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National Center for Food and Ag. PolicyNational Center for Food and Ag. Policy
Washington, DCWashington, DC
The Benefits of Agrochemical Research: The Benefits of Agrochemical Research: Case Study of ImidaclopridCase Study of Imidacloprid
Sujatha Sankula & Leonard GianessiSujatha Sankula & Leonard Gianessi
Agrochemical categoriesAgrochemical categories
Herbicides (47%)Insecticides (29%)Fungicides (18%)
Fumigants & growth regulators (6%)
Agrochemicals are necessary to…Agrochemicals are necessary to…
Prevent yield losses Ensure quality Make crop production easier & cheaper
Crop yield response to agrochemicalsCrop yield response to agrochemicals
0
20
40
60
80
Corn Soybean Potato Wheat Cotton Rice
Th
eore
tica
l att
aina
ble
yie
ldT
heo
reti
cal a
ttai
nab
le y
ield
Without agrochemical use; With agrochemical use
Area farmed globally for food Area farmed globally for food production in 2000production in 2000
0
1
2
3
4
With agrochemicals Without agrochemicals
Bil
lion
ha
Bil
lion
ha
Global value of agrochemicals Global value of agrochemicals in 1998in 1998
$31.25 billion (crop uses)
$10.5 billion (non-crop uses)
Worldwide crop protection markets Worldwide crop protection markets in 2001in 2001
0
2000
4000
6000
8000
USAJa
pan
Brazil
Franc
e
China
Ger
man
y
Canad
a
Argen
tina
Italy UK
India
Austra
lia
Mex
ico
Sale
s in
mil
. $Sa
les
in m
il. $
Goal of aGoal of agrochemical researchgrochemical research
To discover, develop, and understand new products for the safe and effective pest control and to maximize food production
Agrochemical discovery & development Agrochemical discovery & development programs are driven by:programs are driven by:
Population growth Food and health needs Pest resistance issues Safety considerations Economic incentives Replacements and phase-outs
Recent setbacks to agrochemical Recent setbacks to agrochemical discovery programs:discovery programs:
Fewer players Large investments Great risks High stakes Economics Higher standards of potency and safety
Insecticide categoriesInsecticide categories
Organic (eg. DDT, chlorpyriphos)Botanicals (eg. pyrethrum, nicotine)
Inorganic (eg. boric acid, sulfur)
Market dominance of commercial Market dominance of commercial insecticide categoriesinsecticide categories
CategoryCategory ##
InorganicsInorganics 8 8
BotanicalBotanical 5 5
Synthetic organicsSynthetic organics 192 192
Major insecticide classes by Major insecticide classes by importance as of 1995importance as of 1995
Class Class ~ Entry year~ Entry year Market valueMarket value
(%) (%)
Chlorinated hydrocarbonsChlorinated hydrocarbons 19471947 5 5
OrganophosphatesOrganophosphates 19651965 34 34
MethylcarbamatesMethylcarbamates 19691969 20 20
PyrethroidsPyrethroids 19791979 23 23
BenzoylureasBenzoylureas 19831983 5 5
Others Others 19821982 8 8
Human toxicity and insect resistance to the first Human toxicity and insect resistance to the first generation neuro-active insecticides such as generation neuro-active insecticides such as carbamates and OPs led to the search for new carbamates and OPs led to the search for new agrochemicalsagrochemicals
Significant discovery - ImidaclopridSignificant discovery - Imidacloprid
ImidaclopridImidacloprid
Classification: Chloronicotinyl
First registered insecticide in its class Year of registration in US: 1995
World sales of top selling World sales of top selling pesticides in 2001pesticides in 2001
Glyphosate $2.4 billion
Imidacloprid $540 million
Source: PANUPS 2002
Structural comparison of Structural comparison of nicotine and imidaclopridnicotine and imidacloprid
Characteristics of imidaclopridCharacteristics of imidacloprid
Novel mode of actionBroad spectrum of activityFavorable environment fate
Mode of action of imidaclopridMode of action of imidacloprid
Binds to nerve receptors called nicotinic acetylcholine receptors (nAChRs), interferes interferes with the transmission of stimuli in the insect with the transmission of stimuli in the insect nervous system leading to the accumulation nervous system leading to the accumulation of acetylcholine resulting in paralysis.of acetylcholine resulting in paralysis.
Site of action is different than other insecticides Site of action is different than other insecticides to which insects developed resistance.to which insects developed resistance.
Low toxicity to vertebrates due to low binding to nACh receptors.
Imidacloprid provides a broad Imidacloprid provides a broad spectrum of activity against:spectrum of activity against:
Sucking insects (leaf and plant hoppers, aphids, thrips, whiteflies, scales, and plant bugs)
Some coleopteran insects (CPB, leaf beetles)
Select lepidopteran and dipteran insects
No activity on mites and nematodes
Imidacloprid has both contact and systemic Imidacloprid has both contact and systemic action.action.
Imidacloprid can be applied as a soil, seed, Imidacloprid can be applied as a soil, seed, or foliar treatment.or foliar treatment.
Readily absorbed by plant roots and transmitted through xylem.
Effective at low rates than conventional insecticides (0.33 lb versus 1-2 lb of OPs)
Trade names of imidaclopridTrade names of imidacloprid
Gaucho (seed treatment)Admire (soil applied)Provado (foliar)
Use range of imidaclopridUse range of imidacloprid
Potato AppleTomato GrapeBroccoli CitrusLettuce CornSugarbeet HopsCotton Rice
Tobacco
Impacts of imidacloprid on US Impacts of imidacloprid on US crop productioncrop production
Silverleaf whitefly
First discovered in 1986 in FL
Widespread damage in 1991 in CA and AZ
Reduction in planted crop acreage
Yield and quality losses; transmits viruses (ToMoV and YLCLV)
Silverleaf whitefly is a billion dollar pest
Primary hosts of silverleaf whitefly
BroccoliCauliflowerCabbageLettuceMelonsCucumbersTomatoesCotton
Silverleaf whitefly management
Three classes of effective insecticides (pyrethroids, OPs, & chlorinated hydrocarbons)
Most common combination: bifenthrin + endosulfan (2-3) fb. esfenvalerate + endosulfan (1-3)
No residual control and periodic treatments (4-6 sprays)
Insect resistance to three chemical classes
Section 18 permits for imidacloprid (Admire) in California
Broccoli/Cauliflower 1993 1994Lettuce 1993 1994Cucurbits 1995 1997Tomatoes 1994 -
First issue Reissue
Vegetable production statistics for CA
Broccoli 92Lettuce 71 (head)
88 (leaf)Cauliflower 89Tomato 32 (fresh)
92 (processed)Cantaloupe 58
2001 Acreage (% of US total)
Use of imidacloprid (Admire) in Use of imidacloprid (Admire) in California in 1995California in 1995
0
40
80
Brocc
oli
Caulif
lower
Hea
d lettu
ce
Leaf l
ettu
ce
Fresh
tom
ato
Canta
loupe
% t
reat
ed a
crea
ge%
tre
ated
acr
eage
Impacts of imidacloprid (Admire) on CA crop production
Number of insecticide applications with Number of insecticide applications with AdmireAdmire and and next best alternativenext best alternative
0
2
4
6
Brocc
oli
Caulif
lower
Hea
d lettu
ce
Leaf l
ettu
ce
Fresh
tom
ato
Canta
loupe
# tr
eatm
ents
# tr
eatm
ents
Cost of insecticide programs with Cost of insecticide programs with AdmireAdmire and and next best alternativenext best alternative
0
50
100
150
200
250
Brocc
oli
Caulif
lower
Hea
d lettu
ce
Leaf l
ettu
ce
Fresh
tom
ato
Canta
loupe
Cos
t of
pro
gram
s ($
)C
ost
of p
rogr
ams
($)
Yield increase due to Admire compared to Yield increase due to Admire compared to traditional alternatives in CA traditional alternatives in CA
0
1
2
3
4
5
Broccoli Cauliflower Headlettuce
Leaf lettuce Cantaloupe
% y
ield
incr
ease
%
yie
ld in
crea
se
Value of delayed planting
Warm weather: heavy whitefly pressure
Growers shift the planting date to cooler periods to avoid peak infestations
Imidacloprid facilitated marketing at the height of infestation
Increase in grower benefits due to delayed Increase in grower benefits due to delayed planting facilitated by Admireplanting facilitated by Admire
0
2
4
6
8
10
Broccoli Cauliflower Headlettuce
Freshtomato
Cantaloupe
% in
crea
se%
incr
ease
Impact of imidacloprid on insecticide use in FL fresh tomato for whitefly and other sucking pest control
Buprofezin - 2000Chlorpyrifos 22,000 -Endosulfan 89,000 34,900Esfenvalerate 5,700 2,200Imidacloprid - 8,400Methamidophos 74,500 9,100Methomyl 47,100 -Permethrin 10,900 8,000
Total 249,200 64,600
1992 2000------------- lb --------------
Colorado Potato BeetleColorado Potato Beetle
Green peach aphids
Insecticide use: CPB/aphids
• 1920’s - 1940’s Lead arsenate• 1950’s - 1960’s DDT, Parathion,
Endrin• 1970’s - Present Aldicarb, Phorate,
Methamidophos,
Carbofuran,
Endosulfan
Permethrin
CPB management problemsCPB management problems
CPB resistance to all synthetic insecticides registered for use
Cross-resistance of CPB between insecticide classes
Imidacloprid – unrelated chemistry and thus a new tool in resistance management programs
Imidacloprid treated potato Imidacloprid treated potato acreage (%) in 1999acreage (%) in 1999
Idaho 8Maine 90Michigan 93Minnesota 70North Dakota 68Oregon 35Pennsylvania 81Washington 4Wisconsin 74
Leading insecticides used for CPB Leading insecticides used for CPB control in 2001 (in order of importance)control in 2001 (in order of importance)
ImidaclopridCarbofuranPermethrinPhorateEsfenvalerateEndosulfanMethamidophosAzinophos-methylAldicarbMethyl parathionDimethoate
Reduction in insecticide use following Reduction in insecticide use following imidacloprid use in potato (1994 –1999)imidacloprid use in potato (1994 –1999)
0
40
80
Maine Michigan
% r
edu
ctio
n%
red
uct
ion
Source: NASS
Pierce’s disease on grapes
Glassy-winged
Bluegreen
Sharpshooters
Pesticides registered for Pesticides registered for sharpshooter controlsharpshooter control
Dimethoate 1.32Kaolin 23.75
Imidacloprid 0.05(Admire)
Average use rate (lb/A)
Other grape insects controlled Other grape insects controlled by Admireby Admire
Grape mealybugVine mealybugLeafhopperPhylloxera
Insect management problems Insect management problems in citrus in in citrus in CACA and and FLFL
Glassy-winged sharpshooter (overwintering host)California red scale (resistant to OP &carbamates)Citricola scale (increasing in problem)
Brown citrus aphid (vectors citrus tristeza virus)
Use of imidacloprid on citrusUse of imidacloprid on citrus(Section 18 in (Section 18 in CACA and and FLFL))
Glassy-winged sharpshooterCA red scale
Citrus brown aphidCitrus leaf miner
Cotton pest problems
Escalation of secondary pest problems
Insecticide resistance
Losses due to aphids in CA cotton in 1997
Crop loss Control costs
Aphids 34 38All insects and mites 66 167
--------------- Million $ -----------------
Imidacloprid treated cotton acreage in Imidacloprid treated cotton acreage in CaliforniaCalifornia
0
40
80
1995 1996 1997 1998
% t
reat
ed a
cres
% t
reat
ed a
cres
Source: NASS
Summary
Sucking pests have not been a significant problem to growers in the recent years, largely because of the advances in agrochemical research that resulted inthe development of imidacloprid.
American growers were able to increase crop yields,reduce crop production costs, and insecticide usefollowing the introduction of imidacloprid.
No agrochemical is immune to problems.
Conclusions
With the increasing safety and environmental concerns, there will be loss of some agrochemicals. Search for replacement products that can live up to both regulatory and grower standards necessitates continued agrochemical research.
Agrochemical research should continue to meet the increasing demands of growing population.
Continued agrochemical research will provide solutions to evolving pest and their management problems.
www.ncfap.org