Unit 6 Pesticide Application Equipment

Question 1

Name some of the things that affect the efficacy of a pesticide application

Answer 1

Proper timing to treat susceptible pest stages
Favorable treatment conditions (temp, time of day, moisture and plant condition)
Thorough coverage

Pesticides must be delivered to the target at the correct rate to do their job

Question 2

How are dusts, granules and wettable powders alike? How are they different?

Answer 2

All 3 are solid formulation pesticide products. Wettable powders are not ready to use. They must be mixed with water and sprayed. Because they do not dissolve in water, the mixture (suspension) must be agitated. On the other hand, dust and granules are ready to use. They are applied dry, right out of the container. However dust particles are much smaller than granules. Dusts and granules require different types of application equipment. Usually granules are applied to soil and dusts are applied to foliage.

Question 3

What are some things to consider before choosing a piece of application equipment?

Answer 3

Is the equipment well suited for the target you need to treat?
Will it apply the formulation you wish to use?
Is it affordable?
Is it sturdy and durable enough to do the job?
Is it easy to fill, operate and clean?
Will it apply pesticides in an environmentally sound manner?

Question 4

What are some advantages and disadvantages of spray applications?

Answer 4

Spray applications use water as a carrier. If done properly, a spray application reduces droplets containing dilute pesticide. These droplets are directed to a target where they coat its surface. Many types of spray equipment are on the market. Some pesticide formulations cannot be applied as a spray. Others must be agitated to keep insoluble particles from settling. Liquid spray particles can drift if not managed properly.

Question 5

Name the major parts of a spraying system

Answer 5

Holding tank
Nozzle
Hose or tube connecting the tank with the nozzle
The device or system that applies the pressure

Question 6

Why is sprayer configuration setup important?

Answer 6

To produce a uniform spray

Question 7

Describe the function of the spray tank

Answer 7

It holds the mixed liquid pesticide

Question 8

How should you care for a spray tank?

Answer 8

TO keep tanks in good condition, handle them with care. Careful handling and proper storage can help to prevent cracks and leaks. Keep spray tanks clean. Debris from a dirty tank may block narrow passages in hoses or tubes, screens and nozzles. Contaminants may affect a spray solution, resulting in incompatibility or phototoxicity. Herbicide residue from a previous application in a tank may harm the plants an insecticide or fungicide application is supposed to protect. Plant health managers should have at least 2 spraying systems, one for herbicides and another for fungicides and insecticides

Question 9

What do the hoses do?

Answer 9

Hoses carry the liquid from the tank to the nozzle. Like all sprayer components, they should be chemical resistant. This will prevent them from swelling or breaking down when exposed to organic solvents like those found in many liquid pesticide formulations. Check them on a regular basis to be sure there are no cracks or leaks.

Question 10

What is the function of the nozzle?

Answer 10

Pressure forces the spray through one or more nozzles. The shape and size of the nozzle orifice affects the flow ans rate pattern. Nozzles are made for many different spraying requirements. Manufacturers of sprayer nozzle tips supply data sheets for the delivery rate (usually in gallons per minute within a range of pressures) and pattern. However these specifications sheets cannot give the actual application rate. This is because the application rate is also dependent on speed and pressure.

Question 11

Why is it a good idea to have some sort of filter or screen in your spraying system?

Answer 11

Filters or screens will trap particles. Particles in the system can cause problems by plugging hoses and damaging the pump. Proper use of filters protects the working parts of the sprayer and reduces nozzle wear.

Question 12

What are the parts of a complete nozzle assembly?

Answer 12

Body, screen, cap, and tip or orifice plate. The nozzle tip is an atomizing device. It produces liquid droplets that form the spray pattern.

Question 13

Why is it important to match the pressure of a sprayer with the nozzle used?

Answer 13

Nozzles have a prescribed pressure range. If the pressure is too low, the pattern the nozzle is supposed to produce will not form properly. Spray distribution will not be even or as expected. High pressure increases the rate of nozzle wear and the drift hazard.

Question 14

What is the difference between a flat fan and a cone nozzle?

Answer 14

Nozzle tips are classified according to the spray pattern they produce. A fan produces a fan shaped spray. The liquid released is narrow at the nozzle and becomes increasingly wider as the distance from the nozzle increases. A regular flat fan nozzle makes a narrow oval (elliptical) pattern with lighter edges. The orifice opening in this type of nozzle is also elliptical. Cone nozzles produce circular patterns. The hollow cone nozzle delivers most of the material to the circumference of the circle. The full cone nozzle delivers liquid droplets to the entire area of the circle. Both types of nozzle tips have circular openings.

Question 15

How are flat fan nozzles best used?

Answer 15

Broadcast spraying. Regular flat fan nozzles are designed to be mounted on a boom. They are positioned so the liquid they release is overlapped 30-50 percent for even spray distribution across the boom. When a series of flat fan nozzles are properly configured on a boom, the spray material is distributed much more evenly. than it would be with any other type of nozzle. It is possible to keep the boom relatively low to reduce the drift hazard. Special flat pattern nozzles usually called even flat fan nozzles are available for band spraying in rows. They may also be used with a backpack (single nozzle) sprayer. Flat fan nozzles are well suited for applying herbicides.

Question 16

How are cone nozzles best used?

Answer 16

Applying insecticides or fungicides in situations where complete coverage of the leaf surfaces is extremely important. They are not ideal for mounting on a boom.

Question 17

Why is it a good idea to use a nozzle screen?

Answer 17

Placing nozzle screens behind the nozzle tip and in the nozzle body helps to eliminate or reduce clogging. When a sprayer is turned on and off frequently - when working in small plots or when spot spraying - nozzle dribble may become a serious problem. A nozzle screen with a check valve in it will eliminate dribble. The screen will not affect the operation of the sprayer, as long as you maintain andWhat should you check to be sure a nozzle is working properly? inspect the check valve.

Question 18

What should you check to be sure a nozzle is working properly?

Answer 18

Keep nozzles clean and in good condition. Check the flow rate and pattern on a schedule. Replace them before they become worn. The nozzle orifice will enlarge with wear, especially if abrasive materials are used. Nozzle wear changes both the spray pattern and the flow rate. If the flow rate is off by 10% replace it. Also replace any nozzle that is producing a non standard pattern.

Question 19

What is the function of the sprayer pump?

Answer 19

The pump forces the liquid through the system. It moves the pesticide mix or solution from the tank through the hoses and out the nozzles.

Question 20

Name one formulation that requires agitation to be applied as a spray

Answer 20

To make a uniform spray application with a wettable powder (WP) or a water dispersible granule (WDG) formulation, use a sprayer with an agitator. Neither of these materials dissolve in water. Constant agitation will keep particles from settling in the spray tank.

Question 21

Name some types of hand sprayers

Answer 21

Pressurized aerosol can
Trigger pump sprayers
hose end proportioners
push pull pump sprayers
backpack (knapsack) sprayers

Question 22

List some advantages and disadvantages of using a hand sprayer

Answer 22

Hand sprayers have a number of advantages. They are relatively inexpensive, simple to operate, maneuverable, easy to clean, and easy to store. Most backpack hand sprayers have an adjustable handgun. Small spray booms are available on some models. They are well suited for spot treatments and spraying small areas. They are also used for treating sites that are not suitable for larger units. They can be used to treat steep slopes or areas with limited areas.

Their limitations include a relatively small capacity - usually 1-4 gallons. Pressure and output may fluctuate. Some do not have a good way to provide agitation. Therefore they are not useful for applying suspensions like wettable powder spray mixtures.

Question 23

What special risk must be managed when using a hose proportioner?

Answer 23

Be sure to prevent backsiphoning. Use these devices only if you have an air gap or a fail safe backflow prevention device between the hose end proportioner and the water supply.

Question 24

List some advantages and disadvantages of using a small motorized sprayer, like a power backpack sprayer or an estate sprayer.

Answer 24

Small motorized sprayers have a larger capacity than hand sprayers. They can operate within a wide range of pressures. Many have built in hydraulic agitation. Some are small enough for use in confined areas or small spaces. Like hand sprayers, they may not be suitable for wide area use. They may not generate enough pressure and flow to allow for good coverage of a large tree,

Question 25

List some advantages and disadvantages of using a large high pressure sprayer

Answer 25

Large high pressure sprayers are able to treat dense foliage and reach the cannopy of a tall tree. They may be used with a boom to spray a wide area. They provide good penetration, reach and coverage. They are usually durable and long lasting if cared for properly.

However they are relatively expensive,. They require large amounts of water and fuel. Because of their size, they may not be suitable for all sites.

Question 26

What is a wick applicator? Describe a situation where a wick applicator would be useful.

Answer 26

Wick applicators use pieces of rope, absorbent fabric or a sponge to transfer the pesticide to the target. Wick applicators apply a concentrated herbicide mixture directly to a target weed. The wet wick is wiped directly onto the weed. Wick applicators are easy to operate. If used properly only the target is affected. There are no particles to drift.

Question 27

When and where are aerosol generators and/or foggers used?

Answer 27

With certain pesticide formulations. They convert these products into very small, fine droplets. Single droplets are too small to see with the naked eye. Large numbers of droplets are available as a fog or mist. This method is a good way to treat a large number of plants in an enclosed area. Aerosol generators and foggers fill a space with pesticidal fog. In some cases, insects are killed on contact. Some formulations provide residual control and others do not. In other cases, the mist simply repels the insects. In the case of repellants, the insect pests may return after the mist settles.

The mists produced by aerosol generators and foggers can penetrate dense foliage .Some indoor use devices are automated. Limitations include the potential for drift, sue to the very small droplet size these devices produce. Plant health managers can avoid drift in enclosed settings by sealing the area to prevent drafts or air leaks. It is important to follow label directions for keeping an area off limits. Some labels require that you close the treated area for a prescribed period. As a rule, treated areas must be properly ventilated before people return to the site.

Question 28

How do ready to use aerosols work? How are they usually used? What are some advantages and disadvantages?

Answer 28

Ready to use aerosol containers contain a pesticide dissolved in a volatile liquid under pressure. The pesticide vaporizes when it is discharged from the pressure cylinder or bomb. After release, the pesticide is suspended in the air in fine particles. Aerosol cans or bombs are convenient for applications made in small installations or to a limited number of plants. They are easy to use. Most products available are labeled for insect and mite control. Ready to use aerosols do not penetrate soil. Follow all label directions, including the distance between the release point and the plant. Exposure to the escaping propellants can damage plant tissues. As a rule, do not use ready to use aerosol products when temps exceed 85 degrees or leaf surfaces are wet.

Question 29

What special risks must be managed when using pesticides in vapor form?

Answer 29

Vaporized pesticides pose an inhalation exposure risk. This is due to their small particle size and the fact that the particles are airborne. Treat all pesticides in vapor form with extreme caution, especially when working in enclosed spaces. Wear a respirator. Some labels have specific use conditions (dry foliage, temp range). Applications made at cool temps may not be effective. If the temp is too hot, plants may be injured. Follow label directions and take all special precations.

Question 30

What are smokes, and how are they used?

Answer 30

Smokes are cans of insecticide mixed with combustible materials. They are ignited in their container. They produce an insecticidal smoke. Smokes are easy to handle. They are particularly useful in small enclosed areas.

Question 31

How are dusts applied? Describe some common dust applicators.

Answer 31

Dust applicators combine a dust formulation pesticide with air to distribute the pesticide evenly over a target area. Power dusters use a motorized fan or blower to propel dust to the target. Bulb or hand dusters re used in small areas. They use devices like a squeeze bulb, bellows, shaker, or hand cranked fan to distribute the dust. Some dusters have attachments to extend the reach of the tube and the direction of the dust.

Question 32

What are some advantages and disadvantages of using dusts?

Answer 32

Because dusts are ready to use, there is no mixing or dilution involved. Dust applicators are lightweight, simple in construction and easy to maintain. No water is needed. Duet may be propelled into hard to reach places. However, dusts may not stick to foliage. Because dust particles are small and light, drift potential is high. Applications may be hard to direct to the target, and coverage may not be uniform.

Question 33

When and how are granular pesticides used?

Answer 33

Granular formulations are commonly used for soil treatment in established vegetation like turf. This is because they fall through or roll off the plant surfaces and land on the ground. Some granular products are applied so the particles are evenly distributed over an area. Other product labels may direct you to a certain volume around the base of the plant or use a certain amount per container. Some need to be watered in. Others are soil incorporated. Like dusters, granule applicators are simple devices. Granules are ready to use so there is no mixing. No water is needed. They have little or no drift potential. They pose a very low exposure hazard to the applicator. However they will not adhere to foliage. If you use a drop spreader to apply granules, you must recalibrate for each formation.

Question 34

What is a bait? When and where are baits usually used?

Answer 34

Most baits consist of a pesticide mixed with a food or am attractant. Many are available in ready to use, tamper proof stations. Well designed bait stations attract only the target pest. If used properly there is little or no exposure risk to applicators, building occupants or nontarget organisms. The entire area does not need to be treated because the pest comes to the bait. They are best used to control social insects, foraging insects, and rodents. Baits are most effective if competing food sources are reduces or eliminated.

Question 35

How can traps help you manage certain pests?

Answer 35

Traps use something to attract and hold or kill pests. Traps may be a good way to monitor pest populations. In some situations, traps are also a very effective pest control method.

Question 36

What is injection technology?

Answer 36

It is a way to apply pesticides to large woody plants. One method places pesticide to the soil surrounding a tree, where it is taken up by the tree. Another introduces chemical directly into a concentrated area of the root zone.

Question 37

Describe tree injection and infusion.

Answer 37

Tree injection indicates forceful introduction of a chemical into a tree. Used this way the term injection is comparable to a shot a person gets from the doctor. Tree infusion or gravity flow is like an intravenous application. A reservoir of liquid hangs from the tree trunk, and the liquid is drawn in by the tree’s own uptake system. Trunk implantation devices are also used. Trunk implants use a capsule which is placed into a freshly drilled output by changing the speed and/or pressure. To make major changes the operator must change nozzle tips.

Question 38

In general terms, what is involved in calibrating a sprayer?

Answer 38

Measure the amount of liquid released by the nozzle. Collect the liquid delivered. Record the volume, the time it took to spray it, and the area covered. Calibration is like figuring out how much paint or siding you need to cover a house.

Question 39

Your backpack sprayer treats a swath 16 inches wide. You walk and spray for 150 feet. How large is the area you treated?

Answer 39

A= L x W

1.33 feet wide by 150 feet long so 199.5 sq feet

Question 40

You want to calibrate a backpack in a 200 sq foot area. Your swath width is 21 inches. How far must you walk and spray?

Answer 40

200/1.75 = 114.3 feet

Question 41

The label of the product you wish to use calls for using two quarts of product per 1000 sq feet delivered in one to two gallons of water. When you made your first calibration test you used twenty ounces of water to treat 200 sq feet. Is the sprayer calibrated to deliver this product as directed? Explain.

Answer 41

No. Here is why. In your first trial you used 20 ounces of water to treat 200 feet 200 sq feet is 1/5 of 1000 sq feet. As configured your sprayer will deliver five times that amount of liquid to cover 1000 sq ft. 20 x 5 = 100 ounces. 128 ounces in a gallon. One hundred ounces is short by 20%. 100 divided by 128 is about equal to 80%

Question 42

If you need to increase the amount you apply per unit area with a backpack sprayer, what should, you do…change the speed you walk, increase the pressure, or change the nozzle you’re using? Explain.

Answer 42

Change the nozzle. In the case previous, the sprayer as configured applied too little carrier (water). You should substitute a nozzle with a larger orifice and a greater flow rate and try again. Many backpack sprayers do not have a setting for adjusting pressures. Most applicators find it is not practical to adjust their normal walking speed. They revert to what is natural for them. The simplest and most effective thing to do is change the nozzle. You can choose one with a larger orifice for a greater flow rate or one with a smaller orifice for a lower flow rate. Its a good idea to use a sling or some method (resting your arm on your hip) to be sure that your release height stays the same. That will help to keep your swath width uniform.

Question 43

You have calibrated your backpack sprayer for the product you wish to apply. The product label calls for applying 5 quarts of product per 1000 sq feet in 2 gallons of water. How much product should you use to treat 500 sq feet?

Answer 43

Half the amount. 2 1/2 quarts of product (2.5 qts = 80 ounces) and one gallon of water.

Question 44

Using a backpack sprayer, if you walk faster will you apply more or less chemical than you do when you walk slower?

Answer 44

Less. The sprayer is putting out material at a more or less constant rate in a unit of time, based on the pressure (range) of the sprayer and the nozzle you’re using. If you walk faster, you cover a larger area in a given unit of time. If you walk slower, you treat a smaller area in the same unit of time. Your sprayer delivers the same amount of product in both cases. You will apply the same amount of chemical in 60 seconds - more per unit area when you walk slower and less when you walk faster. For comparison imagine the amount of paint you would apply with a swift vs. a slow brush stroke.

Question 45

The application directions for Herbicide A tell you to Mix this product in clean water and apply to the foliage of the vegetation to be controlled. Make applications on a spray to wet basis. Spray coverage should be uniform and complete. Do not spray to the point of run off. Use a 1% rate to control annual weeds, a 2% rate to control herbaceous perennials and a 5% rate for woody brush. Right below this paragraph is a chart which tells you how much product to mix in the water to get the right dilution (1,2 or 5%)

The application directions for Herbicide B instruct you to use one to two gallons of water to apply six quarts of product per 1000 sq feet. Which product must be applied with a calibrated sprayer? Explain

Answer 45

Herbicide B must be applied with calibrated equipment. This is because a set amount - no more no less is used to cover a given area. On the other hand, herbicide A is sprayed on a spray to wet basis. Foliage is covered. However, even when using Herbicide B you should figure out how many plants you have to treat, so you can mix up the right amount.

Question 46

Why is precide calibration needed when applying granular pesticide products?

Answer 46

When using granular products, applying less than 90% of the labeled rate to the target area may result in an ineffective control. Applications greater than recommended amounts are costly. In addition, an overapplication ,ay injure the target as well as nontarget organisms.

Question 47

What factors affect the amount of product applied by a granular applicator?

Answer 47

The amount applied depends on the size of the metering opening, the applicator speed, the terrain, and the flow rate of the granules.

Question 48

Why is it necessary to recalibrate a granular applicator for each product?

Answer 48

The application rates for granular products are expressed in weight to be used per unit area. Each product may differ in density and in the amount that must be applied per unit area. Granules flow at different rates, depending on their size and density and on environmental factors like temp and humidity. Therefore, it is necessary to recalibrate your applicator for each different formulation. It is also wise to re-check the delivery rate often. Weather conditions can affect granular flow rates so be alert for changes.

Question 49

How should you unplug or clean a nozzle?

Answer 49

Use compressed air, an old toothbrush or a brush with soft bristles. Never blow into a nozzle to clean it. Never use a pin, knife or other metal object to unplug a sprayer nozzle.

Question 50

How can you minimize spray drift?

Answer 50

Use the largest nozzle and the lowest pressure that will apply the pesticide properly. Use low drift nozzles if possible. Use the lowest release height or boom height you can. Spray when winds are slow and steady. Avoid strong gusty winds and inversion conditions.

Question 51

Why is it a good idea to have one sprayer for herbicides only and another for insecticides and/or fungicides?

Answer 51

In some cases it is difficult to remove chemical residue from a sprayer. Herbicide residues may remain at the bottom of a tank, in hoses or other sprayer parts. Some products are active at very low rates. If a sprayer containing herbicide residue is used to treat a sensitive plant, the plant may be injured or even killed.