Special Collections Research Center Teacher Resources: Lesson Guides: Pesticides
Pesticide Development and Use in North Carolina
This lesson plan focuses on pesticide use and development in the United States and North Carolina between the 1930s and 1970s. It asks students to consider why pesticides have been developed and used during the 20th century and what the effects of their use are. The guide includes primary sources for students to examine that document the development of pesticides and how the government has instructed citizens on their use. To view primary source materials beyond those provided here on this topic, please visit d.lib.ncsu.edu/collections.
The Common Core standards this lesson guide works with are 8.G.1.3 from the North Carolina 8th Grade Social Studies Standards and EX.8.C.2.2 and EEn.2.8.2 from the North Carolina 8th Grade Science Standards.
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Agriculture has always included different means of pest control. Pest control can include things like: crop rotation, weed control, and treatment with chemicals to control disease and insects. Many of these practices have existed since agricultural practices began. The use of chemicals to control weeds, diseases and plant-destroying insects increased with the introduction of DDT in 1939. Developed by a Swiss scientist, the chemical was adopted more widely after World War II, and was used as an effective means to manage pests. However, it could not control all pests. Other means of pest control were needed, and scientists continued research and experiments to find better means of controlling pests.
Why Use Pesticides?
The chemical based pesticides were very effective at ridding large scale crops of weeds and bugs that plagued them. Because the pesticides were cheap, effective, and fairly easy to apply, farmers in the 1950s and 1960s increasingly adopted them as the primary method for controlling pests on the farm. Getting rid of the pests meant that less labor was needed to weed and kill pests manually, and the harvests were larger because the plants were not being destroyed prior to full growth. However, the success of the pesticides also lead to severe overuse by farmers and others in the agriculture business and people began to wonder about if there might be unintended effects of such use.
Growing Concern over Impacts of Pesticides
In 1947, The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) was passed to protect farmers, consumers and the environment. The FIFRA was enforced by the United States Department of Agriculture. All scientific research fitting within the categories of insecticides (chemicals designed to control insect pests), fungicides (chemicals designed to control fungi), and rodenticides (chemicals designed to control rodents) all became subject to FIFRA and the Department of Agriculture.
Chemicals used to kill plants (especially weeds) and fungi were developed and used abundantly throughout the 1950s, with little consideration given to possible environmental impact and/or effects. The sprayers used to spread the pesticides often sprayed more into the air than on the plants themselves. In addition, the pesticides often washed off the plants easily, getting into the water system. And those that did stick on the crops often stayed on right until it came home with a consumer, who then ate the sprayed food. It didn’t take long before scientists and researchers picked up on some of the possible impacts of pesticides. These images show some of the common methods of distributing pesticides.
Measures were needed to limit the amount of pesticides going both into the air and water, as well as make them safer for humans and animals who came in contact with them.
During the late 1950s and 1960s, the Agricultural Extension Service in North Carolina added pest control to its research interests. The NC State Agricultural Extension Service conducted research and produced publications and public television programming to educate the public on pest control advances and issues. Chemicals for pest control were not the only items of research, but the ways in which the chemicals were applied to plants became the subject of much research.
Just such a researcher, Rachel Carson, wrote a book Silent Spring in 1962. The book specifically pointed out the harm DDT use had on the environment. The book became a bestseller and alerted the public to the dangers of pesticide use. In the 1960s a new approach (Integrated Pest Management or IPM) to pest control was developed. IPM uses crop production methods to discourage pests, encouraging parasites or predators that attack pests, and timing pesticide application with the time the pest is most susceptible to attack. The focus is not on getting rid of the pest completely, but on a tolerable population of the pest. It does not replace the use of pesticides, but simply makes the use of pesticides more effective (which inevitably reduces the use).
By 1972 Carson’s book, along with public involvement due to the distribution of the book and the environmental impact of pesticides began to cause changes. At this time, FIFRA was changed to become the FEPCA (federal environmental pesticide control agency), filled in the gaps of the FIFRA and shifted more responsibility to manufacturers. With the revisions came a shift in administration to the Environmental Protection Agency. The EPA took over the job of monitoring pesticide use and development and banned the use of DDT. DDT was found to cause a thinning of the eggshell of certain breeds of birds. This caused a decline in the number of birds who developed enough to hatch, and the bird population declined drastically.
IPM also encourages the use of genetic engineering to produce pesticides that are naturally occurring. These include genetically-engineered plants that are resistant to pests and molds as well as organic-based compounds for treating. These compounds have little to no noticed impact on people and animals (as of yet).
Work in North Carolina
North Carolina State College Professor of Entomology, T.B. Mitchell, wrote in 1946 in a School of Agriculture publication that DDT could kill honeybees and other beneficial insects. Near the end of the decade, other questions were raised about pesticide residues and potential effects on humans and other animals. In the early 1950s, the Pesticide Residue Research Laboratory was established at North Carolina State University, mainly because of the concern for possible health problems and complaints about pesticide residues on tobacco. Through the years it monitored residues in tobacco and other crops and experimented with various application rates and methods to determine the most effective means of avoiding pesticide residue on crops. The School of Agriculture put together an interdisciplinary group to do research into methods to make pesticides useful for farmers while making them safer for the environment and humans. Agriculture professors worked with entomologists, plant pathologists, chemists and other colleagues to find solutions. William Splinter, Henry Bowen, and Walter Carleton were a key part of the pesticide education team set up in 1964 at NCSU to educate farmers on how to safely use pesticides. Their slogan was "Making Chemicals Work FOR, instead of AGAINST man." Much of their work was sponsored in part by the National Cotton Council of America, which was interested in finding ways to reduce the impact of the boll weevil on the cotton crop. In 1967, a degree program in conservation was established, jointly administered by the School of Agriculture and Life Sciences, and the School of Forest Resources. A graduate degree program in ecology was established in the early 1970s. The Agricultural Extension Service, developing a five-year program that began in 1972, added a new dimension to its projected goals - protect and improve quality of the environment.
The story of pest control in North Carolina is still not finished. Continuing research and experiments are needed to develop better means to control pests with less impact on the environment.
Read the two primary resources below. What arguments are being made for why pesticide research should be done at a university? How does the argument for doing research at a university compare to the other document’s argument on why the research should be done specifically in North Carolina and at North Carolina State University?
Take Home Exercise
Watch this 1960s pesticide film developed by the USDA.
Have students bring an example -- written or visual -- of a pesticide or means of pest control used in their household. These can include sprays, traps, bait, etc. Have students share and discuss more natural means of pest management in the home and why pest management is necessary.
To view a print version of the primary sources, click here.Return to home.