No Muss, No Fuss Spray Rig for
Around the ARS Crop Science Research Laboratory at Mississippi State,
Mississippi, maintenance mechanic Stan Malone is regarded as an engineering
Last summer, Malone put his exceptional talents to work when Quinnia L.
Yates, a biological lab technician, proposed the idea of automating an
insecticide spray system for greenhouse-grown plants. After surveying
Yates greenhouse, Malone envisioned an overhead pesticide-misting rig
that might best fill that bill.
But none of the commercial greenhouse suppliers they later contacted sold
any such rig matching his conception. We tried everywhere, Malone
says, but there was nothing out there we could find.
His next move was to team up with Dennis Rowe, who heads up the labs
Forage Research Unit.
With the units help, Malone then designed a system of his
owndrawing on such off-the-shelf items as a toggle switch, timer clock,
pressurized pesticide tank, chemical hoses, flora nozzles, and other components
chosen from various commercial equipment suppliers.
With the new system, theres no human involvement except for
mixing of pesticide according to the manufacturers label, Malone
says. You simply fill your tank with whatever insecticide you need to
control the insects, set the timer clock, and turn on the switch and
Automatic spray rig system for greenhouse
This activates electrical relays that temporarily close the
greenhouses exhaust fans, motorized windows, and vents. A special valve
attachment then releases compressed air into a 5-gallon tank, forcing pesticide
into overhead hoses and brass irrigation nozzles. These mist the chemical over
the plants, providing full coverage in 2-½ minutes for a 30- by 40-foot
The system then flushes its hoses clean with blasts of air and, after the
pesticide settles, restarts the green-house's environmental controls.
Before the automatic systems installation, it took Yates about 45
minutes to manually spray insecticide to curb populations of whiteflies, mealy
bugs, and other destructive insects. Left unchecked, their feeding damage can
jeopardize the uniformity of plants grown for research. But 1994 EPA worker
protection standardswhile effectivemade routine spraying arduous,
costly, and unpleasant.
The standards dictate that greenhouse workers wear a respirator, protective
suit, gloves, goggles, and boots when spraying. But in a hot, humid greenhouse
where temperatures can reach 110oF, a suited worker can easily
become faint or dizzy.
Because of this, we sometimes would neglect spraying until we got a
buildup of insects, Yates says. But with the new spray rig,
its not necessary to risk a buildup. It also eliminates the need
for the costly disposable suits.
The system can be set to spray at night or on the weekends. Also,
users can modify it to fit their applications, says Malone. He has
installed the new rig in 15 of the ARS labs 30 greenhouse rooms.
The costs for materials start at $700 for a 30- by 40-foot room.
Computer-controlled foggers and other commercial devices that apply pesticide
in greenhouses range in cost from $2,000 to $5,000. The greatest gain I
see, says Rowe, is knowing workers are not exposed to spray.
Rowe, Malone, and Yates intend to submit detailed plans for the new system
to a trade journal. By Jan Suszkiw, ARS.
Malone is at the USDA-ARS Crop Science Research Laboratory, P.O. Box 5367,
Mississippi State, MS 39762; phone (662) 320-7447.
Rowe is in the Waste Management and Forage Research Unit, phone (662)
"No Muss, No Fuss Spray Rig for Greenhouses" was published
in the July 1996
issue of Agricultural Research magazine.