The Bugwood Network


Tools of the Trade

  • Ground based
    • Manual
    • Mechanical
  • Aerial

Ground Based Application Systems

Mechanical granule spreaders

Mechanical granule
spreader; skidder mounted
Granule spreader on a John Deere 450

Ground Based Application Systems

Mechanical liquid applicators

Two nozzle head mounted
on a boom on a dozer
Close up of a shorter boom
apparatus for broadcast spray

Two nozzle head on boom in use

Another view of the boom in action

Shorter boom in use to control kudzu

Efficacy of kudzu topkill – will
need to be repeated for control

Multi-nozzle assembly for mounting
behind a tractor or dozer

Assembly in operation

Similar multi-nozzle assembly in operation

Side view showing downward
directed spray – minimizes drift

Palmetto-gallberry incursion
following clearcut (Osceola NF)

Four wheeler strip spray – palmetto-
gallberry – Garlon 4 + Arsenal

Different view of same treatment

Tree planter modified to spray
seedlings over-the-top at planting

Radiarc nozzle head

Radiarc nozzle head in use

4-wheeler adapted as a
twin-nozzle spray platform

Mist blower in operation in a seed orchard

Ground Application Tools

  • Cut surface tools
    • Injection
    • Hack & Squirt
Cranco injector bar
Cranco injector bar - parts

Jim-Gem injector bar

Jim-Gem injector bar - parts

Injector bar in use – jab tree
base, pull wire & inject herbicide

Jim-Gem injector in use – jab,
push handle, jab, push handle,…

Cran-jector (Cranko Co.
injector bar) – from ad

Cran-jector (Cranko Co. injector
bar) – from mimeographed ad

Hypo-hatchet and belt
mounted herbicide reservoir

Hypo-hatchet and belt
mounted herbicide reservoir

Hypo-hatchet – ready to use

Hack-and-squirt apparatus –
a hatchet and a squirt bottle

Hacking (right hand) and squirt (left hand)

Girdled tree – notches
not deep enough –
tree survived

Hack-’n-squirt tree – good
deep cuts – red dye marks
herbicide excess

Squirt part of Hack-’n-squirt

Ground based manual tools

  • Liquid applications
    • Backpack foliar
    • Soil spot
  • Generally selective – but not always
Most common manual tool –
a backpack spray assembly
Tank (1); Diaphragm pump (2);
Pump lever (3); Hose (4)

Valve assembly (5), Wand or
extender tube (6), Nozzle (7)

Veterinary syringe (spot gun) for spot applications – squeeze trigger, metered amount dispensed

Vet gun in operation –
target selective operation

Model 30 Gunjet

Model 30 Gunjet

Field use of spot guns – spray to side,
walk through untreated vegetation

Backpack herbicide reservoir –
spray nozzle at end of long wand

Soil spot treatment (note blue dye)
next to a released seedling

Broadcast Pronone site preparation

Close up of efficacy of the hexazinone treatment in the previous slide

Avoid using Velpar near a
(loblolly pine) RCW cavity tree

Red maple stump sprouting
can be a serious problem

Use of spotgun to "streamline"
an undesirable tree – note band
and drip

Oil stain from JLB Oil Plus
Improved (vegetable oil) several
days after treatment

Streamline is often the best
method to treat multiple stems

Effective removal of a multi-stem
competitor of a desirable seedling

Kudzu infestation overtopping trees

Four wheeler carrying a nurse tank – spot gun with hose to allow mobility beyond the vehicle

Effectively a broadcast spray
of kudzu despite using the
4-wheeler unit

Clopyralid treatment – pine unaffected

Foliar treatment to release oak seedlings

Mortality to non-target oaks
which were inadvertently sprayed

First growing season - can’t
separate material to be treated

Second growing season – ideal
time to treat using foliar spray

Fourth growing season - for F.S. this treatment is too high risk (spray over shoulder height)

"Blue Worker" – shirt, face and arms
dyed due to improper application

Difficult situation – competition too
high to safely treat ex. by streamline

Chestnut as nurse crop for white
pine – no release necessary,
chestnut blight will do the job

Foliar application from horseback

Moving spray equipment from site to site

Aerial Pesticide Application

Where is it the appropriate tool?

  • Herbicide application from the air is limited for use in R8 by the Vegetation Management EISs – more later
  • Insecticide application from the air is permitted in the Region for defoliator control when necessary and for some applications made to seed orchards
  • Cost may be prohibitive if areas are small
  • Often when it is considered – applicator safety is an issue in alternative treatments
  • Helicopter application only for herbicides in R8
  • Potential problems
    • Treatments are broadcast
    • Evaporation and drift are real environmental concerns

Tools most commonly used to dispense pesticides from aerial platforms.

Aerial application by helicopter –
boom spray standard nozzles
Why a wing lifts
Vortices form at wing tips
causing pattern disruption

Often – as here – to
control insect infestations

Standard aerial application
nozzle assembly on a boom

Boom spray rig mounted under
a helicopter, with a nurse tank

Some nozzles are machined to
produce swirls of liquids which
then break up into droplets

The effect is a curtain
of droplets falling onto
target vegetation

Or, if pointed down, a fairly
heavy flooding or rain of droplets –
generally used for herbicides

Microfoil nozzle section –
note the tubes forming a
comb like edge

A different configuration of
the Microfoil technology
Nozzle puts out streams of liquid which subsequently fragment into large droplets
Microfoil nozzles mounted on a boom

A third configuration of the Microfoil nozzle

Microfoil nozzle mounted on
the boom and ready for use

Microfoil nozzles in any configuration generally produce a curtain of droplets

Application of granular pesticides from aerial platforms.

A fertilizer spreader can be
used to apply granular pesticides
DuPont’s turnkey application
of Velpar ULW granules

Loading the granule hopper with a premeasured amount of material

Where to look on the next slide

Granules being blown
out of the dispensing pipe

Another "Where to look…"

Granule application as seen
from the helicopter

Site preparation using the Velpar
ULW aerial distribution system

Pattern distortion during to fixed
wing application of pesticides

Restrict the boom to about 2/3
the wing length to avoid vortices

Distortion of distribution
pattern caused by propeller

Redistribute nozzles on boom to
compensate for the distortion

Effect of nozzle orientation on droplet size

Aerial Application; Don’t
Apply Up and Down Hills

Aerial Application: Apply Along Slopes

Powders or granular products which
are to be liquefied are measured
by weight prior to addition to tank

Nozzles and Calibration

A brief overview of nozzles, their composition and performance, and the numbers used to describe them.

There is a wide variety of nozzles
for a variety of purposes
Agricultural multi-nozzle booms
are the most common pictures

Agricultural multi-nozzle booms
are the most common pictures

Nozzle catalogs are a good
source of information

Catalog information

Catalog information

Catalog information

Catalog information

Catalog information

Catalog information

Catalog information

Catalog information

Nozzle types: Flat and flat fan nozzles

Nozzle types: Flat and flat fan nozzles

Nozzle types: Flat fan nozzle

Nozzle types: Low pressure flat fan nozzle

Nozzle types: Extended range flat fan nozzle

Nozzle types: Hollow cone

Nozzle types: Hollow cone

Nozzle types: Solid cone

Nozzle types: Solid stream

Nozzle types: Solid stream - disk

Nozzle types: Also...

  • Twin stream
  • Raindrop
  • Flooding

Nozzle types:

  • Flat fan and stream nozzles are the most common in forestry use

TeeJet Nozzle Code

Generally a four digit code like – 2503 or 4502

The first two digits (three when >99°) reflect the angle of coverage at 40 psi

25XX = 25°
80XX = 80°

The third and fourth numbers reflect the flow rate in tenths of a gallon per minute at 40 psi.

An XX02 nozzle is calibrated to put out 0.2 gallons per minute at 40 PSI
An XX04 is calibrated to put out 0.4 gallons per minute at 40 PSI.

Reducing pressure from 40 psi

  • Reduces angle of coverage
  • Reduces volume per minute applied
  • Increases droplet size

To protect nozzles from unnecessary wear, add a filter to remove abrasive contaminants from the mixture.

  • XX01 & XX02 nozzle – use a 100 mesh screen
  • XX03 or greater nozzles use a 50 mesh screen

For thinline and streamline applications a different numbering system comes into play.

Disc nozzles (0° angle) are commonly used and they are numbered:

  • D1 (0.1 gpm)
  • D1.5 (0.15 gpm), and
  • D2 (0.2 gpm)

These discs require a 25 mesh screen or its equivalent.

Delavan uses a different "Color-bration" scheme

Screens or strainers

In-line screens or strainers are used to reduce wear of the orifice of nozzles.

In-line Strainers vs. Screens

In-line strainers may be substituted for screens as long as the slots have the equivalent straining capacity as the recommended screen mesh.

Tip material

Wear is also affected by the material used to make the tip; brass, aluminum, plastic, nylon, stainless steel and hardened steel are among the materials available.


Stainless steel or hardened stainless steel nozzles are recommended.

Nylon, brass, and aluminum nozzles all have characteristics which make them less desirable; primarily a shorter working life due to being softer and wearing faster. In addition, nylon nozzles shrink and swell.

Graphic showing comparative output of worn or damaged tips.

Graphic showing comparative cost and wear of different tips.

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University of GeorgiaThe Bugwood Network Forestry Images The Bugwood Network and Forestry Images Image Archive and Database Systems
The University of Georgia - Warnell School of Forestry and Natural Resources and
College of Agricultural and Environmental Sciences - Dept. of Entomology
Last updated on Wednesday, November 06, 2002 at 10:10 AM
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