Pesticides are substances used to control pests in agriculture, forestry, and residential settings. The main types are insecticides, herbicides, and fungicides. Pesticides allow for increased food production but can also harm non-target species and contaminate water and food if not applied properly. After application, pesticides can move in the environment through runoff, volatilization, leaching, and degradation, potentially impacting other plants and animals if not contained in the application area. Proper application and adherence to product labels is necessary to maximize pest control and minimize environmental and health risks.

2. Pesticides
 Pesticides are substances meant for
attracting, seducing, destroying, or
mitigating any pest.
 Goal: to stop or limit pest occurrence
 Types:
 Insecticides – kill insects
 Herbicides – kill weeds
 Fungicides – suppress or kill fungi

3. Benefits
 Allow agricultural producers to improve
the quality, quantity, and diversity of our
food supply.
 Used in timber, turf, horticulture, aquatic,
and structural pest control industries.
 Homeowners and home gardeners often
use pesticides in their homes, yards, and
on pets.

4. Disadvantages
 Reduction of beneficial species. Non-target organisms, including predators and parasites
of pests, can also be affected by chemical application. The reduction of these beneficial
organisms can result in changes in the natural biological balances
 Residues in food for humans and feed for livestock can be a consequence of direct
application of a chemical to the food source, by the presence of pollutants in the
environment or by transfer and biomagnification of the chemical along a food chain. Not all
residues are undesirable although good agricultural practice must be observed to prevent
unnecessary and excessive levels of residues.
 Ground water contamination by leached chemicals can occur in high use areas if
persistent products are used.
 Resistance to the pesticide used can develop in target pests due to overuse and incorrect
use of the chemical.
 Poisoning hazards and other health effects to operators can occur through excessive
exposure if safe handling procedures are not followed and protective clothing

5. What Happens after Application?
 When pesticides are applied the goal is that
they will remain in the target area long
enough to control a specific pest and then
degrade into harmless compounds without
contaminating the environment.
 Once applied, many pesticides are mobile in
the environment (air, soil, water).
 This movement can be beneficial (moving
pesticide to target area, such as roots) but
can also reduce the effect on the target pest
and injure nontarget plants and animals.

6. Pathways of pesticide movement
 Runoff
 Chemical degradation
 Volatilize (gas vapor)
 Leaching and breakdown in soil
 Leaching and degradation by microbes
 Photo degradation (sun)

7. Conditions where & when applied
 Geology – depth to water table (larger
distances give more soil to act as filter)
 Surrounding water sources – nearby water is
more susceptible to contamination when
pesticides are applied to highly erodible soils,
over-irrigated, or rain-soaked soils. Managing
crop residues and maintaining grass
waterways and filter strips help to protect
surface waters from sediment and pesticide
pollution.

8. Conditions where & when applied
 Environmental conditions – heavy or sustained
rainfall or irrigation shortly after pesticide
application can increase runoff, leaching, and
volatilization.
 Soil temperatures (extremely high or low) can
interfere with pesticide performance. Pesticides
generally become more volatile in high
temperatures and windy weather.
 Pesticides can be incorporated (disked in) or
applied directly into the soil to decrease the
potential for drift and volatilization.

9. Product labels
 The pesticide label is a binding, legal
document. Compliance is required by
state and federal regulations.
 Label directions must be carefully followed
– from purchase to container disposal.
 High risk pesticides may only be
purchased and applied by certified
persons.

10. Pesticide Use
 Careful selection for a specific pest –
understand the pest, site, product, and
risks.
 Careful and responsible use.
…shows a consideration for the
environment.
….responsible stewardship