PCC MarchApril Final Draft

A New Generation of
Precision Spray Technology
New retrofit kit creates automated universal intelligent
spray control system for existing sprayers that could
benefit growers and the environment.
By HEPING ZHU | Agricultural Engineer and Lead Scientist, USDA-ARS Application Technology Research Unit
and STEVE BOOHER | Founder & CEO, Smart Guided® Systems, LLC
Fruit, nut, ornamental nursery,
horticultural and greenhouse
industries are among the fastest-growing
enterprises in US agriculture.
Application of pesticides
and other production strategies have
ensured their high-quality products
meet stringent market requirements.
However, low-efficiency, decades-old
spray technologies are commonly
used to treat these specialty crops and
have caused an enormous amount of
pesticide waste, additional costs in
crop production and concerns around
worker safety. The pesticide waste has
also caused environmental contamination
and ecosystem damage because
pesticide sprays indiscriminately kill
both pests and beneficial insects. Spray
drift and off-target loss will likely
remain a major problem as long as pesticides
are applied using indiscriminate
spray equipment.
Need for Efficient Technologies
Pesticide application is the most
complicated operation in crop production
because there are many variables
affecting spray strategies and practices.
In many cases, when decisions must
be made to apply chemicals within a
very narrow time window in response
to escalating pest pressure, a simple
“best guess” practice is often under
vague labeling of pesticide rates to
control pests that may result in excessive
application of pesticides.
Given constrained environments for
specialty crop production, an ideal
spray management program for pests
and diseases should include improved
delivery systems that are flexible for
spraying the amount of chemicals
to match tree structures instead of
acreage base. Such spray application
will also produce minimum spray drift
and off-target loss of pesticide on the
ground and in the air.
To achieve this goal, a new automated
universal intelligent spray control system
was developed as a retrofit kit to
attach on existing sprayers. With the
intelligent control system, the conventional
spraying systems can determine
the presence, size, shape, and foliage
density of target plants such as trees
and grape vines, and then automatically
apply the amount of pesticides
as needed according to plant architectures
in real time. With the control
system, growers themselves can upgrade
their own sprayers to precision
sprayers with intelligent functions
rather than buying new sprayers, and
sprayer manufacturers do not need to
change their current sprayer designs.
The primary requirement for the
upgrade action is to connect a variable-flowrate
solenoid valve to each
nozzle, and all other components are
attached to the sprayer body without
changing the sprayer structure.
This new system is the product of a
decade of research and development
by engineers at USDA-ARS at Wooster,
Ohio in collaboration with researchers
at The Ohio State University, Oregon
State University, University of Tennessee,
Clemson University, Texas
A&M University, Iowa State University,
Washington State University,
Penn State University, University of
Queensland and USDA-ARS.
Since 2013, the system has been tested
as a retrofit on different types of the
air-blast sprayers for pest control effectiveness,
reliability and repeatability
on real farm fields. Comparative field
biological tests were also conducted
to evaluate insect and disease control
for the sprayers with and without the
intelligent-decision control capabilities
in commercial nurseries, apple
orchards, peach orchards, pecan
orchards, vineyards and small fruit
productions as well as university research
farms in Ohio, Oregon, Tennessee,
South Carolina, Texas, California
and Washington.
These activities were voluntarily held
by UCCE in Napa County and University
of Queensland in Australia.
System Features
Spray deposition uniformity insidecanopies,
chemical usage and off-target
losses were investigated for the
plants at different growth stages in
ornamental nurseries, apple orchards,
peach orchards and vineyards. Multiyear
field tests have demonstrated the
intelligent spray system is reliable and
can reduce pesticide use in a range between
30% and 90%, reduce airborne
spray drift between 60% and 90%,
4 Progressive Crop Consultant March / April 2021