## BAYER CROPSCIENCE SUBMISSION

APPLICATION METHODS AND UTILITY OF SULFONYLUREA
HERBICIDES IN NON

‐ CROP, RANGELAND, AND FORESTRY AREAS

MARCH 2016

Bayer CropScience LP

2 TW Alexander Drive

RTP, NC 277091



## APPLICATION METHODS AND UTILITY OF SULFONYLUREA HERBICI DES
IN NON

- CROP, RANGELAND, AND FORESTRY AREAS

Harvey A. Holt , Ph.D. Professor Emeritus, Purdue University Seattle, WA 98146 holth@purdue.edu Page Rights

- of

- way

................................ ................................ ................................ ................................ .. 3 Right

- of

- Way Resource

................................ ................................ ................................ ....... 4
Roadside

................................ ................................ ................................ .............................. 6 Safety Recovery Zone (Clear Zone)

................................ ................................ ......... 6 Sign Visibility

................................ ................................ ................................ ........... 6 Sight Distance

................................ ................................ ................................ .......... 7 Drainage Enhancement and Ditches

................................ ................................ ....... 7
R oad Surface Degradation

................................ ................................ ...................... 8 Snow Drift Control

................................ ................................ ................................ .. 8
Fire Hazard Reduction

................................ ................................ ............................. 8 Appearance

................................ ................................ ................................ ............. 8
Guide Rails

................................ ................................ ................................ .............. 9
Median Barriers

................................ ................................ ................................ ...... 9 Sign Posts and Delineators

................................ ................................ .................... 10
Fences

................................ ................................ ................................ ................... 10 Structures, A butments, Headwalls and Inlets

................................ ...................... 10 Storage Yards

................................ ................................ ................................ ........ 10
Road Shoulders

................................ ................................ ................................ ..... 10
Cur bs, Gutters and Median Islands

................................ ................................ ....... 11 Broadleaf Weeds

................................ ................................ ................................ ... 11 Special Grass Control

................................ ................................ ............................ 11 Electric Utility

................................ ................................ ................................ .................... 12
Conductor Clearance

................................ ................................ ............................ 12
Structures

................................ ................................ ................................ .............. 13 Emergency Line Service

................................ ................................ ........................ 13
Substations and S torage Yards

................................ ................................ ............. 13
Railroads

................................ ................................ ................................ ............................ 13
Yards

................................ ................................ ................................ ...................... 13 Bridges

................................ ................................ ................................ .................. 14
Line

- of

- Road

................................ ................................ ................................ .......... 142 Road Crossings

................................ ................................ ................................ ...... 15
Brush Control

................................ ................................ ................................ ........ 15 Pipelines

................................ ................................ ................................ ............................ 16 Right

- of

- Way

................................ ................................ ................................ ......... 16 Pumping Stat ions

................................ ................................ ................................ .. 16 Summary

................................ ................................ ................................ ........................... 16 Rangeland

................................ ................................ ................................ ................................ ..... 17 Forestry

................................ ................................ ................................ ................................ ......... 18
Noxious Weeds

................................ ................................ ................................ ............................. 19
He rbicide Application Equipment

................................ ................................ ................................ . 20
Bro adcast Liquid Application

................................ ................................ ............................ 20 Boom with Conventional Tips

................................ ................................ ............... 20 Regular Flat Fan

................................ ................................ ........................ 20 Flooding Flat Fan

................................ ................................ ....................... 20
Whirl

- Chamber Nozzle

................................ ................................ .............. 21 Rain Drop

................................ ................................ ................................ .. 21 Boomless Spraying

................................ ................................ ................................ 21 Off

- Center Nozzle

................................ ................................ ...................... 22
Boom

- Buster Nozzle

................................ ................................ ................. 22 Straight Stream Nozzle

................................ ................................ .............. 22
Radiarc

................................ ................................ ................................ ...... 23
Directa

- Spra

................................ ................................ .............................. 23 Directed Liquid Application

................................ ................................ ............................... 24 Handgun

................................ ................................ ................................ ................ 24 Backpack Sprayer

................................ ................................ ................................ .. 24 Dual Spray Gunjet

................................ ................................ ................................ . 25 Aerial Application

................................ ................................ ................................ .............. 26
Micro

- Foil Boom

................................ ................................ ................................ ... 26
Thru

- Valve Boom (TVB)

................................ ................................ ......................... 26 Summary

................................ ................................ ................................ ........................... 27
R ole of Specific SU Herbicides

................................ ................................ ................................ ...... 27
The Realities of Buffers

................................ ................................ ................................ ................. 27 Appropriate Ways

................................ ................................ ................................ ............. 28 Appropriate Equipme nt

................................ ................................ ................................ .... 29 Knowledgeable Applica tors

................................ ................................ .............................. 30 Summary

................................ ................................ ................................ ................................ ....... 31
References

................................ ................................ ................................ ................................ .... 31 Acknowledgements

................................ ................................ ................................ ....................... 323

Credentials

................................ ................................ ................................ ................................ .... 334



## THE USE AND BENEFITS OF SULFONYLUREA HERB ICIDES

Harvey A. Holt , Ph.D. Professor Emeritus, Purdue University Seattle, WA 98146 holth@purdue.edu

When the sulfonylurea (SU) herbicides entered the market in the 1980’s, the y revolutionized

non

- crop use. Sulfometuron

- methyl, metsulfuron

- methyl and chlorsulfuron had a special fit in

non

- crop uses. First, weed control was better. In an application industry that lives on guaranteed contracts, no one is going to pass on improved weed control, regardless of specific objective . The perennial weed bouncing bet ( Saponaria officinalis ) was a common occurrence on railroads . It literally disappeared after sulfometuron

- methyl u se. Second, t he ability for 4
ounces of sulfometuron

- methyl to replace 6

- 8 pounds of simazine + 6

- 8 pounds of diuron was fantastic on so many levels. The obvious thought is reducing the environmental load of
herbicide. Ounces replaced pounds. Operationally , applicators that haul their herbicides on
their trucks could literally haul more acres of products before reloading. Applicators using large tanks spent less time because opening a jug took less time tha n opening bags and bags. Applicators using small ta nks had to find new ways to measure very small amounts of a herbicide . Because the products were priced per ounce, proper sprayer calibration was especially critical and precise application became the prime objective. That the new herbicides
were incredibl y active at low rates meant that drift control was imperative. The application industry accepted, adapted, and embraced these new products because their advantages greatly exceeded their potential issues.

O bjective s of this document are to educate on curre nt application technology; educate on the importance of IVM and ROW vegetation management; and to highlight the importance of SUs to IVM across the non

- crop markets. The document will discuss the general area s of non

- crop vegetation management in which SUs play a role. For example, SUs are not used for tree injection so this practice will not be discussed.



### RIGHTS

- OF

- WAY

The nation’s rights

- of

- way (ROW) provide a major conduit for the flow of goods and services vital to the American economy. Major ROW include lands set aside for roadside, electric utility, railroad, and pipelines, and total more than 6 0 million vegetative acres across the country (Table 1) . Since ROW are related to supplies and services for people, most ROW acres are located in the hea vily populated eastern U.S. ROW in eastern U.S., that area east of the Mississippi River, are located in a climatic zone favorable for vegetation growth. Generally adequate rainfall throughout the growing season and warm temperatures serve to enhance weed growth and reduce prolonged herbicide control

. In the absence of any control program5

hardwood tree species would become the dominant vegetation on the ROW. Northern conifers are prevalent in the the northeast and lake states; southern pine and mixed hardwoods in the south and southeast. These two regions are separated by the Central Hardwood region. Tall grass and short grass prairies dominate the states of the C entral
P lains. Trees mostly occur along water courses. The Rocky Mountain s has its compliment of woody species, but tree growth tends to be slow. West of the Rocky
Mountain tends to be semi

- arid to arid except along the west coast and particulary
the far corner of the Pacific Northwest where abundant rain makes for rapidly

grow ing trees and other vegetation. (Figure 1)

R eliability and public safety are major
concerns across all ROW. The ROW must allow workers to perform their function without hazards to those that use and depend on
them. Unlike other use site s , mismanagement of vegetation on ROW can have drastic and fatal
effects on peoples ’ lives.



### RIGHT

- OF

- WAY RESOURCE

Rights

- of

- way are co rridors that traverse a continuous array of properties, ownerships, topography, and adjacent crops. Generally speaking, only railroads and highways actually own the ROW. Electric utilities and pipeline companies generally have easements to access, manage

a nd maintain the ROW and the infrastructure on
it.

Table 1 illustrates the s cope and magnitude of vegetative acres in ROW of the U.S. ROW are most impacted by the imposition of buffers because a ROW is essentially a very narrow strip
of land. Table 1 lists the distance to the edge of
the ROW. I mposing a 25 ft buffer on any ROW 25 ft wide or less would preclude the use of any SU
herbicide on that ROW. It’s not just a buffer. It actually impacts the vegetation management on literally millions of acres (Figure 2) . The tragic part is that the buffer alters the management on rural county roads, which, according to the Figure 1. Vegetation zones of the U.S.

Figure 2 . The vegetat ive area for county roads is so narrow that any buffer effectively eliminates the SU herbicide from the programs of the greatest number of roadside miles.6

Dept. of Transportation, “in an era where we’ve seen a 25% decline in roadway fatalities over the past 10 years, far too many deaths are still occurring on the roads” managed by county
governments.

Table 1. V egetative ROW acres based on widths for major ROW types. (ROW sources listed in Reference section)

ROW Type (Date of data) ROW

Width (ft) Vegetation

Width (ft) Distance to

ROW edge (ft) US Total

(miles) US Total

( vegetation acres) Railroad (2012) 100 1 100 50 138,524 1,679,079 Highway

– rural 2 (2015) Interstate, freeways, & expressways 300 252 3 126 34,561 1,055,681
Principal & minor arterials 75 51 4 26.5 222,974 1,378,199
Major & minor collectors 50 26 5 13 668,8000 2,107,733

Local 50 26 6 13 2,049,049 6,457,609 Oil pipelines (2013) 50 50 25

Crude 50 50 25 49,974 302,873 Product 50 50 25 87,452 530,012 Gas pipelines (2013) Distribution mains 20 20 10 1,255,035 3,042,509 Transmission 50 50 25 302,777 1,835,012 Gathering lines 20 20 10 17,369 42,107 Electric transmission (private utilities) (structure miles) 7 (1974)

<31 KV 40 40 20 7,622 36,955 31

- 50 KV 50 50 25 397,885 2,411,424 51

- 131 KV 75 75 37.5 1,259,473 11,449,755 132

- 188 KV 110 110 55 752,480 10,033,067 189

- 253 KV 125 125 62.5 487,381 7,384,561 254

- 400 KV 150 150 75 332,636 6,047,927 401

- 600 KV 180 180 90 193,244 4,216,233 601

- 850 KV 225 225 112.5 46,500 1,268,182 Grand Total: 61,278,918

1 ROW width based on discussions with railroad applicators.

2 ROW width currently based on discussions with DOT personnel from IN and MD, and FHA personnel.

3 Excludes two lanes, each 24 ft wide.

4 Excludes a 24 ft road

5 Excludes a 24 ft road

6 ROW width based on consultation with county noxious weed coordinators.

7 ROW widths made in consultation with electric utility and other knowledgeable personnel. The ROW of agencies such as TVA and BPA are not included.7 ROADSIDE
Maintaining the nation's roadside ROW , the areas between the edge of the pavement and the
outside ROW boundary, focuses on safe travel for the motoring public. These areas may be either constructed or natural, and they may include the median strips on multilane highways and interchange areas. Roadside vegetation is controlled for 1) safety concerns, 2) road structure maintenance, and 3) appearance or beauty. Historically, the following roadside sites were managed manually or mechanically. Herbicides proved to be more effective at less cost.
Th e array of alternative herbicide treatments presented by the family of SU herbicides enhanced the chemical option.

Safety Recovery Zone (Clear Zone)

Vehicles need a safe place to stop when they accidentally leave the road. This area is called the safety recovery zone or clear zone. Roads designed for higher traffic speed and density h ave wider safety recovery zones than roads designed for slower speeds and less traffic (Figure 3 )

. Cut slopes require narrower safety recovery zones than do flat areas. Steep fills require the widest safety recovery zones. Since many vehicles
continue on t o the bottom of steep slopes, a clear area beyond the edge of the slope is desirable. Trees are the major vegetation problem in the safety recovery zone . Trees are the single greatest
cause of fatalities from vehicle collisions with fixed objects. Individu al state policies differ on the size and height of trees permitted in the recovery zone, ranging from no trees allowed at
all to trees allowed that are less than four inches in diameter at one foot above ground.

Sign Visibility
Signs along roadsides must be visible regardless of season, time of day, or weather conditions (Figure
4 ). Signs convey warnings, guidance, and information. They are an important part of road safety, and can prevent accidents and driver confusion. Hidden signs are a safety hazard
b ecause their message is obscured. Undesired vegetation can be near the sign or between the sign and the point where the driver should see the sign. Figure 3

. The safety recovery zone is an integral part of the highway design.

Figure 4 . Signs need to be visible for traffic safety and driving convenience.8 Sight Distance
The length of road visible to the driver is the sight distance. Clear sight distance is needed for stopping and for making decisions about turning, changing lanes, passing, and entering the roadway. As speed increases, greater sight distance is needed. Vegetation has its greatest
effect on sight distance on two

- lane, rural highways. Vegetation can block sight distance at
intersections and across curve s (Figure 5 ).
Depth perception on the right side of the vehicle is difficult for many drivers. Vegetation encroaching from the shoulders often forces or subtly directs
drivers to the center of the road on two

- lane highways. This can reduce driver safety. E ncroaching vegetation affects driver behavior most when weeds occur in short, isolated sections. Tall vegetation and overgrown shrubs should be kept far enough from the roadside so as not to influence driver behavior.

Drainage Enhancement and Ditches
Vegetation growing on the road shoulder can slow w ater from draining off the road

. Water on the road surface can cause automobile hydroplaning or become ice patches in winter. Water that does not run off the road often collects or runs down the pavement. T he flowing water gathers force and eventually breaks over the edge. The increased water pressure causes erosion of the shoulder at that point. Weed dams are a particular problem under guide rails where machine grading is not possible , but herbicide treatme nt is

. Weeds growing around or over inlets can slow water drainage. The area around drainage inlets should be kept free of
weeds.
Drainage ditches in eastern U.S. are usually managed in a selective manner, i.e., woody plants are controlled while leaving g rass cover . Woody plants and other plants that catch debris and restrict water flow are the main problem in these ditches. Low

- growing grass is desirable because it controls erosion, and it minimizing interference with flowing water. Grass buffers
can also act as biofilters by trapping sediment. Vegetation control promotes rapid drainage and often improves the appearance of the ditch.

Sometimes roadside drainage ditches are maintained weed free to facilitate rapid water movement after storms, particularly in western U.S. The presence of vegetation slows water Figure 5

. The encroaching trees obstruct vision across the curve for motorists on the roadway and prevent snow melt

.9

flow and traps soil in the ditch. Over time the ditches accumulate soil that m ust be mechanically removed to maintain the ditch. Residual soil active herbicides are applied on these drainage ditches during dry periods.
Road Surface Degradation
Water can speed the degradation of pavement and road surfaces, soften and reduce the supporting ability of subgrades and shoulders

. Weeds can destroy paved shoulders by growing through cracks and accelerating deterioration. Once established in the crack where the shoulder meets the road surface, roots or creeping rhi zomes can punch through the road surface. The surface of roads shaded by trees dries slower, and ice and snow take longer to melt. Water reduces the life of the surface, especially asphalt.

Snow Drift Control
Snowdrifts occur on the downwind side of any ob stacle that slows the wind. Tall vegetation, either trees or weeds, can cause drifts as the snow piles up behind the vegetation. Fences, barriers, median plantings, and guide rails clogged with weeds or overgrown with vines can
cause snow to drift. Narrow bands of vegetation upwind from the road and downwind from
wide

- open spaces increase snowdrifts on the road. Since an obstacle has an influence distance
of 15

- 20 times its height, vegetation some distance from the roadside may require control in

areas susc eptible to snow drifting.

Fire Hazard Reduction
Hot catalytic converters and mufflers can ignite dry vegetation. In western U.S. where annual grasses such as wild oats and cheatgrass complete their life cycle with the onset of drought
, weed

- free areas wider than the normal
road shoulders are maintained so vehicles can pull off the road without risk of igniting a fire (Figure 6 ).

Appearance Figure 6 . Roadside fires can be serious problems when invasive grasses mature.10

Roadsides are highly visible to the public. Vegetation management enhances the appearance of the roadside and gives the road a definite delineation to motorists (Figure 7 ). Their appearance varies from rough turf to manicured lawns and from planted flowers to native vegetation. Managing roa dsides to meet the requirements of native vegetation can maintain
their dominance. When roadside vegetation management meets the functional requirements for transportation (safety recovery, sight distance, sign visibility), improved appearance can be a low

cost fringe benefit.

Guide Rails
Guide rails prevent cars from leaving the road where adequate recovery space is not available. They are a visual warning to the motorist to be alert. Weeds must be controlled to ensure that guide rails are seen by motorists and inspected by maintenance per sonnel (Figure 8 ). Weeds growing around the guide rails also hold moisture, which causes the guide rails to rust. Guide rails are usually established in asphalt, gravel, or grass. Aggregates and winter

- applied abrasives tend to accumulate under guide rails . These materials hold moisture that degrades the asphalt and promotes weed growth. Also, weeds grow in the crevices around the guide

- rail support posts when they are set in asphalt. Guide rails can be treated with a variety of techniques, such as a handgu n, a Radiarc, a short boom with nozzles spraying each side of the guide rail, flood nozzles,
or off

- center nozzles treating in front of and under the guide rail.

Median Barriers
Median barriers prevent traffic from crossing into

on

- coming lanes. Median barriers catch and accumulate aggregates and abrasives that support weed growth (Figure 9 ). Herbicides are applied with a variety of methods including Figure 7 . Vegetation management improves appearance and road delineation.

Figure 8. Guide rails need to be seen by motorists as well as maintenance inspectors.

Figure 9 . Weeds will grow in the aggregate that accumulates at the base of median barriers.11

handguns, of f

- center, or straight stream nozzles. Treatments are commonly only spot applications.12

Signposts and Delineators
Like guide rails, signposts and delineators are anchored in soil or asphalt. They are also subject to rusting caused by weeds. Mowing next to these types of obstructions is not possible.
Removal of weeds with a nonselective herbicide
treatment in an area a round the posts large enough to overlap with mowers is usually done with handguns (Figure 10 ).

Fences Mowing around or next to fences is difficult. The
ideal control is a banded residual weed control treatment (Figure 1 1 ). Weeds near fences are commonly treated with handguns or backpack

sprayers.

Structures, Abutments, Headwalls, and Inlets
Vegetation degr ades abutments and headwalls. However, mowing around them is troublesome. Weed control around drain inlets is necessary for visibility and drainage maintenance. Usually herbicides are applied with handguns or backpack sprayers. Care must be taken not to

sp ray in to the drain itself.

Storage Yards
Weed control in storage yards provides a safe work area, enables workers to find parts and supplies when needed, and reduces equipment deterioration. Weed control with herbicides is commonly used because obstruction s make mowing difficult, especially in areas other than the alleyways. If size permits, broadcast herbicide application equipment can be used in combination with handguns for inaccessible areas. Granular and pelleted formulations are
convenient to use in s torage yards.

Road Shoulders
Total vegetation control eliminates the deteriorating effect of weeds growing through the edge of the asphalt. It provides a clear area for motorists to stop, and it reduces the risk of fire (Figure 1 2 ). Weeds growing through t he shoulder loosen the soil. A weed free shoulder stays Figure 10. Total vegetation control around delineator posts facilitates mowing.

Figure 11 . Weed control under fences reduces maintenance costs.13

compacted, making it safer for vehicles to stop and start. Maintaining a compacted shoulder
reduces soil erosion and the need for mechanical grading operations to smooth and dress the
shoulder area. A nonselective herbicide treatment is used for maintaining this weed

- free zone without disturbing the shoulder. In most cases,
shou lder treatments are applied with a moving vehicle equipped to treat the shoulder area ;

Radiarc, Boom

- Buster, or small OC nozzle

. Curbs, Gutters, and Median Islands
Curbs, gutters, and med ian islands have a variety of surface materials, including soil, concrete, asphalt, gravel, or brick. The non

- soil surfaces have cracks where weeds can grow (Figure 1 3 ).
Weeds attract litter and harbor rodents. A herbicide treatment is applied to these cra cks and crevices to prevent weed growth, and is usually applied with a backpack or handgun.

Broadleaf Weeds
The presence of tall growing broadleaf weeds gives the roadside an unkempt appearance. Control of these weeds is the major effort of many vegetation management programs. Broadleaf weed control can be done throughout the growing season. If treatments are

co nducted in the spring while the weeds are small and hidden by the grass, the results will be less noticeable. Fall applications are effective for controlling germinating winter annuals and biennials in the rosette stage. Treatments to control broadleaf wee ds can be applied as a spot or a broadcast treatment by a variety of methods, including boom and boomless spray equipment.

Special Grass Control
Special grass

- control programs include Johnsongrass, fescue, or wild oat co ntrol, and Bermudagrass release . Controlling one grass species in another grass can sometimes be accomplished by 1) careful control of application rate or treatment timing, 2) using directed application, or 3) taking advantage of the difference in plant heights. These treatments are

app lied by broadcast, spot, or wiping equipment. Figure 12

. Vegetation on the road shoulder increases maintenance problems.

Figure 1 3 . Cracks and crevices support vegetation on roadsides.14 ELECTRIC UTILITY
Electric utilities control vegetation to keep electricity flowing through the conductors, promote public safety, allow inspection of the infrastructure, insure emergency access, and maintain equipment operation.
Conductor Clearance

Conductor clearance around an electrical transmission
line is at the heart of vegetation control for a utility. Transmission lines carry electricity from generation
source to substation and substation to substation. Unlike distribution lines transmission voltages are measured in thousands of volts (KV), personal contact is fatal, and contact with vegetation causes regional blackouts. While tall growing trees are usually considered to be major culprits, the relative height of the tree to the conductor is more important (Figure
1 4 ) . Transmission lines sag under load, the lines sway in wind, and the arcing distance increases with increase voltage. Consequently, as transmission voltage increases poles or towers become taller, insulators become longer, and the ROW increases in width.
While trees at mid

- span are usually of concern, as transmission lines cross undulating terrain the short tree on the ridge may be a more serious issue than the tall tree in the valley. Mismanagement of vegetation on a transmission line is likely a career altering event for the person in charge.

All ROW ma nagers in the eastern U.S. and the Pacific Northwest contend with trees. Trees also occur in other regions of the U.S., but are notably sparser or slower growing. Usually the objective is to selectively control some trees. Typically, control is directed at the tall woody species with the goal of releasing lower growing vegetation that will occupy the site and hinder tree species establishment. Because of their size, woody plants can be treated individually or collectively , and in a number of ways

. The SU he rbicides used for woody plant control are applied to the foliage.

Foliar applications are an easy way to control dense stands of woody plants. The largest selection of herbicides is available for this method of control. These applications can be made
with a hose and handgun for spot or broadcast treatment s, or other broadcast equipment

. The brown foliage that results from many herbicide treatments (brownout), particularly for tall trees, may create a visual problem for the public. Brown foliage on small tre es is not as noticeable. When brush control treatments are applied in late summer or early fall, the brown foliage blends better with natural leaf senescence. Figure 14 . Because transmission line sag under load and sway in the wind, structure height and ROW width increase as voltage increases.15 Structures
Both wooden and steel structures should be free of vegetation so structures and insu lators can be inspected for preventative maintenance. Inspection can be done from helicopter or ground
surveillance.
Emergency Line Service

Electric transmission ROW need to be free of large vegetation so crews have access to sites for emergency line service. Lines free of overhanging vegetation are less likely to be taken down by limbs falling during storms.

Substations and Storage Yards
Total weed control is important in substations and storage yards (Figure 1 5 ) . Vegetation poses a fire hazard, harbors insect pests and rodents, disrupts the equipment in substations, and is an aesthetic problem. It is important to keep these areas weed free to prevent tripping and falling when employees are working with the elect rified equipment.

R AILROADS
Railroads need to control vegetation for the similar reason s as electric utilities and roadsides. The areas of control fall into five broad groups: yards, bridges, line

- of

- road, road crossings, and
brush.

Yards
Weed control in yards is done to provide the safe work place required by the Federal Railroad Administration (FRA); to prevent fires around buildings and storage sites; to prevent wheel slipp age; to facilitate maintenance and inspection; and to improve appearance (Figure

1 6 )

. Railroad yard treatments use residual soil active herbicides applied early in the growing season to prevent weed and grass growth around yards, switches, buildings, and s torage areas. Long

- term vegetation control is desired. The equipment most often used is a fixed boom sprayer equipped with flat fan , Boom

- Buster or off

- center nozzles mounted on a hi

- rail truck. Figure 16

. Vegetation in yards is a serious hazard to railroad employees. Figure 15

. Substations are kept weed free for employee safety and fire hazard reduction.16

Boom

- Buster and o ff

- center (OC) nozzles are used to supplemen t the fixed boom in order to treat adjacent tracks in a single pass. A hand

- held spray gun may be needed around buildings or
on “stub” tracks and other areas inaccessible to a track mounted vehicle.

B ridges
Vegetation control around bridges, especially wooden bridges, is necessary to reduce fire hazard and to facilitate structure inspection and
maintenance (Figure 1 7 )

. Railroad bridge
treatments involve the use of residual soil a ctive herbicides applied early in the growing season to prevent vegetative growth around the supports of wooden bridges. Vegetation control for the length of the growing season is desired.

Line

- of

- Road

The line

- of

- road phase of railroad vegetation
control refers to main lines and branch lines , as well a s signals and structures along the tracks . It usually has the greatest number of treated acres compared to the other phases of railroad vegetation management (Figure 1 8 )

. Vegetation control is needed to protect the roadbed by maintaining proper drainage, to allow track inspection, to improv e visibility
, and working of signals, switches, signs, and crossings, and to reduce fire hazard along the ROW. Line

- of

- road

operations usually require a postemergence treatment for short

term weed control. Weeds are present when the treatment is
made and n ew weeds may begin growing before a killing frost. The equipment usually used is the same as that used in the yard treatment

-- a hi

- rail truck or spray train usually equipped with fixed booms and
Boom

- Buster nozzles (Figure 1 9 ). Figure 1 7

. Vegetation around wooden bridges is a serious fire hazard.

Figure 1 8 . Vegetation control in roadway ballast preserves ties and track stability.

Figure 1 9 . Hi

- rail trucks are used to treat line

- of

- road
, yards
, and bridges.17

Most line

- of

- road is treated as a spot treatment only at areas where weeds are growing. The
four feet on each side of the tracks at the edge of the ballast (the toe path) is the only part that is generally treated continuously . Most railroads a monitored f or weed presence at least twice in the growing season. The second application is focused on weed escapes and vines encroaching from the ROW edge.

Road Cro s sings
Road crossing treatm ents are applied to the areas on either side of highway grade crossings to improve visibility and comply with state legal requirements by both the automobile and the train engineer (Figure 20 )

. Road crossing treatments are usually applied after weeds have emerged, and are usually intended to suppress the vegetation on the railroad right

- of

- way rather than to eliminate it. Because track time
is so critical and often limited and road crossing

are readily accessible by road, crossing treatments tend to be conducted by special crews with

a variety of hand equipment and an array of herbicides to apply the most effective treatment to the vegetation, which can vary by quadrant of the road crossing.

Brush Control
Brush control is necessary to maintain visibility around signs, signals, and crossings. Brush
control is for clearance to keep woody plants from encroaching and striking railcars or employees as they pass (Fig u re s 21 a, 21b ) . Woody plant control is generally on a 3

- 4

- year cycle Figure 20

. Both trains and traffic need to be seen at road crossings.

Figure 21a

. Brush control prevents limbs from hitting railcars and employees. Figure 21b. Brownout resulting from chemical side trimming to reduce encroachment.18

and is a major program in eastern U.S

. The brush treatments amount to side trimming to reduce encroachment. The brown foliage can be managed by herbicide selection and timing of application.

PIPELINES

Right

- of W ay Vegetation management issues for pipelines parallels electric utilities in many respects. Vegetation control on the pipeline ROW is necessary for inspection, access, and safety.
ROW free of brush can be inspected to find warning signs of leaks (Figure 2 2 ). Open ROW
enable crews to conduct maintenance and emergency repairs. Total vegetation control around pumping stations and storage tanks is important for reducing fire hazard.

Pumping Stations
Season long vegetation control is necessary in pumping stations for fire hazard reduction and facility reliability (Figure 2 3 ) . Handgun applications are most common around the actual equipment a nd facilities. Some areas with substantial open ground can be treated with short booms on light trucks or all

- terrain vehicles

.

SUMMARY
Rights

- of

- way vegetation management is necessary for adequate safety, infrastructure maintenance, and improved appearance. All contribute to safe and reliable operations. Vegetation management performed for fire prevention, employee and public safety, faci lities inspection, as well as noxious weed law compliance, are important for all ROW . The goals
remain the same

– protect people, move goods and services, and protect the environment. Figure 22. Brush control on pipelines is necessary for leak inspection and ma intenance.

Figure 2 3

. Total vegetation control is imperative at pumping stations.19 

### RANGELAND

Range and grassland pasture is perhaps the largest land use area in the U.S.; approximately 587 million acres ( Lubowski, Vesterby, Bucholtz et.al., 2006) (Figure 24). Most is controlled by federal agencies; particularly the Bureau of Land Management. Range improvement is largely a matter of controlling undesired we eds, of which most fall in the legal category of “noxious weeds”. Legally, a noxious weed is any plant designated a federal, state, or county government to be injurious to public health, agriculture, recreation, wildlife, or any public or private property. The list maybe defined at the state or even the county level. Each government entity can define the nature of control that should be or must be applied to that weed’s occurrence.

Most of our rangeland weeds originated in Europe or Asia and were introduce d to the western ranges in the nineteenth century. Without their native controls of insects, pathogens , and
herbivores these weeds dominate the U.S. native plants and can create large monocultures. These monocultures can increase wind and water erosion, de crease capture, storage, and proper release of rainfall, as well as alter nutrient cycling. These monocultures reduce biological diversity by displacing the fauna that depend on the native plants for habitat and food. The grazing capacity of weed

- infested land can be reduced by up to 75% (Sheley, Petroff, and Bormann, 1998).

Once non

- indigenous plants become established, they are usually permanent in ecological time and very difficult to manage (Coblentz, 1990). Developing a noxious weed control program requires using a combination of methods to limit weed encroachment (Sheley, Manoukian and Marks, 1999). Such methods include:

 Limiting weed seed dispersal

 Containing neighboring weed infestations

 Minimizing soil disturbance Figure 24. The range resource encompasses millions of acres. The sagebrush on the left is critical habitat for the sage grouse; the annual grass on the right depletes soil moisture a nd become a fire hazard.20

 Detecting and eradicating weed introductions early

 Establishing competitive grasses

 Properly managing grasses None of these principles involve buffers. Buffers are counterproductive to controlling noxious
weeds.



### FORESTRY

The U.S. forest resource cove rs about 517 million acres (Lubowski, Vesterby, Bucholtz et.al., 2006). The conifer regions (about 300 million acres) of southern and southeastern U.S., the Pacific Northwest, the Lake States, and northeast are the areas of major industry ownership and the most intensive culture These are the areas of greatest herbicide use for site preparation (Figure 25 ), plantation establishment (Figure 26) , and conifer release (Figure 27)

. Applications are made from the ground or aerially.

The Central Hardwood region (a pproximately 125 million acres) between the conifer regions of eastern U.S. is characterized by private ownership. The primary herbicide use is banded treatments to establish newly planted seedlings (Figures 28 and 29)

Competition control before planting or at planting results in increased height and diameter growth of pine seedlings until crown closure. In studys duplicated in Te xas, Mississippi, and South Carolina all Figure 25 . Site preparation controls vegetation left on site af t er harvest.

Figure 26. Herbicide applied at edges of planting bed for residual control

.

Figure 28 . Herbicides banded at planting gives seedlings site resources to become established. Figure 27. Aerial application o f herbicide to release conifer plantation from hardwood trees and related plants

.

Figure 29 . Directed herbicide gives selectivity for plantation release

.21

treatments containing sulfometuron

- methyl had greater height and diameter growth than untreated plots (Ezell, A.W., J.L. Yeiser and L.R. Nelson, 2013).



### NOXIOUS WEEDS

Most rights

- of

- way managers are confronted with “ noxious weeds.” Many states have declared certain plants to be "noxious weeds" because they have a detrimental effect on public health, agricultural crops, natural ecosystem function, or animal production. State law may require their control. If the agency or company responsible for the property does not control these weeds, local governments can contract the work to an outside group and charge the negligent
party.
Noxious weeds earn their notoriety not just by reducing grazing and related Animal Unit Months. Also included in the array of their undesirable characteristics:

Toxic to horses , cattle, pigs, humans Seed awns cause injury to nose and eyes of grazing animals Dense stands crowd out native vegetation Deplete soil moisture early Liver damage when ingested Contact with sap causes severe dermatitis on people Spread seeds by tumbling Degrades wildlife habitat Causes birth defects Climbing growth smothers trees Causes abortions Creates impenetrable barrier Causes tainted milk Causes photo

- sensitization when grazed

There are serious reasons why noxious weeds have that designation. The idea of only controlling some of them because they are too close to the edge of the field is incongruous.



### HERBICID E APPLICATION EQUIPM ENT

A pplications of the sulfonylurea (SU) herbicides are made in a liquid form. All liquid spray equipment has unique advantages and disadvantages. Most are usually operated at low pressures, less than 40 psi at the spray tip.

B ROADCAST LIQUID APPLICATION

B oom sprayers are used for broadcast applications of herbicides. The boom is equipped with a
row of similar nozzles that break the spray solution into small drops and distribute the spray in a specific pattern. Nozzle performance depends on nozzle type , tip design, operating pressure, size of the opening, discharge angle, speed, and distance of nozzle from the target.

Boom w ith Conventional Tips22

Regular Flat Fan
The regular flat fan (Figure 30 ) is the most commonly used nozzle for boom application of liquid sprays. The regular flat fan tip makes a narrow oval pattern with tapered edges. It is used for broadcast applications at 15

- 40 psi. Fan spray angle is the angle between the edges
of the s pray pattern. Tips are available with fan spray angles of 25, 50, 65, 73, 80, and 110 degrees. The nozzles are usually spaced 12

- 20 inches apart on the boom. Boom applications are particularly useful over railroad ballast. To prevent drift typical nozzle tips are 80 degrees or less and apply one gallon or more per minute (8010, 8015, 8020), which is about 2X the usual agriculture nozzle tip.

Flooding Flat Fan Nozzle

A flooding flat fan nozzle deli vers a wide

- angle flat spray pattern, 115

- 125 degrees. It also operates at low pressure and produces large spray droplets (Figure 31 ). Droplet distribution is fairly uniform across the pattern, but is not as even as the pattern of a regular flat fan nozzle. Tips should be tilted 45 degrees for broadcast spraying. The recommended nozzle spacing is 40 inches. These nozzles should have 100% overlap so the width of the spray pattern on the ground is twice as wide as the nozzle spacing. Boom height should be adjusted until this overlap is
achieved.

Whirl

- Chamber Nozzl e

The side

- entry hollow cone or "whirl

- chamber" nozzle produces a very wide angle, hollow cone spray pattern at very low pressures (Figure 32 ). It has a large opening and resists clogging. Because of the wide spray angle, the boom can be operated close to the ground, thus reducing drift. Spacing for double coverage and angling 15 Figure 30 . Regular flat fan nozzles used to treat railroad ballast.

Figure 31 . Widely spaced flood tips with 100% overlap.

Figure 32 . Side

- entry hollow cone nozzles should be angled to the rear rather than pointing straight down.23

to 45 degrees to the rear is recommended for uniform application.
Rain Drop®
The Rain Drop nozzle produces a hollow

- cone pattern and large droplets for drift control. Although the pattern is similar to the whirl

- chamber tip, this nozzle contains a secondary chamber where the swirling action of the spray solution further reduces sma ll droplets (Figure
33 ). The spray angle varies from 80

- 100 degrees depending on disc

- core combination in the nozzle. The nozzle should be angled 30

- 45 degrees from horizontal to obtain uniform distribution when used for broadcast application. This nozzle is generally used at 20

- 40 psi. These nozzles should also have 100% overlap and this boom height should be adjusted until this overlap is achieved.

Boomless Spraying
Boomless spraying enables the application equipment to stay on the tracks or roadside and spray areas off the side of the equipment. This results in a more uniform speed and rate of application as well as faster speed. Obstructions can interrupt the spray pattern but do not interfere with boomless spray application as much as with a boom applic ation. Even though this equipment is usually mounted on the side of the application equipment, it can also be attached to the end of a boom to spray a wider swath or a greater distance from the equipment.

Off

- Center Nozzle

Off

- center (OC) nozzle tips produ ce a flat fan spray pattern with the nozzle at the side rather than over the center of the pattern (Figure 34 ).
OC nozzles are used either without a boom or
at the end of booms to extend the effective swath width. The ability to treat a wide swath,
the var iety of sizes available to alter swath width and gallons applied per acre, the ease of mounting, and the low cost all contribute to the popularity of these nozzles. Coverage can
be variable because air turbulence distorts the Figure 33 . The Rain Drop® was one of the first nozzles designed for reducing spray drift.

Figure 34 . An OC nozzle (at the end of the boom) is often used to exten d the swath width of a spray boom.24

spray pattern as it leaves the nozzles. They are usually permanently mounted to the application equipment at a height that gives a specific desired swath width. Drift control
additives can be used with these nozzles.

Boom

- Buster® Nozzle

The Boom

- Buster nozzle is a straight stream diffuse nozzle. The spray solution is split by a nylon

v ane and forms a fan pattern very similar to the OC nozzle (Figure 35 ). The Boom

- Buster nozzle produces larger droplets than a regular OC nozzle and has replaced much of the OC nozzle use

. The Boom

- Buster spray pattern is more stable than the OC pattern. The nozzle has all of the
same uses as the OC nozzle.
Straight Stream Nozzle
Straight stream nozzles produce a solid stream pattern like water flowing from a pipe. These nozzles are used to spray a distant or specific target. For right

- of

- way application, they are most commonly used as a cluster of nozzles (Figure 3 6 ). Each part of the cluster is set to treat a defined section of the right

- of

- way. A nutation action break s the solid stream into large droplets. Swath width is adjusted by turning specific nozz les or sets of nozzles in the cluster off

or on.

Radiarc® Figure 35 . The Boom Buster® is used in place of an OC nozzle. Figure 36 . Straight stream nozzles are used to treat a swath to the side of the sprayer

. Oscillating the spray tips breaks the streams into drops.25

The Radiarc is a group of straight stream tips aligned in a single plane like the fingers of a hand (Figure 3 7 a and 3 7 b). It uses an oscillating motion to mechanically break up the streams of spray solut ion. Swath width is adjusted by plugging selected tips. A Radiarc can be mounted to spray either a horizontal or vertical spray pattern. It can be adjusted to treat a swath from 4

- 25 feet wide. Uniform spray pattern is obtained by altering the sizes of the tips.

Directa

- Spra®

The Directa

- Spra also uses straight stream nozzles. The units are fitted at the factory to spray an arc of 90, 180 or 360 degrees; 180 degrees is the most common. The nozzle clusters rotate around the center point (Figure 38 ). Swath widths from 10

- 25 feet and applications of 25

- 50 gallons per acre are obtainable

Figure 37a . A close

- up view of the Radiarc ® Figure 37b . The spray pattern of a Radiarc®.

Figure 38 . The Directa

- Spra® control s drift by using clusters of straight stream tips.26 D IRECTED LIQUID APPLI CATION

Handgun
The handgun is a common and versatile type of spray equipment. It is used to treat accessible and inaccessible sites with spot and broadcast treatments. The handgun is attached to a hose that in turn is attached, through the pump, to any size tank holding the herbicide mixture. The handgun is usually adjustable to change the spray pattern from a solid stream to a wide cone pattern (Figure 3 9 ). Pump capacity (gallons/minute), hose diameter, and hose length limit the distance the applicator can move
from the sprayer. The handgun is usually used for high

- volume applications, generally more than 100 gallons of solution per acre. When equipped
with off

- center tips, it can be used as a boomless sprayer for low

- volume application , or for spot

treatments (Figure 40) . All types of liquid formulations and drift control products can be applied.

Backpack Sprayer

A ba ckpack sprayer is a self

- contained unit (tank and pump) carried on the back of the applicator (Figure 41 ). The capacity of these sprayers is usually less than 5 gallons. A mechanical agitator plate may be attached to the pump plunger. The entire tank may b e pressurized or only a small
chamber that draws from the main tank. This equipment is useful for selective applications and spot treatments. Backpack sprayers are very adaptable to a wide range of nozzle configurations

– short booms, Boom

- Busters, adjusta ble cone nozzles, swivel tips, and rollover Figure 39 . The handgun is a versatile piece of equipment.

Figure 41 . The backpack sprayer is quiet and very efficient when treating low numbers of stems per acre or treating bands

. Figure 40 . Treating noxious weeds made easy with the adaptability of the handgun.27

nozzles for treating individual plants. This sprayer is versatile, quite, relatively inexpensive, and unobtrusive. Consequently, it is the major way of treating many acres on many types of ROW. Applications made from backpacks are obviously a very targeted application

Dual Spray Gunjet®

The dual spray Gunjet (Figure 4 2 ) has been particularly useful for treating individual foliage with backpack sprayers but is adaptable to all types of sprayers. The traditional Gunjet is fitted with a unique roll

- over valve that accommodates two spray tips with different volumes and diffe rent patterns , e.g., 6503 and 4003 . Only the selected tip operates. A particular spray tip can be immediately switched to another by rotating the selector to the desired tip. A t ypically set up would include a very narrow fan tip , about 15 degrees, and the other is a wider even fan tip,

e.g., 0

- 65 degrees. A hollow cone adjustable tip
also works in this set

- up.

Figure 42

. The two different nozzles enable the applicator to treat weeds close and at a distance by easily switching to the second nozzle.28 AERIAL APPLICATION

Ju st as the application industry has created and adapted special equipment to control drift from ground applications, it has developed special equipment to control drift from aerial applications.

Micro

- Foil Boom

The Micro

- Foil boom was developed primarily for use by helicopters. It has been the dominant piece
of equipment used for spraying electric ROW. Each nozzle is an airfoil shape on the leading edge with a row of straight stream nozzles on the back edge (Figure 44) . The herbicide solution is sprayed
into still air. The solution falls to the ground as a

wet curtain (Figure 45)

.
T h ru - Valve Boom (TVB)

The TVB® is a precision application device which enables herbicide application accurately, uniformly and on target. The TVB® was developed to enable operators of fixed

- wing aircraft to apply herbicides quickly and accurately (Figure 46)

. However, the TVB allows helicopter and fixed

wing applicators to apply herbicides sprays to forests, rangeland, and utility rights

- of

- way on target and at the desired rate (Figure 47)

.

T he TVB® will produce particles free of aerosol at speeds of 100 to 180 mph and greater. At low airspeeds up to 20 mph, these droplets simply spread out to form a swath and fall to the ground by grav ity to give a uniform spray pattern on the ground. At higher speeds of 50 to 180 mph, the forward motion of these droplets is sufficient to make them unstable. With minimal shear action, the droplets tend to flatten out from the continued forward motion an d form "donut" shaped droplets with essentially no aerosol, allowing for the spraying of herbicides from helicopters and fixed

- wing Figure 44. The individual nozzles of the Micro

Foil boom.

Figure 45. The spray pattern of a Micro

- Foil
boom.

Figure 46. Spray pattern of a TVB.29

aircraft with greatly reduced risk of injury to

non

- target vegetation.

SUMMARY There is an array of equipment available for applying herbicides. Each is designed for specific application situations. Although low pressure and large drops are a common characteristic, t he applicator controls t he quality of the results.



### ROLE OF SPECIFIC SU HERBICIDES

The vast array of weed control situations that fall in the general area of non

- crop means there is a role for several SU herbicides. Historically, sulfometuron

- methyl (Oust XP ) has been the primary product for total vegetation control with residual soil activity for railroads, road shoulders, and electric substations and pumping stations. At lower rates Oust and Oust Extra are the major herbicides for selective uses in conifer and hardwood forestry . M etsulfuron

methyl (Escort XP) has a major role in woody plant control critical to electric and roadside sites.
C hlorsulfuron (Telar XP) is especially effective on controlling broadleaf weeds and releasing grass species in pasture, range, and noxious wee ds on all non

- crop sites . These herbicides are also components of numerous premixes; e.g., Landmark, Oustar, Oust Extra, Pastora, Perspective, Throttle, Viewpoint, and Westar.



### THE REALITIES OF BUF FERS

1. Buffers do not improve weed control. If the ability to use the most effective herbicide is
restricted the end result can be less th a n desired.
2. Buffers do not improve drift control. Buffers have nothing to do with drop size.
3. Buffers do not make applicators better. All commercial applicators are certified and
li censed by state programs that have been approved by EPA.
4. Buffers are contrary to the concepts of Integrated Vegetation Management Programs. The precepts of IVM require all treatment options be available for consideration. Figure 47. Helicopter equipped with a TVB.30

5. Buffers are in conflict with the legal requirements of states to control noxious weeds. State laws require the landowner to control noxious weeds across their property. Having
to leave a buffer of uncontrolled noxious weeds is in conflict with state law and
maintains a source of reinvasio n, which negates any control efforts.

The SU herbicides are not the first highly efficacious products to enter the market

. The application industry has adapted and used these products safely for more than a quarter of a century. The extreme activity is the characteristic that influences their use. Their activity is analogous to the use of toxic products. There is no hazard wi th a very toxic product if there is no exposure. A very active herbicide does not pose a hazard to off

- site plants if the herbicide never gets there. And there are years of experience to prove that herbicides such as sulfometuron, metsulfuron and chlorsulf uron can be and have been used without disastrous
off

- target results. This is because the products have been applied in appropriate ways and with appropriate equipment by a cadre of well trained and knowledgeable applicators.
Appropriate Ways
These ways in clude the professional ways of avoiding herbicide drift and movement, which are already on the product labels , such as Oust XP

.

 Do not spray when the product cannot be kept to the site. Wind speed is most critical.

 Do not spray when wind is blowing toward sensitive crops/plants/sites. Herbicides will not drift upwind.

 Do not make applications to natural or man

- made bodies of water such as lakes, reservoirs, ponds, streams and canals.

 Do not apply if prevailing local conditions may be expected to result in off

- site movement and cause damage to neighboring desirable vegetation or agricultural crops.

 The user must read and understand all label directions, precautions, and restrictions.

 Leave treated soil undisturbed to reduce the potential for herbicide moveme nt by soil
erosion due to wind or water.

 Do not apply in or on irrigation ditches or canals including their outer banks.

 Injury to or loss may occur if equipment is drained or flushed on or near desirable trees or other plants or in locations where the che mical may be washed or move into contact
with their roots.

 Treatment of powdery, dry soil or light, sandy soil when there is little likelihood of rainfall soon after treatment may result in off target movement and possible damage to susceptible crops when soil particles are moved by wind or water.

 Applications may not be made to soil that is subject to wind erosion when less than a 60% chance of rainfall is predicted to occur in the treatment area within 48 hours.

 Applications made where runoff water flows onto agricultural land may injure crops.31

 Application made during periods of intense rainfall, to soils saturated with water, surfaces pave with materials such as asphalt or concrete, or soil through which rainfall will not readily penetrate may result in r unoff.

 Do not treat frozen or snow covered soil.

 Be sure the sprayer is calibrated before use.

 Avoid overlapping and shut off spray booms while starting, turning, slowing or stopping to avoid injury to desire species.

 Avoiding spray drift is the responsi bility of the applicator.

 The most effective drift management strategy is to apply the largest droplets which are consistent with pest control objectives.

 Drift potential is lowest when applications are made in light to gentle sustained winds (2

- 10 mph), w hich are blowing in a constant direction.

 Avoid gusty or windless conditions.

 Drift potential is high during a surface temperature inversion.

 Making applications when there is a sustained wind moving away from adjacent sensitive areas (e.g., residential a reas, bodies of water, known habitat for threatened or endangered species, non

- target crops) is an effective way to minimize the effect of spray drift.

 Using product compatible drift control additives can reduce drift potential.

 When applications are made in a crosswind the swath will be displaced downwind.

 Applications with wind speeds greater than 10 mph are prohibited.

 Applications into temperature inversions are prohibited.

 Apply spray as the lowed height that is consistent with pest control objectives.

 Applications must be made using equipment delivering an extremely coarse or coarser droplet size spectrum as defined by ASABE S572.1 There is also the operational practice of spraying parallel to the stream border or bank as the applicator approaches wat er to avoid spraying into the water.

Appropriate Equipment
ROW applicators have always dealt with the issue of drift and have developed equipment and practices that are worlds apart from the typical agricultural crop use situation. If you browse through a Spraying Systems catalogue, you will note that most of the nozzles have spray angles greater than 80 degrees; 110 degrees is probably most common. Also most of the nozzle top out at 0.5 to 0.8 gallons per minute. More common nozzles in railroad application s apply at least one gallon per minute (Table 2 ).32 Table 2 . Examples of nozzle and tip sizes used by commercial applicators treating ROWs.

Nozzle Type Output @ 40 psi

(gallons/minute)

Spraying Systems 6510 1.0

Spraying Systems 8010 1.0

Spraying Systems 8015 1.5

Spraying Systems 8020 2.0

Spraying Systems 4040 4.0

Delavan Raindrop RA

- 30NY 140 3.0

Boom Buster 180

- 6 4.3

Boom Buster 375 16.7

Boom Buster 437 21.5

OC 40 17

OC 150 15

StreamJet 0010 1

StreamJet 0015 1.5

Knowledgeable Applicators
These herbicides are not present in the consumer market. Being present only the professional applicator arena means that the products are being applied by or under the supervision of a state licensed applicator. Each state, as per EPA mandate, licenses commercial applicators. Licensure requires, in all states, certification and certification is obtained by examination. Every state exam contains questions about drift. Every state has an annual weed conference or vegetation management association, and nearly every program has topics on pesticide drift; causes, problems, and prevention. Every state DOT has in

- house or external continuing education programs. All application companies conduct training programs because no one wants to be paying for inj ured crops or plants. The application industry that services railroads has their own annual initial training and continuing education conference that always has a topic on drift.33 

### SUMMARY

 SU’s are a very effective class of herbicides that are critically important for managing undesirable vegetation in Industrial, Forestry, Range and Pasture settings.

 The general diversity of SU products available is important to provide efficient and
effe ctive control.

 Controlling vegetation is important for protecting infrastructure and maintaining a safe transportation system such as railways and roadways, as well as ensuring the reliable and safe flow of utilities through electric transmission lines and gas /oil pipelines.

 SU’s are important for controlling invasive and noxious weeds in Range and Pasture areas in order to maximize grazing and forage production to optimize food production.

 Many SU’s can be safely used over grasses which are important f or reducing erosion and important for wildlife habitat restoration and protection such as in rangeland areas and utility rights of way.

 Many SU’s can be applied safety around trees and are essential tools for vegetation management in forestry production.

 Specific SU’s provide control of weeds where no other product can provide selectively.

 SU’s are a very cost effective family of herbicides which helps reduce the cost of maintaining public and private lands

 Additional buffers that do not take into acco unt vegetation management practices would render these products non

- usable



### REFERENCES

Coblentz, B.E. 1990. Exotic organisms: a dilemma for conservation biology. Bio. Cons. 4:261

- 65.

Ezell, A.W., J.L. Yeiser , L.R. Nelson. 2013. Fifth

- year pine growth response to woody release treatments in young loblolly plantations. Pages 223

- 225 in J.M. Guldin, editor, Proceedings of the 15th Biennial Southern Silvicultural Research Conference. Hot Springs, AR. e

- Gen. Tech. Rep. SRS

- GTR

- 175. Asheville, NC: USDA, Forest Service, Southern Research Station.

Holt, H.A., F. Whitford, J.M. Di Tomaso, et. al. 2002. Model Certification Training Manual for Right

- of

- Way Pesticide Applicators. https://www.agriculture.purdue.edu/pesp/rowmanual/34

Miller, J.H., S.T. Manning, and S.F. Enloe. 2013 (slightly revised 2015). A Management Guide for Invasive Plants in Southern Forests. Gen. Tech. Rep. SRS

- 131. Asheville, NC. USDA, USFS, Sout. For. Res. Stat. 120 pg.

Panter, K.E., M.H. Ralphs, J.A. Pfister, et.al. 2001. Plants Poisonous to Livestock in the Western States. USDA, Ag. Res. Serv., Agri. Info. Bull. No. 415. 107 pg.

ROW statistics Highways

– rural: https://www.fhwa.dot.gov/policyinformation/statistics/2014/hm220.cfm Pipelines: http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national

- _transportation_statistics/html/table_01_10.html
Railroads: https://www.aar.org/Style%20Library/railroads_and_states/dist/data/pdf/

- State%20rankings.pdf Electric: Federal Power Commission. 1976. Statistics of privately owned electric utilities in the U.S., 1974. Class es A and B companies.

Sheley, R. M. Manoukian, and G. Marks. 1999. pg 69

- 72. In: Sheley, R.L. and J.K Petroff (ed.). 1999. Biology and Management of Noxious Rangeland Weeds. Oregon State University Press, Corvallis. 438 pg.

Sheley, R.L., J.K. Petroff, and M.M. Borman. 1998. I ntroduction. pg 1

- 3. In: Sheley, R.L. and J.K Petroff (ed.). 1999. Biology and Management of Noxious Rangeland Weeds. Oregon State University Press, Corvallis. 438 pg.



### ACKNOWLEDGEMENTS

A number of people have contributed to the concepts and details inclu ded in this document. Atkins, Lee, Progressive Solutions, L.L.C
., Natchez, MS Blase, Gerry. Asplundh Railroad Division, Ironton, OH Earnest, Donnie, Enable Midstream Partners, Oklahoma City, OK Ezell, Andy, Mississippi State University, Starkville, MS
Good fellow, John, BioCompliance, Redmond, WA Hecox, Doug, FHWA, Washington, DC Johnstone, Rick, IVM Partners, Inc., Newark, DE Kortum, Brian, NiSource Environmental, Merrillville, IN Miller, Jim, Southern Forestry Experiment Station, Auburn, AL Rumble, Jason, Ferrosafe, LLC, Glendale, AZ35 

### CREDENTIALS

HARVEY A. HOLT, Ph.D. Professor Emeritus, Purdue University

Address
Green Systems Analytics, LLC 765

- 427

- 5661 (voice) 10203 47th Avenue SW, B

- 9 holth@purdue.edu (email) Seattle, WA 98146

Education

B.S. Oklahoma State University 1965 Forest Management M.S. Oregon State University 1967 Forest Management Ph.D. Oregon State University 1970 Forest Ecology

Work Experience
Green Systems Analytics, LLC January 2010

- Present Manager

Consulting on herbicide p roduct development and application.

Purdue University, Department of Forestry and Natural Resources January, 1975

- July, 2009 Associate Professor, Professor, and Professor Emeritus

Research activities focused on industrial vegetation management (electri c, railroad, and highway rights

of

- way, total vegetation control, and forestry), and trees in the urban environment. Research also encompassed tree growth retardants, pruning effects, planting treatments, herbicides, biopesticides, and application technolo gy. Teaching included FNR 444 Arboricultural Practices and FNR 445 Urban Forestry Topics. The Midwest Urban Tree Care Forum, started in 2003, brought college students from surrounding states to Chicago for a weekend with the urban forestry profession. The extension program emphasized professional education for right

- of

- way managers, commercial pesticide applicators, commercial and municipal arborists, state and federal agency personnel, consulting and industrial foresters, and landowner and grower organizat ions. The Weed Control Seminar for the National Railroad Contractors Association was conducted annually for more than 30 years.

University of Arkansas, Department of Horticulture and Forestry September, 1970

- December, 1974 Assistant Professor

Research emphasized forest vegetation management and evaluation of new application techniques. This included right

- of

- way brush control, weed control in pine and walnut plantations, tree injection, and chemical site preparation. Teaching responsibilities included Fundamentals of Forestry and Dendrology.

Citations in Biographical Works American Men and Women in Science, 1972, 12th Edition36

Professional Organizations

- Memberships International Society of Arboriculture

- Board of Directors, 1993

– 2008

- Executi ve Committee, 2001

- 2002

- Student Activities Committee, Chair, 2005

- 2008 Indiana Arborist Association

- ISA Chapter Representative, 1993

- 2008 Pacific Northwest Chapter, International Society of America Arboriculture Research and Education Academy U tility Arborist Association Western Society of Weed Science Weed Science Society of America American Railway Engineers and Maintenance

- of

- Way Association

- Committee 1 (Track), Subcommittee 9 (Vegetation) Council for Agricultural Science and Technology (C AST) National Roadside Vegetation Management Association

Honorary Organizations Alpha Zeta

- National Agricultural Honorary Epsilon Sigma Phi

– National Extension Honorary Gamma Sigma Delta

- National Agricultural Honorary Phi Kappa Phi

- National Scholastic Honorary Sigma Xi

- National Honorary for Scientists Xi Sigma Pi

- National Forestry Honorary

Special Recognitions 1978

- 1979

– Chairman, Walnut Council 1979

– Chairman, Indiana Chapter, Society of American Foresters 1981

– Program Chairman, Walnut Council Annual Conference 1987

- Outstanding Paper Award, Weed Science 1991

– Distinguished Service Award, National Roadside Vegetation Management Association 1992

– Silver Member Certificate, Indiana Society of American Foresters 1996

- Outstanding Teacher, Department of Forestry and Natural Resources, Purdue University 1997

- Meritorious Service Award, Indiana Arborist Association 1998

- Excellence in Roadside Manage ment

– Roadside Support Category, National Roadside Vegetation Management Association 2002

- Education Award, Utility Arborist Association 2004

- Outstanding Counselor, Department of Forestry and Natural Resources, Purdue University 2005

- Special Recognit ion Award, Illinois Arborist Association 2005

- Award for Excellence in Arboricultural Education, International Society of Arboriculture 2006

- Distinguished Service Award, Indiana Arborist Association 2006

- Adjunct Research Professor, Changbai Mountain A cademy of Science, Jilin Province, China 2008

– Richard Harris Authorship Award, International Society of Arboriculture 2009

- Honorary Life Member, Indiana Arborist Association