S
oil pH varies greatly, even within the same field. pH
variations as much as 2 pH units are common. Composite
soil samples taken across an entire field, such as those
samples taken for soil fertility recommendations, may not
detect areas of high pH. Subsampling is recommended for
areas likely to have pH values higher than the field average.
The following is a non-inclusive list of potential high pH
areas where subsampling is recommended.
• Where different soil types are evident within a field,
sample soil types separately.
• Where conditions vary within a field, sample areas
separately, such as:
- areas bordered by limestone gravel roads,
- river bottoms subject to flooding,
- low areas in hardpan soils where evaporative ponds
may occur,
- eroded hillsides,
- along drain tile lines, and
- areas where drainage ditch spoil has been spread.
• Where lime has not been deeply incorporated, soil may
exhibit significantly higher pH values in the upper 3
inches of soil. Composite soil samples taken at a 6-8 inch
depth may not reflect the elevated pH near the surface. In
these cases shallow sampling, the upper 3 inches, is
advised.
Determine soil pH by laboratory analysis using a 1:1
soil:water suspension.
Prior to application of
DuPont™
CLASSIC®, start with
clean, well maintained application equipment. Immediately
following application, thoroughly clean all application
equipment. Postponing action, even for a few hours, only
makes effective cleanup more difficult. Failure to clean
spraying equipment thoroughly may result in injury to
subsequently sprayed crops.
When spraying multiple loads of CLASSIC® over an
extended period of time, rinse the equipment with clean
water at the end of the day. Leave water in the equipment
overnight to prevent deposits from drying on surfaces.
When applications of CLASSIC®
are completed and prior
to using the sprayer and associated equipment for other
products or for crops other than soybeans, thoroughly clean
the equipment using the procedure below.
STEP 1. Drain spray equipment. Thoroughly rinse sprayer,
and flush hoses, boom and nozzles with clean
water.
Loosen and physically remove visible deposits.
STEP 2. Fill the sprayer with clean water and add
household ammonia (one gallon of 3% active for
every 100 gallons of water) or correct amount of a
DuPont approved cleaner*. Flush hoses, boom
and nozzles. Turn off the boom and top off the
tank with clean water. Circulate through the
s
praying system for 15 minutes. Flush the hoses,
boom and nozzles with the cleaning solution.
Drain the tank.
S
TEP 3. Remove and clean nozzle, screens and strainers in
a bucket of fresh cleaner and water.
STEP 4. Repeat STEP 2.
STEP 5. Thoroughly rinse the sprayer, hoses, boom and
nozzles with clean water, several times.
Clean all other associated application equipment. Take all
necessary safety precautions when cleaning equipment. Do
not clean near wells, water sources or near desirable
vegetation. Dispose of waste rinse water in accordance with
local regulations.
* For additional information on sprayer cleanup and a listing of DuPont-
approved cleaners, see DuPont Bulletin “A Guide To Application
Equipment Cleanout For DuPont Sulfonylurea Herbicides”.
The interaction of many equipment and weather-related
factors determines the potential for spray drift. The
applicator is responsible for considering all these factors
when making application decisions.
AVOIDING SPRAY DRIFT IS THE RESPONSIBILITY
OF THE APPLICATOR.
IMPORTANCE OF DROPLET SIZE
The most effective way to reduce drift potential is to apply
large droplets (>150 - 200 microns). The best drift
management strategy is to apply the largest droplets that
provide sufficient coverage and control. The presence of
sensitive species nearby, the environmental conditions, and
pest pressure may affect how an applicator balances drift
control and coverage. APPLYING LARGER DROPLETS
REDUCES DRIFT POTENTIAL, BUT WILL NOT
PREVENT DRIFT IF APPLICATIONS ARE MADE
IMPROPERLY OR UNDER UNFAVORABLE
ENVIRONMENTAL CONDITIONS! See Wind,
Temperature and Humidity, and Temperature
Inversions
sections of this label.
Controlling Droplet Size - General Techniques
• Volume - Use high flow rate nozzles to apply the highest
practical spray volume. Nozzles with higher rated flows
produce larger droplets.
• Pressure - Use the lower spray pressures recommended
for the nozzle. Higher pressure reduces droplet size and
does not improve canopy penetration. WHEN HIGHER
FLOW RATES ARE NEEDED, USE A HIGHER-
CAPACITY NOZZLE INSTEAD OF INCREASING
PRESSURE.
•
Nozzle Type
- Use a nozzle type that is designed for the
intended application. With most nozzle types, narrower
spray angles produce larger droplets. Consider using low-
drift nozzles.
Contr
olling Dr
oplet Siz
e - Aircraft
• Number of Nozzles - Use the minimum number of
nozzles with the highest flow rate that provide uniform
coverage.
SPRAY DRIFT MANAGEMENT
SPRAYER PREPARATION AND
CLEANUP
THE IMPORTANCE OF SOIL PH
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