Pesticides are substances or mixtures of substances used to destroy, repel, or control pests. The wide variety of commercially available pesticides reflects manufacturers' attempts to market products that best manage each type of pest problem. Carefully consider the pesticide characteristics and how they will affect your particular problem.

Choose a pesticide that is:

• acceptable to the public
• labeled for the pest
• able to produce the desired level of control
• least disruptive to the environment
• not phytotoxic to the turf or other ornamental plants
• economically practical
• compatible with other materials you plan to use

Pesticide Toxicity
To help conserve pest enemies that are naturally present and limit applicator risk and public concern, whenever possible use pesticides with the highest LD₅₀ (lowest toxicity). Many effective pesticides are in Categories III and IV. Because they are considered less toxic, Category III and IV pesticides have fewer regulations governing their use and less liability associated with pesticide accidents.

Pesticide Mode of Action
The manner in which a pesticide works, influences its ability to control pests and its potential for endangering nontarget organisms. Broad-spectrum pesticides are developed to suppress a wide range of pests. This feature makes broad-spectrum pesticides convenient but hazardous to non-target organisms biologically similar to the pest. Whenever possible limit the use of these pesticides to situations where there is more than one target pest.

Pests that are destructive for long periods of time or which are highly mobile, may be managed most effectively with a pesticide that remains effective for a longer time (Longer residual). Use of a longer residual pesticide may reduce the number of applications required to control persistent pests. Remember that a longer residual pesticide is not useful if it remains active after the period of pest susceptibility. Do not expose nontarget organisms to pesticides for longer than necessary to manage pests.

Systemic pesticides are absorbed into and travel within the plant. This mode of action makes systemic herbicides superior to contact herbicides in treating persistent perennial weeds. Contact herbicides kill only the plant portions to which they are applied, leaving the underground plant parts intact to produce new top growth. Systemic herbicides travel inside weeds, killing both top and underground plant parts. Insect pests, feeding on plants, consume systemic insecticides which makes these insecticides useful for controlling insects that are difficult to reach with contact sprays. There is less risk of injuring beneficial and non-target organisms when using systemic insecticides, since much of the material is within the plant.

Pesticide Formulation
There are advantages and disadvantages associated with the use of any one of the many pesticide formulations. Formulations vary in their cost, ease of application and potential threat to the applicator and other nontarget organisms:

• Some formulations require constant spray tank agitation; others do not.
• Liquid formulations are easier than dry formulations to measure in the field.
• During storage, subfreezing temperatures have less affect on dry formulations than liquid formulations.
• Some formulations of a pesticide cost more per pound active ingredient than others. Ready-to-use formulations are generally the most expensive.
• Spray solutions applied under high pressure have a greater potential to drift.
• Volatile herbicides have the potential to drift or contaminate stored pesticides.
• Some materials are more phytotoxic than others.

PESTICIDE APPLICATION EQUIPMENT

No matter how simple or sophisticated, application equipment must be in proper working order and correctly calibrated to deliver a uniform and consistent rate. Familiarize yourself with all equipment operation and maintenance procedures. Use an equipment safety check list, such as the sample below, to check for malfunctioning and worn parts. Keep a record of the maintenance schedule for all equipment. These practices will help you avoid costly accidents and breakdowns.

Mechanical Equipment Safety Checklist

Regularly inspect equipment for any of the following problems:

• Worn Hoses
• Poor hose to reel attachment (leaking)
• Poor hose attachment to spray gun or boom (leaking)
• Leaking spray gun or nozzles
• Poor adjustment of spray gun or nozzle output
• Worn seal in pump (leaking)
• Poor seal of pump to tank (leaking)
• Leaking tank
• Worn pressure regulator valve
• Poorly functioning pressure relief valve
• Truck or trailer tires worn or with malfunctioning lights, brakes, etc.

The best type of equipment to use for a turf application depends upon the target area, type of pest and pesticide formulation. The following, describes turf application equipment and its maintenance.

Granular Spreaders
Granular spreaders consist of a hopper to hold the pesticide and a metering device (feeder gate) that regulates the flow of granules through the outlet holes at the bottom of the hopper. A mechanical agitator at the base of the hopper provides continuous feeding of the material to the feeder gate. Check for a good agitator when selecting a spreader. Choose a model that is easy to fill and clean.

Granular spreaders should be thoroughly cleaned after each job or at the end of each day's use. Remove corrosion on the feeder plates or agitator with a wire brush, file, or sandpaper. Be sure that you securely tighten all nuts and bolts and lubricate the equipment according to the manufacturer's specifications. Because it can be phytotoxic to turf, keep the outlets free of lubricant.

Drop (gravity) spreaders are available in widths from one-half to 3 feet. An adjustable sliding gate opens the outlet holes allowing the granules to flow out by gravity feed. To assure uniform dispensing, a revolving agitator is activated when the spreader is in motion Drop spreaders provide somewhat uniform coverage, but create an application pattern with abrupt edges. Therefore, even a small error in steering will result in untreated or over-applied strips. Also, some drop spreaders will not deliver larger-sized granules.

Rotary spreaders distribute granules to the front and sides of the spreader, usually by means of a spinning disc or fan. This method creates more drift than drop spreader application. Most rotary spreaders produce a swath width of 6 to 8 feet. Both power-and hand-driven models are available.

Spray Output Equipment
The four basic components of sprayers are the tank, pump, valving, and nozzles. The component that has the greatest impact on applications is the nozzle selection. Whether a spray gun, a single nozzle or a boom, the output part of a sprayer is designed to accurately and effectively deliver the spray solution. Although manufacturers have developed guns and nozzles for practically every type of spray application, only a few are commonly used for turf.

Because of the difficulty in obtaining uniform coverage, traditional spray guns, which were designed for ornamental plant applications, are not useful for spraying turf. The "ChemLawn" shower head gun, and similar models by other manufacturers, is specifically designed for lawn applications. These guns create a wide spray stream, and can be fitted with different nozzles to adjust the rate of output from about one-half to 4 gpm. Drift is limited, as the droplets are relatively heavy. These guns are most commonly used with power sprayers for landscape lawn applications.

A spray wand is a long, rigid tube that attaches the hose to a single nozzle. Wands allow applicators to make low-volume, spot treatments with great accuracy.

Spray booms deliver spray material to nozzles. The length of the boom and its height from the ground determines the swath width. Spray booms for turf range in size from small, hand-operated models to large units mounted on tractors.

Spray booms, wands and guns are fitted with nozzles. Nozzles break up spray solution into droplets and spread them in a specific pattern. Nozzles are classified by the spray delivery pattern, spray angle, discharge rate and materials from which they are made.

The nozzle orifice size is determined by the size of the nozzle, or by interchangeable discs. Manufacturers supply information sheets on the delivery rate (usually gallons per minute) of their nozzle models at various operating pressures. Select nozzles that will provide the desired droplet size and application rate when used according to the manufacturer's recommended range of pressures. Nozzles used outside specified rates and pressures will not distribute material uniformly. Abrasive materials, like wettable powders, cause nozzles to wear. As they wear, the orifice becomes larger and the nozzle output increases. Reduce wear by using hardened stainless steel, chrome-plated brass or ceramic nozzle components.

To reduce nozzle wear due to abrasion, use nozzle screens to filter out larger dirt and pesticide particles. Nozzle screens also reduce clogging of nozzles. Consult nozzle manufacturers' recommendations when choosing the mesh size of screens. Check and clean nozzle screens frequently. Use of screens may affect pressure at the nozzle. Check for a change in the rate of output after installing or changing nozzle screens.

Controlled Droplet Applicators (CDAs)
These sprayers are commonly known as rotary spray nozzles. CDAs have a spinning cup with small grooves that spiral up the inner wall. The nozzles are gravity-fed from the spray tank and are powered by small electric motors. Centrifugal force moves spray solution in the spinning cup up the grooves. When the spray solution reaches the edge of the cup, it is distributed in a hollow-cone pattern. The spray droplets fall nearly vertically onto the target. The droplet size varies with cup diameter, speed and flow rates. Large truck-mounted and small hand-held models are available.

Because they provide adequate coverage with a small amount of pesticide, controlled droplet applicators are well-suited to turf IPM. Delivery rates of 3 gallons of spray per acre or less are possible. Low volume application reduces the amount of water and fuel used and allows use of smaller and lighter spray equipment.

One word of caution when using CDAs; because of the small amounts of material coming out of the sprayer, CDAs are very susceptible to drift, even in a slight breeze. Whenever using CDAs in breezy conditions, use extreme care around sensitive areas and near desirable plant material.

Small-Capacity Sprayers
Small-capacity sprayers are used for spot treatments and small turf areas. They are also useful for applying pesticide spray solution to areas that are inaccessible to larger units. Small-capacity sprayers are relatively inexpensive, simple to operate, maneuverable and easy to clean and store. Most are hand sprayers that use compressed air to pressurize the tank and deliver spray solution. They may be fitted with a wand, gun, or small boom.

Backpack sprayers are used for many of the same kinds of applications as hand held units. To lessen fatigue, the applicator supports the weight of the 2 to 6 gallon sprayer on his or her shoulders. A hand-operated piston or diaphragm pump supplies pressure. To maintain pressure, the applicator must provide strokes to the pump every few seconds. A uniform mixture of spray is maintained by mechanical or hydraulic agitation. Like a hand-held model, these units usually are fitted with an adjustable gun or a wand.

Hydraulic Sprayers
Most large-scale turf applications are made by hydraulic sprayers. Hydraulic sprayers deliver spray material through a hand-held gun or multi-nozzle boom. The rate and distance of the spray depends upon the pressure the solution is pushed through the nozzles. Hydraulic sprayers produce pressures that range from nearly 0 to 500 psi. Application rates of 1 quart per 1000 sq ft to over 100 gallons per acre are possible. Hydraulic sprayers have 30 to 1000 gallon tanks and are usually mounted on tractors, trucks, or trailers.

APPLYING PESTICIDES

Correct application of a pesticide to the turf is as important to successful pest management, as your choice of pesticide and application equipment. Apply only the amount of pesticide necessary to get the desired level of pest control. Over-applying material does not result in better pest control, but rather, wastes money and exposes the applicator and environment to unnecessary contamination. Under-application results in poor pest management.

Application Technique and Pest Habits
Pesticide is wasted when applied where pests are not present. For example, pest infestations commonly occur only on weakened, susceptible turf areas. Applying pesticide to an entire lawn for control of crabgrass that is localized around a cement drive is a waste of time and material. Use IPM monitoring techniques to decide precisely where to apply pesticides.

Once you apply a pesticide, be certain other activities do not undermine its effectiveness. For instance, preemergent herbicides form a chemical barrier that prevents weed seeds from growing. Disturbances to the treated area, such as footsteps, is this a good example? How about raking or dethatching? May break the barrier and reduce the effectiveness of some herbicides.

The pesticide application technique should reflect pests' feeding, germinating or inoculation habits. Using a contact insecticide spray will not effectively control root-feeding grubs. So that the material can penetrate the turf and reach the soil, many grub insecticides are formulated as a granular, many fungicides act as a plant protectant, by preventing fungal inoculum from entering the plant leaf. The level of control produced by protectant fungicides depends upon effective coverage of grass blades.

As these examples illustrate, it is critical to tailor pesticide applications to pest habits. Refer to the pesticide label and other pest management resources for application timing and technique, and protective equipment recommendations.

Applying Granular Pesticides
Practice or review the following granular application techniques:
1. Fill the spreader on a paved surface. Spills are more easily cleaned off pavement than turf.
2. Begin the application by moving counterclockwise around the right margin of the property. Make two complete swaths around the perimeter of the turf stand (this area is the header strip). Avoid casting material into flower beds or across the property line by closing the openings that feed the right side of the spreader.
3. Treat the area with series of parallel passes that overlaps the previous swath. Overlapping swaths assures uniform distribution of granules. Make applications parallel to the street so that if uneven growth and color responses occur, they will be less obvious.
4. Because you have already treated the header strip, turn the spreader off before beginning a turn. Be sure to turn the spreader on as you leave the header strip.
5. Shut off the spreader as you come to obstacles. Go to the opposite end of the pass and come back to the obstacle.
6. Keep the spreader level. Do not pump the handle up and down as you walk.
7. Remember to walk at a consistent pace.
8. Never stop with the spreader in the open position, as too much product is likely to be released.
9. Do not operate the spreader backward; unacceptable patterns or rates will result.
10. Clean and check the spreader for loose parts daily.

Follow these techniques, and carefully calibrate your spreader to insure proper granular pesticide rate and placement. Recalibrate the spreader weekly, or whenever you change materials.

OPERATING AND MAINTAINING SPRAYERS

Properly operating and maintaining spray equipment is essential for safe and effective pest management. Routine maintenance significantly reduces repair costs and prolongs the life of equipment.

Before Spraying
Put on appropriate personal protective equipment. Rinse out the entire system and remove and clean the gun, nozzles, nozzle screens, and strainers. Be sure to dispose of the rinsate by properly returning it to the tank after you have completed your equipment check. Check to be sure that all nozzles are of the same type, size and fan angle. Do not over-tighten nozzle caps or use cracked ones, especially if they are plastic. After filling the tank with water, check the lines, valves, seals and tank for leaks. Adjust nozzle height and spacing as suggested by the nozzle manufacturer and the pesticide label. To limit drift, set the boom no higher than is necessary to get good coverage. Check nozzles for uniform output and then spray water on the pavement and watch for streaks as the spray dries. Replace any nozzle with a flow rate five percent more or less than the average, as well as those producing heavy or light streaks.

During Spraying
Check the label and wear at least the minimum recommended personal protective equipment. Do not operate pumps at speeds or pressures higher than specified in the owner's manual. Do not use travel speeds too high for the conditions of the turf. Check for nozzle clogging and changes in nozzle patterns during applications. If nozzles clog or other trouble occurs in the field, shut off the sprayer and move to an unsprayed area before dismounting to work on the sprayer. Remember to put on all necessary protective equipment before attempting sprayer repairs. Clean and unclog nozzles with a toothbrush or toothpick. Do not use metal objects on nozzles. Never try to unclog a nozzle by blowing through it with your mouth.

After Spraying
While wearing protective equipment, clean the outside of the sprayer thoroughly before doing any maintenance or repair work. Skin readily absorbs pesticide residues which can cause serious pesticide exposure. After each use, wipe off the surfaces of spray trucks, tanks, guns, booms, and hoses, flush out residues inside of spray guns, nozzles, hoses and the pump, by running fresh water from the spray tank through the nozzle. Be sure to spray the rinse water back into the spray tank. Remember, herbicide residues cannot be adequately washed off application equipment. Never use herbicide application equipment for any other type of application. Tighten or repair all leaky tank seals and fittings. Make sure sight gauges can be read. Check pressure gauges frequently against an accurate test gauge. Inspect all strainers, screens, and nozzles tips after each day of spraying. Clean them if necessary by soaking and brushing; never use metal objects for cleaning. Do not allow hoses to become kinked or abraded; rinse the hoses frequently to prolong their life.

Applying Pesticide Sprays
The following are guidelines for making pesticide spray applications on foot with a shower head nozzle. Some of these techniques can be applied to boom spraying as well.
1. Hold the shower head nozzle at an angle pointed away from your feet and legs.
2. Do not drape the hose around your neck or around your back. The hose should be in front of you and held comfortably.
3. Squeeze the trigger only partly open and start the nozzle in motion from side to side.
4. Apply pesticide uniformly and accurately - concentrate on pattern, walking speed, and pressure.
5. Spray in parallel swaths. Do not walk in circles or change directions within a spray area.
6. Sidewalks and driveways are straight edges that make excellent guides as you begin spraying. Avoid curved flower beds as a starting place.
7. Maintain a straight walking line by heading toward a tree, fence post or other landmark.
8. Holding the gun close to your side walk at a comfortable pace. Move your forearm (elbow to hand) from side to side in a steady motion. Do not spray with your wrist only. If you hit a spot two or three times as you pass it your pace is about right.
9. Make parallel overlapping swaths. The degree of tapering on spray pattern edges determines the amount of swath overlap required to get uniform application. An overlap of one-half swath width is usually used with showerhead nozzles. This technique is sometimes referred to as "overlap back to the footsteps" of the previous swath. Weeds are often found in strips along the margins of streets, sidewalks and driveways. It is important that these areas receive the proper rate, neither more nor less. With the above spray pattern, margins receive only half rate. "Trimming" is a technique where another half dose is applied. You trim by speeding up the rate of the side-to-side arm movements, walking at a faster pace and closing down the throttle of the gun. Since applicators use it frequently, practice your trimming technique.
10. When finished with the application, turn off the pressure and place the gun in its hanger or suspend it over the spray tank. After winding the hose onto the reel, release any pressure remaining in the gun by releasing it into the tank.

RECORD KEEPING

Besides being an essential part of a pest management program evaluation, it makes good business sense to keep accurate records of all pesticide applications. Applicators should record the following information at the time of application:
1. Address or location of the pesticide application.
2. Name and concentration of the pesticide applied.
3. Amount of pesticide applied.
4. Target pest or purpose of the application.
5. Where applicable, the method and the rate of application.

These records should be maintained for at least one year after a general use pesticide application, and for at least three years after a restricted use pesticide application.

Other information important for your protection and useful for management decision-making includes:

• Name of the applicator.
• Certification or Registered Technician number.
• Product EPA registration number.
• Date of last calibration.
• Time of application.
• Weather conditions during and after application.
• Specific turf area(s) treated.
• Target pest stage at time of application.

A SPECIAL NOTE WITH REGARD TO APPLICATIONS OF RESTRICTED USE PESTICIDES (RUP)

The United States Department of Agriculture - Agricultural Marketing Service (USDA-AMS) is the agency responsible for implementation of Section 1491 of the Food Agriculture, Conservation and Trade Act of 1990 which became effective on May 10, 1993. If you keep your state's record-keeping requirement for restricted use pesticides, the only other thing you must do is, within 30 days of a restricted use pesticide application, provide a copy of the pesticide application record to the customer.