Custom Search
|
|
|
||
 57
AFM 91-19 / TM 5-629 / NAVFAC MO-314
24 May 1989
tor and the spray boom, to indicate nozzle
or ditch spraying, or vertical to spray above
pressure.
trees, shrubs, and tall weeds. Each boom seg-
ment is hydraulically controlled by an operator
(2) Two types of control valves are in
sitting next to the driver.
general use. A quick-opening valve is used to
turn the flow on or off to all nozzles, and
(3) For roadside spraying, two or more
selector valves control the flow to individual
nozzles are grouped together and mounted on an
sections of a spray boom. Selection valves en-
arm that reaches over mailboxes, highway signs,
able an operator to spray from any or all
and similar obstacles. A truck-mounted boom
sections of a boom.
designed to spray under guard rails reaches over
e. Hoses and Strainers:
the rail and sprays from the outside toward the
pavement.
(1) Hoses on sprayers should be of a mate-
rial that will withstand the chemicals used,
h. Mist Blowers. Mist blowers disperse highly
particularly petroleum solvents. Synthetic rubber
concentrated sprays in a finely atomized form at
and plastic are most common. Heavy-walled
low volumes per acre. The herbicide is carried
hoses or metal pipe are used for extremely high
principally in an airstream instead of a liquid.
pressures.
These sprayers are free of boom and nozzle
(2) Strainers or filters are used between the
problems, require minimal amounts of water,
tank and the pump as line filters and behind
cover vegetation rapidly, can be used for areas
each nozzle orifice. Some have built-in valves to
that are inaccessible to other power equipment,
prevent nozzle dripping. In filling the tank, a
and are cheaper than conventional hydraulically
coarse strainer should be used to filter the spray
powered equipment. They are very useful for
liquid. Wettable powders rarely pass through
spraying under fences, around stone piles, along
screens finer than 50 mesh. Screens for emul-
roadsides, in drainage ditches, and under power-
sions should be about 100 mesh.
lines. The use of mist blowers for herbicides,
however, is limited by the serious hazard of
f. Boomless Sprayers. Boomless sprayers with
drift. Mist blowers in 5 to 12 horsepower sizes
cluster nozzles are well adapted for spraying
are useful for brush spraying where drift is not a
roadsides, ditchbanks, rights-of-way, fence rows,
problem. A 2-horsepower knapsack mist blower
and areas where trees would interfere with the
is useful for brush up to 30 feet tall, and for
operation of booms.
spot spraying.
(1) Boomless sprayers are less expensive,
simpler to operate, and have less nozzle trouble
i. Wipe-on Equipment. This equipment is a
than boom sprayers. They can pass between
means of using nonselective herbicides with no
trees and shrubs, be maneuvered close to obsta-
drift hazard and with almost no soil residues. It
cles, and are practical for rough ground. They
is especially useful for controlling taller weeds
spray a 20- to 30-foot swath with large volumes
and brush sprouts in low-growing grass and
that provide moderately good coverage.
other ground covers.
(2) The equipment can be mounted on a
(1) The rope wick applicator consists of
four-wheel-drive vehicle or caterpillar-type trac-
several loosely woven wicks, the ends of which
tor. The chief disadvantage of boomless sprayers
are inserted into holes in a large plastic pipe.
is that the spray swath is greatly affected by
The pipe contains the herbicide solution. The
wind. They should not be used when the wind
applicator is adjusted to a height just above the
may cause drift to nearby sensitive vegetation.
lower-growing, desirable vegetation, and kills
g. Boom Sprayers:
only the taller plants that are wiped by the rope
wick as it goes through the field. There are
(1) Boom sprayers are adapted for large
variations for specialized uses, such as around
areas where completed coverage is necessary,
shrubs, small trees, and other obstructions. One
and for turf areas adjacent to roads where
such is the hand-held "hockey stick" applicator
applications can be made from tractor- or truck-
which has special padding fashioned for the
side-mounted booms. These units have spray
curved lower end of a stick. This is moistened
booms with evenly spaced nozzles.
with herbicide through a plastic tube having a
(2) For roadside or ditchbank spraying, re-
hand-operated valve. Such items are available
motely controlled truck-mounted side-arm
commercially.
booms are advantageous. The boom may have
nozzles evenly spaced along each segment of the
(2) The rolling carpet applicator is used in
the same way as the rope wick applicator. It
arm, and may terminate in a boomless-type
spray nozzle. It may be horizontal for roadside
consists of a horizontal rotating, carpet-covered
|
 
|
|
|
||
