|
| South Carolina Category 5Aquatic |
Category Definition
Category 5 Aquatic Pest ControlUnit 1 Aquatic Plant Management
Unit 2 Regulating Aquatic Plant Management
Unit 3 Herbicide Technology
Unit 4 Herbicide Safety
Unit 5 Adjuvants in Aquatic Plant Management
Unit 6 Equipment Selection and Methods of Application
Unit 7 Applying the Right Amount of Herbicide
Unit 8 Other Methods of Aquatic Plant and Fish Management
Unit 9 Environmental and Public Health Relationships
Unit 10 Aquatic Plant Identification
Test Your Knowledge
You must have a free copy of Adobe Acrobat® Reader for viewing PDF files, please visit Adobe. Resources found at Clemson University
Other South Carolina resources:
Other selected resources found on the Web
Return to List of Category Manuals Return to Category 5 Index Return to Top | ||||||||||||
This category is for applicators using or supervising the use of any restricted use pesticides purposefully aplied to standing or running water, excluding applicators engaged in public-health-related activities included in Category 8. Performing "aquatic
pest control activities" includes, but is not limited to, the
use of any pesticide with the intent to prevent, destroy, repel or
otherwise mitigate any pest of publicly or privately owned waters,
including ponds, lakes, oceans, rivers, streams, reservoirs, and
impoundments, whether or not they are navigable, for compensation
on the property of another or as a government employee, including
the installation of devices. Aquatic pest control activities also
includes the soliciting, advertising, or making of sales proposals
in any form for any services involving the use of pesticides or devices
with the intent to prevent, destroy, repel, or otherwise mitigate
any pest of publicly or privately owned waters, including ponds,
lakes, oceans, rivers, streams, reservoirs, and impoundments, whether
or not they are navigable, for compensation on the property of another.
(SCPCA 2006)
Beginning
on January 1, 2006, a license will be required for applicators working
in this category on someone else's property unless they are working
under the supervision of someone who is properly licensed. Use of
either a Restricted Use Pesticide (RUP) or a general use pesticide
will require a license. |
Q. What are the aquatic plant management responsibilities of
the Water Resources Division of the S.C. Department of Natural Resources?
A. The Water Resources Division administers the State Aquatic
Plant Management Program which includes developing and implementing
the annual State Aquatic Plant Management Plan. The Division also coordinates
the receipt and distribution of available public and private funds
for aquatic plant management activities and research in public waters.
Q. What is the role of the S.C. Aquatic Plant Management Council?
A. The S.C. Aquatic Plant Management Council is a ten-member
board that provides valuable interagency coordination of aquatic plant
management activities in public waters and serves as the principal
advisory body to the Department of Natural Resources on all aspects
of managing nuisance aquatic plants. The Council establishes statewide
management policies and approves all aquatic plant management plans
for public water bodies.
Q. What resource is available for management of aquatic plants
in private waters?
A. Assistance, in the form of advice regarding plant control
agents and methods, is available to owners of private waters through
the Clemson University Cooperative Extension Service, the Wildlife
and Freshwater Fisheries Division of the S.C. Department of Natural
Resources and the Soil Conservation Service of the U.S. Department
of Agriculture. Owners may choose to implement control methods themselves
or arrange for a commercial lake management firm to do so.
Q. Who makes up the membership of the S.C. Aquatic Plant Management
Society, a nonprofit organization formed in 1978 to promote the management
of noxious aquatic plants?
A. The Society's membership includes individuals from the private,
public and academic sectors with interest in all aspects of aquatic
plant management. The Society provides members with the most current
information in the field of aquatic plant management through newsletters
and annual meetings.
Q. How do algae and aquatic macrophytes act as the basis of
the food chain?
A. They provide food for small animals which in turn become
the food for successively larger animals. Plants also provide shelter
and breeding habitat for a wide variety of animals including fish,
waterfowl and aquatic mammals.
Q. What are restricted-use pesticides (RUPs)?
A. Pesticides that are more toxic or hazardous to the environment
than others and require special handling and user training. Law requires
that they be applied by licensed, certified applicators or persons
working under their direct supervision.
Q. What is meant by the triple-rinse method?
A. The triple-rinse method is done by filling the container
to at least 10 percent of its volume (preferably 1/4 to 1/3 of volume),
shaking the container and draining the container into the mix tank.
Repeat this two more times. When not using a mix tank, apply the rinse
water from the container in the same manner as the pesticide in the
container.
Q. Who should you contact to find out more information on the
pesticide container recycling program in South Carolina?
A. Check with your local Cooperative Extension agent for pesticide
container recycling dates in your area.
Q. How may new infestations of noxious weeds be quarantined
and controlled or eradicated under the Noxious Weed Act?
A. A permit from the USDA is required to import plants or plant
products into this country. Another permit is required to move all
designated noxious weeds into and throughout the United States, whether
by mail, freight, baggage or on the person.
Q. Why are contact herbicides more effective on annual plants?
A. Perennial plants that persist from year to year can be defoliated
by contact herbicides, but they quickly resprout from unaffected plant
parts.
Q. What is meant by cell division?
A. This process involves increasing the number of cells and
replacing old cells. It is how plants grow.
Q. What is meant by preemergence?
A. During early growth or before weed seeds germinate (pre-emergence)
is when herbicides are most affective.
Q. What is meant by a plant growth regulator?
A. When a herbicide causes abnormal tissue development, abnormalities
such as twisting of stems and leaves may be evident. If enough abnormalities
occur, plants can die. Herbicides that act in this manner are often
called plant growth regulators.
Q. What is photosynthesis?
A. Photosynthesis is the process by which plants use carbon
dioxide, water and sunlight to produce relatively simple molecules
that are the building blocks of other complex molecules that make up
the plant body.
Q. What is meant by broad spectrum and when is it used?
A. Broad spectrum (sometimes called nonselective) herbicides
are those that are used to control all or most vegetation. This type
of herbicide is often used for total vegetation control in areas such
as equipment yards and substations where bare ground is preferred.
Q. How does lack of rainfall affect herbicide efficacy?
A. Lack of rainfall can affect herbicide efficacy because drought
stressed plants are less likely to absorb both foliar and soil applied
herbicides.
Q. How does temperature affect herbicide efficacy?
A. Low temperature affects herbicide efficacy indirectly by
affecting plant growth. At less than ideal temperatures, plant growth
slows down, and this may decrease herbicide absorption and activity.
Excessively high temperatures can affect foliar applications of some
herbicides by causing them to volatilize (change from liquid to vapor)
before they are absorbed into the plant.
Q. What methods might you use when controlling aquatic weeds
in flowing water?
A. 1) Use of invert emulsions or polymers and trailing hoses
to aid sinking the herbicide and adhering it to the plants. 2) Use
of special herbicide formulations for flowing water such as slow release
pellets. 3) Use of rapidly absorbed herbicides. 4) Use of sequential
applications or injection equipment to increase contact times.
Q. What kind of soil has greater capacities for binding herbicides?
A. In general, soils with more organic matter and clay have
greater capacities for binding herbicides and require higher application
rates than other soil types, such as sandy soils.
Q. What is the importance of numerical values on the pH scale?
A. The pH scale goes from 0 to 14, where 7 indicates neutrality.
Values less than 7 indicate acidic water, and values greater than 7
indicate a basic condition.
Q. What is turbidity?
A. Particles suspended in the water decrease the water's ability
to send light and this is called turbidity.
Q. What causes water hardness and how is it expressed?
A. The dissolved metals calcium, magnesium, iron and strontium
cause water hardness. Hardness is usually expressed in terms of ppm
calcium carbonate and can range between close to zero and over 100
ppm.
Q. What precautions should be taken when obtaining make-up water
for tank mixes?
A. 1) Use the cleanest water available. Avoid sediments. 2)
When tank mixing herbicides that are known to be inactivated by hard
water, use the softest water available. If possible use softened or
distilled water; lake water is the next best choice. Avoid using well
water. 3) Minimize the amount of time that herbicides remain mixed
in tanks. 4) Read the label for special precautions or instructions.
Q. What are the advantages and disadvantages of granules?
A. Granules are convenient for spot treatments, are ready to
use and require no mixing, reduce drift hazards and can be applied
easily. Disadvantages of granules are their sometimes high cost and
their ineffectiveness as a foliar treatment.
Q. What are advantages and disadvantages of using wettable powders?
A. Advantages of a WP are lower cost, ease of handling and ease
of measuring. Some disadvantages of WP are the abrasion by suspended
particles on spray equipment and the requirement for constant tank
agitation.
Q. What are the most common causes of chronic toxicity?
A. Chronic exposure is most often the result of contaminated
clothing, leaky spray equipment, inadequate protective clothing and
equipment, improperly cleaned spray equipment and, most importantly,
failure to clean yourself.
Q. What are causes of oral exposure?
A. Oral exposure can be caused by accidental swallowing, usually
from carelessness. Eating, drinking and smoking while applying pesticides
or before properly cleaning hands can also contribute to oral ingestion
of pesticides.
Q. What is the minimum requirement of protective clothing?
A. When working with pesticides, wear, at the least, a long-sleeved
shirt, long pants, shoes and socks. When handling pesticide concentrates
or mixing and loading the sprayer, a liquid-proof apron and rubber
gloves is suggested.
Q. What kind of gloves should be worn when handling concentrates?
A. Gloves should be unlined and made of a waterproof material
that does not contain any cotton, leather or other fabric that will
absorb chemicals. Sleeves should be worn on the outside of the gloves.
Q. What type of hats and boots should be avoided when applying
pesticides?
A. Hats should be easy to clean, or they should be disposable.
Avoid hat fabrics that absorb liquids. Unlined rubber boots are a good
investment for pesticide applicators because they are waterproof and
easy to clean. Work shoes made of canvas or leather absorb pesticides
and cannot be decontaminated easily.
Q. What kind of face protection should be worn anytime concentrate
is handled?
A. Wear goggles or a face shield anytime concentrate is handled.
Q. What are some examples of activator adjuvants and what is
their purpose?
A. Adjuvants can be grouped into three classes, activator adjuvants,
spray-modifier adjuvants and utility-modifier adjuvants. Activator
adjuvants increase the activity of the herbicide. Surfactants are associated
with the enhancement of penetration of the spray solution through the
leaf tissues. Wetting agents are spray additives that increase the
ability of water to displace air or liquids from a plant surface.
Q. What is the purpose of spray-modifier adjuvants and what
are some examples?
A. This group of adjuvants has its greatest influence on the
delivery and placement of the spray solution. Additives which alter
or change the spray, such as polymers, inverts and foams, are included
in this group.
Q. What is the purpose of utility-modifier adjuvants and what
are some examples of each?
A. Utility modifiers are materials that when added to the spray
solution improve the conditions in which the formulated mixture is
useful. Types of modifiers include emulsifiers, dispersants, stabilizing
agents, coupling agents, cosolvents, compatibility agents, buffering
agents and antifoam agents.
Q. What is the importance of maintaining good agitation during
a spray-tank application?
A. Good agitation is important for maintaining a uniform spray
mixture and for mixing of adjuvants such as inverting oil or polymers.
Q. When is a hydraulic agitation system inadequate?
A. A well designed hydraulic agitation system that uses a venturi
device for stirring is adequate for keeping wettable powders in suspension.
However, this type of agitator will not stir the mixture enough to
form invert emulsions or mix polymers.
Q. When is hose size important?
A. Hose size is important because the pressure loss in the hose
depends on the hose inside diameter (ID), length and flow rate. For
example, a 1/2-in. hose loses 1 psi per foot at a flow rate of 10 gal
per min.
Q. What are the benefits of using diaphragm pumps?
A. Diaphragm pumps are now used in many applications instead
of piston pumps. Benefits of diaphragm pumps include relatively low
cost, low maintenance and small size compared with other pumps with
similar flow and pressure ratings.
Q. What is the importance of the spray nozzle during chemical
applications?
A. The spray nozzle forms the spray pattern, determines the
droplet size and meters the flow rate. Base nozzle selection on a balance
of these three functions.
Q. What is the difference between an invert emulsion and a normal
emulsion?
A. An invert emulsion contains water droplets dispersed in a
continuous oil phase. This is contrasted to a normal emulsion which
is oil droplets dispersed in a continuous water phase.
Q. What is meant by the term calibration and why is it so
important?
A. Adjusting application equipment so that it delivers the
correct amount of pesticide is called calibration. Calibration
of equipment for application of herbicides to agricultural crops
must be precise because there is often a thin line between the
rate at which a herbicide will damage the crop or carry over to
a following crop.
Q. Why is maintaining constant application rate when applying
aquatic herbicides difficult?
A. Maintaining constant application rate is difficult when
applying aquatic herbicides because the equipment is mounted in
a boat. Also, it is difficult to maintain a constant speed and
perfect course due to environmental factors such as wind velocity
and speed, water flow and vegetation density.
Q. Why must separate calibration tables must be made for different
sized pellets and granules?
A. Spreader output will be different at given settings for different-sized
particles.
Q. What is the difference between the introduction approach
and the augmentation-manipulation approach to biological control?
A. In the introduction approach, small numbers of biocontrol
agents are released, where they previously did not exist, so that they
can increase to a point where they are in balance with the target pest
(weed) and can establish a self-perpetuating population. The augmentation-manipulation
approach involves releases of biological control agents at strategic
times and at levels capable of providing control.
Q. Why should carp be at least 12 inches long at stocking?
A. Predators such as largemouth bass, snakes, fish-eating birds
and alligators can adversely effect grass carp survival, especially
if small fish are stocked.
Q. Why is annual restocking of tilapia necessary in South Carolina?
A. Tilapia will not overwinter in water below 55 °F.
Q. What three insects have been successfully released for the
control of alligatorweed?
A. Three alligatorweed bioagents include the alligatorweed flea
beetle, the alligatorweed thrips and the alligatorweed stem borer.
Q. What three species of insects have been released for control
of waterhyacinth and which was the most effective?
A. The three species of insects that have been released for
control of waterhyacinth are the mottled waterhyacinth weevil, the
chevroned waterhyacinth weevil and the waterhyacinth borer. The weevils
(especially the chevroned) have been the most effective of the waterhyacinth
insects.
Q. What is a disadvantage to using plant pathogens for biological
control of aquatic weeds?
A. Pathogens tend to be environmentally sensitive and can be
rendered ineffective by extremes of temperature or humidity.
Q. Why is mechanical removal not practical for large bodies
of water?
A. Because of its high cost, mechanical control is generally
practical only for small areas such as marinas, swimming areas, boating
trails or where other methods are not feasible or are undesirable.
Q. What are some of the disadvantages associated with mechanical
harvesting?
A. Mechanical harvesting is usually higher in cost and much
slower than other methods, and there are high maintenance and repair
costs. Some water bodies are not suitable for mechanical harvesting
because of water depth and presence of obstructions. A suitable area
for disposal of harvested plants must be available. Wildlife and desirable
vegetation is removed along with the harvested weeds. Plant fragments
drift to infest new areas. Increased turbidity may result from disturbance
of sediments.
Q. How is water level manipulation used for aquatic plant management?
A. Water level manipulation refers to the raising of water levels
to control aquatic vegetation by drowning or lowering to control aquatic
vegetation by exposing them to freezing, drying or heat.
Q. In what season and to what extent of time should drawdown
be conducted for best results?
A. Drawdown is usually conducted during winter months so that
plants are exposed to both drying and freezing. For best results, a
drawdown should last 60 to 90 consecutive days.
Q. What are methods of reducing light penetration to control
submersed aquatic plants?
A. Light penetration can be reduced by the use of special pond
dyes, special fabric bottom covers or fertilization.
Q. What kind of personal safety precautions should an applicator
take when applying rotenone?
A. Rotenone in powder form may cause respiratory irritation
if inhaled. A proper respirator mask should be used during mixing of
rotenone powder. Liquid rotenone spray should not be allowed to drift
onto personnel.
Q. What kind of environmental precautions should be taken when
using rotenone?
A. Fish killed by rotenone may not be eaten according to regulations
of the U.S. Food and Drug Administration. Treated water is not harmful
to animals which may drink from the pond if the rotenone is applied
in accordance with instructions on the label. Swine may in some instances
be sensitive to rotenone, and caution should be exercised before allowing
swine to drink from treated ponds. Rotenone may not be applied to flowing
or public waters except by authorized personnel.
Q. Why is lowering the water level when treating with rotenone
recommended and who is responsible for non-target fish kills downstream?
A. Lowering the water level of the pond by draining or pumping
is recommended because it will reduce the volume of water to be treated
and the amount of rotenone that must be purchased. Drain outlets in
the pond must be closed prior to the application rotenone. Any rotenone
that escapes downstream is toxic to fish, and the applicator and/or
pond owner is responsible for any fish mortalities.
Q. When making partial applications of herbicides that can be
toxic to fish at use rates, why should you begin applications near shore
and proceed toward open water?
A. This allows fish to escape to untreated water. All precautions
should be taken to avoid conditions that can lead to potential fish
kills when applying aquatic herbicides.
Q. What is the average time for complete decomposition of 2,4-D?
A. Complete decomposition of 2,4-D usually takes about three
weeks in water and can be as short as one week.
Q. What are the naturally occurring compounds which occur when
endothall is broken down?
A. The by-products of endothall dissipation are carbon dioxide
and water.
Q. What are some advantages of maintenance control of plants
at low levels before they reach a problem level?
A. Detrimental impacts of aquatic weeds on native plant population
are reduced. Detrimental impacts of aquatic weeds on water quality
are reduced. The amount of organic matter deposited on the lake bottom
from natural processes is reduced, as well as a reduction following
control of the plants. Less herbicide is used in the long run.
Q. What is one reason why public education is an important part
of a successful maintenance control program?
A. When conducting a maintenance control program, the public
may not perceive a weed problem and may question the need to spray.
Q. Why is correct identification of aquatic plants so vital
to aquatic herbicide applicators?
A. Correct identification is necessary to select the proper
herbicide for control of a particular weed. Nontarget aquatic plants
are important to identify so that herbicide damage can be minimized.
There are many aquatic plants, which may become problems, that herbicide
activity has not been determined for and knowledge of the taxonomic
relationships between plants can aid in predicting herbicide sensitivity.
Q. In South Carolina, how can positive identification of aquatic
plant species be obtained?
A. Positive identification of aquatic plant species may be obtained
by submitting a sample to the Clemson University Plant Problem Clinic
through local Clemson Cooperative Extension Service county offices
(listed in the telephone directory under Clemson University Extension
Service). There is a Clemson Extension office located in each county
in the state.
Q. Why is it helpful to use the official common name that is
accepted by the Weed Science Society of America or other standardized
listing?
A. Common names can be confusing because several common names
may be used for the same plant and the same common name is sometimes
used incorrectly for unrelated plants.
Q. What is the difference between submersed, emersed, floating
and floating leaf plants?
A. Submersed plants grow completely below the water surface
and depend on surrounding water for support of the plant body. Emersed
plants are rooted in the bottom, extend above the water surface and
are self-supporting. Floating plants are not attached to the bottom
and float on the water surface. Floating leaf plants are attached to
the bottom and have leaves that float on the water surface. These plants
may or may not be self-supporting and can also be emersed.
Q. What are the three separate growth forms of algae?
A. Planktonic algae are single-celled or small colonies of algal
cells that are attached to each other and free-floating or suspended
in the water column. Filamentous algae are multi-cellular algae composed
of cells attached end to end so that they form long threads. Macrophytic
algae are large, multi-cellular, branching algae.
Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer. Clemson University Cooperating with U.S. Department of Agriculture and South Carolina Counties, Extension Service, Clemson, S.C. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914.
Site maintained
by Rachel Rowe | Pesticide
Information Program | Entomology
at Clemson
Clemson University Cooperative
Extension Service | Clemson
University
Last Updated: October 3, 2005
