Hello everyone! So today we will discuss pesticides and the effect of pesticides
in the environment. My name is Zohir Chowdhury. Let's get into it! So
pests compete with us for food resources spreads diseases destroys wood in homes and are
responsible for many other damages pests can be insects rodents weeds and a host of other unwanted
organisms we use pesticides to control pests and thus pesticides are any substance or mixture of
substances intended for preventing destroying repelling or mitigating pests and examples could
be insecticides herbicides fungicides etc attacks on agriculture crops occur today as pests feed up
on all different parts of agricultural agriculture plants many agricultural crops are specially
vulnerable due to the way they were domesticated when early agriculturalists were domesticating the
stable food crops they selected for the types that had the highest yield of food instead of those
types that were most resistant to pests because only those high yielding strains were selected for
the crops now lack genetic diversity without diversity in the genetics of the crop plants
if a pest comes along that the crop is vulnerable to then all of the crop will
suffer to combat this problem agriculturalists have had to employ widespread pesticide use
so pesticides are used in a variety of settings agricultural non-agricultural and then within
the non-agricultural spectrums we have homes industrial institutional application as well
as professional applications of pesticides so when we say agricultural usage it can be either
production-oriented agriculture or non-productive non-production-oriented agricultural usage so the
production-oriented agriculture usage where pesticides are used this is any pesticides
that are used to produce a plant or animal agricultural products such as
food feed fiber ornamental or forests that will be distributed in the channels of trade on the other
hand non-production oriented agriculture use is any pesticide used on watersheds
right-of-way and landscaped areas example golf courses parks recreational areas and cemeteries
will fall under non-production oriented agricultural usage
on the other hand non-agricultural usage in home it's the typical application that we have at home
used in and around the immediate environment of a household licensed
professional pesticide applications are reported as non-agriculture use uh usually uh usually under
landscape maintenance uh unlicensed non-professional residential pesticide
applications around a home or garden are not required to be reported um industrial usage of
pesticide um it's that type of pesticide study that is used to uh in in factories processing
plants packaging houses or similar building or use for a manufacturing mining or chemical process
institutional usage of pesticide is on property necessary to operate buildings such as hospitals
office buildings libraries auditoriums or schools and uh this also include includes pesticide use on
landscaping and around walkways parking lots and other areas bordering the institutional buildings
note that the healthy school act of 2000 imposes additional pesticide use reporting
requirements if the pesticide application takes place at a school or child care center regardless
of whether or not the application was made by a licensed professional
and then finally uh professional usage of pesticides
uh can be structural application can be for vector control as well as for veterinary usage
uh in these images you can see pesticide usages and applications in agricultural
fields pesticides are applied by a number of methods including spraying from
tractors and widespread broadcasting by aerial spraying the image on the left illustrates
an airplane used for spraying a field although highly efficient these methods of spraying can
cause pesticide drift and lead to contamination of waterways according to usda pesticides are a vital
input in today's agriculture uh protecting food and fiber from damage by insects weeds diseases
nematodes and rodents u.s agriculture spends about eight billion dollars annually on pesticides about
seventy percent of all pesticides sold in the sold in the country it is estimated that each dollar
invested in pesticide pesticide control returns approximately four dollars in crops saved
so pesticides can be classified based on the pest that they control um
and they can also be classified by their chemical makeup or mechanism of
action we will discuss the first type of classification of pesticides right now
and then we'll follow up with the classification based on chemical makeup later on um so
the application of pesticides that are derived from synthetic hydrocarbon-based chemicals
flourished during the 20th century the golden age of discovery of insecticides occurred in
the mid-1990s with the invention of neuroactive chemicals such as chlorinated hydrocarbons or
or organochlorides organophosphates organocarbonates and pyrothrips i meant in the
in the mid mid-1900s not 19 19 19 19 1900 that's when uh these chemicals were um uh discovered
and synthesized so uh major types of pesticides by the pest they control they can be insecticides
to kill insects a pesticide compound specifically used to kill or prevent the growth of insects is
known as insecticides on the other hand herbicides are plant killer and a chemical pesticide
designated to control or destroy plants weeds or grasses is known as an herbicides and typically
herbicides interferes with the photosynthetic channels create excess growth hormones or kills
and as well as can kill soil microorganisms as well once you apply some of these herbicides some
examples of herbicides are atrazine paraquat as well as agent orange which was used in the vietnam
war to clear forest cover um fungicides it's a fungus killer a pesticide that is used to control
deter or destroy fungi and pneumatocytes are warm killers a chemical agent that is destructive to
nematodes or worms rodenticides on the other hand are rat or musculars and a chemical or
agent used to destroy rats or other rodent pests or to prevent them from damaging food crops etc
um so here you can see these two figures that illustrates the historic pesticide usage in
the state of california which produces a wide variety of agricultural produce such
as nuts vegetables and fruits the crown the contrast between measuring pesticides used by
pound which is shown in here as compared to by acre which is shown in here can be seen by looking
at these two different pesticides the use of different pesticide types in both figure one and
figure two in here so figure one uh the amount of uh uh demand applied by weight or in pounds
uh shows that pesticides with both fungicidal and insecticidal properties such as fungicide
insecticides such as sulfur had the highest use in 2000 in in 2018.
the fungicide insecticide category was followed by insecticides flumigans herbicides
fungicides and finally other types of pesticides which grouped all remaining types of pesticides
that did not have large enough amounts used to warrant their own graft trend line in this chart
so other pesticides in here include rodenticides algaecides and other types of repellents
disinfectants as well as bio biocides in contrast by cool by cumulative areas um or acres uh treated
uh shown in figure two and insecticides and herbicides and fungicide had the highest
usage followed by fungicide insecticides category and other and finally the few negan's at the end
so since 1990 which is shown in here the reported pounds of pesticides applied and acres treated
have fluctuated from year to year as you can see in here these fluctuations can be attributed
to uh to a variety of factors including changes in planted acreage crop planting pest pressures
and weather conditions an increase or decrease in use from one year to the other or in or in
the span of a few years may not necessarily indicate a general trend in use but rather
variations related to changes in weather pricing supply of raw ingredients or regulations
regression analysis on use over the last 20 years do not indicate a significant
trend of either increase or decrease in total pesticide usage crops treated with
the greatest total pounds of pesticides in 2018 were almond wine grape table and raisin scrape
processing of tomato and oranges where most of the pesticides were utilized besides total
pounds the magnitude of changes in use can be of interest in understanding pesticide use trend
so i hope that you learned something about pesticides thank you for listening please
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