This document describes a Spray Rodeo Day event organized to calibrate large-boom sprayers used in Florida's sugarcane industry. The event aimed to calibrate eight sprayers servicing 80,000 acres. Operators navigated their rigs through four calibration stations: 1) verifying ground speed, 2) adjusting nozzle output and pattern, 3) calibrating the spray pump, and 4) checking sprayer safety. Eighteen sprayers servicing 200,000 acres were calibrated. Before the event, only 6 of the 18 sprayers had acceptable nozzle patterns. After calibrating at the event, operators reported confidence in the accuracy of their groundspeed, nozzle, and pump calibrations. The event

1. Spray Rodeo Day: A Calibration Field Day for Large-Boom Commercial Sugarcane Spray Rigs
Ronald W. Rice (FACAA/NACAA), Palm Beach County Extension, 2976 State Road 15, Belle Glade, Florida 33430 / email: rwr@ufl.edu
Leslie E. Baucum (FACAA/NACAA), Hendry County Extension, PO Box 68, LaBelle, Florida 33975 / email: lbaucum@ufl.edu
Abstract Spray Rodeo Day Station 1: Verifying Ground Speed
National surveys indicate that >50% of pesticide application errors are due to  Expand impacts of annual Assumption: Operator’s
improper equipment calibration. Since 2006, the UF/IFAS Sugarcane Extension Objectives Spray-Smart Workshops perceived ground speed
program has organized 5 Spray-Smart Workshops to emphasize hands-on
Calibrate eight (8) large-boom sprayers
calibrations on multi-nozzle booms, including drift management, nozzle  Provide the opportunity for
servicing one-fifth (≈ 80,000 acres) of Ground Speed Calibration Station
technology, and calibration math demonstrations. Objectives: Expand Spray- applicators to calibrate their
Florida’s sugarcane acreage
Smart Workshop impacts with a Spray Rodeo event, where operators calibrate sugarcane spray rig Targeted ground speed (mph)
their own spray rigs, targeting at least 8 large-boom sprayers servicing one-fifth
Distance of Run (feet) 400
(80,000 acres) of Florida’s sugarcane acreage. Methods: Operator/supervisor Methods
teams navigated rigs through 4 stations (ground speed verification, nozzle Run #1 time (seconds)
 Spray rigs visited 4 stations:
output/pattern calibration, spray pump calibration, and sprayer safety). All Run #2 time (seconds)
1) ground speed verification
calibration data were documented to improve spray records. A 25-question
survey summarized operator/supervisor knowledge regarding their spray rig 2) nozzle output/pattern calibration Run #3 time (seconds)
performance and knowledge gained at the 4 stations. Results: 18 spray rigs 3) spray pump calibration Average ground speed (mph) †
servicing 200,000 acres of sugarcane were calibrated, with rig-specific gallon-per- 4) sprayer safety issues Given: 1 mph = 88 ft/min = 1.467 ft/sec
acre (GPA) quantified. All operators expressed confidence they were accurately  25-question survey (knowledge † Ground speed (mph) = Distance (ft) ÷ Time (sec) ÷ 1.467
calibrated for groundspeed, nozzle outputs, and pump pressure. Before the Spray gained; prizes to top 3 survey scores)
Rodeo event, 6 of 18 spray rigs emitted acceptable nozzle spray patterns while the
Fact: Operator’s actual
remaining two-thirds had significant errors. Comparing target GPA vs. actual GPA,
measured ground speed
5 rigs were within 5% accuracy, 12 were within 10% accuracy, and 5 exceeded a
10% error rate. Conclusions: By quantifying calibration errors, this Spray Rodeo
Station 2: Nozzle Calibration
event identified appropriate adjustments, allowing spray operator/supervisor
teams to accurately calibrate their large-boom sprayers for the 2011 spray season.
Station 3: Pump Calibration
Savings (costs and environment) are significant. One large-boom rig servicing
60,000 acres/season, spraying 10% over target rate, would over-apply roughly
$150,000 of unnecessary pesticide.  The John Deere SPRAYSTAR system auto-
calibrates to provide optimal control for
Why Calibrate ? many spray event set-ups
 Calibration is needed if display shows
either A or B parameter as out-of-range:
Over increased
chance of crop
environmental
impacts from
wasted product
(increased Spray Rodeo Day
Spray Operator:
Supervisor:
xxx
yyy
• A range = 2500 – 3600
applications injury off-label rates costs) Company/Farm: zzz
Manually enter nozzle
• B range = 5500 – 7300
Spray Rig ID: John Deere 6
Station #2 Date: 11 January, 2012 volumes into the Excel
Volume Nozzle status spreadsheet  Calibration is needed if any of these
Nozzle
Under poor pest
need for re- yield losses to number
collected High / Low Limits have been modified, repaired, or
application pests ounces 10% 5%
applications control
(higher costs) (less income) 1 27 ok ok General Info - Manual Entry
Manually enter nozzle replaced:
specifications
2 29 ok ok Pressure (psi) 40 • Solution pump/hydraulic motor
3 29 ok ok Nozzle type/brand A.I.
4 27 ok ok Nozzle size 11008 • Proportional valve
Nebraska: 66% of the pesticide applicators 5 28 ok ok Nozzle capacity (gpm) 0.8 • Hydraulic pump
had GPA errors > 5%
Spray applicators that 6 28 ok ok
7 27 ok ok Calibration Data - Manual Entry • Spray rate controller
calibrated > 1 time per
North Dakota: 60% of tested sprayers had 8 29 ok ok Average run time, seconds 21
Equations in the  Calibration takes 2 minutes
year ….. 9 25 LOW LOW Ground speed (mph) 12.75
calibration errors > 10% 10 28 ok ok Nozzle spacing (inches) 20 “Nozzle Status” column
indicate status after
Most errors were due to improper calibrations ….. 75% were within 5% 11 31 HIGH HIGH Nozzle collection time (seconds) 15
manually entering
12 29 ok ok
and/or worn nozzles of their target GPA 13 29 ok ok Nozzle Volumes - Auto-calculated nozzle volume Results / Impacts
14 28 ok ok Number of nozzles 48
15 28 ok ok Total volume sprayed (ounces) 1,343
16 30 ok HIGH Average volume/nozzle (ounces) 28.0  Eighteen (18) large-boom sprayers servicing ≈ 200,000 acres of Florida’s
17 30 ok HIGH Plus/minus range (%) = 10 5 All entries in this sugarcane acreage were calibrated at Spray Rodeo Day
18 30 ok HIGH HIGH LIMIT nozzle volume (ounces) 30.8 29.4 section are calculated
19 27 ok ok LOW LIMIT nozzle volume (ounces) 25.2 26.6 on-the-fly when nozzle  706 nozzles tested were tested (≈ ¼ mile of boom length was calibrated)
Spray Smart Workshops 20 27 ok ok volumes are entered
21 29 ok ok Spray Application Rate - Auto-calculated
22 28 ok ok Constant 5,940 Values in the “Nozzle
Traditional Annual Calibration Training - Everglades Agricultural Area 23 28 ok ok gpm (single average nozzle) 0.874 Status” column are re- Table 1. Percentage of nozzles that were bad (out-of-range)
24 27 ok ok mph 12.75 calculated as new data
25 27 ok ok W (nozzle spacing in inches) 20 are entered
PowerPoints Hands-on Calibration Activities No problems < 5% 5% to 10% > 10%
26 26 ok LOW
• 1/128 calibration method (with math • large boom sprayer 27 28 ok ok
Based on the nozzle 6 rigs 4 rigs 4 rigs 4 rigs
28 28 ok ok
Target gallons/acre (GPA) = 18.64 specifications entered
exercise worksheets) • backpack spot-sprayer 29 29 ok ok
under “General Info”
30 27 ok ok 33 % 22 % 22 % 22 %
• banded vs. broadcast applications • math worksheets 31 28 ok ok
Actual gallons/acre (GPA) = 20.37
Calculated on-the-fly
32 29 ok ok when nozzle volumes
• pesticide drift and 33 27 ok ok
Actual vs. Target GPA % Difference 9.3%
are entered
droplet size demos 34 27 ok ok Spray Rodeo addressed this 44% error
• new chemistries
• label updates John Deere Rig 6
Graph is auto-generated Table 2. Comparing Actual vs. Target GPA % Differences
• surfactants when nozzle volume data
are entered into the Excel Within 1% 1% to 5% 5% to 10% > 10%
• container recycling spreadsheet
1 rig 4 rigs 8 rigs 5 rigs
Total of 48 nozzles
Using ± 10% error limits: 6% 22 % 44 % 28 %
2 nozzles out-of-range (4.2%)
Grower Feedback: “Spray Smart Workshops are great … but we Using ± 5% error limits:
6 nozzles out-of-range (12.5%)
want to calibrate OUR large-boom spray rigs” Spray Rodeo addressed this 72% error
Spray Rodeo Product
The spray operator receives a
hard-copy of the spreadsheet One large-boom spray rig,
as well as the graph
Nozzle corrections can be made
servicing 60,000 sugarcane acres/season,
on the spot followed by spraying 10% over desired Target GPA rate,
another nozzle testing to
finalize the spray rig calibration would over-apply ≈ $150,000/season of unnecessary pesticide