Surveys have shown that many farmers are using inaccurate sprayers. Faulty sprayers contribute to increased drift levels and waste money through inefficiency and overuse of chemicals. For example, the cost of replacing a faulty pressure gauge that has been indicating at 15% below the actual pressure is recouped in around two hours' operation.

Maintenance measures such as fitting a new set of nozzles at the beginning of each season also save money. Even when overdosing occurs by as little as 5%, the cost of a new set of nozzles would be recovered in less than a day's work.

Sprayers must be checked over regularly to ensure that proper maintenance has been carried out and that no outstanding repairs need to be done. Before attempting any work on a machine, make sure that it is fully supported on stands and that all necessary protective clothing is on hand.

7.1.2 Fitting the Sprayer to the Tractor

The selected tractor must always be powerful enough to operate the sprayer efficiently under the working conditions that will be encountered. All its external services - hydraulic, electrical, and pneumatic - must be clean and in working order. Tractors fitting with cabs must have efficient air filtration systems. All protective guards must be in place. Trailed sprayers are often close-coupled to the tractor, so it is essential that the drawbar and the PTO shaft are correctly adjusted for turning. PTO shafts must be disengaged when making very tight turns.

CAUTION

· Take great care when adjusting a sprayer while the tractor engine is running.

· Always ensure that the fan is stationary before approaching the rear of the sprayer.

· Engage the handbrake when leaving tractor seat.

7.1.3 Checking the Operation of the Sprayer

Partially fill the tank with clean water and move the sprayer to uncropped waste ground. Remove the nozzles. Although you are not using any chemical at this point, get into the habit of wearing a coverall, gloves and a face visor when working with the sprayer. Engage the PTO and gently turn the shaft, increasing speed slowly to operating revs. Test the on/off and pressure relief valves, and check the agitation system. Flush through the spray lines, and then switch off the tractor. Refit the nozzles and check the liquid system again for leaks.

It is a valuable exercise to assess the spray deposits at various points in the canopy and on upper and lower leaf surfaces of the trees to be sprayed. This is particularly important if the foliage is dense or if the trees are grown in beds of three or more rows. Water-sensitive papers or fluorescent tracers are available for this purpose. An increase in spray volume or adjustment of the nozzles and their locations may be necessary in order to achieve the correct deposits.

7.1.4 Pre-season Maintenance

Use the following checklists before you begin spraying:

Hoses

ü for splits and cracks

ü connections to ensure they are water-tight

ü for hose chafe, particularly in routing clips

Action:

Replace damaged hoses.

Filters

ü for missing filter elements and seals

ü for leakage

ü for blocked or damaged filters

Action:

Replace any damaged or blocked filters.

Tank

ü for fractures and any other damage

ü that the tank sits firmly in its mount

ü that the securing straps are correctly adjusted

ü that the agitation is working

ü that the tank is clean

Action:

See the supplier/manufacturer now about fractures and any other repairs.

Controls

ü the control circuitry (electrical, hydraulic or air) for correct operation

ü valves for both internal and external leaks

Action:

Replace leaky valves, which waste money and are potentially dangerous to operators and the environment.

Pump

ü lubrication levels

ü for leaks

ü that the air pressure in the pulsation chamber (if fitted) is at the recommended level

ü that the pump rotates freely without friction or noise. (Do so by rotating manually or starting at low speed, as corrosion may cause seizing up)

Pressure Gauge

ü The pressure gauge is vital for indicating whether the nozzles are delivering the correct amount of chemical per unit time while spraying. If you have any doubts about the pressure gauge, replace it or refer the problem to the manufacturer or supplier.

Nozzles

ü that all nozzles are the same

ü that all nozzles are in good condition, with no leaks around the body

ü that all nozzles are clean and free from obstruction (Note: clean with a soft brush or airline - don't damage nozzles by using wires or pins)

ü that all nozzles deliver to within + or - 5% of the manufacturer's chart value

Action:

Always ensure the correct nozzles and operating pressure are selected before use. Have two or three sets of nozzles in stock to meet different spray qualities at different volume rates. Inspect nozzles throughout the season to avoid faults which could prove both costly and damaging to the environment if they develop unchecked.

Calibration

ü If your sprayer has automatic controllers to monitor the speed of the sprayer and the flow, pressure and area sprayed, check

ü that they are in good condition and properly maintained

ü that they are frequently calibrated for accuracy, with calibration being checked after every 250 acres' use

ü for leaks, blockages, variations in pressure or any minor damage during spraying

Action:

See "Sprayer Calibration," above for detailed information on how to calibrate your sprayer.

Routine maintenance

Lubricate the sprayer at the time intervals specified by the manufacturer. The following components must be checked daily when a sprayer is in use:

ü Pump crankshaft oil level

ü Fan drive gearbox oil level

ü Fan drive shaft bearings

ü Agitator shaft bearings

ü PTO shaft bearings

ü PTO shaft safety cover

ü Wheels, wheel bearings, and tire inflation

ü Rotary atomizers (for damage and lubrication)

In addition, the following checks should be carried out routinely:

ü All hoses are tightly connected and free from sharp bends; cracked or damaged hoses must be replaced.

ü All controls move freely and are fully adjustable.

ü Pressure gauge reads zero.

ü Pump can be turned over by hand.

ü Fan turns freely and is not obstructed; bearings are sound and lubricated.

ü Air pressure in pump accumulator (if fitted) is correctly adjusted.

ü Drain plugs and clean filters are in position.

ü Tires on trailed machines are sound and correctly inflated; wheel nuts are tight.

ü Occasionally…
for example, after a complete spray round - check the spray liquid system for leaks and signs of damage or wear; make repairs at once.

7.1.5 Nozzles on the Net

http://www.albuz.com.fr/

This web page contains product information on agricultural and industrial nozzles. Albuz offer a variety of nozzles and whirl plates for application systems. There are also a number of educational fact sheets about Albuz nozzles located on the webpage: www.hypropumps.com. Albuz nozzles are distributed throughout America by this company. Also on the web page they offer technical training and information about the use of each nozzle.

http://www.delavanagspray.com/Index.htm

This web page contains product information on nozzles, nozzle accessories, sprayer accessories, high pressure guns/nozzles, pumps and high pressure washers. They offer educational material on calibration of nozzles and sprayers. They also have a nozzle type selection guide that is very useful to help select the right nozzle for your specific application. There are conversion factors for broadcast nozzle spacing and metric and imperial gallon conversion.

http://www.hardi-us.com/html/home.html

This web page contains product information on sprayers for all crops, nozzles, pumps and electronic controllers. They feature new products in the marketplace and educational materials which provide knowledge on servicing your sprayer. Also there is an online nozzle selection guide that is very useful in selecting the correct nozzle for your specific application.

http://www.hypropumps.com/Agriculture/default.cfm

This web page contains product information on Ag pumps, boom and sprayer components, nozzle bodies, pressure washer pumps, and spray tips. They also list educational guides that help you select the correct nozzle for your specific application. They are the distributor for Albuz nozzles in US.

http://www.lechlerusa.com/whois.asp

This web page contains product information on nozzles and sprayer components. They offer many educational resources including a conversion program for sprayers and other aids to assist you in nozzle selection and sprayer use. They have catalogs you can download about their nozzles and other sprayer components such as nozzle bodies. They have a section that features all their new products, you can also shop online for spray nozzles and parts.

http://www.teejet.com/ms/teejet/

This web page contains product information on all different types of nozzles, spray guns, valves, manifolds, boom components, electronic controls and guidance systems. They provide educational support with the use of a spray calibration calculator. They also have a nozzle selection guide you can download to help you in making a decision on which nozzle is good for your application.

http://www.turbodrop.com/index.html

This web page contains product information on nozzles for turf, vegetables and other crops. The featured products are the turbodrop, spraymax and airmix nozzles. There is a nozzle guide to assist you in locating a nozzle for your application. There are educational materials such as droplet size data, independent test data and news articles you can look through.

http://www.wilger.net/home.html

This web page contains product information on various sprayer parts and nozzles. Some of their featured products include tips, caps, strainers, nozzle bodies and flow indicators. Their web page also has a nozzle selection calculator called tip wizard which helps you locate the correct nozzle for your application. Tipnology is another link on the web page which explains everything about each nozzle.

http://www.nysaes.cornell.edu/ent/faculty/landers/pestapp/

This webpage contains information on various types of sprayers (air-blast, boom and knapsack etc). There are links to most of the manufacturers of orchard, vineyard, turf and vegetable spraying equipment. The website contains useful information on sprayer calibration, nozzles, sprayer manufacturers and agricultural links for that particular crop. In each one of the specific crop spraying sections also there are extension publications and research publications covering research projects conducted on sprayers in the northeast.

7.2 Equipment for Weed Control in Vineyards

Herbicides, although relatively inexpensive, require good application techniques if improved deposition and drift reduction is to occur. Some of the commonly used herbicides damage vines and so great care must be taken. Drift has been a major concern for some years, off target application wastes money, reduces deposition on the target plant, damages vines, can lead to pesticide residue on grapes, pollutes water courses and may cause nausea to other people.

7.2.1 Boom Applicators

Two main types of boom applicator are available. A frame can straddle over the top of the canopy, spraying under the vine each side of the target row, or a boom maybe fitted to the front of the tractor spraying one side only of the adjacent rows. 20 -30 gallons per acre are typical spray volumes.

In all cases the use of hoods and break-back devices are important. A hood will protect the vines from drift created by the small droplets being emitted from the conventional flat fan nozzle. A simple hood can be made from a used plastic drum cut in half or a simple plastic tarp. A break-back device will protect the sprayer boom and nozzle from damage caused by inadvertently striking a trellis post etc. Break-back devices normally comprise a spring-loaded arm.

Correct nozzle selection is one of the most important yet inexpensive aspects of pesticide application. A nozzle’s droplet size spectrum determines deposition and drift and is referred to as spray quality. Modern nozzle catalogues provide information on spray quality for each nozzle, when applying herbicides we need to select a MEDIUM quality spray. Conventional flat fan nozzles produce droplets in the range of 10 – 450 microns. There are 25,000 microns in one inch. Drift is a major problem with droplets less than 100 microns.

Increasing the Volume Median Diameter (VMD) will certainly reduce drift, but too large a droplet (>300 microns) will bounce off the leaves to the ground, thus causing pollution, wasting money and resulting in less product on the target.

7.2.2 Conventional Flat Fan Nozzles

Nozzles with 80°degree angle produce coarser droplets than 110⁰at the same flow rate but 80°nozzles require the boom to be set at 17-19 inches whereas 110° nozzles can be set lower at 15-18 inches above the target. (The lower the boom, the less chance of drift). Spray quality is fine – medium at 15- 60 psi.

7.2.3 Pre-orifice Flat Fan Nozzles

The internal design of this nozzle reduces the internal operating pressure compared to a conventional flat fan resulting in coarser droplets (high pressure creates fine droplets, low pressure creates coarser droplets). Available as 80° or 110° nozzles. Spray quality is medium - coarse at 30- 60 psi. Drift-guard is a well-known trade name.

7.2.4 Turbo-Teejet

A turbulence chamber produces a wide angle flat spray pattern of 150°. Spray quality is medium – coarse at 15- 90 psi. Nozzles can be set at 15-18 inches above the target.

7.2.5 Air Induction Nozzles

Air induction, air inclusion or venturi nozzles are flat fan nozzles where an internal venturi creates negative pressure inside the nozzle body. Air is drawn into the nozzle through two holes in the nozzle side, mixing with the spray liquid. The emitted spray contains large droplets filled with air bubbles (similar to a candy malt ball) and virtually no fine, drift-prone droplets. The droplets explode on impact with leaves and produce similar coverage to conventional, finer sprays.

Air induction nozzles reduce drift even at higher pressures of 80-90 psi. They are available at 110º fan angles so boom height may need to be adjusted to 15-18 inches. The use of adjuvants will certainly help create bubbles. Air induction nozzles work very well for herbicide application; trials with paraquat in vineyards in the Finger Lakes have shown good deposition with no drift.

Boom manufacturers/distributors include:

The Green Hoe Co. Inc

OESCO, Inc.

Nozzle manufacturers include:

Albuz, Greenleaf, Hardi, Lechler, Tee Jet

7.2.6 Sensor-Controlled Applicators

Sensor-controlled pesticide applicators use optical sensors to determine where weeds are located. These sensors, coupled with a computer controller, regulate the spray nozzles and apply herbicides only when needed, thus considerably reducing herbicide use. A computer-controlled sensor detects chlorophyll in plants and then sends a signal to the appropriate spray nozzle, applying the herbicide directly to the weed. The operator calibrates the system to bare soil or pavement, allowing the computer to determine when there is a weed present. Sensor-controlled applicators are often mounted on ATVs, John Deere Gators etc.; they can also be attached to tractors or trucks. Typically, this type of applicator can be used at speeds up to 10 mph. A complete sensor-controlled system consists of a chemical tank, pump, battery power, computer controller, optical sensors and spray nozzles.

Benefits of sensor-controlled applicators -

· Reduced amount of herbicide applied

· Reduced potential for groundwater contamination

· Ability to apply herbicides in dark or light conditions

· If equipped with wind-deflecting shields, can reduce herbicide drift

Manufacturers/distributors include:

Patchen/NTech

OESCO

Zahm and Matson

7.2.7 Controlled Droplet Applicators (CDA)

Traditional flat fan nozzles produce a range of droplets, 10 -450 microns, some drift, some roll off the leaves others will adhere to the target leaves. A CDA herbicide applicator comprises an electrically-driven spinning disc under a large plastic hood or dome. The circumference of the disc has small teeth which break up the liquid herbicide into droplets, of which 95% are the same size. The speed of the spinning disc dictates droplet size. As there are no large or small droplets in the CDA spectrum, all the droplets stick to the plant and so reduced rates can be applied, e.g 1-8 GPA

Various widths of hood or dome can be selected, and are fitted with break-back devices. Where the ground is rough, e.g stones, then a bristle skirt maybe used. In young vines an optional plastic cover can be fitted over the bristle skirt.

CDA sprayers reduce the amount of water required, thus considerably improving spraying logistics. They are lightweight, relatively inexpensive and very maneuverable.

Distributors include:

Bdi Machinery Sales, NorthEastern Equipment, Lakeview Harvesters, Rammelt & Co.

7.2.8 Flame Applicators

Flame applicators simply use a flame to destroy weeds. Most flame applicators burn liquid propane gas to create a flame having a temperature near 2000°F. The flame is applied directly to the weeds using a hand-held wand or with boom-mounted torches attached to a tractor or ATV. The flame is applied to the weed for only a short period of time, usually about 1/10 of a second. The length of time the flame is applied depends on the age, size and tenderness of the weed. It is recommended that the flame be applied to weeds when they are 1 to 3 inches tall and typically in the spring and early summer. When the weeds are exposed to the flame, the water inside the plant cells boil, causing them to burst. (The weeds are not burned up.) By destroying the plant cells, the plant is unable to transport water and continue photosynthesis, causing the weed to wilt and die. Flame applicators should only be used when there is little or no potential for setting fire to dry plant material. Beware of setting fire to trellis posts and poison ivy.

Benefits of Flame Applicators -

· Non-chemical weed control method

· No harmful drift

· No groundwater contamination

· No chemical exposure to workers

Where to look/buy

Albuz nozzles:

651-766-6300
http://www.hypropumps.com/

BDi Machinery Sales, Macungie, PA

1-800-808-0454

Bdi@fast.net

Green Hoe Company Inc
716-792-9433
http://www.greenhoecompany.com/

GreenLeaf nozzles
1-800-881-4832

http://www.turbodrop.com/

Hardi nozzles

563-386-1730

www.hardi-us.com

Lakeview Harvesters, Ont. Ca

1-866-677-4717

www.gregoireharvesters.com

Lechler nozzles

630-377-6611
http://www.lechler.com/seiten/en/lechler.html

Patchen Weedseeker:

1-888-728-2436

http://www.ntechindustries.com/

NorthEastern Equipment

631-765-3865

OESCO Inc., Conway, Ma

1 –800 –634-5557

www.oescoinc.com

Rammelt & Sons

1-800-388-3802

Red Dragon Flame

1-800-255-2469
http://www.flameeng.com/

Rittenhouse, Ont. Ca

1-800-461-1041

www.rittenhouse.ca

Tee Jet nozzles

717-432-7222
http://www.teejet.com/ms/teejet/

Please note: Where trade names, manufacturers or distributors names appear, no discrimination is intended and no endorsement by the author or Cornell University is implied

7.3 Selecting the Correct Nozzle to Reduce Drift

Correct nozzle selection is one of the most important yet least expensive aspects of pesticide application. A nozzle's droplet size spectrum determines deposition and drift. Drift has been a major concern for many years. Off-target application wastes money, reduces deposition on the target plant, pollutes water courses, and may cause nausea in bystanders.

Conventional flat fan nozzles fitted to a crop sprayer produce droplets in the range of 10-450 microns (25,000 microns = one inch). Drift is a major problem with droplets smaller than 100 microns. Increasing the Volume Median Diameter (VMD) certainly will reduce drift, but too large a droplet will bounce off the leaves to the ground, causing pollution, wasting money, and resulting in less product on the target.

Conventional flat fan nozzles

Nozzles with an 80° angle produce coarser droplets than 110° nozzles at the same flow rate, but 80° nozzles require the boom to be set at 17-19 inches, whereas 110° nozzles can be set lower, and 15-18 inches above the target. (The lower the boom, the less chance of drift). Spray quality is fine to medium at 15-60 psi.

Pre-orifice flat fan nozzles

The internal design of these nozzles reduce the internal operating pressure compared to a conventional flat fan, resulting in coarser droplets. Available as 80° or 100° nozzles. Spray quality is medium to coarse at 30-60 psi. Drift-guard is a well-known trade name.

Turbo-teejets

A turbulence chamber produces a wide-angle flat spray pattern of 150°. Spray quality is medium to coarse at 15-90 psi. Nozzles can be set at 15-18 inches above the target.

Air induction nozzles

Air induction, air inclusion, or venturi nozzles are flay fan nozzles in which an internal venturi creates negative pressure inside the nozzle body. Air is drown into the nozzle through two holes in the nozzle side and mixes with the spray liquid. The emitted spray contains large droplets filled with air bubbles (like candy malt balls) and virtually no fine, drift-prone droplets. The droplets explode on impact with leaves and produce similar coverage to conventional, finer sprays.

Air induction nozzles reduce drift even at higher pressures of 80-90 psi. They are available only at 110° fan angles, so the boom height may need to be adjusted to 15-18 inches. The use of adjuvants certainly will help create bubbles, and trials in Europe confirm this.

Air induction nozzles are regarded as expensive. The list price is three times the cost of a conventional flat fan tip, although some nozzle suppliers in New York will set them for approximately twice the cost. Manufacturers include the following:

Greenleaf TurboDrop nozzles consist of two primary components - the venturi air aspirator and the exit pattern tip. A ceramic orifice in the venturi determines the flow rate of the complete assembly. The venturi is ISO color-coded to designate the flow rate. The exit pattern tip does not affect the flow rate: it is used only to form the desired spray pattern. Pressure range is 40-90 psi.

Spraying Systems Tee Jet Air Induction (AI) nozzles comprise a plastic body with a steel tip, rated for 30-100 psi. They are plastic, with a single-piece construction.

Hardi Air Induction nozzles are similar in construction to Spraying Systems AI nozzles. They are one-piece plastic nozzles.

Albuz nozzles are similar in construction to Spraying Systems AI nozzles. They are one-piece plastic nozzles with a ceramic tip.

Current research

Trials are underway at Cornell University to compare air induction nozzles. Although the nozzles physically reduce drift, we need to see how effective they are at delivering materials used to control disease and insects. They certainly work well at delivering materials used to control weeds.

7.4 Sprayer Calibration

7.4.1 Travel Speed Calibration

Sprayer travel speed will influence spray deposition and is a critical factor in maintaining accurate application rates. Although results of studies to determine the effect of travel speed on average spray deposition have been inconsistent, all studies have been in agreement that the higher the travel speed, the greater the variability in spray deposit. This variability is an important factor where uniformity of spray coverage throughout the canopy is required. Conclusions from research were drawn using travel speeds of 1 - 4 mph.

Factors that will affect travel speed include:

· weight of sprayer to be pulled

· slope of terrain

· ground conditions traveled over (wheel slippage)

The best way to measure travel speed is to pull a sprayer half full of water over the same type of terrain on which the actual sprayer will be operated.

Using a tape measure, set up a test course at least 100 feet long. Do not pace the distance. The longer the course, the smaller the margin of error.

Run the course in both directions. Use an accurate stopwatch to check the time required to travel the course in each direction. Average the two runs and use the following to calculate the speed in MPH.

Formula	Ft. traveled	X	60	= MPH
	Sec. traveled		88

Your figures:

Tractor gear___________ Engine revs.___________

____ft.	X	60	= ____MPH
____sec		88

7.4.2 Airblast Sprayer Calibration

- use clean water

1. Pressure check
Place the pressure gauge on the nozzle fitting farthest away from the pump and turn the sprayer on. If pressure is lower at the nozzle than specified, increase pressure at the regulator.

Pressure at nozzle ______________psi

Pressure at sprayer gauge _____________psi

2. Nozzle output
Use a flow meter (obtainable from Gemplers, Spraying Systems, etc.) attached to individual nozzles OR

a. Connect hoses to each of the nozzles and measure the flow from each nozzle into a calibrated jug. Record and total your results using Figure 7.4.1 below.

b. Replace all nozzle tips which are more than 5% inaccurate.

c. Calculate gallons per acre using the following formula.

Formula:

Total GPM X 495
mph X row spacing (ft.)

= GPA

Your figures:

GPM X 495
mph X ft.

= GPA

7.4.3 Calibrating a Kinkelder Sprayer

-use clean water

Forward Row

Rate of spray speed spacing

Gals/acre X mph X ft X 60 gals/hr delivery

500 = or index setting

e.g.

50 gals/acre x 3 mph x 9 ft x 60 = 162 gals/hr delivery

or index setting

Your figures:

gallons/acre X mph X ft X 60 = gals/hr delivery

500 or index setting

This figure should be set on both scales.

Figure 7.4.1. Airblast Sprayer Calibration

Figure 1 copy

Both taps should be set on the distribution conduit in such a way that the index is set on the sign 162 on the index plate of the distribution conduit. The emission indication on the index plate has been fixed at a working pressure of 21 lbs (1.5 bar).

Check the output of the sprayer:

1. Divide the gallons/hour figure obtained above by 60 to give output/minute

e.g 162 gpm divide by 60 = 2.7 gallons/minute total of

left and right side then divide 2.7 gallons/minute by 2 = 1.35 gallons/minute/side

2. Remove the plastic pipes from the nozzles on the left or right side, tie together and place in a measuring jug

3. Run the sprayer for one minute at correct engine speed, collecting the output in a measuring jug

Remember 128 fl. ozs in one gallon. Example: If the output of one side has been measured at 173fl.ozs, then output is divided by 128 = 1.35 gallons per minute.

4. Then check the output of the opposite side.

7.4.4 Calibrating an AgTec Sprayer

-use clean water

1. Calculate the gallons/minute/side:

Speed x gallons/acre x row width = gallons/minute/side

1000

e.g. 3 x 50 x 9 = 1.35 gallons/minute/side

1000

Your figures:

mph X gallons/acre X ft = gals/min/side

1000

2. Check AgTec tables for correct meter setting, select the gal/min as calculated above, and then find meter setting, e.g meter #12 @30psi gives 1.34 gallons/min.

3. Remove the hoses from the nozzles on the left or right side, tie together and place in a measuring jug

4. Run the sprayer for one minute at correct engine speed, collecting the output in a measuring jug

Remember 128 fl. Ozs in one gallon. Example: If the output of one side has been measured at 173fl.ozs, then output is divided by 128 = 1.35 gallons per minute.

5. Then check the output of the opposite side.

7.4.5 Boom Sprayer Calibration

-use clean water

Step 1. Check your tractor/sprayer speed

Formula:	ft. traveled	X	60	= MPH
	sec. traveled		88

Your tractor sprayer speed:

MPH =	ft. traveled	X	60	= MPH
	sec. traveled		88

Step 2. Record the inputs

	Your figures	Example
Nozzle type on your sprayer (all nozzles must be identical)	__________	110 04 flat fan
Recommended application volume (from manufacturer's label)	__________	20 GPA
Measured sprayer speed	__________	4 mph
Nozzle spacing	__________	20 inches

Step 3. Calculate the required nozzle output.

Formula:	GPA X mph X nozzle spacing	=GPM
	5940 (consta

Pest Management Guidelines A Cornell Cooperative Extension Publication	New York and Pennsylvania Pest Management Guidelines for Grapes
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