3. Outline
o Introduction
o History of pestigation
o Factors to be considered before pestigation
o Selected insecticides for Pestigation
o Calibration procedures
o Method of application of pestigation
o Advantages and dis advantages
o conclusion
5. History of pestigation
1958 – 1st
application of fertilizer-Brayan and Thomas
1963-Herbicides applied through irrigation system – P.E.
Heikes
1969-M. Harrison – application of fungicides – potato
diseases – early blight
1976 – Hantsbarger and Pilcher – insecticide mixed with
irrigation water – limited accuracy
1st
trial – field corn
6. Factors to be considered before pestigation
• Pesticides
• Site situation
• Soil & Land characters
• Types of irrigation systems
• Weather
7. Decide pesticide - protect crop from potential problem
Read label – chemigation
Water solubility
Persistency
Pesticides
10. New generation Insecticide recommended for Pestigation
Insecticide Trade Name Rate/Acre Effect to crops Insects
Acetamiprid Assail 30SG 1.5 - 4.0 oz
1.0 - 1.7 oz
Cotton , potato,
tabacco, lawn,
ornamental
gardens
Suking pests, leaf
feeding insects
Assail 70WP 1.0 - 1.7 oz
Flonicamid Decis 1.5EC 1.5 - 2.4 oz Vegtable and
nursery gardens
Most of sucking
pests, flea beetle
Imidacloprid Provado 1.6F 0.96 pts Vegtables crops,
nursery
gardens,Cotton ,
potato, tabacco,
potato
White grub, flea
beetles, leaf hopper,
whitefly
Calarado potato
beetle
Admire 70WG 0.4 – 0.6 oz /
1000 ft row
Thiamothoxam Actara 25WG 3 oz Corn, sweet corn,
potato,
strawberry,
vegetable gardens
ECB, SWCB, all
sucking pests,
defoliators
Spinosad Spin Tor 25 SC 2.8 pts Agricultural crops Sucking &
defoliating insects
(Felsot, 2001)
11. Site situation
• Do not chemigate with pesticides if the irrigation
system will cause offtarget spray or drift on adjacent
homes or occupied buildings, surface water sources,
wetlands, neighboring crops, or roadways.
12. Soil & Land characters
Single field – different type of soils thus movement of water or pesticide differ –
soils
Eg.,
Coarse texture soil high infiltration rates leaching more
Fine textured soil & clay soils low infiltration rates leaching less
Land characters
Field condition – uniform
Hilly areas – variation in elevation – uneven distribution
sloping areas water stagnation crop injury
13. Types of irrigation systems
Apply pesticide water mixture uniformly
Application rate should not exceeded intake rate of soil
Exceeded
Not provide
adequate distribution leaching water stagnation, runoff
ground water adjacent surface water
14. • An irrigation system should be able to apply water at various
application depths. Most of the pesticides only work when
applied with a very light application depth of water (.15 to .25
inches)
• If an irrigation system is three or more years old, evaluate the
water distribution pattern with an infield catch can test before
using for pestigation.
(Palumbo, 1995)
15. • Winds can cause irrigation water droplets to drift. Strong
winds will also cause uneven application of water and
chemicals
• Do not chemigate if winds are strong enough to cause drift
onto non-target areas
Weather
16. Pestigation equipment
A chemical supply tank
• Constructed – corrosion resistant materials or plastic
• Agitation – tank mixes, dry flowables, wettable powders
A chemical injection pump
Piston pumps – used nitrogen fertilizers
Diaphragm pumps - pesticides
17. A calibration tube
• located in the chemical line between the chemical supply tank
• It is used to measure output of the injection unit during calibration
• graduated in units of volume (pints, ounces, milliliters, etc.)
Safety and antipollution devices
• Pestigation can potentially pollute the irrigation water source if
not protected with the proper functioning safety devices.
18. 1.The chemical in the supply tank and in the irrigation pipeline
could flow or be siphoned back into the water source when the
irrigation system shuts down
19. 2.The chemigation system could continue to
inject chemical into the irrigation pipe line
when the irrigation system shuts down. This
causes the chemical solution to flow back
into the water source or spill onto ground
3. The chemigation system could shut down
while the irrigation system continues to
operate and force water back into the
chemical supply tank. This would cause the
tank to overflow and spill onto the ground
20. Chemical injection system anti-pollution devices
Device- Filter
Location – between pump & tank
Purpose – remove sediment – clog pump
Device - Check valve
Location – point of irrigation line
Purpose – prevent backword flow water
Device-closed solenoid valve
Location – between pesticide tank
and injection pump
Purpose - Prevent tank from emptying
unless injector is working
21. Irrigation Antipollution Devices
Device - Main line irrigation check valve
Location - Between well and chemical injection point
Purpose -Prevent back flow of pesticide into water
source
Device - Vacuum relief valve
Location – Between check valve and well
Purpose – Prevent vacuum when pump shuts off; reduces
chance of back flow
22. Device – Low pressure cutoff
Location – Main irrigation pipe line
Purpose - Shut off power to chemical injector
when water pressure is low
(Werner, 1990)
24. Pestigation Calibration
• Is the measurement and adjustment of the chemical injection
and the irrigation systems to insure that an accurate amount of
chemical is being both injected and applied
• Calibration is NOT a cost of application. Costs ARE often
incurred, when you do not calibrate because:
Applying too little or too much chemical is a waste of money;
Applying too much chemical may cause
crop damage
contaminate ground or surface water;
safety hazard,
25. Calibration Procedures
Area in acre to be treated
Total amount of chemical required
Time required to treat the area
Chemical injection rate per hour
Calibration of the chemical injection pump
(Werner, 1993)
26. Calibration procedure fordrip irrigation system
Determine the effective wetting zone
width of wet zone X No of emitters
Determine the total amount of chemical
required to treat the area
Total A to be treated X rate*
*As directed on the product label
27. Calibration procedure – sprinkler irrigation
Determine the area to be treated in acres
Area of the circle = pir2
Determine the total amount of chemical required to treat the area
Total amount of chemical required = acre treated x application rate/acre
Time required to treat area in hours
Revolution time = Circumferance (feet) / travel speed (ft/min)
Travel speed = distance traveled / elapsed time
Circumferance = 2pir
Chemical injection rate
Chemical injection rate in l/hr = total chemical needed / hrs per revolution
(Werner, 1993)
28. Method of application of pestigation
Drip irrigation
Sprinkler irrigation
Surface irrigation
29. Drip irrigation
• Drip irrigation, also known as trickle
irrigation or micro irrigation or localized
irrigation
• It is an irrigation method that saves
water and pesticides by
allowing water to drip slowly to
the roots of plants, either onto
the soil surface or directly onto the root
zone, through a network
of valves, pipes, tubing, and emitters
• It is done through narrow tubes that
deliver water directly to the base of the
plant
30. • Most effective and widely used pesticide delivery
irrigation system among all other methods
o Systemic insecticides suited – drip chemigation
o Compatible with IPM practices
31. Types of Drip Irrigation
Surface drip irrigation
Sub surface drip irrigation
Placed on the soil Buried below soil surface
32. Components of drip irrigation
Pump
Head unit
Central distribution system
A pesticide tank
A filter
PVC main supply line
Sub mains
Plastic drippers or emitters
33. Effect of drip irrigation with pesticide for pest control
Systemic insecticides suited – drip chemigation
Compatible with IPM practices
Neonicotinoid class – Imidacloprid, Thiamethoxam,
Acetamprid – suitable
Imidacloprid effective against aphids – throughout the
season
(Felsot, 2001)
35. Treatment
Rate
(kg ai/ha)
% of fruit damaged
15 DAT 30DAT
Untreated − 18.8 46.7
Chlorantraniliprole
(2 applications)
0.049 0.0 8.3
Chlorantraniliprole
(2 applications)
0.074 1.3 1.7
Chlorantraniliprole
(1 application)
0.099 0.0 5.0
Efficacy of chlorantraniliprole applied through drip chemigation for the control of
Helicoverpa larvae on tomatoes
The 0.049 and 0.074 kg ai/ha treatments were applied twice each and the 0.099 kg
ai/ha was applied once. Fruit were evaluated for % damage on 15 DAT and 30
DAT
Case study - II
36. Casestudy-III
Efficacy of chlorantraniliprole applied through drip irrigation and
Indoxacarb applied through foliar spray for the control of lepidopterous
larvae on tomatoes
Treatment*
Rate
(kg ai/ha)
% of fruit damaged
10 Aug 22 Aug
Untreated − 9.6 a 8.3 a
Chlorantraniliprole (x 5
injections)
0.049 1.2 b 1.2 a
Chlorantraniliprole (x 5
injections)
0.074 0.8 b 2.8 a
Indoxacarb (x 5 foliar
sprays)
0.073 3.9 b 2.2 a
37. Sprinkler irrigation – Over head irrigation
Distributes water – form of rain like droplets
1st
sprinkler irrigation known – 1946
gain popular – 1980 in india
hill areas- for plantation crops
Saves irrigation water - 25- 50% > surface
irrigation
38. Components of sprinkler irrigation
Pumping unit
Main line
Submains
Laterals
Rotate type – wide lands
Sprinklers
Fixed type –small lawns & gardens
Super net sprinkler
39. Different types of sprinkler irrigation system
Center pivot irrigation
Self – propelled linear move
Solid set
Hand move lateral
Side roll lateral
Two – line lateral
Hose drag traveler
40. Effect of sprinkler irrigation with pesticide for pest
management
Contact insecticides – suitable
(Felsot, 2001)
Properly designed, calibrated , operated – uniform
distribution of chemical water mixture
Emulsifiers than oil mixed insecticide – not effective
– foliage feeding insects
(Young et al, 1981)
Two application of fenvelarate (0. 17kg/ha) &
Chlorpyriphos (0.84, 1.12kg/ha) - 98 & 75% southern
corn borer, 92 & 97% European corn borer
(Michels et al, 1983)
41. Treatments Kg AI/ha Pre-
treatment
2DAT 7DAT
No of
larvae/plot
No of
larvae/plot
%
Reduction
No of
larvae/plot
%
Reduction
Cypermethrin .06 24.8 0.5 98.4 0.7 94.4
Esfenvalerate .06 24.8 0.5 98.4 0.8 93.6
Methomyl .028 26.3 3.5 89.5 2.3 82.7
Thiodicarb .067 30.0 3.5 90.8 0.3 98.0
chlorpyrifos .056 23.5 14.5 51.5 2.2 81.4
Untreated - 22.8 29.0 - 17.5 -
Effects of various insecticides applied via chemigation on velvetbean
caterpillar populations infesting soybean
(Channdler and Sumner, 1993)
42. Treatments Dosage
kg (AI)/ha
No. larvae per plant
Aerial Chemigated
Fenvelarate 0.17 0.8 0.7
Chlorpyrifos 1.12 1.2 0.2
untreated -- 1.8 1.5
Comparison of two insecticides applied aerially and through sprinkler
irrigation for control of European corn borer larvae
(Thomas et al., 1992)
43. Surface Irrigation water
Oldest method
Pesticide mixed with surface irrigation
water
Limited potential
Non-uniform
Leveled land – slope < 2-3%
(Booher, 1974)
44. Advantages
• Provides uniform distribution of chemicals when the irrigation
system’s nozzling package is properly selected and maintained
• Offers more flexibility in timing the chemical application,
especially when the field is wet for a tractor or an aircraft is
unavailable
45. • May increase pesticide activity and effectiveness for some
compounds
• Reduce the labour cost
• Reduce mechanical damage to plants caused by ground sprayer
wheels
• Reduce the risk of soil compaction caused by ground application
methods.
(Threadgill, 1985)
46. Limitations and Risks
•Uniform chemical application depends on uniform water distribution
from the irrigation system
•Application time is longer than most other chemical application
methods
•Most pesticide compounds are not approved for application with
irrigation water
• Potential risk exists while pestigation
47. • Farm managers/operators must know the calibration procedure
• Extra investment must be made for pestigation system and for
safety equipments
• Unnecessary irrigation-Using an irrigation system to apply
chemicals may apply moisture to the crop at a time when it is not
required or when the soil is already too wet
