chain. • In birds DDT-induced egg shell thinning has especially affected European and North American bird populations
  20. Water pollution by pesticide • There are four major routes through which pesticides reach the water • Contaminate water when they spraying. Ex. Rice cultivation • It may percolate, or leach, through the soil. • It may be carried to the water as runoff. • Carried to water by eroding soil.
  21. Pesticide effect on plants • Specially pentachlorophenol interfere with legume rhizobium chemical. • Reduction of this symbiotic chemical results in reduced nitrogen fixation.
  22. Soil pollution by pesticide • The use of pesticides decreases the general biodiversity in the soil. • Also affect to the soil micro-organisms & decrease the soil fertility. • Effect on growth of the plants.
  23. Air pollution by pesticide • Pesticides can speared by volatilize and may be blown by winds into nearby areas. • Following factors affect to the spreading of pesticide in the air • Weather conditions at the time of application • Temperature • Relative humidity
  24. Resistance development • When pesticide use long period of time, some pest become resistance to the pesticide. • Because of resistance development pest can not be control. • Farmer have to increase the concentration or change the pesticide it make more & more environmental effects
  25. Effect of pesticides on pollinators • Application of Neonicotinoid insecticides such as Imidacloprids leads to the harmful effects on pollinators. • They include bees (honey, bumble), fruit flies, beetles, birds (humming birds, sunbirds). • Pesticides application affect various activities of pollinators such as: • Foraging behavior • Colony mortality • Pollen collecting efficiency
  26. Effect of pesticides on non-targets organism • Cypermethrin and Imidacloprids cause high mortality rate of the below mentioned predators than when bio-pesticides are used such as neem. • These include coccinellids, braconid wasps and predatory spiders. • Pesticides affect both invertebrates (earthworms) and vertebrates (humans).
  27. Pesticide Biomagnifications • The higher up the food chain more concentrate the pesticide called biomagnifications. • All individuals are part of food chain as a result, toxins stored in the fats & oils pass one trophic level to next trophic level. • This is danger expose to human because they are also in top of the food chains.
  28. Diagram showing the main impacts of pesticides on soil, plant and arthropod communities. Red arrows indicate decreases and blue arrows indicate increases; empty arrows indicate indirect effects. Source:- Centre for Ecotoxicology, University of Technology Sydney, Australia
  29. Safety for using pesticides 1. Reading Pesticide Labels 2. Understanding Pesticide Risks 3. Minimizing Pesticide Risks 4. Reducing pesticide risks at work (and at home) 5. Selecting Pesticides 6. Disposal of Pesticides 7. Storage of Pesticides 8. Poison Prevention 9. Safety during transportation Source: National Pesticides Information Center
  30. 1. Reading Pesticide Labels • Pesticide labels contain detailed information on how to use the product correctly and legally. • Labels also contain information on potential hazards associated with the product and instructions you should follow in the event of a poisoning or spill. • Following label instructions will allow you to minimize the risks and maximize the benefits
  31. 2. Understanding Pesticide Risks • Many people believe that some pesticides are safe, while others are dangerous. • Actually, the words “safe” and "dangerous" are misleading. Any chemical, including any pesticide, can pose risks to people, pets, or the environment. • Understanding pesticide risk will help you take steps to minimize it
  32. 3. Minimizing Pesticide Risks • Consider adopting an Integrated Pest Management (IPM) approach. • This approach emphasizes prevention, sanitation and exclusion, and utilizes pesticides only as a last resort when other options have failed. • Consider using the least toxic methods of pest control to get the job done. • Integrated Pest Management options can be less costly and more effective than traditional chemical control. 4. Reducing pesticide risks at work (and at home)
  33. 5. Selecting Pesticides • Learn about the pest. Has it been properly identified by a professional or an expert? • To reduce risk, choose pesticide products with low toxicity by looking for the "signal word" CAUTION.
  34. 6. Disposal of Pesticides • Pesticides need to be disposed of properly to prevent accidents and to protect the environment. • If you have unwanted pesticide products, store them safely and dispose of them as soon as you can.
  35. 7. Storage of Pesticides • Proper pesticide storage is important to protect people, animals, and the pesticide itself. • Pesticides should be stored in their original containers. The original container is designed to protect the product and it's made of materials that will withstand the chemicals in the product. • Store containers with their original labeling which includes application and disposal directions, ingredient names and emergency information. • Pesticides are best stored between 40-90 °F. (4- 32°C).
  36. 8. Poison Prevention • Store pesticides in locked cabinets, out of the reach of children and pets. • Consider safe use practices so that you are prepared in the event that an accident occurs. 9. Safety during transportation • If a pesticide spill occurs during transport, follow the three Cs control, contain and clean up. • Do not transport food, livestock feed, minerals, seed, grain, and consumer goods with pesticides
  37. Conclusion • The widespread use of pesticides is ineffective and economically harmful in the long run. • Their detrimental effect on health and environment make them an inadequate long term solution. • In addition, most synthetic and natural pesticides are susceptible to ineffectiveness due to resistant buildup in insects. • Thus the only viable solution for the future is IPM. • The economics benefits and reduced social costs of these systems present a logical answer to the pest control problem.