PEST AND PESTICIDE MANAGEMENTON SOUTHERN FORESTS

USDA Forest ServiceSouthern Region

1720 Peachtree Road, NWAtlanta, GA 30309-2417

The use of trade names in this publication is for readerinformation and does not imply endorsement by the U.S. Department

of Agriculture of any product or service.

The United States Department of Agriculture (USDA) Forest Service is a diverse organization committed to equal opportunityin employment and program delivery. USDA prohibits discrimination on the basis of race, color, national origin, sex, religion,age, disability, political affiliation, and familial status. Persons believing they have been discriminated against should,contactthe Secretary, U.S. Department of Agriculture, Washington, DC 20250, or call 202-720-7327 (voice), or 202-720-1127 (TDD).

Management Bulletin R&MB 60 September 1994

Pesticide Precautionary Statement

Pesticides used improperly can be injurious to man, animals, and plants.Follow the directions and heed all precautions on the labels.

Store pesticides in original containers under lock and key - out of the reachof children and animals - and away from food and feed.

Apply pesticides so that they do not endanger humans, livestock, crops,beneficial insects, fish and wildlife. Do not apply pesticides when there isdanger of drift, when honey bees or other pollinating insects are visitingplants, or in ways that may contaminate water or leave illegal residues.

Avoid prolonged inhalation of pesticide sprays or dusts; wear protective cloth-ing and equipment if specified on the container.

If your hands become contaminated with a pesticide, do not eat or drink untilyou have washed them. In case a pesticide is swallowed or gets in the eyes,follow the first aid treatment given on the label, and get prompt medicalattention. If a pesticide is spilled on your skin or clothing, remove clothingimmediately and wash skin thoroughly.

Do not clean spray equipment or dump excess spray material near ponds,streams, or wells. Because it is difficult to remove all traces of herbicidesfrom equipment, do not use the same equipment for insecticides or fungicidesthat you use for herbicides.

Dispose of empty pesticide containers promptly and in accordance with all appli-cable Federal, State and local laws.

NOTE: Some States have restrictions on the use of certain pesticides. Checkyour State and local regulations. Also, because registrations of pesticides areunder constant review by the U.S. Environmental Protection Agency, consultyour State forestry agency, county agricultural agent or State extension special-ist to be sure the intended use is still registered.

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PREFACE

Federal law requires certification for all commer-cial pesticide applicators. The law also requires pri-vate applicator certification for the purchase or appli-cation of “restricted use” pesticides. The Environ-mental Protection Agency (EPA) has set minimumcompetency standards for certification of pesticideapplicators. These standards include a practicalknowledge of pest identification, pest control, labelcomprehension, pesticide laws, and environmentalconsiderations. The certification of applicators isthe responsibility of each individual State. To becertified as a commercial forestry applicator, mostStates require demonstrated competency in the gen-eral use of pesticides, with a specialization in for-estry pesticides. This manual is a supplement, not asubstitute, to the general-use training material. Thatmaterial covers in detail the necessary informationon pesticide labels, general application, and safety.

This manual is intended to provide the informa-tion necessary to achieve specialized certificationfor forestry pesticide applicators in the South. Addi-tional certification may be required for other typesof application used in or near a forestry site, suchas aerial application and aquatic and right-of-wayweed control. The section on applicator safety hasbeen included for completeness, even though this isthoroughly covered in the general category trainingin most States. The materials provided here applymostly to southern pines, although hardwood cul-ture is addressed. Emphasis is placed on herbicideapplications because most pesticides used in for-estry are herbicides. Pesticide use in forest nurser-ies and seed orchards are not covered in detailbecause of their special situations. Specialists in

nurseries and seed orchards receive special trainingin proper pesticide applications for their needs.

This training manual was prepared by an ad hoccommittee appointed by the Southern Group of StateForesters. The committee members are pesticidespecialists. Forest pesticide training manuals fromeach of the southern States were reviewed and themost pertinent sections were assembled along withadditional information and further edited to pro-duce a draft document. Further review and com-ments by each of the State forestry agencies wasincorporated along with review by the Committeemembers.

This manual contains information useful to for-est pesticide applicators and should be a part oftheir common knowledge if they are to be effectiveand safe in their applications. The Committee rec-ommends that the appropriate agencies in each Statecarefully review this manual and incorporate appro-priate sections in their training and reference mate-rials. The Committee also recommends that testingmaterial for each State be periodically reviewed sothat applicators are tested on current methods andinformation.

The Committee would thank the extension spe-cialists whose works have been incorporated in thisregionwide compilation. Special recognition is owedto Dr. James B. Armstrong, Department of Fisher-ies and Wildlife, Auburn University, for providingthe section on Vertebrate Animal Control. The edit-ing of Christopher D. Kahle, Forest Pest Manage-ment, USDA Forest Service, Atlanta, GA, was cru-cial to the accomplishment of this task.

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Committee Members

James H. Miller - ChairpersonResearch ForesterSouthern Forest Experiment StationAuburn University, AL 36849-5426

Ken L. McNabb, Extension ForesterSchool of ForestryAuburn UniversityAuburn University, AL 36849-5418

Brad Barber, Staff Forester Larry M. Bishop, Staff SpecialistForest Resource Development Dept. Cooperative ForestryTexas Forest Service USDA Forest ServiceCollege Station, TX 77843-2136 Atlanta, GA 30367

Michael L. Thompson, Staff ForesterDepartment of Environment, Health

and Natural ResourcesNorth Carolina Div. of Forest ResourcesRaleigh, NC 27611

John W. Taylor, Jr., IPM SpecialistForest Pest ManagementUSDA Forest ServiceAtlanta, GA 30367

Table of Contents

Page

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Forest Ecosystem and Stand Ecology . . . . . . . . . . . . . . . . . . . . .Forest Types of the South . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Forest Pests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Principles of Forest Pest Management . . . . . . . . . . . . . . . . . . . . . . . . . .Integrated Pest Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pest Management Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Steps to Solving Pest Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Forest Pesticides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pesticide Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Vegetation Control Using Herbicides . . . . . . . . . . . . . . . . . . . . . . . . . . .Weed Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Weed Control Treatments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Herbicide Application Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Application Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ground Applications of Forestry Herbicides . . . . . . . . . . . . . . . . . . . . .Woody Plant Control with Sprayers, Spotguns, and Injectors . . . . . .Woody and Herbaceous Control with Granule Applications . . . . . . .Herbaceous Weed Control in Young Pine Plantations . . . . . . . . . . . .

Chemical Insect and Disease Control . . . . . . . . . . . . . . . . . . . . . . . . . . .Pine Bark Beetles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pine Tip Moth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pine Sawflies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Texas Leaf-cutting Ant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pine Reproduction Weevils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Gypsy Moth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Annosus Root Rot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I . . . . . .

Forest Seed Orchards and Nurseries . . . . . . . . . . . . . . . . . . . . . . . . . . . .Seed Orchards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . .1 1 1

1124

999

1011

1 31 31 82 0

2 32 32 42 42 52 52 52 6

2 72 73 7Forest Nurseries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . &I

Table of Contents (continued)

Vertebrate Animal Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Beaver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Deer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Small Rodents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Other Animal Pests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Record Keeping of Pesticide Treatments . . . . . . . . . . . . . . . . . . . . . . . .

Applicator Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .The Pesticide Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Mixing, Handling, and Applying Pesticides . . . . . . . . . . . . . . . . . . . .Pesticide Disposal, Storage, and Transport . . . . . . . . . . . . . . . . . . . .Spill Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pesticide Toxicity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Protecting the Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Off-site Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Off-site Movement in Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Off-site Movement in Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Other Environmental Considerations . . . . . . . . . . . . . . . . . . . . . . . . .Endangered Species Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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INTRODUCTION

Society benefits greatly from the wise manage-ment of forest lands. The management objectivesfor southern forests vary considerably across theregion, especially among ownerships. Managementpractices used by public agencies are usually aimedat balancing the outputs of wood production, wild-life, recreation, range, water, and mineral resources.Intensive forest management practiced by forestindustry often attempts to optimize the productionof wood products while managing the other re-sources of wildlife and water quality. Private man-agement of woodlots and tree farms provides asource of income, recreation, and pride for manyindividual landowners.

Foresters manage groups of trees that are rela-tively uniform in species composition, size, anddensity called stands. Pests affect nearly every for-est stand. Pests are plants, insects, diseases, oranimals that hinder management objectives, espe-cially regeneration efforts. Pests can increase costsof reforestation while reducing stand growth, prod-uct quality, and management efficiency. Pest out-breaks can mar the beauty of recreational forests,hinder plantings for soil stabilization, and compli-cate research studies.

Modem pesticides offer an effective and safe wayto control many forest pests when used properly.However, it is not always practical or cost effectivefor a manager to use pesticides. Integrated pestmanagement is an approach that carefully considersall management options, including pesticides, whenattempting to minimize losses from pests. It isalways beneficial to minimize pest impacts by wisemanagement strategies that enhance stand vigor andby using pest-resistant growing stock. The effectsof any treatment on the overall health of the standand forest must be carefully considered.

Correct use of forest pesticides requires someknowledge of the forest ecosystem, the biology offorest pests, safe pest-control methods, and legalconstraints. It requires knowledge of the pesticidesand their application requirements. Safety of theapplicator, the public, and the environment must beutmost in our considerations at all times.

The Forest Ecosystemand Stand Ecology

A forest is a complex biological community com-posed of plants, animals, insects, and microorgan-isms. The populations of organisms combine in adynamic way with the environmental factors to forma forest ecosystem. Forest ecosystems are drivenby the energy from sunlight. Only green plants arecapable of capturing solar energy and converting itinto sugars through the process of photosynthesis.All animals, insects, and microorganisms in a for-est ecosystem depend on the energy fixed by plantsfrom the sun.

The forest community and environmental factorsare linked together through natural cycles. The watercycle - from rain, to soil, uptake through plants,and out through surface and ground waters or leaftranspiration - is powered by solar energy. Thewater cycle also drives much of the nutrient cycle.Nutrients are released into the soil when leaves,branches, and tree trunks decay in the upper soilzone, called the decomposition zone. Dissolvednutrients from this zone then cycle back to the plants,and are eventually returned to the soil in leaf andstem fall or washed out of leaves by the rain.

Pesticides can also be washed by rainfall into thedecomposition zone, if they are not first brokendown by sunlight to other less toxic molecules whileon plant leaves. Ultraviolet light can break downpesticide molecules. Like other organic molecules,pesticides are also decomposed by microorganisms,water, and chemical reactions. Some are bound tosoil particles until they decompose. Some more per-sistent pesticides may not fully decompose and maybe carried by water in the soil to streams or possi-bly groundwater, especially when misapplicationoccurs. However, most pesticides are degraded tobasic harmless molecules through natural processes.

Within a forest ecosystem, all organisms com-pete for sunlight, energy, water, nutrients, andspace. The more of these resources that trees cangain, the faster and healthier they can grow. The

structure of a forest ecosystem is arranged accord-ing to how the member organisms receive and usethese resources, mainly sunlight and water.

The natural change or maturing of a forest standover time is known as forest succession. Forestsuccession begins with a major disturbance such asa fire or windstorm or, in managed forests, withharvesting (logging). These events create open areasfor development of pioneer plants. Pioneer plantsare those species that become established early insuccession. Most grasses and forbs, which collec-tively are called herbaceous plants, are good exam-ples of pioneer plants. They require full or nearlyfull sunlight to grow. Usually, they grow fromnumerous seeds already present in the soil or fromseeds that have blown in with the wind. As forestsuccession proceeds, most pioneer plants are slowlyshaded out by the developing forest.

Transitional species, usually comprised of light-demanding conifers such as the southern yellowpines, and hardwood species such as gums andmaple, become established after disturbance. Leftundisturbed: transitional species are slowly replacedby shade-tolerant species that are longer lived. Aclimax forest is one comprised of shade-toleranttrees that can regenerate within their own shade.Forest succession going to a climax forest is rarelycompleted over large acreage of forest land. Man’sintervention or periodic natural disturbances fre-quently short-circuit the successional process andcontinuously “recycle” the forest to stands com-posed of transitional species. The expanses of south-ern pines are examples of the recycling of transi-tional species in the succession of a forest.

Forest managers work with natural succession tooptimize timber production, or create recreationalareas, or enhance wildlife habitat, or some othermanagement objective. Proper pesticide applicationscan remedy certain unhealthy conditions in foreststands and prevent the spread and damage frominsects and disease. However, because of the inter-relationships within a forest community, control-ling one component will influence others. Therefore,the forest manager must consider all the effects of atreatment when planning a control strategy to mini-mize undesirable effects.

Forest Types of the South

The South’s varied climate and site conditionssupport a large number of tree species. There areabout 250 different native tree species. Almost halfare considered commercially important. The sevenmajor forest types in the South are shown in figure 1.They are:

1. OAK-GUM-CYPRESS

2. OAK-PINE

3. OAK-HICKORY

4. LOBLOLLY-SHORTLEAF PINE

5 1 LONGLEAF-SLASH PINE

6. CEDAR

7. WHITE PINE-HEMLOCK

Pines are the most important commercial species.Most forest industries depend on pine, but there is agrowing trend toward increasing use of hardwoods.The four major species of southern pine are loblolly,slash, shortleaf, and longleaf; all are classified assouthern yellow pines. Eastern white pine is a white,soft pine of economic importance that is grown inthe southern mountains as well as in the North.Baldcypress is another important conifer in theSouth, but it is restricted to bottomlands, ponds, orswamp areas of the Coastal Plain.

Oaks are the major commercial hardwood. Mostimportant are white oak, southern red oak, andnorthern red oak. Yellow-poplar, sweetgum, black-gum, and water tupelo are important species usedin furniture and veneer manufacturing. Sycamoreand sweetgum are now being grown in plantationsfor energy wood and pulp. The harvesting of hard-woods for use in manufacturing pulp products israpidly increasing, especially when the hardwoodscan be mixed with pine pulp.

2

Figure 1 .-Major Forest Types

Compiled by Forest Surveu Units of theSouthern and Southeastern Forest Eqwiment Stations.

1

OAK-GUM-CYPRESS: Botmm-land forestsin which 50 percent or more of the stand

wood , willow, ash, e l m , hockbern/, andmaple.

PRODUCTIVE-RESERVED FOREST LAND:Productive p u b l i c forest l a n d w,+hdrawnf r o m timber “tllilation through s+(l+u+e orodminirtrotive regulation.

Forest Pests

In forestry, trees are considered to be the “crop. ”Forest pests, therefore, are things that compete with,injure, or spread disease to crop trees. The majorforest pests fall into four groups: weeds, insects,diseases, and vertebrate animals.

Weeds

Weeds are any plants that interfere with landmanagement objectives. They can compete withcrop trees for limited moisture, nutrients, light, andgrowing space. Survival and growth of crop treescan be increased by effective control of weed com-petition, Other forest values, such as recreation andwildlife habitat, can be enhanced with proper vege-tation management. That is why herbicides are themost commonly used pesticide in forests.

Insects

Forest trees are susceptible to insect attack at allstages of growth and development, from seeds tomature individuals. Although the majority of insectspecies are beneficial to a forest’s health, some areexceedingly harmful.

Outbreaks of insects that damage forests economi-cally vary greatly in frequency, size, and duration.Fortunately, most of these outbreaks are small,short-lived, and usually consist of one or a fewspots in a stand or region. Others, however, mayexpand until they encompass hundreds or thousandsof acres and may last for several years, as in thecase of southern pine beetle outbreaks.

Most insecticide applications in forest manage-ment are primarily used in seed orchards and forest

nurseries. Specialized applications are conductedperiodically to control pine tipmoths, leaf cuttingants, gypsy moths, and southern pine beetles.

Diseases

Forest tree diseases include parasitic micro-organisms, mainly fungi, bacteria, and plant rusts.Most microorganisms in the forest are beneficialand necessary for the functioning and health of thestand or ecosystem. Microorganisms are vital tonutrient cycling - they decompose leaves andbranches, which results in the release of nutrients.Special fungi aid in nutrient uptake by tree roots,while most nitrogen for forest growth is suppliedby bacteria living in the soil.

While most microorganisms are beneficial inforests, many are harmful to trees. Parasitic dis-eases can attack trees in all stages of their life cyclesand cause poor health or even death. While someforest tree diseases attack many tree species, otherstarget a particular species.

At this time, the only plant disease treated bychemical applications in southern forestry is annosusroot rot.

Vertebrate Animals

Many kinds of animals can damage trees in theSouth. Their damage may vary from insignificantto very serious. Animal pests are deer, rabbits,squirrels, beavers, and other rodents. Animal dam-age to tree seedlings usually occurs when naturalfood sources are low and/or animal populations arehigh.

PRINCIPLES OF FOREST PEST MANAGEMENT

Integrated Pest Management

Using a combination of prevention and controlmethods is the best approach to pest problems. Theplanned strategy of combining the best methods iscalled integrated pest management @PM). Pestmanagement should be a part of an overall manage-ment plan for a forest area and the need for pestcontrol can usually be minimized through wise,long-term, forest practices. The control method(s)chosen will depend on the kind and amount of con-trol necessary, balanced with costs and benefitswithin legal, environmental, and other constraints.

The most important principle of pest control is touse a control method only when it will prevent thepest from causing more damage than is reasonableto accept. Even though a pest is present, it may notbe necessary to control it. It could cost more tocontrol the pest than would have been lost becauseof the pest’s presence.

Pest Management Strategies

The three main pest management strategies are:

1. Prevention - Keeping a pest from becoming aproblem.

2. Suppression (Control) - Reducing the pestnumbers or damage to an acceptable level.

3. Eradication - Destroying or removing a pestcompletely from an area or geographic region.

Detection, through pest surveys, is an importantactivity with all three strategies. Often these threestrategies are too costly so a fourth option - to livewith the pest problem - is adopted.

Pest Control Methods

Many pest control methods have been knownand used for years in agriculture, and are becomingmore common in forestry. The most important are:

Legal Control - Legal controls result fromFederal, State, or local laws and regulations. Theyinclude such things as quarantines, inspections,embargoes, and compulsory crop or product de-struction.

Resistant Varieties - Trees grown from seedfrom certain areas or from selected individuals canbe more resistant to certain diseases or be generallyhealthier on specific sites. Healthier seedlings dobetter at overcoming competition from weeds andresist disease, insect, and animal attacks. Forexample, tree breeding for resistance to fusiformrust is currently underway.

Biological Control - Biological control uses thenatural parasites and predators of a pest to controlits numbers. For imported pests, this means thecareful introduction of parasites or predators fromthe home country into the new range of the pest inthis country. Biological control can also be achievedby increasing the numbers of native parasites. Forexample, the control of the spread of gypsy moth isbeing attacked by spraying a bacterium or virus thatspecifically attacks the moth.

Cultural Control - Cultural practices that im-prove crop tree establishment and growth will oftenminimize pest influences. These practices includethe use of only the best quality seeds and seedlings,proper seedling care before and during planting,planting patterns, timing of stand establishment,and fertilization. For example, outbreaks of palesweevil can be avoided by delaying replanting afterharvest.

Mechanical or Physical Control - Mechanicaltreatments, such as chopping and shearing, are usedfor woody weed suppression. Traps are sometimesused for rats and voles.

Sanitation - Sanitation involves removing mate-rials infected or infested by pests and the source offood on which pests feed, such as the fell-and-remove method for controlling the spread of south-em pine beetles.

5

Prescribed Burning - Prescribed burning isoften used to help control undesirable forest speciesand is often used in conjunction with other controlmeasures. Some pine stands are prescribe burnedon a regular basis to help control woody plantcompetition. It is an important part of most chemi-cal site-preparation treatments. This practice reducesharvesting residues and thus improves plantingaccess. In other weed-control efforts such as kudzucontrol treatments, prescribed fire is used to aidapplicator access and to reduce vegetation thatshields spray coverage. Prescribed burning also canhelp reduce brown-spot needle blight in younglongleaf pine stands as well as annosus root rot.

Chemical Control (Pesticides) - Pesticides arechemicals used to control, eradicate, or prevent dam-age by pests. Pesticides are tested and labeled forspecific pests, crops, and for specific land-use areas.

Steps to Solving Pest Problems

To solve pest problems, you should:

1. Correctly identify the pest(s).

2. Know what control methods are available.

3 _ Know and follow local, State, and Federalregulations that apply to the situation.

4. Evaluate the benefits and risks of each methodor combination of methods.

5. Choose the methods that are effective yet willcause the least harm to you and the environment.

6. Correctly apply the treatment method and docu-ment the application and results through properrecord keeping.

Pest control involves using all available methodsto keep pest populations below harmful levels, whilesafeguarding the environment; and to recognizewhen direct action, such as a pesticide application,is necessary.

Forest Pesticides

Pesticides are used to regulate or disrupt plantgrowth; control, attract, or repel insect pests; pre-vent and control disease infections; and control,attract, and repel vertebrate animal pests. In south-em forestry, herbicides are the most commonly-used pesticide. Insecticides are seldom used in gen-eral forest management because of high treatmentcosts and because some pest insects are highlymobile. The only disease-control treatment is em-ployed for annosus root rot. Borax, applied to treestumps, keeps the disease from getting establishedand spreading to the roots of nearby trees. Verte-brate animal control is often through trapping orhunting but may employ repellants and poison baits.

Forest Pesticide Registration

All pesticides used in the United States must beregistered by the U.S. Environmental ProtectionAgency (EPA) as specified in the Federal Insecti-cide, Fungicide, and Rodenticide Act (FIFRA)and its amendments. Registration is either condi-tional or unconditional, based on data requirementsset forth in FIFRA. Before a pesticide can be usedoperationally, data on the proposed uses must beevaluated by EPA. To develop a pesticide productand prepare it for registration under FIFRA, yearsof extensive scientific testing must be performed onthe product’s chemical properties, human and envi-ronmental safety, and efficacy (effectiveness). Forforestry products, this may include testing underfield conditions using commercial applicationequipment.

For wider testing of unregistered pesticides, EPAcan issue an Experimental Use Permit (EUP),which establishes the limited conditions when anunregistered pesticide may be transported, applied,and disposed. Products subject to an EUP may onlybe sold or distributed to participants in the test pro-gram and only according to conditions described inthe EUP.

Pesticides are registered by EPA as either gen-eral use or restricted use. A general-use pesticideis one that will not cause adverse effects to theenvironment when used for commonly recognized

6

practices in accordance with its label. Such pesti-cides are usually available to the public. Restricted-use pesticides require special procedures and train-ing for applicators to prevent human exposure andenvironmental damage. EPA limits the purchaseand use of restricted-use pesticides to certifiedapplicators. Some products may be used only bycertain categories of certified applicators. The labelwill state clearly who may use the product. Statescan also place general-use pesticides into the re-stricted-use category.

Another type of registration is commonly calledthe Special Local Need (SLN) registration. UnderSection 24(c) of FIFRA, a State may register anyFederally-registered pesticide for a pest not listedon the Federal label, provided that (1) registrationfor such use has not previously been denied or can-celed by EPA, and (2) a food tolerance (safe levelsin food), if required, has been established for theproposed use. A “special local need” exists whena State has an imminent pest problem for which anappropriate Federally-registered product is not suffi-ciently available. The State registration for theseuses is deemed a Federal registration for purposesof FIFRA, but distribution and application of theproduct for these uses are confined to that Stateonly.

There is a provision in FIFRA for providing assis-tance when unexpected pest problems arise. Sec-tion 18 of FIFRA permits EPA to exempt Federalor State agencies from FIFRA requirements whenemergency conditions exist. This provision permitsFederal and State agencies to respond quickly toemergency pest conditions in their jurisdictions withthe use of pesticides not registered for the particularsite and pest.

Classes of Pesticides

Pesticides can be grouped according to theirchemical composition. The groups are:

l Inorganic Pesticides - These are made fromminerals. Minerals used most often are boron,copper, sulfur, tin and zinc. Example: boratefor prevention of annosus root rot infestations.

l Synthetic Organic Pesticides - These aresynthesized pesticides that contain carbon, hy-drogen, and other elements such as chlorine,phosphorus, and nitrogen. Most herbicides andinsecticides in use are synthetic organic pesti-tides.

l Plant-derived Organic Pesticides - These aremade from plants or plant parts. Examples: py-rethrins from chrysanthemums for insect controlin forest nurseries.

l Living Microorganisms - These are viruses,bacteria, and fungi produced by culture. Exam-ples: the bacterium, Bacillus thuringiensis (B. t.),and a virus, whose commercial formulation isregistered as Gypchek, are being aerially appliedas controls for the gypsy moth.

Pesticide Resistance

The ability of pests to resist poisoning is calledpesticide resistance. The possibility of resistancemust be considered when planning pest control pro-grams that rely on the use of pesticides, especiallylarge insect control programs. Rarely does any pes-ticide kill all target pests. Each time a pesticide isused, it selectively kills the most sensitive indi-viduals. Some avoid the pesticide, while others with-stand its effects. Pests that are not destroyed thatare resistant to the pesticide may pass the trait thatallowed them to survive to their offspring. At pres-ent, pesticide resistance is not an apparent problemin forestry applications, however, it may becomeone in the future.

VEGETATION CONTROL USING HERBICIDES

Weed Categories

Forest vegetation management is a term nowbeing used to describe the planned approach to con-trolling weeds as part of a forest management plan.Weed species, or unwanted vegetation, can beclassed as weed trees, brush, vines, and herbaceousweeds.

Weed Trees

Weed trees are hardwoods and conifers that inter-fere with management objectives or have otherunwanted qualities. They include deformed, defec-tive, or undersized individuals and trees of undesir-able species.

Brush

This is a term for unwanted woody growth thatincludes shrubs and small trees. Brush prevents lightfrom reaching crop tree seedlings and deprives seed-lings and even taller commercial species of waterand nutrients. Brush may interfere with commer-cial plantings and can create a habitat for rodentsthat may damage tree seedlings.

Vines

Vines are plants with climbing or creeping stems,including greenbriar, Japanese honeysuckle, wildgrapes, and kudzu. All of these grow very well onmany forest sites. They over-top trees, drag downbranches and crowns, and compete for light andnutrients. Vines have vigorous sprouting habits andare some of the most difficult weeds to control.

Herbaceous Weeds

Herbaceous weeds are grasses and broadleaf forbsthat retard seedling growth in new plantations andnatural stands, mainly through competition formoisture. Seedlings may develop poorly or die,especially during drought conditions. Herbaceousweeds may also create favorable cover for tree-

damaging animals. They also increase the potentialfor loss of a new plantation by wildfire. Herba-ceous weed control is critical in forest nurseries,seed orchards, and Christmas tree plantings. Herba-ceous weeds can be grouped according to how longthey live - annual (1 year), biennial (2 years), andperennial (for more than 2 years).

Weed Control Treatments

Nearly all vegetation control in forests has beencarried out in intensively managed pine forests andalong forest rights-of-way. Under development andshowing promise are single stem control methodsas well. Herbicides can be used in forest manage-ment for a number of specific purposes.

Site Preparation

When preparing to plant seedlings, it is oftennecessary to reduce competing vegetation, reducedebris, and form beds in poorly drained areas.Mechanical methods for weed control, such as shear-ing and root raking, are expensive and often dam-age the site by displacing valuable topsoil and leav-ing the site vulnerable to erosion. By using herbi-cides for site preparation, applications are made inthe growing season before planting for competitioncontrol, commonly followed by a prescribed burnfor debris reduction to increase planter access. Her-bicides may be applied using either aerial or groundapplication systems.

Herbaceous Weed Control

Research studies show that growth and some-times survival of young pines and hardwoods canbe increased by controlling herbaceous weeds, usu-ally in the first growing season following planting.In addition, risk of fire can be decreased by aneffective weed control program. Care must be exer-cised when controlling herbaceous weeds becausetree seedlings can be damaged if label directionsare not followed carefully. Soil erosion may alsooccur on susceptible soils with excessive control.

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Crop Tree Release

When unwanted woody competition is not ade-quately controlled before planting, severe regrowthcan overtop young pines or desirable hardwoodsresulting in low crop tree survival or slowed growth.Selective herbicides or selective applications areused as release treatments to reduce brush (and her-baceous competition) without causing significantdamage to crop trees. Directed sprays, basal sprays,soil spots, and injection treatments can also be usedto control target woody stems while missing thecrop.

Timber Stand Improvement (TSI)

In maturing stands, it is often profitable to elimi-nate low-value or cull trees that are competing withmore valuable trees. Single-stem control methodsmay be used with injectors, spotguns, and sprays tothe basal bark and cut stumps. TSI treatments withherbicides can also be used to prepare for regenera-tion of both pines and hardwoods in uneven-agedmanagement. These methods can also be used toimprove wildlife habitat by releasing mast and berry-producing trees and shrubs, as well as, creatingopenings that provide edge habitat.

Herbicide Application Terms

Special terms describe how and when to applyherbicides for use in forestry. They appear on labelsand in leaflets and bulletins. Understanding theseterms is very important to proper application.

Application Types

Terms that describe how to apply a pesticideinclude:

Broadcast - Uniform application to an entirearea.

Band - Application to a strip or band over oralong each tree row.

Basal - Application to the lower portion of stemsor trunks.

Cut surface - Application to a cut or incisionin a tree or to a stump.

Directed - Aiming the herbicide at a specificportion of a plant.

Foliar treatment - Application to the leaves ofplants.

Over-the-top - Application over the top of thecrop trees.

Soil application - Application to the soil ratherthan to vegetation.

Soil incorporation - Application to the soil fol-lowed by tillage to mix the herbicide with the soil.

Spot treatment - Application to a small areaon the soil surface.

Stump treatment - Application to the top oredges of a tree stump.

Stem injection - Application into incisionsaround a tree stem.

Application rate - The application rate is thespecific amount of herbicide applied to a treatedacre or target stem.

Application Timing

Herbicides work best if applied when the targetplants are most susceptible or the crop trees aremost resistant to injury. Applying them too early ortoo late reduces or even eliminates their effective-ness and may damage the crop. Terms that describewhen to apply herbicides include:

Preplant - Applied before the crop trees areplanted.

Preemergent - Applied before seedlings orweeds begin to grow (emerge) in the spring. Inforestry, this term most often means applying theherbicide after the trees are planted, but before theweeds begin to grow, usually March to April.

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Postemergent - Used after the crop trees orweeds begin to grow (emerged).

Apply herbicides on woody plants only after allwoody plants have fully resprouted after harvesting,burning, or mechanical treatments.

Application Methods

Herbicides are introduced into unwanted vegeta-tion in several ways. They may enter through thefoliage, stem, or roots. Some can enter plants bymore than one pathway. The application methodfor a herbicide is usually specified on the label.However, unless the label specifies that it is illegalto use a certain application method, any safe methodmay be used. The best method will depend on thesituation, available equipment, and cost. Forestryherbicides are applied by aerial and ground methods.Ground methods will be covered in detail in thenext section. Most States require a separate trainingand testing for aerial certification and so it Will onlybe discussed briefly here. Contact your State for-estry agency for more specific information.

Aerial Application

Aerial application of herbicides is common inforestry because tract size is often large, access isdifficult, and the target vegetation is tall and dense.Large acreage can be treated in less time and oftenmore economically by air. Both liquid and dry for-mulations are aerially applied. Specially designedaerial spray equipment has been developed for her-bicides that minimizes drift and achieves effectivecoverage. Droplet size of aerially-applied liquid her-bicides is larger than that used for insecticides,although the effectiveness of foliar-absorbed herbi-cides may be reduced when large droplets are used.

Granular and pellet formulations of soil-activematerials are also applied aerially. Although lesssubject to drift and weather conditions, uniformdistribution can be difficult with these materials.Ground application methods can often supplementand complement aerial application where more strictcontrol is required.

Mechanical Ground Application

Ground application by machine-mounted sprayersand spreaders offers several advantages comparedto aerial methods. Machines can treat small areasor large ones, provide banded or broadcast applica-tions, and are less limited by weather conditions.They are less visible than aircraft, so they are lessapt to arouse undue public concern. However, dueto terrain and stand conditions, ground machineapplications have definite limitations and are slower.

Crawlers, skidders, 4-wheel drive farm tractors,and ATV’s (all-terrain-vehicles) can be used forherbicide application. The machine used dependson the job to be done, site conditions, and equip-ment availability. The application equipmentmounted on the machine must also be suitablefor the selected herbicide and stand conditions.Broadcast-type sprayers must be able to cover asizable area efficiently and uniformly while beingvery durable. For broadcast applications, boomlesscluster-nozzles and off-center nozzles can bemounted up to 15 ft above the ground to reach tallbrush and can cover a swath of 40 to 50 ft. The useof boomless nozzles has some limits. For example,tall brush may mask a major portion of the spraypattern. Also, the pattern of boomless nozzles isnot uniform across the swath. Spray coverage ofplants should be nearly complete, not just one-sided,for effective control. Various “manifold” typesprayers have also been designed for ground equip-ment as well as electrically-driven control dropletapplication (CDA) systems.

An alternative to broadcast foliar application isto broadcast soil-active, dry herbicides. These aregranules or pellets that can be applied before fullleaf growth masks the distribution. A specializedblower system can distribute these materials in aswath up to 80 ft wide. Fertilizer spreaders can beused to treat short vegetation.

Herbaceous weeds are often controlled in bandswith farm tractors or ATV’s using spray booms.One to three rows of seedlings can be sprayed perpass. The up-and-down sway of the booms shouldbe minimized when treating two or more rowsbecause the rate can change greatly as the boomends change height.

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Control systems are available for both sprayers Manual Ground Applicationand spreaders to ensure that herbicides are applied

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at a consistent rate under varying ground speeds. Manual applications are herbicide treatments thatMaintaining the prescribed rate is critical for over- can be applied using backpack sprayers, spotguns,the-top release applications. With or without con- and injection devices. Manual methods are used totrol systems, calibration of machine application treat woody stems individually, apply granular her-equipment is necessary on a regular basis to assure bicides for woody and herbaceous control, and toaccuracy of rate. Regular replacement of spray tips spray for herbaceous control in bands or spots.is also required for applying accurate and uniformrates.

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GROUND APPLICATIONS OF FORESTRY HERBICIDES

Forestry applicators must be consistent to beeffective, and those who work for a commercialapplicator must be fast to be profitable. Consis-tency means mixing the correct herbicide accuratelytime after time. It means using well-maintainedequipment with a steady effort.

Woody Plant Control with Sprayers,Spotguns, and Injectors

The commonly applied manual treatments forwoody plant control are: (1) directed foliar sprays,(2) basal sprays, (3) soil spots, (4) tree injection,and (5) stump sprays. All sizes of trees and shrubscan be controlled by using the right treatment whenthe proper herbicide is applied at the correct time.Here are the sizes of woody plants that can betreated most effectively by hand methods:

MethodEffective size of

target stemscontrolled

Directed foliar sprays up to 6 ft tall

Full basal sprays up to 6 inches d.b.h.*

Streamline basal sprays up to 2 inches d.b.h.

Soil spots by grid up to 10 inches d.b.h.

Basal soil spots all sizes

Stump sprays all sizes

Injection sizes greater than1 inch d.b.h.

*d.b.h. is diameter at breast height , which is the stem diame-ter measured at 4.5 ft above the ground.

Directed Foliar Sprays

Directed foliar sprays are best used to release l-and 2-year-old pine stands when brush competition

is less than 6 ft tall. Caution must be taken to directthe spray away from pine foliage and growing tips.The benefits of release can be lost when herbicidesare misapplied to needles and shoots and too muchpine is damaged.

Equipment - Directed foliar sprays are usuallyapplied with a backpack sprayer and a spray wandequipped with a full cone, flat fan, or adjustablecone spray tip. Selection of a spray tip depends onthe applicator’s preference. Spray guns with nar-row flat-fan tips are also used by some applicators.

Mixing - Accurate and thorough mixing isneeded to assure consistent control. A wetting agentor penetrant can be added to the mixture to increasecontrol of all herbicides, and is a label requirementfor some herbicides. During windy conditions, adrift control additive can reduce drift that damagespines. Adding water-soluble dyes can help trainnew applicators and also guide experienced appli-caters .

Application Method - Apply the spray on thetarget foliage and be sure to cover the growing tips,but be careful to keep it off terminal shoots andleaves of crop trees.

Basal Sprays

Full Basal - Full basal treatments require thatthe lower 12 to 20 inches of target hardwood stemsbe completely wetted on all sides with the spraymixture. See figure 2. A backpack sprayer is usedwith a wand or spray gun fitted with a narrow-angleflat fan, cone, or adjustable tip. Herbicides are usedthat are soluble in oil and mixed at percentagesspecified on labeled products, usually less than 10percent. Some are sold ready to use.

Streamline Basal - Streamline basal treatmentscan control many woody plants including hardwoodsup to 2 inches d.b.h. Trees of susceptible speciesup to 6 inches in diameter can be controlled. Treat-ment of small hardwoods less than 2 inches d.b.h.results in the most control.

To apply this treatment, a backpack sprayer isused with a spray gun and a low-flow (0.1-0.2gallon per minute [gal/min]) straight-stream spray

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tip. Also, a narrow-angle tip can be used, such as15” and 0.1 gal/min. For controlling herbicide out-put to prevent waste, a pressure regulator is neededto maintain pressure below 30 pounds per squareinch (lb/in2). At these pressures, an effective reachof 9 ft is possible while bark splash is minimized.Sprayers with diaphragm pumps will maintain about30 lb/in2 with slow, steady pumping.

The most commonly used mixture for streamlineapplication includes the herbicide (3 to 20 percent),a penetrant, and a carrier such as diesel fuel ormineral oil. This mixture is clear when made cor-rectly, but a white cloudy liquid or jell will form ifeven a small amount of water is present. No amountof water should be in the sprayer or mixing con-tainer. Make sure that all water has been drainedfrom the sprayer, the pump has been pumped dry,and the sprayer has been rinsed and pumped withdiesel or mineral oil before filling with the mixture.

For treating stems that are less than 2 inchesd.b.h., apply the stream of spray up-and-down sin-gle stems for about 6 to 8 inches, or spray acrossmultiple stems creating a 2- to 3-inch-wide band.Direct the spray stream at a point about 6 to 24inches from the ground, to smooth juvenile bark.Stems that are beyond the juvenile stage, thickbarked, or near 3 inches in diameter require treat-

ment on both sides, unless they are susceptiblespecies. Back-and-forth bands can also be sprayedon larger stems.

Applications are usually made in late winter andearly spring when leaves do not hinder spraying thestem. The best application time will depend on theherbicide, species, and location. Applications shouldb e avoided in young pine plantations on hot days ifan ester formulation is used because pine injurymay occur from vapor drift.

Soil Spot Applications

Spots of soil-active herbicide are applied to thesoil surface in grid patterns or around target stemsfor site preparation and pine release. See figure 3.

In this method, exact amounts of herbicide, speci-fied in milliliters (mL), are applied to the soil sur-face at prescribed spacings. Thus the effectivenessof the treatment depends on the applicator’s accu-racy and consistency in amount applied and spacing.

The rate for soil spot application is determinedo n the basis of whether the treatment is for sitepreparation or release, the texture of the soil, andthe susceptibility of the target species. Because ofpossible pine damage, less herbicide is used forrelease treatments. Less herbicide is also used on

Full Basal Streamline Basal

Figure 2.- Full basal method and streamline method of basal spray treatments for woody plant Control.

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Basal Spots Grid Pattern

0

0

0

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0

0

0

l

l

9l

e

0

e

0

l

l

l

- g’-0 l

l &33l l

l l

0 0

l e

l e

l

9

0

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Figure 3.- Soil spot applications using basal spots and grid pattern.

sandy soils and more on clay soils. Seedling pinescan be severely damaged or killed, especially whenspots are placed too near.

Equipment - Spots are applied to the soil byusing a spotgun or a spray gun equipped with astraight-stream spray tip. The spotgun delivers a setamount while the spray-gun method requires train-ing to judge the amount applied. Both can be con-nected to a backpack sprayer to carry the herbicide,and the spotgun can also be connected to a backpackor side-pack container. A spotgun consists of anadjustable graduated cylinder or syringe that is oper-ated by squeezing the handle. A forceful squeezecan project spots up to 1.5 ft. A spray gun usespressure from the backpack sprayer to project spotsto over 20 ft, thus requiring less exertion.

Spotguns are available in metal and plasticmodels. The more durable metal spotgun is for long-term use, while the plastic guns last for one area orone season. Water should be pumped through thespotgun after use, followed by a light oil for lubri-cation.

Calibration of spotgun - Spotguns are exact-delivery devices and thus either water or herbicidecan be used for calibration. By turning the adjust-ment screw, set the piston of the syringe on theprescribed amount, for example, 2 mL. These gradu-

ations are not exact and must be checked. To dothis, squeeze the handle 10 times and collect thesolution in a container without splashing. Measurethe amount using a container graduated in milliliters.For a 2-mL setting, it should deliver 20 mL after 10squirts. If the total is more or less than the amountexpected, adjust accordingly and repeat the proce-dure until the exact calibration is achieved. Anysmall error becomes large when thousands of spotsare applied per acre and can result in wasted herbi-cide and poor control or pine damage. Calibrationshould be checked at least twice a day.

Spray gun for soil spot application - Withpractice, an applicator can use a spray gun equippedwith a straight stream tip to apply l- to 3-mL spots.The volume is determined by how long the handleis held in the pulled position and the size of thespray tip and pressure. A 0. l-gal/min (gallons perminute) straight-stream tip is best for applying spotsof about 1 mL; a 0.2-gal/min tip for spots of about2 mL; and a 0.3-gal/min tip for spots of about 3mL. Although the spray gun is not an exact deliv-ery device, accurate dosages can be applied withpractice and calibration.

Calibration of a spray gun and straight-streamtip - The backpack sprayer is pumped to the pres-sure that will be maintained during application, 20

1 5

to 30 lb/in2. An appropriate tip is installed thatmatches the prescribed spot volume. For spots ofuneven volume that are specified on the herbicidelabel, a tip should be selected that is closest to theprescribed volume. For example, a 0.2 gal/min tipcan be used to apply a 2.3 mL spot and so on. Thespray gun handle is pulled a few times while theclicking sound is noted, which helps to judge therate of opening and closing of the handle. Using acontainer that prevents splashing, the volume from10 pulls of the handle is collected. This volume ismeasured accurately using a container graduated inmilliliters. The volume should be 10 times thedesired volume per spot. For example, 10 pullsfrom a 0.2-gal/min tip, with a consistent rhythm ofclicks, should give 20 mL. It takes practice to con-sistently apply the correct volume. Calibrationshould be checked at least twice a day.

Application Method - Spots are applied to thesurface soil in grid patterns for treating areas orimmediately around selected target stems.

Spot Grid Applications - Prescriptions for spotapplications are usually specified by the volumeper spot and the spacing between spots. If the pre-scription is given only in quarts per acre, then thevolume per spot can be selected and the spacingcalculated. For example, if the prescription speci-fies 6 quarts per acre and 2 mL spots are chosen,the number of spots per acre can be calculated by:

Number of Spots/acre = Qtiacre ’ 946 ml’qtNumber of ml/spot

= 6 X 946___ = 2,838 spots/acre2

Then to calculate the spacing between spots, thearea per spot must be determined:

Area/spot = 43,560 ft2/acre2,838 spots/acre

= ,15.3 ft2, or 15 ft2

If the area around each spot is 15 ft2, then a 3 ft by5 ft spacing would work. Natural walking stridestend to match spacings of 3, 4, 5 and 6 ft, butstrides must be determined before beginning appli-cation.

Generally, a close-grid pattern is used when thehardwood competition is small and a wider pattern

is used when hardwoods are larger. Thus, closepatterns are more commonly used for pine releaseand the wider spacing for site preparation. Forexample, to control mainly 6 to 8 inch d.b.h. trees,a wide grid is preferred, such as a 6 X 6 ft, 5 X 6 ftor 4 X 6 ft. To control thousands of small stems peracre, the most common pattern is 3 X 3 ft.

Single Stem Application - Apply 2 to 4 mL ofundiluted herbicide for each 1 inch of d.b. h. Thehigher rate is needed for most situations other thansandy soils. Apply the spots on the soil within 3 ftof the root collar of the unwanted tree. When morethan one spot is required per stem, the herbicidemust be evenly spaced around the stem. All smallstems of susceptible species that have roots in thetreated area also will be killed.

Tree Injection

Tree injection is the least costly method for kill-ing hardwoods that are greater than 1 inch d.b.h.This method can be used alone or in combinationwith other individual stem treatments for site prep-aration, pine and hardwood release, timber standimprovement, stand conversion, and creating cav-ity trees for nesting. This physically-demandingmethod requires workers who can repeatedly andprecisely chop into tree trunks deep enough to prop-erly deliver herbicide for uptake in the sap flow.Frequent sharpening and maintenance of injectiontools is needed for best results.

Equipment - Common methods of tree injec-tion use tubular tree injectors, hypo-hatchets, andthe hack-and-squirt method. See figure 4. Tubulartree injectors consist of a long metal tube fittedwith a chisel-type blade that is used to cut throughthe tree bark into the sapwood near the base of thetree. The unit is equipped with a lever, handle, orwire, which is pulled to deliver the herbicide (usually1 mL) from the cylinder into the cut. The deliveryrate can be adjusted for accurate calibration. Tocalibrate: fill and prime the injector; pull the handleor wire 10 times while collecting the herbicide in acontainer graduated in milliliters; if this is not 10times the desired rate, adjust the lock-nut and repeatthe procedure until accurate calibration is achieved.Frequent washings with water, including the pump-ing of water through the device, are the primary

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Figure 4.-Tree injection using (A) tubular injector,(B) hypo-hatchet, and (C) the hack-and-squirt method.

maintenance procedure. Commercial applicatorswill want to carry spares for all rubber gaskets.

The hypo-hatchet consists of a hatchet with aninternal herbicide delivery system that is connectedby a hose to a herbicide container carried on thebelt. When the hatchet strikes a tree, the blade mustpenetrate into the sapwood and the impact drives apiston forward that delivers 1 mL of herbicide intothe cut. The rate cannot be adjusted. Daily cleaningand lubrication of the impact piston is requiredmaintenance, along with periodic replacement ofrubber O-rings and seals. Safety glasses shouldalways be worn when using the hypo-hatchet be-cause of frequent herbicide splashes. CAUTION:All hoses and fittings should be checked daily forleaks and appropriate repairs made to prevent appli-cator exposure.

Hack-and-squirt is a method that uses a narrow-bit ax, hatchet, or machete along with a spray orsqueeze bottle or oiler can. The hatchet, ax, andmachete are used to cut into the sapwood, and theherbicide is squirted into the cut. A grinder can beused to narrow the bit of axes and hatchets foreasier and better cuts. Most commercial spray bot-tles are set to deliver 1 mL with each trigger pull,but each one must be checked prior to use. Safetyglasses should also be worn when using this method.

Waist-high injections by the hypo-hatchet andhack-and-squirt methods are just as effective andfast to perform as basal injections. With largerstems, more herbicide is applied by basal injectionsbecause of the larger groundline diameter comparedto diameter at breast height.

Application Methods - The injection tool isused to cut into the sapwood around target trees atedge-to-edge spacings that are specified on the label.The sapwood must be penetrated, which is difficulton thick-bark species. Each cut must form a pocketin which the herbicide is placed for uptake. Usually1 mL of herbicide is applied to each cut. The herbi-cide should stay in the pocket and not seep outthrough any split sides, because any herbicide onthe bark is wasted. When treating sprouting clumps,each stem must be injected.

Stump Spraying

Stump resprouting of many species can be pre-vented by herbicide treatment. This can be an effec-

1 7

tive, low-cost treatment following harvest for sitepreparation and after partial cuts for timber standimprovement. Hand clearing treatments using sawsor axes for pine release can be enhanced by treatingthe stumps with herbicide to prevent regrowth.

Equipment - A backpack sprayer is used thathas a wand or spray gun equipped with a straightstream, fan, or hollow-cone nozzle. A sawyer cancarry herbicide in a utility spray bottle for treatingstumps after cutting. For small-diameter stumps, awick applicator can be used.

Application - Freshly cut stumps should betreated as soon as possible after cutting. For stumpsover 3 inches in diameter, the outer edge, or cam-bial area, must be completely wetted with the herb-icide. Smaller stumps are usually completely wetted.To be successful, all small stumps should be treated.Thus it is best that the sawyer or companion applica-tor treat soon after felling so no stumps are skipped.

Older, cut stumps can be treated with the stream-line mixture. The mixture is applied to the outer 1inch edge of the stump until runoff and to the baseof any sprouts.

Timing - Cutting and herbicide treatments canbe performed during late winter and summer. Win-ter treatments are slightly less effective than growing-season treatments. Stump treatments within 4 hoursof cutting have been shown effective - the soonerthe better.

Woody and Herbaceous Controlwith Granule Applications

Hand-cranked broadcast spreaders can be used todistribute granular or pelletized herbicides on smalltracts and areas with steep slopes or rough terrain.They can be used where machine spreaders are notsuitable. Advantages of hand-operated spreaders arethat they are small, simple, inexpensive, and gener-ally reliable hand tools. Unfortunately, uniformapplication is often difficult to obtain and treatmentis slow and laborious.

Equipment

Granules and pellets are applied by hand-crankedspreaders, air-blown backpack spreaders, and hand-broadcast. Following are some basic facts abouteach:

Hand-cranked Broadcast Spreaders

l Spread an adjustable swath from 6 to 30ft wide.

l Production rates up to 2 acres/hour.

l Weighs 4 lb unloaded and can carry 20lb of herbicide.

l Models include sack-type, plastic bag, or metaland plastic hoppers.

l Spread is low and often blocked by treesand weeds.

Backpack Mist Blowers Modified to beSpreaders

l Increased individual productivity over hand-cranked spreaders.

l Treats a 30-ft-wide swath with fairly uniformdistribution.

l Production rates up to 2.5 acres/hour.

l Weighs 20 to 25 lb and can carry 30 lb ofpellets.

l High projection is possible for broadcastgranules.

Hand-broadcast and Grid Applications

l Useful for very small areas and for directedor spot applications.

o Production rates up to 1 acre/hour.

l Backhand motions give a more even distribu-tion than forehand applications.

l Large pellets are effectively applied in a gridpattern.

l Less productive than the other two methods.

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l High projection is possible for broadcastgranules.

The choice of method and equipment depends onthe amount of land an applicator intends to treat,the terrain and stand conditions, and the anticipatedeffectiveness of each method. Of these threemethods, hand-cranked broadcast spreaders presentthe best combination of cost and efficiency to mostapplicators and will be the focus here.

Hand Broadcast Spreaders

In general, hand-cranked spreaders are simple tooperate and easy to maintain. In the spreadingoperation, pellets and granules fall by gravitythrough an adjustable gate opening onto a hand-cranked spinning disc that throws the material 20 to30 ft. Much of the mechanisms are the same onmany models, but several types of hoppers are avail-able and each have certain advantages. See figure 5.Sack-type hoppers with zippers do not spill whenaccidentally tipped over on the ground or if theapplicator falls. However, sack-type spreaders re-quire two people for loading because the sides tendto collapse. Metal or plastic hoppers are the easiestto load, but spills can occur when the applicatortrips or falls. Concentrated spills should be avoided.This can be done by using spreaders with a closedhopper. Also with any open hoppers, the applicatoris exposed to fine dust particles.

Calibration - A calibrated spreader is neededto apply accurate rates. Calibrate the spreader byusing the specific herbicide to be applied or byusing blank granules and pellets when possible.Calibration will require accurate weight measure-ments in the field using a small spring balance. Thecalibration procedure is:

1. Adjust the gate opening (to a medium setting)so that the herbicide granules pass freely fromthe hopper onto the spinner disc.

2. Measure the width of the broadcast swath infeet. This can be done on a road or in a parkinglot if blanks are used. Someone marks the out-side edges of the swath while the operator cranksthe spreader and moves forward.

3. Put a known quantity of the granular herbicidein the hopper (usually no more than 1 lb); makesure the herbicide is not clumped. Blank prod-uct (pellets and granules without herbicide) canbe acquired from the manufacturer for this pur-pose.

4. Keeping a steady pace and constant crankingmotion, apply the known amount of product inthe treatment area. Walking speed must be thesame as the actual application. Measure the for-ward distance in feet that are required to applythe known amount.

5. Calculate the pounds applied per acre.

Rate = 43,560 ft2/acre X lbs of test productswath width (ft) X distance traveled (ft)

For example, the test swath was 16 ft wide and thetravel distance was 175 ft. One pound of productwas applied while turning the crank at a constantrate. To determine the application rate:

Rate = 43,560 ft*/acre X 1 lb =16 ft X 175 ft

15.6 lb/acre

6. Adjust the gate opening if the prescribed rate isnot achieved, and repeat the above procedureuntil the desired rate is set.

Application - Spring applications are recom-mended, when rainfall is usually sufficient to acti-vate the herbicide and vegetation is actively grow-ing. Applicators should become familiar with thesite, its access and problem areas before makingthe application. Aerial photographs and topographicmaps are particularly helpful for identifying sensi-tive areas such as streams and steep slopes. Theycan also help plan the locations for application tran-sects and access to flagging stations.

Establish transects or treatment swaths so thatthey are equally spaced and parallel to each other.This is necessary to achieve uniform herbicidecoverage. Flaggers are positioned at the ends ofeach transect to guide the applicator, who is busykeeping a proper pace and cranking speed. Tran-sects can also be flagged before application, alter-nating the colors of flagging by transects.

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.Figure 5.- (A) sack-type and (B) plastic hopper model of hand-cranked spreaders.

Herbaceous Weed Control in To apply banded treatments, the boom or sprayYoung Pine Plantations wand is fitted with a wide-angle flat-fan tip, such

as 80” or llo”, with flow rates of about 0.2 to 0.3

Research has shown that herbaceous weeds are gal/min. A special flat fan tip that is “even” will

often much stronger competitors to pine seedlings increase control on the band edges, compared to a

than are hardwoods. Herbaceous weed control can regular flat fan that applies less herbicide on the

be accomplished using broadcast, band, or spot edges. Also, flood tips, due to their wide angles,

applications. Band applications are possible only are commonly used for banded applications.

when planting rows are well defined. Banded or Pressure regulation and a constant nozzle height

spot applications cost considerably less than broad- are needed to maintain uniform application rates.

cast treatments and only small losses in growth and Use a pressure of 5 to 15 lb/in* to give large drop-

survival have been observed with banded or spot lets with reduced drift. The low flow rates from

treatments relative to broadcast applications. low pressure operation also permit more acreage tobe covered per fill-up, adding to the efficiency of

Banded Applications the operation. Special “extended-range” or “low-pressure” tips are designed especially for low-

Banded treatments are applied using backpack, pressure applications. A pressure regulator is neces-ATV, or tractor sprayers. Backpack sprayers treat sat-y to maintain low pressures with backpack sprayers.one row at a time while machine sprayers can treat Some sprayers can be set at the desired pressuretwo or more rows using a boom with spaced nozzles. while others rely on the installation of regulators inBands usually range from 3- to 6-ft wide. line or on the wand.

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Many types of sprayers can be modified to applybanded herbaceous weed control treatments in pine

plantations. One increasingly common machine isa four-wheel ATV equipped with a sprayer. ATVsprayers can be equipped with sprayer control sys-tems with ground-speed sensing. The sprayer con-trol system maintains a constant application rateover a wide range of operating speeds. Protectiveclothing and equipment like that used in motor-cross racing should be worn when operating anATV sprayer in forestry conditions.

Calibration for Band Applications

Backpack Sprayers - The purpose of calibra-tion is to determine the amount of solution that isapplied per acre within the band. By knowing theamount of water sprayed per acre within the band,the rate of herbicide prescribed per acre can beadded to that volume. Following is a calibration forbackpack banded treatment:

1. Install the appropriate spray tip.

2. Fill the spray unit half-full with water and pumpup the spray unit. Maintain the spray unit atconstant pressure during calibration and appli-cation.

3. Hold the wand at a height that produces thedesired band width.

4. Use the following table to determine the calibra-tion distance required for the desired spray width.

Spray band Calibrationwidth distance

___---- ______ -j&t-------- ______

3 113

4 85

5 68

5. Measure the calibration distance on the groundwithin the area to be treated. Treat this distance

at a walking speed you will use carrying a half-full sprayer and note the time.

6. For the amount of time noted from the abovestep, collect spray from the nozzle(s) and mea-sure in a container graduated in ounces.

7. The ounces collected happens to be equal to thespray rate in gallons per acre.

8. If the total solution delivered per acre is notadequate, or too much, adjust the pressure orchange tips and repeat steps 1 to 6.

9. Mix the desired rate of herbicide prescribed peracre with the gallons of solution delivered peracre.

EXAMPLE:

The measured spray width was 4 ft.

1. The calibration distance (see table) for a 4-ftband is 85 ft.

2. Walking the 85 ft with a half-full spray required28 seconds.

3. The nozzle sprayed 14 ounces in 28 seconds;therefore, the sprayer is applying 14 gallons peracre within the 4-ft band.

Machines - To calibrate a machine sprayer oneneeds to know the same information including speed,band width, and sprayer output. A step-by-step pro-cedure for machine calibration is as follows:

1. Adjust the boom height to give the proper bandwidth and adjust the pressure. This height andpressure should be maintained during calibra-tion and application.

2. Using a throttle and gear setting that will bemaintained during application, measure in feetthe distance travelled in 1 minute. This shouldbe done on terrain similar to the treatment area.

3. Collect the spray volume from all nozzles for 1minute and accurately measure this volume to

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the nearest tenth of a gallon (fluid ounces X0.0078 = gallons).

4. To calculate the portion of an acre treated in 1minute, multiply the band width or sum of mul-tiple-row band widths (measured in feet) by thedistance travelled in 1 minute. Divide by 43,560square ft per acre. For example, one 3-ft band is

total gallons by the gallons per acre and multi-ply by the rate. Use these calcuations:

Amount of herbicide = total gallons x rate

to add to a tank gal per acre

= 200 gal x3oz=3ooz20 gal per acre

sprayed at 145 ft per minute:Thus, add 30 oz of herbicide to 200 gallons of

Portion of an acre water, to treat 10 acres at a rate of 3 oz per acre.

treated in = 3 x 145 = 0.01 acre Check the calibration when you start a new area,

1 minute 4 3 , 5 6 0 use a new rate, or when equipment has been repairedor altered. With proper calibration of the equipment,

As another example, two 3-ft bands are beingbanded applications can begin.

treated by a boom sprayer at 145 ft per minute.Thus, 6 ft of band width would be used in thecalculation and 0.02 acre was treated per minute.

Spot Applications for Herbaceous WeedControl

5. To calculate the amount sprayed in the band,per acre, divide the gallons sprayed in 1 minuteby the portion of an acre treated in 1 minute.For example, 0.2 gal/min is collected and 0.01acre was treated:

Gallons per =0.2 gal/min

- 20 gal peracre 0.01 acre - acre

This is the amount of spray solution being appliedto an acre within the bands.

6. Mix the per-acre rate of herbicide in proportionto the gallons per acre of spray solution. Forexample, if 3 oz of herbicide is the prescribedrate per acre, then 3 oz of herbicide is added toevery 20 gallons of water in the mixing tank. Tomix 200 gallons of spray solution, divide the

Spot applications must be used when plantingrows are not well defined. Spot applications can bemade using the above banding procedure with somechange. Mainly, the sprayer is turned off betweenseedlings as the applicator follows the rows. Thesprayer is turned on about 1.5 to 2.5 ft before theseedling and shut off at the same distance past theseedling. Thus the same tips, pressure, and calibra-tion can be used. The applicator must still maintaina constant walking speed while spraying each seed-ling if the rate is to be constant.

Full cone tips, with flow rates from 0.2 to 0.4gal/min, can be used to apply circular, tree-centeredspots using a backpack sprayer or spotgun. How-ever, full cone tips with these low flow rates pro-duce very fine droplets that are easily blown bywind. An adjustable cone nozzle produces largedroplets, but these droplets are too large to ensureuniform coverage of preemergent herbicides.

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CHEMICAL INSECT AND DISEASE CONTROL

,

Forest trees are susceptible to insect and diseaseattack at all stages of growth and development.Maintaining healthy and vigorous stands and indi-viduals can lower the risk and incidence of insectattack. However, uncontrollable soil, site, andweatherconditions preclude the elimination of diseases andinsects as a threat to forest trees. Only a few forestinsects and only one forest disease are treated chemi-cally in the field for prevention or control.

Refer to the pesticide handbook of your State (ifavailable) or consult a local extension specialist fora list of currently registered pesticides approved forthe following pests.

Pine Bark Beetles

Southern Pine Beetle

The southern pine beetle (SPB) (Dendroctonusfrontalis) is the most destructive forest insect in theSouth. Weakening of trees by lightning, drought,flooding, or windstorms may predispose otherwiseresistant or healthy trees to attack by SPB. Wide-spread subregional outbreaks occur every 5 to 10years and last 1 to several years.

The SPB is a small, reddish-brown-to-blackbeetle about l/8 inch long. The rear of the body isrounded in contrast to the scooped-out posterior ofIps beetles. The first indication of attack is usuallythe yellowing or browning of needles. Small pitchtubes (white, yellow, or reddish brown) about aslarge as a small piece of popped popcorn (or a wadof gum) are sometimes present on the trunk, startingat a point about 3 feet from the bottom of the trunkand continuing up into the lower one-third of thecrown. Under droughty conditions, pitch tubes maybe very small or even absent and only reddish-brown, boring dust will be present.

Adult beetles bore directly through the bark andmate there. The females excavate S-shaped egggalleries in the inner bark, which can be observed bypeeling off the outer bark. These galleries are differ-ent from the Y- and H-shaped galleries of Ips beetles.White eggs are deposited in niches on either side ofthese galleries and hatch into small, legless larvae in4 to 9 days. The larvae mine for a short distance

23

before boring into the outer bark where they pupate.The larvae are about l&inch long, white, and havereddish-brown heads. The pupae are pure white andabout l/&inch long.

There are 3 to 7 generations per year, dependingon locality and weather. Soon after a tree is attacked,all the needles usually turn yellow and then brown.

In addition to causing direct damage, SPB’sintroduce blue-stain fungi, which may clog the wa-ter-conducting tissues. Death may be hastened whenblue-stain fungi are introduced. The stain decreasesthe value of the tree.

There are several alternatives to chemically con-trolling SPB infestations that can be used in appro-priate circumstances. These include cut-and-leave,pile-and-bum, andcut-and-remove. Cut-and-remove,the preferred method, and pile-and-burn can be usedyear-round; cut-and-leave should only be used dur-ing the summer. All require that a buffer strip ofgreen, uninfested trees be cut at the head of an activeSPB spot; professional help is recommended to bestimplement any of these methods.

Ips Beetles

Ips beetles (Ips grandicollis, I. calligraphus, I.amlsus, andI. pini) usually attack trees weakened bynatural or man-made causes, and often follow SPB’s.They usually attack and kill only one or a few treesin a given spot, but if conditions are satisfactory, theymay become edpidemic and destroy hundreds oftrees. Adults girdle trees quickly as they constructtheir egg galleries in the inner bark. Death is usuallyhastened by the introduction of blue-stain fungi,which block the flow of sap and degrade the wood.

Ips beetles are yellowish, dark reddish-brown, orblack. They are l/8- to l/4-inch long. They are easilyrecognized by the scooped indention of their poste-rior end which is surrounded by tooth-like projec-tions. Pitch tubes on bark or branches, or the pres-ence of boring dust, often indicate Ips attack. If thetree is healthy, attack by Ips may not be successfuleven though pitch tubes are present.

Fully grown larvae and pupae are yellowish-white and range from l/8 to l/4 inch long. Gallerypatterns are more or less Y- or H-shaped. The eggs

are small andwhite. Eggs are laid in small egg nichescut along the main tunnels. Upon hatching, larvaefeed, forming fine tunnels perpendicular to the eggniche. Later feeding results in meandering tunnels,usually filled with boring dust and frass. In hotweather, it takes only 18 to 25 days to complete onegeneration. Four or five generations occur each year.

Black Turpentine Beetle

Generally not considered a major forest pest, theblack turpentine beetle (BTB) (Dendroctonusterebruns) can kill apparently healthy trees in astand. Attacks are increased by natural and man-caused stress, such as drought and logging damageto trees and soil.

TheBTBisthelargestofthemajorsouthembarkbeetles. It is l/4 inch or more in length and the rearend is rounded. The color is reddish-brown to black.Large pitch tubes (up to walnut size) are caused bythis insect. BTB’s attack the lower trunks of livingpines (from the base to 15 feet up, but generally in thelower 8 feet). The beetle attacks fresh stumps andlivingtreesbyboringthroughthebarkandconstruct-ing galleries on the face of the sapwood where eggsare laid. Fifty to 200 eggs are laid in a group. Theyhatch into white larvae, which feed on the inner bark.

BTB’s may girdle and kill trees when severalbroods occur at about the same height. Generally, 10to 25 percent of the infested trees die. The entire lifecycle takes 2-l/2 to 4 months, depending on tem-perature. Each year in the South there are usually twofull generations and part of a third.

Bark Beetle Chemical Control

Many trees newly attacked by BTB can be savedby spraying from the baseup to the highest pitch tubeon the trunk with an approved insecticide.

If insecticides are used to control an active SPBinfestation, the following procedures are recom-mended. Fell all infested trees. Do not fell a bufferstrip of uninfested trees or vacated trees. Limb andcut the felled trees into workable lengths. Using alow-pressure sprayer, treat the entire bark surfacewith an approved insecticide, turning the logs asnecessary.

Pine Tip Moth

The Nantucket pine tip moth (Rhyacioniufnrstruna) is common in the South. Its importance inpine plantations and nurseries varies widely withtree species, tree vigor, and environmental factors.Heavily infested trees may be severely stunted ordeformed but are rarely killed. Generally, the treegrows out of the susceptible stage within a few years.All species of pines are attacked except white andlongleaf.

The adult moth is mixed gray and shiny coppercolored with a wingspan of about l/2 inch. Theyoung larvae are light cream colored; mature larvaeare light brown and about 3/8-inch long. Pupationoccurs in the damaged pine terminal.

Adults begin to emerge on warm days in latewinter or early spring and begin laying eggs withina few days. Eggs are deposited on needles, stems,developing tips, or buds. The larval period lasts 2 to4 weeks. Several generations occur each year.

Tipmoth Chemical Control

Insecticide spraying for tipmoth is not generallypracticed, except in special cases such as progenytests, Christmas tree plantations, research studyplots, and some intensively managed pine planta-tions. Insecticide application must coincide withmoth emergence, which varies by location. Trap-ping insects can identify the times of emergence, andspraying treatments planned accordingly.

Pine Sawflies

The redheaded pine sawfly (NeodiprionZecontei), blackheaded pine sawfly (N. excituns),and loblolly pine sawfly (N. taedae linear-is) attackmost species of southern pines. All have caterpillar-like larvae that feed on pine needles and can defoli-ate seedlings and saplings. Usually they attacksingletrees or small groups of trees; however, if conditionsare favorable, they may infest and defoliate thou-sands of acres of naturally regenerated or plantedpine. Repeated attacks on the same trees for 2 ormore years may kill them, but the main loss is in treegrowth. Sawflies are not economically important

2 4

pests of most forest stands, except in Florida whereinsecticide treatment is necessary.

Pine Sawfly Chemical Control

Treatment is usually by aerial applicator forlarge plantations or ground equipment for smallerones.

Texas Leaf-cutting Ant

Texas leafcutting ants (Attu texana), also knownas town ants, are destructive reproduction pests inTexas and Louisiana. This ant can completely defo-liate and girdle a small tree overnight. Such defolia-tion can be fatal to young pines. The ants strip theneedles and leaves from both pines and hardwoodsand use this plant material to culture a fungus that istheir only known food. Damage is most severe topines in the winter when there are no other greenplants. Pine reproduction can seldom become estab-lished where ants are present because they destroynewly germinated or planted seedlings.

Texas leafcutting ants are rust-brown to darkbrown and differ greatly in size. Workers range froml/16 to 1/2-&h long and have three pairs of promi-nent spines on the thorax. From April to June wingedmales and females leave the colony on mating flightsand subsequently establish new nests. An ant nestarea, or “town,” is marked by many cone-shapedmounds, usually 5 to 14 inches high and about 1 footin diameter. The town may cover an area fromseveral square feet to nearly 1 acre.

Texas Leaf-cutting Ant Chemical Control

Find and treat all nests in or near areas to beplanted. Scouting is easiest during fall and earlywinter when the ants are active and their mounds arenot hidden by vegetation. A formulation of the fireant bait Amdro is registered for leaf-cutting antcontrol. Fresh bait from a newly opened containershould be used for most effective control. Coloniescan also be eliminated by fumigating with methylbromide or carbon bisulfide. However, fumigatingshould not be done near human dwellings.

Pine Reproduction Weevils

The pales weevil (Hylobiuspales) and the pitch-eating weevil (Pachylobius picivom) are very de-structive of first-year pine plantations growing onrecently cut-over sites. Weevils eat patches of barkfrom the stem of a seedling and when these feedingareas overlap, the seedling is girdled and dies. Bothweevils will feed and develop on all species of pinewithin their range. Adults are oblong, black to red-dish-brown, less than l/2 inch long. Winter is spentas an adult or mature larvae in a chip cocoon con-structed under the bark of a pine stump. In spring,adults emerge and feed on the bark of saplings andat the bases of seedlings.

The weevils feed at night and hide under debrisat the bases of seedlings during the day. Ifthe insectsare abundant, they may remove all the bark andfoliage, leaving only yellowish, pencil-like stubs.Most damage occurs in spring and fall. The adultsare attracted to the odor of freshly cut pine stumps,scorched pines, or dying trees and feed on the tenderbark of nearby seedlings. When these high-hazardconditions (fresh stumps, scorched stems, etc.) oc-cur, weevils may kill 90 percent or more of the pineseedling in the reproduction areas; 30-60 percentpine seedling mortality is not uncommon.

The most practical method of control is to delayplanting recently harvested areas for 9 to 12 months.

Pine Reproduction Weevil ChemicalControl

Infestations of pine reproduction weevils can beprevented by dipping seedling roots in an insecti-cide/kaolin clay mixture, top dipping seedlings, orover-the-top insecticide spraying.

Gypsy Moth

When it is present, the gypsy moth (Lymuntria&spur) is one of the most damaging forest pests.Females do not fly. This peculiarity probably ac-counts for the insect’s slow spread from establishedinfestations into new areas. (Note: In 1993 an Asianstrain of this moth was introduced in several loca-

25

tions on the eastern seaboard of the United States.The females of this strain do fly and are expected toseverely impair future control efforts. However,how bad the problem will be is not yet known. So,the remainder of this discussion is limited to theEuropean strain of gypsy moth currently found inthe East.

The moths are harmless, but the caterpillars feedon the leaves of forest, shade, ornamental, and fruittrees as well as shrubs. A single defoliation can killsome softwoods, tsvo or more defoliations can killmany hardwoods. Large infestations involve mil-lions of caterpillars and can degrade esthetic andrecreational values of forests, parks, and woodedhomesitesFew trees are killed outright by gypsymoth defoliation, but many trees are weakenedand become susceptible to secondary attack byother insects or plant diseases. During the last 80years, parasites of this pest have been introducedinto infested areas. However, control of the gypsymoth by its natural enemies has been less effectivethan hoped.

Gypsy Moth Chemical Control

Aerial spraying with the insecticide dimlinhas been done in several southern States to controlgypsy moths and may be required in other Statesas the moth migrates southward. The bacteriumBacillus thuringiensis (B.t.) and avirus (Gypchek)are being aerially applied to control gypsy moths.

Annosus Root Rot

In the South the only tree disease chemicallytreated on an operational basis in the forest isannosus root rot. It infects many pines and otherconifers. Infected trees grow slower and are moresusceptible to bark beetle attack than healthy

trees. Infected trees are also susceptible to spon-taneous root failure and windthrow. The root rotis caused by Heterobasidion annosum, a fungusthat grows in the duff at the base of potential hosttrees. An example is shown on the front cover,bottom inset photo. This fungus causes a white,stringy, rot of the roots and occasionally the buttsof living trees. Eventually, the entire root systemmay be destroyed. The fungus spreads by air-borne spores that germinate on freshly cut stumpsurfaces. Infections in plantations can usually betraced to root contacts or grafts between healthyand infected trees.

Infected trees have thin, light-green to yellowcrowns and short needles, tufted at the branchend. Conks (the shelf-like fruiting structure of thefungus) are not produced on most trees and areoften difficult to locate when they do appearunless the duff layer is removed.

Trees tend to die in pockets, with trees in thecenter dying first. In thinned pine plantations,high-hazard sites can be 80+ percent infected.High-hazard sites are well drained soils with atleast 65 percent sand in the upper 12 inches of soiland a low water table.

Annosus Root Rot Chemical Protection

Sodium tetraborate (borax) is the most effec-tive protection against stump surface coloniza-tion, residual tree infection, and mortality. Justsprinkle borax or Borateen on a stump with a saltshaker or any other shaker-type container. So-dium tetraborate will not prevent transmission ofH. annosum through root systems in alreadyinfected stands. Such stands should be treatedwith Phlebiu gigantea, a fungus that competesnaturally with H. unnosum. Thin the infectedtrees in the summer.

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FOREST SEED ORCHARDS AND NURSERIES

Seed Orchards

About 10,000 acres of forest tree seed orchardsin the South are intensively managed to produce theseed required for artificial regeneration programs.While these seed orchards represent a very smallarea, their impact upon forest production in theSouth is very large. In 1987, these seed orchardsproduced enough seed to grow 1.3 billion seedlingsthat were used to reforest 1.8 million acres of land.This represented 85 percent of all reforestationefforts in the South. A conservative estimate ofgenetic gain for these seedlings is a lo-percentincrease in volume growth, which has a value of$43.5 million ( 1990 figures). Additional value willbe created by improvements in form and diseaseresistance.

Intensive management is critical to obtain therequired amount of seed from these orchards. Cone-and seed-insect control programs are an integralcomponent of a seed orchard management programbecause these insects can easily destroy more than50 percent of the potential seed crop. In some cases,losses to cone and seed insects have exceeded 90percent of the potential seed crop. Additional con-trol techniques, both biological and chemical, areneeded to ensure a continuing supply of genetically-improved seed for future reforestation efforts.

Chemical control is achieved by ground and aerialapplication methods. Hydraulic sprayers, airblastsprayers (mistblowers), and handheld compressed-air sprayers are all used to control different speciesof seed- and cone-insect pests. Aerial application isincreasing. Both helicopters and fixed-wing aircraftare used to apply insecticides with either conven-tional or ultra-low volume equipment. The use ofaircraft has resulted in much less exposure to work-ers at seed orchards and reduced losses due toinsect damage.

Insecticides used in seed orchards range fromvery toxic (azinphosmethyl) to very non-toxic (syn-thetic pyrethrins) to man and animals. Research forsafer insecticides is continuing.

Forest Nurseries

Forest tree nurseries are intensively-managed sitesthat use considerable amounts of pesticides. Nurser-ies in the South grow about 80 percent of all thebareroot stock produced in the United States. Lob-1011~ and slash pine account for about 90 percent ofthis production, although in recent years there hasbeen increasing interest in longleaf and sand pine,as well as hardwoods. Most of the pesticide technol-ogy now used in forest nurseries was developed forpine seedling cultivation.

Fumigants, herbicides, fungicides, and insecti-cides are used routinely to control a number ofmajor pests of tree seedlings. A number of pesti-cides have labels specific to tree-seedling nurseries.The Environmental Protection Agency also allowsthe use of pesticides labeled for horticultural nur-series to be applied in forest-tree nurseries. Individ-ual States, however, may find exception to thisgeneral policy.

Fumigants are used in nurseries to control patho-gens and weeds. Weed control alone, however, doesnot sufficiently justify fumigation as there are cost-effective herbicides specifically labeled for use withpine seedlings. On the other hand, pathogens canbe a serious problem so protection from variousdamping-off fungi and other soilborne organisms isconsidered a wise investment. Proper soil condi-tions are essential for effective fumigation.

Herbicides used in nurseries have been devel-oped mainly for pine production. A number of effec-tive compounds are labeled to control grasses andbroadleaf weeds in pine seedbeds. Herbicides areusually applied over-the-top of the beds when weedsfirst appear. Applications are repeated throughoutthe growing season as deemed necessary. Weedcontrol in hardwood nurseries is more difficult. Notonly are fewer compounds labeled for weed controlin hardwoods, but herbicides are specific for hard-wood species. If not properly matched, serious seed-ling damage can result. Herbicides are also used forbroad-spectrum weed control by spot treatmentaround irrigation lines, roads, and buildings.

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Fungicides are most often used in forest nurser- Insecticides are commonly used in nurseries.ies to prevent and control fusiform rust. Fungicides Some of the more common insect pests are lessermay also control damping-off during and immedi- cornstalk borers, spider mites, aphids, lygus bugs,ately after seed germination. Several stem and foliar and white grubs. A number of insecticides arediseases also periodically require use of fungicides. labeled for insect control in forest nurseries, althoughUnder nursery conditions of dense seedbeds, high the chemical must be matched with the pest forfertilization, and irrigation, disease problems must maximum effectiveness.be found and addressed quickly.

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Many kinds of animals can damage live trees inthe South. Their damage may vary from insignifi-cant to very serious. The mammalian pests - deer,rabbits, squirrels, and other rodents - present themost serious problems. With an animal-damagesituation, always check State and local regulations.Due to their potential for greater economic impact,beaver and deer will be discussed separately. Otherspecies may cause damage locally, but are not awidespread or severe threat to trees.

Beaver

Beavers are capable of greatly altering their habi-tat to suit their needs. As they girdle and fell treesto build a lodge and dam, standing timber oftenbecomes flooded and eventually dies. From a wild-life management standpoint, beaver ponds are verybeneficial; from a timber producer’s standpoint, bea-ver ponds may be costly.

Due to the sizeable beaver population in theSouth, live-trapping and relocating offending ani-mals is no longer a realistic control alternative.There are no repellents, toxicants, or fumigantsregistered for beaver control. Eliminating beaverfrom an area requires a combination of trapping orshooting, and destroying their dams. One of themost effective traps for beaver is the 330 Conibear.This trap, when properly set, kills the beaver in-stantly. When all the beavers have been trappedfrom a pond, the dam can be destroyed and thewater drained from the flooded timber.

Deer

Deer, like beavers, have expanded in the South.High populations, coupled with voracious feedinghabits, can badly damage newly established forests.Deer prefer to browse on the leaves, stems andbuds of woody plants. They will browse on bothpine and hardwood seedlings. Browsing damage bydeer is easy to identify by the presence of the dis-tinctive deer tracks and the characteristic pattern ofnipping the plant. Deer have no upper front teeth,so they must tear off pieces of the plant, leaving ajagged end. Bucks may also rub small pines with

their antlers during the rutting season. Damagecaused by antler rubbing appears as an area wherebark has been scraped off the tree trunk. Generally,rubbing damage to young pines (up to 4 inches indiameter) by rutting bucks does not present an eco-nomic threat except in high-value plantings such asseed orchards and Christmas trees.

Deer are protected as game animals throughoutthe region, but in cases of severe damage, it may bepossible to obtain a permit to shoot depredatingdeer. Various scaring devices may be effective forshort periods, but deer soon become acclimated tothem. Repellents are short-lived and expensive. Inareas with many deer, seedlings can be treated witha repellant and planted late in the season to extendthe effect. The most effective control measure maybe exclusion of deer from the area. This can beaccomplished by 8-foot high woven-wire fencingor various configurations of electric fencing. Sporthunting in the area may help control populationexpansion.

Small Rodents

Cotton rats may feed on the roots, stems, andleaves of seedlings. Cotton rats prefer dense cover;therefore, keeping the area around the young treesclean through herbaceous weed control will help toreduce cotton rat problems. In small areas, cottonrats may be excluded by using sheet metal fencing;the bottom of the fence should be buried 6 inches inthe ground. Repellents, toxicants, and fumigantsare not effective in large-scale operations. The dam-age caused by this species is generally local.

Voles, small mouse-like animals with short tails,may damage seedlings by girdling. They usuallyhave extensive systems of burrows and runways inthe ground litter. Trapping is not effective in large-scale operations; however, some success may beachieved with repellents and toxicants such as zincphosphide. Check local regulations before usingany chemical control measures. Voles rely onvegetative ground litter for cover, so keep the areaaround young trees clear of vegetation to help reducevole damage.

VERTEBRATE ANIMAL CONTROL

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Pocket gophers are burrowing animals that eatparts or entire root systems and expose roots so thatthey dry out. Gophers can often be detected by thepresence of surface mounds. They are not usually apest in forest situations. However, damage can bequite significant where pastures and old fields hav-ing sandy soils are machine planted to pine. Pocketgophers can be controlled using baits containingzinc phosphide .

Rabbits may damage young trees by girdling orclipping off branches. Their damage may be distin-guished from deer browsing by the smooth-angledcut left at the end of the branch. Rabbit droppingscan usually be found in the damaged area. Likedeer, rabbits are game animals that are protected byState regulations, but some States do allow excep-tions in damage cases. Exclusion and trapping aregenerally not effective for large-scale operations.Some repellents containing thiram have proveneffective in discouraging rabbit browsing andgnawing. Eliminating brush piles and other covermay be useful in reducing high rabbit populations.Biological control of rabbits, by encouraging thepresence of natural predators (hawks, owls, andsnakes) may help lower populations. Sport huntingon an area can aid in population control.

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Other Animal Pests

Fox squirrels may damage pines in the South byeating cones, and by chewing pine bark. Fox squir-rels are game animals and are covered by seasonsand other regulations. In isolated cases, squirrelsmay be prevented from climbing individual treesby installing a 2-foot-wide sheet of metal aroundthe trunk. For large-scale forestry operations, toxi-cants and repellents are usually not effective. Trap-ping or shooting can generally be used to eliminateoffending animals, but during peak years, new squir-rels may soon move into the area to replace thosethat were eliminated.

Feral hogs are descendants of free-rangingdomestic hogs or those released for sport hunting.Feral hogs may damage young stands of timber byrooting around the bases of trees. Large-scale fenc-ing to exclude hogs is generally not practical, andthere are no toxicants registered for hogs. Live-trapping and removal during the spring and sum-mer when acorns are scarce, and hunting during thefall and winter may be effective in controlling feralhog populations.

RECORD KEEPING OF PESTICIDE TREATMENTS

Keeping records of pesticide usage is required bylaw. By Federal regulations, records for each appli-cation of “restricted use” pesticides must be kepton file for at least 2 years. Records can establishproof of proper use in damage suits, and they arehelpful in finding the cause of error if an error wasmade. They can also provide information to traceresidue and damage problems. Such records canalso be helpful in liability cases.

Records can also help save money. They allowcomparison of results obtained from different pesti-cides, which can improve efficiency and reducepesticide misuse. Also, with careful records, win-ter inventories can be reduced by only buying theamounts required.

The more information recorded, the more usefulthe records will be. Carry a notebook to the applica-tion site and record all necessary and helpful infor-mation. Do not try to memorize all the necessaryitems. A standard form can be used to ensure thatall necessary data is obtained. Following is a list ofthe minimum information needed:

l Time of day and date of application

l Target pest(s)

l Equipment used

l Pesticide used:- Common name- Brand name- Formulation and percent of active ingredient- EPA registration numbers- Establishment and lot numbers (in case of

cross-contamination or failure to control)- Total formulation added to tank or hopper- Amount of mixture used- Acres treated

l Additional comments:- Location- Weather- Applicator/crew chief/responsible individual- Severity of infestation

On every record form there should be a space leftfor ‘ ‘additional comments. ’ ’ Use this space to writedown information for your personal use. This infor-mation can be used to improve your business eitherthrough better customer relations or by savingmoney. Record-keeping requirements may vary byState; check with the appropriate agency.

31

APPLICATOR SAFETY

The safety of forest pest applicators is assuredonly if proper procedures are followed. The properprocedures for handling, storing, transporting, andapplying pesticides are presented in this section.This information is intended as a supplement toother pesticide safety instructional materials.

The Pesticide Label

The single most important source of informationfor safe pesticide use is the label. The label con-tains comprehensive information and instructions.Look for precautionary statements and warningsthat are important in proper use. Detailed informa-tion appears for the application, storage, and dis-posal of the product. In addition, the label containsa telephone number of expert advice during an emer-gency and address of the manufacturer. Informa-tion regarding the brand name, chemical name, typeof formulation, and EPA registration number arealso included. These items are important to a physi-cian in case of an accidental poisoning. The mostimportant time in pesticide application is the timespent reading and understanding the pesticide label!Always read the label four times:

1. Before buying the pesticide.

2. Before preparing the material for use.

3. Before mixing and applying.

4. Before storing or disposing of the pesticide.

Before buying a pesticide, read the label to ensurethat the chemical is properly labeled for your particu-lar job. Make sure that it is suitable for your equip-ment, conditions, and site. Before preparing thechemical for use, read the label again for any warn-ing or precautionary statements. Use all protectiveequipment recommended.

The label also specifies rates, methods of appli-cation, and sometimes compatibility with otherchemicals or carriers such as diesel fuel. In addition,the label gives the waiting period for crops and

entry by animals and any restrictions in the use ofthe chemical.

Mixing, Handling, and ApplyingPesticides

The pesticide label contains precautionary state-ments, warnings, and often lists protective clothingand equipment required when using that pesticide.Read the label before mixing or applying.

Mixing

When handling a concentrated pesticide, precau-tions should always be taken. In their concentratedform, many pesticides may cause skin irritation andeye damage. Therefore, always use protective eyewear and neoprene or rubber gloves when mixingpesticides. Wear protective clothing such as long-sleeved shirts, long pants, and water-resistant boots.Be sure all skin abrasions or cuts are properly band-aged to prevent exposure before mixing chemicals.

On windy days, always pour pesticides by stand-ing so that the wind comes from behind or from theside - never pour upwind. Keep the container spoutbelow eye level. Small pumps can often be used totransfer pesticide, minimizing the risk of exposure.

Applying

When applying pesticides, avoid unnecessaryexposure. Use protective clothing and equipmentspecified on the label. Bring wash water and deter-gent to the field in clearly-marked containers. Beforeapplication, use water to check equipment for leaksand proper calibration. When applying a pesticide,always stay upwind from the nozzle.

If pesticide is spilled on you, wash it off im-mediately. Also, take a change of clothes to theapplication site in case your clothes become con-taminated. Before eating and smoking, always washyour hands and face thoroughly. Always wash con-taminated clothes by themselves.

After application, clean and rinse the equipment.The best area for cleaning is on a wash rack or aconcrete apron with a good sump. A second alterna-

33

tive is to apply the rinse water carefully on the sitewhere the pesticide was applied, in compliance withthe label.

When using pesticides, whether mixing, applying,or rinsing equipment after use, always be certainnot to contaminate someone’s water supply. Sev-eral precautions can be taken to avoid theseproblems. First, never apply near a well or otherwater source. When possible, use a nurse tank tomix only the pesticide needed for that day’s workin the field. When filling from a well, use a sepa-rate pump equipped with check valves to preventback siphoning.

Pesticide Disposal, Storage,and Transport

Disposal

After applying a pesticide, excess chemicals andempty containers should be disposed of or storedproperly. Preventing pesticide surplus is the bestway to minimize disposal problems. Before buying,make sure the pesticide is labeled for the intendeduse. Carefully estimate the amount of pesticideneeded to complete the job and buy only whatis needed.

Check the site and be sure weather conditionswill allow proper application before mixing thepesticide. Also, mix only what is needed forthat day.

Although steps can be taken to minimize anyexcess chemicals, empty containers must always bedisposed of properly. After application, triple-rinseall empty containers. Pour rinsate back into thespray tank, not directly on the ground. Punch holesin non-returnable containers so they cannot be usedagain, and dispose of them in a sanitary landfill.Returnable containers are to be returned.

Storage

Proper storage of pesticides is essential to theirsafe use. The first step in proper storage is to desig-nate an area where only pesticides are to be stored.This area should be secured with a lock and promi-nently posted at each entrance: WARNING -PESTICIDES - KEEP OUT. Ideally, the stor-age area should be made of fire-resistant materials,

including a concrete floor. The storage area shouldbe cool and dry and have an exhaust fan for properventilation.

Never store pesticides near food, feed, seed, oranimals. Separate each type of chemical so thatherbicides, fungicides, and insecticides are storedseparately. Also, each formulation of pesticideshould be grouped separately. Always store contain-ers so that labels can be clearly seen. It is also agood practice to store containers off the ground onpallets to avoid moisture problems. An up-to-dateinventory of all chemicals that are stored is recom-mended, including the date they were placed instorage and the date they are used.

The storage area should be kept clean and orderly.Absorptive clay, activated charcoal, pet litter, orsawdust should be readily available at the storagesite to help clean any spill. A shovel, broom, anddustpan should also be available, and always keepa fire extinguisher in the area.

Transport

The following precautions can be helpful in safelytransporting pesticides:

l Be sure the containers are not damaged beforeloading or during transport.

l Take only the amount needed for that day.

l Do not transport pesticides in the passenger sec-tion of a vehicle.

l Do not transport pesticides in the trunk of passen-ger cars or in trucks with wooden beds. Use atrailer to transport pesticides when using a car.

l Secure all containers so they will not move dur-ing transport, using ropes and straps. During thetrip, check the containers periodically to be surethey have not shifted and spilled.

l When at the application site, park the truck orstore the containers in the shade; direct sun cancause the containers to overheat, resulting inpressure build-up. A tarp can be used duringtransport.

34

Spill Procedures

If an accident occurs during transport and a minorspill results, administer first aid to anyone whomay have been injured. Confine the spill if it startsto spread. Dig a dike around the area to contain thespill. Always take a shovel when hauling pesticides.Use an absorbent, such as those mentioned pre-viously, to soak up the pesticide, or use clayey soil.Dispose of the contaminated absorbent as you wouldan excess pesticide.

Some accidents may result in a major spill - onethat endangers people, property, or the environment.Your first priorities would be to administer firstaid, contain the spill if possible, and then call themanufacturer. The number to call in case of anaccident is prominently displayed on every label.The manufacturer will tell you which authorities tonotify and what action to take.

Pesticide Toxicity

Toxicity Terms and Definitions

Toxicity - The measure of the ability of a chemi-cal to injure or kill.

Exposure - Coming into contact with a chemicalby swallowing, breathing or through contact withthe skin.

Hazard - The degree of exposure combined withthe level of toxicity.

LDSO - The amount (or lethal dosage) of a chemi-cal required to kill 50 percent of the test animals.

Acute toxicity - A measure of the ability of achemical to injure or kill from one exposure.

Chronic toxicity - The ability of a substance toinjure or kill after long-term exposure.

Oral toxicity - The ability of a substance to injureor kill if swallowed.

Dermal toxicity - The ability of a substance toinjure or kill if passed through unbroken skin.

PPM (parts per million) - A way to express theamount of pesticide in water, plants, food, or ani-mals (1 ppm is equal to about 1 oz in 62,500 lb or 1tablespoon in 3,906 gal),

PPB (parts per billion) - Another expression ofthe amount of pesticide in water, plants, food, oranimals that is 1,000 times LESS than a part permillion (1 ppb is equal to about 1 oz in 62,500,OOOlb or 1 tablespoon in 3,906,OOO gal).

Half-life - The time required for one half of theinitial concentration of a chemical to be degraded.

Volatility - The ability of a liquid to evaporate.

Measuring Toxicity

Toxicity, the capacity of a substance to injure orkill, varies with each chemical. Chemicals rangefrom extremely toxic to essentially nontoxic. How-ever, large enough amounts of almost any substancecan be toxic. Knowing how toxicity tests are con-ducted is the key to understanding the toxicity ofpesticides. Test animals (mice, rats, or rabbits) arefed a measured dose of a chemical. By increasingthe amount of a chemical fed to test animals, thequantity required to kill 50 percent of the animalscan be determined (LD,,-J. This dosage is usuallyreferred to in terms of the weight of the chemicaland the weight of the test animal. For example, theherbicide Roundup has an LD5e rating of 5,400mg/kg. Approximately 1 pint of Roundup in theconcentrated form would have to be swallowed fora 175-pound person to reach the LDsO dose.

Table 1 gives toxicity categories for pesticides,and table 2 provides LD5e ratings for commonpesticides; other common substances that are fre-quently handled are listed for comparison. Table 3provides estimates of the LD5a for a 175-poundperson for a range of substances. This informationimplies that as the LD5c rating becomes larger, thesubstance becomes less toxic. For example, Prod-uct A with an LD5e rating of 40 mg/kg is muchmore toxic than Product B which has an LDsc rat-ing of 4,000 mg/kg. Also note that many pesticideshave acute toxicity ratings that are lower than manycommonly used household compounds.

Many people wonder how a herbicide that suc-cessfully kills unwanted plants can have little toxiceffect on humans. Plants differ from humans inmany ways; researchers produce chemicals thatinterrupt a plant’s function, but have little or noeffect on humans. For example, in the photosyn-thetic process plants produce their own food by

35

Table 1. Toxicity categories for pesticides

Toxici ty Signalcategory word

AcuteoralL&o

AcutedermalL&o

Acuteinhalat ion

L&oEye effects

Est imated amountSkin effects needed (orally) to

kill the averageperson

I DANGER

(mgkd<200

II W A R N I N G 50-500 200-2.000

III C A U T I O N 500-5,000 2,000-20,000

IV C A U T I O N >5,000 >20,000

(m&z)co.2 Corrosive; cornea1 Corrosive

opacity not rever-s ible wi thin 7 days

A taste (~7 drops)to a teaspoonful

0.2-2.0 Cornea1 opacity Severe irr i tat ionreversible within at 72 hours7 days; i r r i ta t ionpersis t ing for 7 days

A teaspoonful toan ounce

2.0-20 No cornea1 opacity; Moderateirritation reversi- irritation atble within 7 days 72 hours

An ounce to ap in t

>20 No irr i ta t ion Mild or s l igh tirritation at72 hours

Greater than ap in t

> = Greater than.< = Less than.

usihg carbon dioxide from the air, water from the similar way, resulting in the death of plants, butsoil, and sunlight. A chemical that blocks this pro- having no effect on people.cess would kill a plant but may not affect humans Although the acute LDSO rating may indicate thatsince people cannot photosynthesize. Other plant the compound is relatively low in toxicity, it isprocesses, such as producing a particular amino wise to take precautions when mixing, handling, oracid that only plants can make, can be altered in a applying any pesticides.

3 6

Table 3. Estimated acute oral and dermal toxicity’ (fluid ounces) of 18 chemicals for a175-pound person

Trade nameApproximate Toxicityacute oral LD,,’ category

Approximateacute dermal LDsO1

(jl ounces) (jl ounces)

NicoteneMethyl parathion (80%)3CaffeineLindane (20%)3Sevin (50%)Aspirin2,4-DMalathion (91%)BanvelGarlonTordon 1013Table saltBanvel CSTOustPronone iOGRoundupTordon 101RVelpar L

0.02 Extreme N/A0.03 Extreme 10.21 Extreme N/A

2 Moderate 112 Moderate 3

3.5 Moderate N/A3.7 Moderate 4

4 Moderate 1 27 Moderate 67 Moderate 118 Moderate 79 Moderate N/A

1 4 Slight 61 4 Slight 1 41 4 Slight N/A15 Slight 1 41 8 Slight 1 12 0 Slight 1 5

N/A = Not applicable.l The estimated toxicity for the pesticide is based on the formulated product (as in the container

before any additional mixing).2 Most LDSO’s are expressed as a range, reflecting experimental conditions, type of carrier, species

of test animals, and precision of the tests, These estimates fall within the range and are onlyprojections based on animal tests.

3 Restricted-use pesticide.

38

PROTECTING THE ENVIRONMENT

Forest pesticides are registered only after the EPAhas sufficient information that their proper use willnot cause unreasonable harm to people or the en-vironment, including wildlife and aquatic organisms.Special concern is placed on environmentally sensi-tive areas that are in or around treatment areas.These include streams, ponds, wells, special wild-life habitats, threatened and endangered species,homesites, orchards, crops, and beehives. Specialprecautions regarding such areas are often specifiedon the label. Problems usually occur when applica-tors do not follow label directions or they applypesticides when conditions are not favorable. Dam-age to the environment usually is the result of oneof the following:

- Off-site application- Off-site movement in air- Off-site movement in water- Pesticide persistence

Each applicator must be aware of these problemsand constantly work towards eliminating or mini-mizing adverse effects to the environment.

Off-site ApplicationTo prevent off-site application or the accidental

treatment of environmentally sensitive areas, markboundaries clearly and use obvious, natural, or con-structed features that can be readily identified by allapplicators. Set up buffer strips as specified on labelsand for protecting sensitive boundaries. Mark bufferstrips around streams and ponds and take specialcare when treating sites near such areas. Every per-son doing the application should be informed andmade aware of boundaries and their identification,as well as, any special precautions that should beused. Ground guidance for both aerial and groundapplication should be used whenever feasible tohelp the applicator to remain in the target area andmake uniform applications.

Off-site Movement in Air

Chemicals may drift through the air from thearea of application and cause considerable injury ifthey contact susceptible plants and animals, or sen-sitive humans. Movement through the air may resultfrom spray drift or volatility.

Spray drift is the movement of airborne sprayparticles. The amount of spray drift depends upon( 1) size of the droplets, (2) amount of wind, and (3)height above the ground that the spray is released.Droplet size depends mainly on pressure, design ofthe nozzle, and surface tension of the spray solution.In general, low pressures tend to produce large drop-lets and high pressures, small droplets. Small noz-zle openings tend to produce small droplets andsolutions possessing low surface tension tend toproduce small droplets. To minimize drift, use thelargest nozzle opening and lowest pressure combi-nation that is effective.

Volatility refers to the tendency of a chemical tovaporize or give off fumes. The amount of fumesor vapors given off is related to the vapor pressureof the chemical and the temperature when applied.High temperatures will increase volatilization. Vapordrift is the movement of these vapors or fumes. Thevapors may damage susceptible crops, cause aller-gic reactions by sensitive humans, and may reducethe effectiveness of the pesticide treatment due toloss. Volatilization can occur when ester formula-tions of forestry pesticides are applied during hightemperatures. Formulations that are salts should beused to stop volatile losses when the form of theactive ingredient is not important. Ester formula-tions should NOT be applied at high temperatures,such as greater than 90”F, when crop injury or offsitemovement is a problem.

Granular materials, specialized spray equipment,low-drift adjuvants, and other precautions can reducethe chance of offsite movement. Select nonvolatilepesticides when sensitive species are nearby.

39

Off-site Movement in Water

Pesticides can find their way into aquatic environ-ments from areas that have been treated unlessproper precautions are followed. While pesticidesmay be present in very dilute quantities, they tendto be actively or passively magnified or concen-trated by way of suspended particles that are dis-persed in water.

Pesticides enter the aquatic environment by fourprincipal mechanisms:

l Point Source (e. g . , industrial effluents) -Pesticide contamination of the aquatic environ-ment by point sources such as industrial efflu-ents may result in immediate biological catas-trophes or in long-term adverse effects.

l Runoff - Pesticides can move off a treatmentarea when dissolved in rainfall or on suspendedparticles in surface drainage water as overlandflow (on compacted logging trails), streamwater, and in ditch water.

l Leaching - Ground water or subsurface watermay also be contaminated by pesticides. Thereare examples of contamination of wells andmunicipal water supplies.

l Spillage, Accidents, and Careless Handling- Pesticides may also enter water coursesthrough inadvertent spillage (for example,around industrial sites). Other ways pesticidesenter water include cleaning of applicationequipment in streams and careless aerial appli-cation of pesticidal chemicals. Back-siphoninginto wells during loading should be preventedby using proper procedures and back-siphoningcheck valves.

The applicator must be knowledgeable of the fac-tors that lead to runoff and leaching, while con-stantly guarding against spillage, accidents, andcareless handling.

Solubility

Because there are many different chemical com-positions of pesticides, one might expect them to

vary considerably in the way they react with soil,water, and other substances. Pesticides vary in theirpotential for moving in soils and to groundwater.Three major characteristics influence such move-ment: solubility, persistence, and soil characteristics.The geology of the treatment area also influencespossible movement into groundwater.

Chemicals vary greatly in water solubility; thegreater the water solubility, the greater the poten-tial for movement of the product to groundwater.Pesticides with low water solubility have less ten-dency to both move off-site with storm runoff orleach into the soil. More soluble compounds mayleach deeply enough through sandy soils to contami-nate groundwater. Soil-applied pesticides may washor move into the water table more readily than foliar-applied materials.

Persistence

Although some chemicals degrade quickly, oth-ers breakdown slowly. The slowly degrading, or“persistent’ ’ materials, are more likely to reachgroundwater over a period of time.

Soil Characteristics

Some chemicals become tightly attached(“strongly adsorbed”) to soil particles and do notmove in the soil. Some are not so strongly adsorbedand are more likely to move. Soil characteristicsare also important in the movement of chemicals.Your local Soil Conservation Service office canhelp you determine which types of soil are in yourarea.

Three major soil characteristics affect chemicalmovement:1. Soil texture - This is an indication of the rela-

tive proportions of sand, silt, and clay in thesoil. Coarse, sandy soils generally allow waterand solutes to move rapidly downward and offerfew opportunities for adsorption. Finer-texturedsoils generally allow water to move at muchslower rates and they contain more clay, silt,and organic matter to which pesticides may beadsorbed.

2. Soil permeability - A general measure of howfast water can move downward in a particular

40

soil. The more permeable soils must be care-fully managed to prevent any form of chemicalfrom reaching groundwater.

3. Soil organic matter - Influences how muchwater the soil can hold before movement occurs.Increasing organic matter will increase the water-holding capacity of the soil. Some pesticidesmay also be adsorbed onto organic matter.

Geology

Distance of groundwater from the surface isanother important factor. If the groundwater iswithin a few feet of the soil surface, pollutants aremore likely to reach it than if it occurs at greaterdepths.

Permeability of geological layers between thesoil and ground water is also important. If surfacewater can move quickly to the groundwater, thepotential for pollutants reaching groundwater isincreased.

Sinkholes - Especially troublesome. Surfacewater often flows into sinkholes and disappearsquickly into the groundwater. If a chemical is ap-plied to an area that drains to a sinkhole, evenmoderate rain may carry some of the material di-rectly to the groundwater.

Other Environmental Considerations

There are many species of beneficial forest in-sects, some of which are very abundant. Some feedon forest debris and aid in its deterioration; othersfeed on organic matter in the duff and soil andcontribute to improvements in soil fertility. Manyothers are parasites or predators of destructive in-sects. Most are important food sources for birdsand other small animals. Bees and certain otherinsects are important pollinators of some commer-cial crops as well as forest plants and trees.

Forest managers and pesticide applicators mustbe aware of these and other wildlife members of the

forest environment. Pesticide labeling gives usefulinformation about toxicity to nontarget life forms.Learn as much as possible about environmental haz-ards and potential nontarget impacts of pesticides.Select the pesticide and application method thatwill have the least adverse impact and still get thejob done.

Fish or wildlife kills in any area should be re-ported to the appropriate State agency. They maywant to investigate the reason for such a kill to helpprevent future occurrences. Many factors other thanpesticides can kill fish or wildlife.

Endangered Species Act

The Endangered Species Act provides:

l Legal protection for endangered and threatenedspecies.

l That all federal agencies (EPA and USDA ForestService, for example) ensure agency actions willnot jeopardize the existence of any endangeredspecies.

About 58 endangered species (17 percent of thecurrent endangered species) live in forests in theUnited States. About 24 pesticides presently labeledfor use in forests are considered to have an adverseeffect on one or more of these endangered species.These numbers doubtless will change over time,but are given only to indicate that many endangeredspecies live in forest habitats - and a number ofpesticides will affect them. Every affected pesti-cide sold since 1988 shall have a warning on thelabel which prohibits pesticide use in the range(occupied habitat) of endangered species. Each Statewill have an enforcement plan to implement theEndangered Species Act in the near future. Consultwith a county extension agent for the currentregulations.

41

SUGGESTED READING LIST

American Farm Bureau Federation. 1987. Protect-ing our groundwater: a grower’s guide. ParkRidge, IL: American Farm Bureau Federation.8 P.

American Pulpwood Association. 1985. Guidelinesfor effective and safe aerial application of her-bicides. American Pulpwood Association, Inc.,Forest Management Committees, SoutheastTechnical Division, Southwest Technical Divi-sion. 23 p.

Baker, Whiteford L. 1972. Eastern forest insects.Miscellaneous Publication No. 1175. Wash-ington: U. S . Department of Agriculture.642 p.

Cantrell, Rick L., ed. 1985. A guide to silvicul-tural herbicide use in the southern United States.Auburn, AL: Auburn University School ofForestry, Auburn, AL. 500 p.

Clemson University. 1984. Herbicides, prescrip-tion and application, proceedings fourth annualforestry forum, 1984 March 21, Clemson Uni-versity, Department of Forestry. Clemson, SC:Clemson University. 65 p.

Ebel, Bernard H.; Flavell, Thomas H.; Drake, LloydE.; Yates, Harry 0. III; DeBarr, Gary L. 1975.Southern pine seed and cone insects. Gen. Tech.Rep. SE-8. Asheville, NC: U.S. Departmentof Agriculture, Forest Service, SoutheasternForest Experiment Station. 40 p.

McNabb, Ken. 1991. Forest herbicides are environ-mentally safe. Forest Farmer. 50(3): 16-18.

Miller, James H.; Mitchell, Robert J., eds. Rev.1990. A manual on ground applications of for-

estry herbicides. Management Bulletin R8-MB21. Atlanta: U.S. Department of Agriculture,Forest Service, Southern Region. 389 p.

Miller, James H.; True, Ronald E. 1986. Herbicidetests for kudzu eradication. Georgia ForestResearch Paper 65. Macon, GA: Georgia For-estry Commission. 11 p.

Near-y, Daniel G.; Flinchum, D. Mitchell; Cantrell,Rick L. 1984. Safety with forest pesticides.Forest Farmer. 43(5):16-18.

Newton, Michael. 1976. Apply pesticides correctly,a guide for commercial applicators, Forest pestcontrol. Report No. EPA/540/8-761023. Wash-ington: U . S . Environmental Protection Agency.14 p.

Singer, James. Rev. 1982. Pesticide safety guide-lines for personal protection. USDA ForestService, FPM 83-l. Davis, CA: U.S. Depart-ment of Agriculture, Forest Service, Forest PestManagement. 45 p.

Southern Forest Products Association. 1983. Thesafe use of herbicides: A brief summary of infor-mation presented in the herbicide safety work-shop program. New Orleans: Southern ForestProducts Association. 7 p.

Thatcher, Robert C.; Searcy, Janet L.; Coster, JackE. ; Hertel, Gerard D. 1980. The southern pinebeetle. Technical Bulletin 163 1. Washington:U.S. Department of Agriculture. 266 p.

Timm, Robert M., ed. 1983. Prevention and con-trol of wildlife damage. Lincoln, NE: Univer-sity of Nebraska, Cooperative ExtensionService. 661 p.

4 3

INDEX

Acute toxicity, 35.Aerial application, 11.Annosus root rot, 26.Annosus root rot chemicial protection, 26.Application rate, 10.Application timing, 10.Application types, 10.Applying pesticides, 33.

Bald cypress, 2.Banded applications, 20.Bark beetle chemical control, 24.Basal soil spots, 13.Basal sprays, 13.Beaver, 29.Biological control, 5.Black turpentine beetle, 24.Broadcast, 10.Brush, 9.

Calibration for band applications, 2 1.Cedar, 2.Chemical control, 6.Chronic toxicity, 35.Climax forest, 2.Cotton rat, 29.Crop tree release, 10.Cultural control, 5.Cypress, bald, 2.

Decomposition zone, 1.Deer, 29.Dermal toxicity, 35.Directed foliar sprays, 13.Diseases, 4.Disposal of pesticides, 34.

Endangered Species Act, 41.Environmental considerations, 4 1.Experimental Use Permit, 6.Exposure to pesticides, 35.

Forest, 1.Forest ecosystem, 1.Forest nurseries, 27.Forest pests, 4.Forest succession, 2.Forest types, 2.Fox squirrels, 30.Full basal sprays, 13.

General-use pesticide, 6, 7.Geology, 41.Granule applications, 18.Gum, 2.Gypsy moth, 25.Gypsy moth chemical control, 26.

Half-life, 35.Hand broadcast spreaders, 19.Hazard, 35.Hemlock, 2.Herbaceous weeds, 20.Herbaceous weed control, 9, 20.Hickory, 2.Hogs, feral, 30.

Injection, 13.Inorganic pesticides, 7.Ips beetle, 23.Insects, 4.Integrated pest management, 1, 5.

LD5a, 35.Legal control, 5.Living microorganizms, 7.

Manual ground application, 12.Mechanical ground application, 11.Mechanical or physical control, 5.Mixing pesticides, 33.

oak, 2.

Federal Insecticide, Fungicide, and Rodenticide Pales weevil, 25.Act, 6. Parts per billion (p.p.b.), 35.

Foliar sprays, directed, 13. Parts per million (p.p.m.), 35.

4 5

Persistence, 40.Pests, forest, 1.Pest management strategies, 5.Pesticides, 6.Pesticides, disposal of, 34.Pesticides, exposure to, 35,Pesticides, general use, 6,Pesticides, inorganic, 7.Pesticide label, 33.Pesticide mixing, 33.Pesticide resistance, 7.Pesticide toxicity, 35.Physical control, 5.Pine

loblolly , 2.longleaf, 2.shortleaf, 2.slash, 2.white, 2.

Pine bark beetle, 23.Pine reproduction weevils, 25; chemical control

of, 25.Pine sawfly, 24; chemical control of, 25.Pine tip moth, 24.Pioneer plants, 2.Pitch-eating weevil, 25.Plant-derived organic pesticides, 7.Pocket gopher, 30.p.p.b. (part per billion), 35.p.p.m. (parts per million), 35.Postemergent, 11.Preemergent, 10.Preplant, 10.Prescribed burning, 6.

Rabbits, 30.Rat, cotton, 29.Resistant varieties, 5.Restricted-use pesticide, 7.Rodents, small, 29.

Sanitation, 5.Seed orchards, 27.Sinkholes, 41.Site preparation, 9. ISoil organic matter, 41.Soil permeability, 41.Soil spot application, 14.Soil spots by grid, 16.Soil texture, 14, 40.Solubility, 40.Southern pine beetle, 23.Special Local Needs (SLN) registration, 7.Spill procedures, 35.Spot applications for herbaceous weed control, 22.Spotguns, 15.Sprays, directed foliar, 13.Squirrels, fox, 30.Stands, forest, 1.Storage of pesticides, 34.Stream line basal sprays, 13.Stump sprays, 13, 17.Synthetic organic pesticide, 7.

Texas leaf-cutting ant, 25; chemical control of, 25.Timber stand improvement, 10.Timing of applications, 10.Tipmoth chemical control, 24.Toxicity, 35; dermal, 35; categories, 36.Transitional species, 2.Transport of pesticides, 34.Tree injection, 16.

Vertebrate animals, 4; control of, 29.Vines, 9.Volatility, 35, 39.Vole, 29.

Weeds, 4; categories, 9.Weed trees, 9.Weevil, pales, 25.

4 6