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NOXIOUS
VEGETATION CONTROL
A FERAL AID PROJECT
BULLETIN NO. 2
DON R. LUETHY
CHmEF OF FISH MANAGEMENT
FlOD GAME AND FEBS= WATER FISH COMMISSION
a .-., Eq
NOXIOUS
VEGETATION CONTROL
A FEDERAL AID PROJECT
BULLETIN NO. 2
DON R. LUETHY
CHIEF OF FISH MANAGEMENT
FLORIDA GAME AND FRESH WATER FISH COMMISSION
PREFACE
This completion report is presented, not only as
required in Federal Aid Acts, but also as a possible
guide to assist any agency similar to the Florida Game
and Fresh Water Fish Commission that is possibly
interested in initiating a like program. Certainly, if
such information had been available to this Commis-
sion, many days and dollars could have been saved
during the organization period.
The success of this program was a direct result
of the hard work and loyalty of Phil Phillips, Willie
Geiger, Jack Carter, Warren Land, and Secretary Eva
Brice.
TABLE OF CONTENTS
INTRODUCTION Page 1
PRELIMINARY SURVEY Pages 2- 3
DETERMINING ACREAGE Pages 3- 4
AERIAL TREATMENT Pages 4- 5
AERIAL-TRUCK OPERATION Pages 5- 6
AERIAL CHEMICAL APPLICATION Pages 6- 8
BOAT SPRAY EQUIPMENT Pages 9-10
AIRBOAT SPRAY TECHNIQUE Pages 10-11
BOAT SPRAY CHEMICAL APPLICATION Pages 11
CHEMICAL COST AND RATES OF APPLICATION Pages 12-13
GENERAL DISCUSSION AND PROBLEMS Pages 13-16
CONCLUSIONS Pages 16-17
TABLES, CHARTS, PHOTOGRAPHS Pages 18-26
STATE-Florida
PROJECT NO.-F-2-D-2
DATE-May 6, 1955
COMPLETION REPORT FOR
DEVELOPMENT PROJECT
As Required by
FEDERAL AID IN FISH AND WILDLIFE
RESTORATION ACTS
TITLE OF PROJECT: Noxious Vegetation Control
LEADER: Don R. Luethy
REPORT OF ACTnvTIES: Following is a presentation of the required
completion report for the Noxious Vegetation Control Program
(F-2-D-2). This project was approved on April 3, 1952 and active
pursuit toward the designated objectives was continued under Federal
Aid jurisdiction until June 31, 1953. Also, on this date the activities
and direction of this project were financially and otherwise assumed
by the Florida Game and Fresh Water Fish Commission without
Federal Aid and is being continued on a somewhat enlarged scale.
INTRODUCTION
The creation of this project, which for all practical purposes
could be titled Hyacinth Control, was a result of numerous com-
plaints from sportsmen and Commission personnel that many of
our favorite fishing streams and lakes were being or were totally
covered with water hyacinth (Eichornia crasippes). Other agencies
previously active in hyacinth control were limited almost exclusively
to efforts to aid drainage and navigation. Hence, a large majority
of our inland waters received no attention toward controlling this
vegetation menace to fisheries. The popularity of this program, which
is more successful than originally expected, is exemplified by the
numerous requests received weekly for consideration on treating
new lakes and streams. This is especially true since the requesting
parties realize that they must furnish funds for all chemicals used
in the operation.
TECHNIQUES AND EQUIPMENT
Preliminary Survey
Upon receiving and accumulating several requests from any gen.
eral area of the state, the supervisor must, through correspondence,
make tentative dates for a visit to the lakes or streams for an all
important preliminary survey. While making this survey the fol-
lowing information should be gathered:
1. Are the waters open to the public.
2. Does the interested person or party want all of the vegeta-
tion treated, including any connecting waters that might be
a source of re-infestation.
3. Does the interested person or party agree to defray all cost
of chemicals and carrier oils.
4. Are the areas open enough for aerial spraying, or can all
of the vegetation be sprayed by boat.
5. If the vegetation is hyacinth, is it single layered or in mats.
6. If there are agriculture crops in the area, will the landowners
sign a waiver of liability, and if not, when will the crops be
harvested.
7. Determine the acreage of vegetation to be treated.
Some outside investigation is often necessary to determine if
a lake or stream is actually open to the public. In several cases,
a body of water heretofore closed to the public will be opened to
fulfill the requirements for this control operation. If such is not
the case, then the request is not approved. Also, as a preliminary
requirement all vegetation in a given body of water must be treated,
including any inflowing stream or adjoining lake that might be
infested with such vegetation.
Because of the magnitude of this project, and the limited budget,
it was decided that the interested person or party would pay for the
cost of chemicals and carrier oil, if oil is used. The Commission
would furnish operational cost, equipment, and personnel to prop-
erly complete all control operations.
Another policy set up as a preliminary requirement is that a
majority of the vegetation must be in the open if there are more
than 15 acres. That is, the plants must be available to aerial spray-
ing. This is necessary because of the large demand for this work
and the slowness of boat spray treatment on large rafts of vegeta-
tion. For instance, the spray plane can treat 15 acres of vegetation
in 2.5 minutes of actual spraying time. It might be a several day
operation for the boat crew to cover the same area.
To closely check the vegetation, especially hyacinth, is important.
If the hyacinth is dense but not matted in layers, then the usual
estimate of $4.00 per-acre-cost for chemicals is valid. However, if
the hyacinth is matted in several layers the cost might run up to
$8.00 per acre, and take several months to sink. This problem will
be discussed in a later part.
The possibility of damaging agricultural crops in the vicinity
of a spraying operation is quite serious. This is especially the case
when spraying with aerial 2,4-D ester in an area near garden crops. It
has been learned that the vapor from this chemical will drift for a
considerable distance and is lethal to almost all farm crops. When
such crops are in an area of operation, then the local wildlife officer
is requested to circulate a form for signatures releasing the Com-
mission from liability in case of damage. If the release is not acquired,
the lake or stream is not approved until such crops are harvested.
In case the domestic vegetation in the area is perennial, such as
various yard shrubs or citrus trees, then the lake or stream is definitely
disapproved pending a property damage release. As yet, the Com-
mission has not been able to acquire* liability insurance to cover
any unintentional crop kills.
Determining Acreage
Having acquired the above mentioned information, and having
the lake or stream approved, then our airplane must visit the area
for aerial photography. The photograph is used, with the aid of a
planimeter, to plot the actual acres of vegetation so that the proper
amount of chemicals can be applied. Because of the large number
of required photographs, and the high rates of commercial photogra-
phers, a Crown Graphic camera has been purchased for this work,
and a complete dark room set up for developing and enlarging. Two
types of cameras are satisfactory in acquiring aerial photographs. The
mechanical aerial camera (Army or Navy K-2 surplus) adapted for
film pack or film slides, offers good results. Also, a 4"x5" Speed or
Crown graphic is usable, if care is taken to protect the bellows from
the propeller blast.
In taking an aerial photograph suitable for plotting acreage with
a planimeter, care must be taken to snap a vertical shot, with as
little deflection as possible. Also, if a photograph is desired on a
small lake, some unnecessary altitude is desirable to partially elim-
inate focal distortion. To acquire a given dimensional ratio, the
use of aerial markers is satisfactory, or one may use identifiable pin-
pointed objectives near the lake shore which show up in the photo-
graph, and measure the actual distance between them. For instance,
you find that the inside measurement between two buildings shown
in an aerial photo is 100 yards, or perhaps the aerial markers put
out previous to taking the photograph are 100 yards apart. Then
by drawing a perfect square on the photo, using the alignment be-
tween these two points as one side, we know that the rectangle en-
closes 10,000 square yards, or approximately 2.66 acres. Then by
running the planimeter pointer in a clockwise manner around the
rectangle, we might possibly have an increased reading of 14. By
moving the pointer in the same manner around the mass of hyacinth
shown in the photo, we find an increased reading of perhaps 1400,
which would indicate some 266 acres of hyacinth infesting the lake.
Of course, if the hyacinth are not in a solid mass, the planimeter
is run on the open water interior area and the difference subtracted.
All planimeter calculations are collected with the base of the instru-
ment in a given place, and all indicated differences are collected in
at least triplicate, with the mean average figure being used.
AERIAL TREATMENT
Equipment
The most economic method to apply herbicides over a large area
is with aircraft. To apply the proper amount of chemicals over a
given area, one must be thoroughly familiar with the operation of the
installed spray unit. In the case of our unit, a four-mile flight run
is necessary before emptying the 40-gallon chemical tank. During this
run a 30-foot swath is sprayed. Thus, we have distributed 40 gal-
lons of spray over 633,600 square feet, or approximately 15 acres.
With the 40-gallon tank loaded with 7.5 gallons of chemical and 32.5
gallons of carrier fluid, either diesel or kerosene, we have treated 15
acres of vegetation at the rate of one-half gallon of chemicals per
acre. Any normal variation in air speed has little or no effect on this
rate of application as the propeller-driven chemical pump discharg-
ing the spray works at a speed proportional to the speed of the spray
plane. The aircraft, a PA 18 Piper with a 125 h.p. engine, has a
removable chemical tank. Two principal benefits are derived in
having such a unit. One, is that once the tank is removed after spray-
ing operations, the plane is covered by insurance during transition
flights. A conventional type sprayer or duster plane with non-remov-
able tanks is either not insurable at any time, or the cost for such
insurance is prohibitive. Also, with the chemical tank removed, a
photographer may accompany the pilot on preliminary survey flights
to take aerial photos, make notes on nearby agriculture crops, and
observe dangerous flight obstacles that might be encountered during
future spray runs. An observer is also helpful in making periodic
checks on kill results and progress on the numerous projects.
If a larger project is contemplated, where two or more spray
planes are needed, the Piper convertible spray plane should be
supplemented with a Stearman or similar type aircraft. These planes,
powered with a 300 or 450 h.p. engine, can easily carry from 140 to
160 gallons of chemical mix per load. The advantage of such a larger
plane is the ability to treat a greater acreage of vegetation in a
shorter period. This plane can treat three or four times more acre-
age per trip than the Piper. Time is of all importance, because of
the usually short calm period for spray applications either at dawn
or late afternoon. For instance, on one occasion, aerial spray opera-
tions commenced at dawn on a 205 acre raft of hyacinth. An hour
and thirty minutes later, the calm broke and the wind started drift-
ing the spray toward cultivated fields. The pilot was forced to stop
spraying after 8 loads with only 120 acres treated. The raft shifted
into open water, and the treated area mixed with the untreated. The
dead hyacinth could not sink because of the attached green masses,
and as a result all of the area had to be sprayed again. A Stearman
spray plane could have easily finished the job before the calm broke.
However, if only one plane is to be acquired, then the lighter plane
is preferable because of lesser operational expense in ferrying, in-
spection trips, and aerial photography. The Stearman is not con-
veniently adapted for removable spray tanks.
Aerial-Truck Operational Techniques
The supervisor, while conducting the preliminary survey, locates
the nearest airfield or strip. If the local landing strip is too far from
the proposed area, as is the case in most instances, a near pasture
or highway is selected as a base for aerial operations. The pilot and
loader, through two-way radio communications, rendezvous at such
operational sites and set up for dawn spraying. Before landing the
pilot checks the lake for spray-run planning, and if the lake is par-
tially covered with water hyacinth, locates the raft at this time. Two
or more lakes or streams are tentatively scheduled for treatment.
Because of the intense demand for hyacinth control, the supervisor
can plan a given local area with several pending operations simul-
taneously. In doing so, the pilot can quickly change the agenda to
a secondary lake in case conditions are not favorable on the primary
project. The basis for such an elastic schedule may lie in the follow-
ing conditions:
1. Heavy rains may flood out the predetermined landing area
on one project, however, a nearby project may be near a paved
landing strip.
2. The pilot may find the body of water partially covered with
water hyacinth in a non-rafted condition; however, in a nearby
secondary project the vegetation is in rafts for convenient
aerial spraying, or another near project is totally covered
with hyacinth so that they can not disperse.
3. Weather forecast predicts an unfavorably high wind velocity.
The pilot can choose a smaller project where he can be more
apt to finish spraying before the dawn calm breaks and the
chemicals commence drifting.
All final spray preparations are completed during the previous
afternoon or before dawn, with the exception of mixing the spray
load. The volatility of the chemical is such that after several hours
of exposure in an open mixing drum it is relatively ineffective.
It is nearly impossible for ground flaggers to direct pilots on in-
dividual spray runs because of the usually dense wooded shoreline areas
or non-navigable waters. The pilot must become efficient without such
aid. Often a ground observer carrying a walky-talky radio set can
be of valuable assistance in directing the pilot for better coverage.
During the summer season the aerial applicator can, on most occa-
sions, observe any untreated greener areas a few hours after the
initial application. In such cases he can return with an additional
load to treat the areas for an almost 100% coverage. The rapid effec-
tiveness of the hormone herbicide makes for such conditions only
during the warm summer and spring seasons. Summer applications
are usually 5 to 10% more effective than winter applications because
of this better chemical coverage.
Aerial Chemical Application
2,4-D
Thus far, the discovery and production of 2,4-D, a hormone type
herbicide, has contributed more to chemical control of emergent
aquatic vegetation than any other chemical discovery in history.
This chemical is manufactured in numerous concentrations and in
two primary types, the amine and ester. This herbicide is produced
by many chemical companies and sold under even more trade names.
It is wise, before making large purchases, to have a sample analyzed
for specific strength in percentage or pounds acid-equivalent, good
emulsion and volatility. Our preliminary research on the use of both
amine and ester 2,4-D, ranging from low volatile 2.0 pounds acid-
equivalent to high volatile 8.0 pounds acid-equivalent aero concen-
trate, has resulted in the following recommendation for hyacinth con-
trol: For aerial spray the 3.34 pounds acid-equivalent ester type,
applied at .5 gallons per acre, has constantly given the desired results.
One-third gallon application was used throughout the period cov-
ered by this report with satisfaction. However, the small additional
chemical cost to increase the rate to .5 gallons per acre, as compared
to operational cost, is well worthwhile to insure a more complete kill.
It is quite possible that the amine type chemical would be as effective,
if not more so than the ester form for aerial spray, were the amine
soluble in oil.
Carrier Fluids
All aerial applied 2,4-D ester is discharged with an oil base mix-
ture, either kerosene or diesel oil. The reason for this is that an aerially
applied spray load must, because of the relatively small load-carrying
capacity of the aircraft and the all important time element involved,
be discharged in a concentrated mixture over a large given acreage
of vegetation during a relatively short period of calm. To aerially
apply this concentrated mixture as mentioned, one must consider
two factors:
1. If the spray was not of an oil non-water soluble base, then an
unforeseen rain could wash off several hundred dollars worth
of chemicals, resulting in a total loss.
2. The oil base is more tenacious than water, keeping down fluid
runoff.
Chemicals applied aerially for other vegetation include 2,4-D amine,
2,4,5-T and sodium arsenite. An unsuccessful attempt was made
in applying T.C.A. (sodium trichloroacetate) mixed with 2,4-D, by
plane on water lilies (Nymphaea sp.). The powder was mixed in a
concentrated form to meet application requirements. The result was
a jelly-like solution, resulting in no end of trouble in cleaning out the
spray system. A later liquid type of T.C.A. was developed for such
aerial application. However, research studies indicated the solution
was unstable, and further production of the chemical was terminated.
The use of 2,4,5-T as a herbicide has presented various results.
The use of this chemical in its pure form invariably leads to good
kills on both aquatic and woody plants. The use in pure form is
not common because of high cost. Usually the chemical is mixed
in several proportional ratios with 2,4-D, and applied at an approxi-
mate rate of .25 to .50 gallons per acre. This chemical mixture is
of considerable value when spraying areas infested with borderline
and shallow-water woody plants. The 2,4,5-T to 2,4-D ratio may
be predetermined by estimating the area infested with woody plants
in proportion to the area infested with fleshy aquatics. For instance,
on a 60-acre area there are 15 acres of water willows (Salix sp.) scat--
tered among 45 acres of hyacinth, so it is recommended that one
gallon of 2,4,5-T in pure form, be mixed with three gallons of 2,4-D
ester, both chemicals with approximately 3.34 pounds acid-equivalent
strength. This 2,4,5-T 2,4-D mixture is applied at .50 gallons per
acre. Applications of 2,4,5-T are as effective in killing hyacinth as
is 2,4-D; however, 2,4-D is, per equal concentration, approximately
half as expensive but is not as effective as 2,4,5-T on woody plants.
Hence, with such a mixture, one can control both types of vegetation
during a common treatment in the most economical manner. In
similar cases when the woody vegetation infests only five to fifteen
percent of the area, then the woody plants are ignored during aerial
treatment and destroyed later with airboat spray during clean-up
operations.
Sodium arsenite, unfortunately, is of little or no value to this pro-
gram as an aerial herbicide. Were it not for the chemical's toxicity
to animals, sodium arsenite would be of value in controlling both
emergent and submergent aquatic vegetation in larger lakes. We
experienced considerable success in controlling pepperweed (Pota-
mogeton sp.) in a 20-acre lake with aerially applied sodium arsenite.
No actual rate of application was recorded because of a malfunction
in the spray system. With the release valve jammed open, the pilot
attempted to spiral over the lake until, the chemical tank emptied.
Observers stated that a considerable amount of the sodium arsenite
was released on nearby pastures. The landowner strongly confirmed
the chemical's killing effect on pasture grasses. Fortunately, no live-
stock was in the area. Following this experience, no further sodium
arsenite treatments have been undertaken by spray planes.
Unrelated to this program, but in cooperation with other fish
management projects, the spray plane was used with exceptional
success in applying liquid rotenone over approximately 8 miles of
canal, some 42 acres. The chemical was evenly distributed over the
desired area, with insignificant loss of poison, in two hours.
BOAT SPRAY EQUIPMENT
After considerable study on various types of inboard and out-
board motor boats and barges, it is definitely concluded that the
only completely satisfactory boat for applying spray is an airsled.
This boat, if properly constructed, can travel at high speeds across
large lakes and marshes to and from work, it can idle at slow speed
with good maneuverability in a few inches of water, offer a barge-
like stability to work from, is easily portable from one area to an-
other, and will safely take rough water. The spray from this boat
is usually directed laterally; however, with some experience, the
operator can partially "bog" it down on the shore or in thick vege-
tation rafts, direct the spray through the propellor and air blast the
chemical up to a hundred yards distance under over-hanging trees
or other inaccessible areas.
This sled should be approximately 5'6" at the bottom beam, 6'6"
at the gunnel beam, and 14' long with a 30" free board. The shell
is constructed of %" plywood, with aluminum sheet metal or fibei
glass over the bottom. The sled should be powered with a 108 to
150 horsepower aircraft engine with a pusher propeller. Two 30
gallon drums located on either side of the engine mount, with a
common pump connection, is satisfactory for chemical tanks. Two
such units, mounted on underslung trailers pulled by pickups, can
possibly take care of cleanup and maintenance spraying for one spray
plane, along with lake areas that do not call for aerial spraying.
The most successful pressure spray pump located thus far is a
600-pound-pressure sprayer manufactured by the Bean Company.
This piston pressure type pump has a low volume capacity (8 gal-
lons per minute) which makes for spraying the proper rate of chem-
ical on a given area, and eliminates the handling of large quantities
of carrier fluids. This pump is powered with a 3 h.p. air-cooled gaso-
line engine. The combined weight is such that it is easily portable
by two men. The pump is easily repaired, and complete repair kits
are available at low cost. The pistol-grip adjustment nozzle, also a
Bean product, has been satisfactory. Various sized orifice washers
may be used to get the desired spray discharge.
AIRBOAT SPRAY TECHNIQUE
The technique for uniformly applying the proper amount of
chemicals on a given area of aquatic vegetation from an airboat is
considerably more difficult than aerial operations. To properly pre-
pare for any boat spray operation, the following knowledge is neces-
sary:
1. The spray operators must have an index to estimating acreage
of vegetation by visual references. Certainly it is impractical
to make an aerial photo planimeter survey of each borderline
area.
2. The operator must know the approximate lineal distance he
can cover, dependent upon the navigability of the water,
adjacent to the vegetation to be sprayed, with a given pump
discharge rate and the volume of spray liquids aboard the boat.
An experienced boat spray operator with the above knowledge
will approach a job in the following manner:
1. By keeping in mind that an average 15 feet margin of vege-
tation some 3,000 feet in length is one acre, or an average
30 feet margin some 1,500 feet in length is approximately one
acre, or with other comparable dimensional index references,
the operator can become, for all practical purposes, accurate
in estimating acreage.
2. With the acreage estimated, and the knowledge that his pump
discharges eight gallons per minute, and the average mar-
ginal strip is 30 feet wide, then at five miles per hour approxi-
mately 500 feet of spraying will empty his 50 gallon chemical
tank. The operator can by mixing one quart of 2,4-D to each
three loads of water apply three-fourths gallon of actual chem-
ical to an acre of vegetation, as is recommended by the writer
for boat spray treatment to kill hyacinth.
Actual checks on such spray operations have shown amazing ac-
curacy on the part of experienced operators in estimations based
on the above principle. In discussion of airboat spray techniques, it
might be stated that any area of marginal vegetation consistently over
30 feet in width, if at all possible, should be treated aerially. If not
open to aerial spraying, then the boat operator must treat the area
in periodic sequence as the outside treated margin sinks and exposes
the untreated vegetation within the range of the spray pump. The
above mentioned pump can effectively treat only a 30 foot swath of
marginal vegetation.
Boat Spray Chemical Application
Noxious aquatic vegetation treated with various chemicals from
boats include water hyacinth, cattail (Typha sp.), water lily (Nym-
phoea sp.), maiden cane (Panicum sp.), pond weed (Potamogeton
sp.), coontail (Ceratophyllum sp.), water willow (Salix sp.), button
bush (Cephalanthus sp.), and water lettuce (Pistia sp.).
In controlling water hyacinth, using boat applications, three-fourths
gallon of 2,4-D amine (4.0 pounds acid-equivalent per gallon) per
acre is recommended. Lesser applications if evenly distributed can
give satisfactory kill results. However, in consideration of overall
economy and human error in applying chemicals, the heavier rate
is preferable. The operational cost of spraying operations is approxi-
mately 40 percent more expensive than cost for chemicals when applied
at this recommended rate. Using lesser rates of applications, the
spray operation cost usually exceeds twice the cost for chemicals.
It is also recommended that 2,4-D never be diluted more than one
pint to 50 gallons of water for hyacinth control spraying.
The use of the above described 2,4-D in controlling water lilies
offers erratic results when used with a water carrier alone. To insure
favorable kill results it is recommended that water lilies be treated
at the rate of one gallon .2,4-D, 50 gallons of water, two gallons of
kerosene, and two ounces of spreader sticker or one-fourth pound of
commercial detergent. The kerosene activator plus the adhesive effect
of the detergent tends to break down the wax protective layer
encasing the leaf and exposes the plant to the effects of the 2,4-D.
Spreader sticker is a trade name for a highly concentrated commercial
detergent. It is recommended that water lettuce be treated in the
same manner and rate as water lilies.
Because of the nature of this developmental program, too little
research has been completed to offer boat spray chemical application
recommendations on the treatment of pond weed, water willow, cat-
tail, coontail, and button bush. Varied and non-consistent success
has been experienced in treating these various species of vegetation.
Chemical Cost and Rates of Application
As previously mentioned the cost for necessary chemicals to con-
trol any vegetation problem within the scope of this project is
furnished by the interested persons, whereas all operational costs
for personnel and equipment are defrayed by the project. This ar-
rangement has been gratifying in that more active participation,
cooperation, and enthusiasm has been demonstrated by these people
than in other cases of "for free" public service fisheries programs.
Interested persons responsible for furnishing funds for chemicals
include sportsmen clubs, county commissions, Forestry Department,
health departments, civic clubs, flood control agencies, real estate
groups, landowners, cattlemen, park service, and others. Sportsmen
clubs and county commissioners supply a majority of the funds. To
offer an anticipated amount of money necessary to reimburse the
project for chemicals used on any one project is difficult. However,
with some experience one can during the preliminary survey make
a fairly accurate estimate and then add a substantial amount for
safety. Arrangements should be made for the money, with exception
to government agencies, to be placed in escrow for periodic reim-
bursement withdrawals. Thirty-one bodies of water are tabulated
in Tables I, II, III, IV to demonstrate the cost for chemicals and
rates of chemicals necessary to control them. These waters are
controlled and maintained. Costs and rates of chemicals for main-
tenance spraying have not been determined at this time. All costs
and chemical data are based on the original number of acres of
vegetation. In the case of Lake Hamburger (Table II) with 60 acres
of layered hyacinth completely covering the lake, it was necessary
to treat some 150 acres aerially and 70 acres by boat before the 60
surface acres of water could be cleared. Dense layered conditions
of the hyacinth, plus spring regrowth during a low water level period
before the airboats were acquired, made for this exceptionally diffi-
cult project. The conventional outboard spray boat could not navi-
gate the lake for a period of several months.
The average cost for chemicals per original acre of hyacinth (Table
I) to acquire a controlled condition, is $2.99 per acre. Cost for
2,4-D at that time was approximately $4.00 per gallon. Cost for car-
rier oils and detergents was included in this cost. The average amount
of chemical 2,4-D per original acre of hyacinth (Table II) necessary
to acquire a controlled condition is .64 gallons.
These costs and application data determinations were acquired
during the period when one-third and one-half gallon of 2,4-D was
aerially and boat applied per acre of hyacinth rather than the now
recommended one-half and three-fourths gallon treatment. In several
instances, such as Big Alligator Lake, frost kill and dropping water
levels in the northern sector of the state decreased the normal neces-
sary number of applications of chemical for control. A controlled
body of water, in this instance, is one that has all rafts and marginal
vegetation killed, sunk, and only occasional maintenance spraying
is necessary to kill back any reproductions.
In Tables III and IV chemical application rates and costs are
presented to demonstrate data collected on bodies of water infested
with vegetation other than hyacinth, or combinations of hyacinth
and other species of vegetation. As previously stated the erratic re-
sults from various chemical applications are such that no recom-
mendation can be generally offered at this time. However, these eight
lakes are under control, and in some instances maintenance problems
are not as demanding as are waters originally infested with only
water hyacinth. In most of these eight bodies of water, unnecessary
amounts of chemicals were used because of the experimental nature.
Table V offers a general view of progress for all bodies of water
that were in the process of control treatment, or controlled and/or
maintained.
General Discussion and Problems
Some of the major problems encountered in organizing and oper-
ating this project may be discussed in the following sequence:
1. Seasonal effects on chemical treatment
2. Desired borders for fish cover and cattle grazing
3. False charges of animal toxicity of chemicals
4. Political pressure
5. Depleted chemical funds of sponsors
6. Collection of outstanding chemical bills
7. Bookkeeping
8. Pro and con publicity
9. Personnel
10. Determination of future equipment needs.
The eventual kill result of any hormone type herbicide application,
in so far as seasonal temperature variations in Florida are con-
cerned, is of no consequence with the exception of the lapse period
involved. A mass of water hyacinth may be killed and sunk, in some
instances, during the summer months in half the time required dur-
ing winter months. Contact-type chemical herbicides seemingly are
as effective one season as another, with small variation in kill periods.
Frost kills during the colder season are of considerable benefit in
keeping down maintenance spraying. Also, during the fall and winter
months reproduction by stolons and seeds is almost totally retarded.
Hence, during this period maintenance and clean-up spraying opera-
tions should be intensified as a safeguard against the spring re-
infestation period.
In several instances considerable objections have been presented
against a total water hyacinth kill. Certain misinformed people have
contended that a marginal border of the vegetation should be un-
treated so as to have fish cover around the marginal edges. Also,
a few cattlemen insist that water hyacinth offer a substantial relief
to winter pastures during dry seasons. There is little or no validity
to these two contentions and most certainly the maintenance of any
existing margin would be a constant source of expense and effort.
With the exception of the previously mentioned application of
sodium arsenite, no herbicides have been used that were toxic to
animal life. However, on occasions some persons will falsely state
that their animals have been killed by the herbicide chemicals. Usual-
ly the matter can be settled by visiting the complainant and discuss-
ing the non-toxicity of the chemical to animals. Sometimes it is
necessary to present publications refuting the animal toxicity of the
herbicide.
As in all cases of public services being offered, there exists political
pressure for attention to numerous waters in excess of facilities. This
is especially true when the interested persons have money for pur-
chasing chemicals to treat various waters in excess to what can be
utilized by the crews. In most such cases, the interested persons
have their local senator or representative apply pressure for early
attention. The project leader can usually offset these instances by
visiting the public official, explaining the situation, and making a plea
for more money for equipment and personnel. This approach to all
political pressure cases has, without exception, been successful.
Probably the most frustrating problem encountered during the
early part of the program was a result of the sponsoring party de-
pleting their chemical funds. As a necessary policy of the program,
the spraying activities were terminated until more money could be
collected by the sponsor. In some cases the project was abandoned,
in other cases the project was renewed, but in all cases considerable
effort and expense were wasted because of phenomenal regrowth of
the vegetation in the partially controlled waters. This problem has
been eliminated through requiring the sponsor to deposit adequate
funds for the project in escrow.
Another problem has also been eliminated by requiring the spon-
sors to deposit sufficient chemical funds in escrow, therefore, elim-
inating the time consuming collection of funds for chemical reim-
bursements. By making large purchases of chemicals, the project
leader can acquire herbicides cheaper than the sponsors; hence, in
almost all cases the sponsors prefer to reimburse the program rather
than acquire their own materials. In the early part of the program
considerable time was directed toward the collection of this reim-
bursement and despite every effort some $1,404 was never collected
A simple but complete bookkeeping ledger should be acquired,
with columns entered so as to compile data and also to keep a running
account on all projects. (See Chart) Also, it is recommended that
a punch card system (Charles R. Hadley Unisort Cards) be kept up
to date and coded so that lakes by type, lakes with outstanding ac-
counts, status of control, lakes due for inspection, lakes due for main-
tenance spraying, etc., may be pulled simultaneously from the file
for periodic attention.
The popularity of this program created an unusual problem. In
all other Commission projects considerable time and effort are di-
rected at publicizing the various activities. In this case, because of
limited facilities, it was necessary to purposely avoid publicity on
many projects. Otherwise, the project leader would receive large
numbers of new requests and be tied up with numerous appoint-
ments, only to advise the interested persons of temporary disapproval.
The success of this program, as all other public service programs
requiring the services of non-technical employees, is dependent upon
the circumstances under which the men are hired. This is especially
true in state wide work where the men are not under direct super-
vision and are working on their own initiative. Every effort should
be made to hire men whose loyalty and continued employment are
dependent upon the responsibility of the project leader rather than
upon their political affiliations.
The determination of increased future equipment and personnel
requirements is indeed a difficult problem, not only in the light of in-
adequate facilities to answer an ever increasing demand for this type
work, but also as to what ratio of boat spraying effort is needed to
balance aerial spraying. Two air-sleds can now adequately take care
of all clean up spraying following aerial treatments. However, in the
future these two airsleds will have a full time job in maintenance
spraying on an undetermined number of controlled lakes. At this
stage of progress, the program will either have to be enlarged or the
spray plane discarded and the program limited to maintenance of
controlled lakes.
CONCLUSIONS
1. The Noxious Vegetation Control Program (F-2-D-2), during
a period of approximately one year, has been more successful than
originally anticipated because of the following: (a) unlike other
fisheries programs, the results are usually visually apparent in a
short period, (b) exceptional results were experienced through the
use of modern chemicals and specialized equipment such as air pro-
pelled boats and spray planes, (c) the hiring and continued employ-
ment of personnel depended upon performance rather than political
affiliations, (d) the program's limited facilities were directed toward
areas of apparent need rather than toward political areas of lesser
need, and (e) the prompt and sincere attention given disappointed
officials pleading for additional services, makes for perpetuated pro-
gram popularity.
2. A complete preliminary survey is of prime necessity before
undertaking any proposed project.
3. The use of hormone type herbicides such as 2,4-D amine,
2,4-D ester, and 2,4,5-T is recommended on most all emergent aquatic
vegetation.
4. For aerial application it is recommended that .5 gallons of
2,4-D ester (3.34 pounds acid-equivalent) be applied with oil car-
rier to one acre of water hyacinth.
5. For boat application it is recommended that .75 gallons of
2,4-D amine (4.0 pounds acid-equivalent) with water carrier be
applied to one acre of water hyacinth.
6. The recommended rate of 2,4,5-T per acre varies with the
type and percent infestation of various aquatic and non-aquatic
vegetation.
7. It is recommended that water lettuce and lily pads be treated
with one gallon 2,4-D amine (4.0 pounds acid-equivalent) with 50
gallons of water and a strong detergent activator added for one acre
of vegetation.
8. Too many erratic results were experienced thus far to offer
recommendations on the control of cattail, maiden cane, water willow,
button bush, coontail, and pond weeds.
9. The average amount of 2,4-D type chemical necessary to bring
about a controlled condition per acre of water hyacinth was .64
gallons. Variation in necessary chemical application per acre ranged
from 1.56 gallons to .35 gallons.
10. Average cost for chemicals to bring about a controlled con-
dition per acre of water hyacinth is $2.99. The cost per acre ranged
from $6.44 per acre to $1.50 per acre.
11. Cost for chemicals and necessary rates for control of other
species of vegetation are considered non-significant because of in-
complete studies.
12. The total average cost per acre for hyacinth control is ap-
proximately $8.03. The program's operational expense makes up $5.04
of this amount. Numerous factors such as cooperative services to
unrelated conservation work, and estimated value of inventorial equip-
ment, etc., were considered, and probably with considerable error, to
arrive at this operational expense estimate.
13. Some 104 lakes and streams were surveyed during this period
of operation with 31 being under control and maintained and 16 others
in process of being controlled. Some 5,940 acres of hyacinth were
killed and sunk to clear an original 3,909 acres of infested waters.
Submitted by:
DON R. LUETHY,
Project Leader
Approved by:
A. D. ALDRICH, Director
Game and Fresh Water
Fish Commission
Date: May 6, 1955.
s.!jI-9-47394--8-56
Table I-Cost for Chemicals Necessary to Control Wate r Hyacinth on Bodies of Water Classified as Controlled.
Aerial Chemical Boat Chemical Overall Chemical
Ref. Name of Lakes Surface Acres of
No. Acres Hyacinth Total Acre Total Acre Total Acre
4 Bailey................................. 65 8 84.30 1.40 72.00 1.20 156.30 2.60
5 Bay................................... 65 60 84.30 1.40 72.00 1.20 156.30 2.60
7 Big Alligator............................ 1,250 300 513.10 1.66 45.50 .15 558.60 1.81
9 Brewster............................... 74 35 137.39 3.92 29.75 .85 167.14 4.77
15 Burkett ................................ 125 74 117.67 1.59 32.00 .43 149.67 2.02
17 Church................................. 140 16 .......... ........ 47.10 2.94 47.10 2.94
19 Conlin ................................. 3,500 8 .......... ........ 12.00 1.50 12.00 1.50
22 Drane.................................. 1,250 220 506.40 2.30 47.00 .21 553.40 2.51
G 23 Duff................................... 60 60 256.20 4.27 130.00 2.17 386.20 6.44
26 Hamburger............................. 60 60 304.80 5.08 48.50 .80 353.30 5.88
28 Harper................................. 40 40 105.70 2.64 10.50 .26 116.20 2.90
29 Helvenston ............................. 65 14 .......... ....... 26.00 1.87 36.00 1.87
36 Johnson................................ 318 60 199.45 3.33 26.00 .43 225.45 3.76
75 Lake O' Woods ........................ 78 58 83.80 1.44 28.00 .48 111.80 1.92
50 Newnan................................ 2,550 231 276.70 1.19 296.00 1.28 572.70 2.47
53 Orange....................... ...... 19,264 1,120 2,270.05 2.03 1,120.53 1.00 3,390.58 3.03
55 Pasadena............................... 750 208 453.28 2.18 430.00 2.07 883.28 4.25
56 Pearl .................................. 82 55 74.60 1.35 75.50 1.08 149.60 2.43
60 Priest .................................. 10 2 .......... ........ 8.00 4.00 8.00 4.00
61 R ock ............................... ... 3 3 .......... ........ 8.00 2.67 8.00 2.67
67 Smith....................... ........ ...1 1 .......... ........ 4.00 4.00 4.00 4.00
69 Trafford. ............................... 1,940 341 532.15 1.56 355.50 1.04 881.65 2.60
73 W hite ...................... .. ....... .. 175 41 .......... ........ 96.50 2.33 96.50 2.33
1 1 1 1 1 1 =
Table II-Chemical 2,4-D Rates Necessary to Control Water Hyacinth on Bodies of Waters Classified as Controlled.
Aerial Chemical 1 Boat Chemical 2 Overall Chemical
Ref. Name of Lakes Surface Acres of
No. Acres Hyacinth Total Acre Total Acre Total Acre
4 B ailey ................................. 65 8 .......... ........ 4 .5 .56 4 .5 .56
5 Bay................................... 65 60 15.0 .25 18.0 .30 33.0 .67
7 Big Alligator ............................ 1,250 300 107.0 .31 13.0 .04 120.0 .35
9 Brewster............................... 74 35 25.0 .71 8.5 .85 33.5 1.56
15 Burkett ................................ 125 74 22.5 .30 8.0 .12 30.5 .41
17 C church ................................. 140 16 .......... ........ 11.5 .72 11.5 .72
19 C onlin ................................. 3,500 8 .......... ........ 3.0 .37 3.0 .37
22 Drane.................................. 1,250 220 96.5 .44 13.0 .06 109.5 .50
23 Duff................................... 60 60 50.0 .83 35.0 .58 85.0 1.41
26 Hamburger............................. 60 60 61.0 1.01 13.5 .23 74.5 1.24
28 Harper................................. 40 40 20.0 .5 3.0 .07 23.0 .57
29 H elvenston............................. 65 14 ......... ... ........ 6.5 .47 6.5 .47
36 Johnson ................................ 318 60 40.0 .66 6.5 .11 46.5 .77
75 LakeO' W oods......................... 78 58 17.0 .29 7.0 .12 24.0 .41
50 Newnan ................................ 2,550 231 55.0 .24 74.0 .32 129.0 .56
53 Orange................................. 19,264 1,120 476.0 .42 307.0 .27 783.0 .69
55 Pasadena ............................... 750 208 91.0 .44 118.5 .57 209.5 1.01
56 Pearl .................................. 82 55 15.0 .27 20.0 .36 35.0 .63
60 Priest .................................. 10 2 .......... ........ 2 .0 1.00 2 .0 1.00
61 R ock .................................. 3 3 .......... ...... 2 .0 .67 2 .0 .67
67 Sm ith .................................. 1 1 .......... ........ 1.0 1.00 1.0 1.00
69 Trafford................................ 1,940 341 100.0 .29 62.5 .18 162.5 .47
73 W hite............. ..................... 175 41 .......... ........ 25.5 .62 25.5 .62
1 All aerially applied 2,4-D was in ester form with 3.34 pounds acid-equivalent.
2 All boat applied 2,4-D was in amine form with 4.0 pounds acid-equivalent.
Table III-Cost for Chemicals in Controlling Aquatic Vegetation Problems Other Than Water Hyacinth on Bodies
of Water Classified as Controlled.
Names of Lake, Pond,
Pool, or Stream
Belleview Lake..............
Bundy Pond .............. .
Correll Lake................
H ardin Pool................
lamonia Lake...............
Lucina Lake................
Melbourne Pool .............
Panasoffkee Lake........... .
Surface
Acres
8
30
80
1
5,000
80
5
4,000
Total Acres and Types
of Vegetation
2 Lily Pads..............
25 Maiden Cane...........
fl5 Hyacinths............1
20 Lily Pads .............
1 C attail................
43 Lily Pads..............
42 Lily Pads..............
1 C attail................
fl2 Hyacinth ............1
Maiden Cane ........... f
t 5
12
16
27
32
40
45
54
AerialCost
Total A
Boat Cost
. ....... .
. .. .... ..
330.70
. .. .... ..
. .. .... .. .
Total
29.20
20.05
184.45
25.41
152.60
16.38
65.00
.. ... ....
. .... .. ...
7.69
...... ....
...... ...
Acre
14.60
8.02
5.27
25.41
3.62
16.38
3.61
All Cost
per Acre
14.60
8.02
5.27
25.41
7.69
3.62
16.38
3.61
Table IV-Chemical Rates Necessary in Controlling Aquatic Vegetation Problems Other Than Water Hyacinth
on Bodies of Water Classified as Controlled
Ref. Names of Lake, Pond,
No. Pool, or Stream
Belleview Lake............. .
Bundy Pond................
Correll Lake ................
Hardin Pool......... ....
lam onia......... .........
Lucina Lake .............. .
Melbourne Pool.............
Panasoffkee Lake............
Surface
Acres
8
30
80
1
5,000
80
5
4,000
* Gallons 2,4,5-T.
(All other amounts indicate gallons of 2,4-D.)
Total Acres and Types
of Vegetation
2 Lily Pads..............
25 Maiden Cane............
{15 Hyancinth ............
20 Lily Pads .............
1 C attail ................
43 Lily Pads..............
42 Lily Pads ............ .
1 C attail ................
{12 Hyacinth............
6 Maiden Cane..........
Aerial Chemical
Total Acre
. . . . . .
. . . .
85.0
. . . . .
. . . . .
. . . . .
.........
2.0
... . . .. .
..........
. . . . .
Boat Chemical
Total Acre
1.5 .75
70** 35**
2.5 1.0
30** 12**
35.0 1.0
220** 11**
3.0 3.0
40** 40**
21.5 .51
197** 47**
2.0 2.0
25** 25**
13.0 .72
3.0* .17*
** Pounds of TCA
5
12
to 16
27
32
40
45
54
All
Chemicals
Per Acre
.75
35**
1.0
12**
1.0
11**
3.0
40**
2.0
.51
47**
2.0
25**
.72
.17*
Table V-General Summary of Progress on All Lakes and Streams
Treatments Chemicals Used
Name of Lake or Stream Location-County Surface Acres of Control
Acres Hyacinth Aerial Boat Aerial Boat Status
Airport Lake.................
Altoona Lake................
Apopka Lake............. . .
Bailey Lake .............. . .
Bartow Phosphate Pits ........
o Bay Lake....................
to Belleview Lake..............
Big Alligator Lake .......... .
Brewster Pools...............
Bundy Pond .................
Burkett Lake .............. ..
Church Lake.................
Collins Mill Pond .......... .
Conlin Lake..................
Cooter Pond..................
Correll Lake..................
Drane Lake..................
Duff Lake....................
Eaton Lake..................
Hamburger Lake..............
Hardin Pool ............... .
Harper Lake .............. .
Helvenston Lake.............
D uval..............
Lake...............
Lake...............
Duval .............
Polk ............. .
Orange.............
M arion.............
Columbia...........
Polk ...............
Clay ...............
Orange .......... .
Marion............
Jackson ...........
Osceola ............
C itrus..............
M adison ......... .
P olk ...............
Polk ...............
Marion............
Columbia...........
Okeechobee ........
Columbia...........
Suwannee ........ .
25
160
38,000
65
30
65
8
1,250
74
30
125
140
21
3,500
20
80
1,250
60
650
60
1
40
65
15
85
210
8
20
60
*** 2
300
35
251
74
16
*** 12
8
15
*** 35
220
60
112
60
** 1
40
14
17
28
21
0
5
15
0
107
25
0
22.5
0
0
0
22
0
116.5
50
50
61
0
20
0
3
0
0
4
2
25.5
1.5-701
13
4.5
2.5-301
17
13.5
6-100 '
3
0
20-220
13
35
4
13.5
3-401
3
10
% Controlled
80
75
25
100
85
100
100
100
100
100
100
100
80
100
20
100
100
100
75
100
100
100
100
Iamonia Lake ................
Jeffries Lake................ .
Johnson Lake ............... .
Lucina Lake ................ .
M adison Lake.................
M artha Lake..................
M ary Lake..................
M attie Lake.................
Melbourne Pool ............. .
Middle Lake Hamilton ........
Newnan Lake...............
Okeechobee Lake ........... .
Orange Lake ............... .
Panasoffkee Lake ........... .
Pasadena Lake...............
Pearl Lake..................
Priest Lake..................
Rock Island................ .
Seneca Lake.................
Sm ith Lake ..................
Trafford Lake ................
Umatilla Lake...............
White Lake ................ .
Woods (Lake O' The) ........
Leon ..............
Alachua........... .
Marion . . . . . .
Duval ............ .
M adison ..........
Orange..............
Lake..............
Polk ..............
Brevard. .......... .
Polk ............ .
Alachua............
Okeechobee........ .
Marion ........... .
Sumter .......... .
Pasco ..............
Orange............
M arion............
H ardee .............
Lake..............
M arion............
Collier.............
Lake..............
Suwannee .........
Orange ........... .
*2,4-D plus 2,4,5-T.
** Designates Cattails
*** Designates Lily Pads
5,000
250
318
80
50
83
180
2,550
5
45
2,550
460,800
19,264
4,000
750
82
10
3
120
1
1,940
105
175
78
*** 43
105
60
*** 42
2 10
6
90
280
** 1
45
231
20
1,120
18
208
55
2
3
40
1
341
60
41
58
1 T.C.A. pounds
2 Maiden Cane
4-501
0
13
16-127'
7-1001
2
0
0
2-251
0
74
0
45-15'
* 12
17
5
2
2
0
1
53.5
0
14.5
7
LEDGER CHART
NAME
SERIAL SPRAYING OPERATIONS
Amount
Date Chemicals
Used
Fuel Used Cost Total Credit
Gallons I
Balance e
BOAT SPRAYING OPERATIONS
Amount
Date I Chemicals
Used
Cost
______ ____________ 11 ______ _________ t _________ II ________ _____________________
_______________________ 1 _______ _____________ _______ _____________ 1 _______ 1 __________ 1 __________ II _________
_______________________________________ I _____________ ____________________ ____________ _______________________ _________________ _______________
Fuel Used Cost Total
Gallons
Credit I Balance
kt~.. wwwiwr"~ ~W4~%
Spray plane-The most efficient
and effective method of apply-
ing herbicides.
Airboats are easily moved on
special roller-bed trailers. The
boat is often loaded on the trail-
er with the boat's own power.
The flat bottom air-propelled
boat can operate in depths of
only a few inches.
Orange County's 60-acre Bay Lake was almost completely covered with
hyacinths when this photo was taken in July, 1952.
- 1" 0 rj4
//7d:f[/ '"II'... : -f : ,' -., ^. :.-.:...-.-..f.. w
Bay Lake five months later, following one application of spray from
plane and five by boat.
|
