Introduction


This chapter presents a brief introduction to pesticides and pesticide safety. For further information consider taking the B.C. Pesticide Applicator Course for Agricultural Producers which is available from the BC Government Distribution Center (toll free phone number at 1-800-282-7955). A list of course instructors is available at the BC Ministry of Environment/Pesticides & Pest Management web page Pesticide Certification Trainers in BC. Other sources of information on pesticides and pesticide safety include the BC Ministry of Agriculture's (BCMA)  Pesticide Wise web site and WorkSafe BC's publication Standard Practices for Pesticide Applicators

This chapter presents general guidelines for the proper storage, handling, application and disposal of pesticides. Information on the handling, application, storage and safety precautions of specific pesticides is available on the respective product labels which can be viewed online using the Pest Management Regulatory Agency's (PMRA) Pesticide Label Search database.  You can access the labels by visiting the web site from a computer or by a smartphone or tablet.

Computer access - From the Search Product Label page, under Initial Criteria, click the Search Field arrow and click on Product Name. Next type in the product name in the box next to Criteria. At the bottom of the page in the Marketing Type box, click on Commercial: (only agricultural/commercial products will be listed). Click on Submit Search Requirements, and when the list appears, click on the Registration Number of the product label of interest. You can also save the labels to your computer for future reference.

Smartphone or tablet access - Download the new mobile application from the web page Pesticide Label Search.

 

Emergency Response

Keep emergency numbers visible and nearby your pesticide storage facility and/or pesticide fill station.

Fire: 911

Police: 911

Ambulance: 911

Poison Control Centre: 1-800-567-8911

Provincial Emergency Response (Spill Reporting): 1-800-663-3456

  • Have safety gear, first aid supplies and personal protective equipment easily available.

  • Keep absorptive material, a container for contaminated waste, tools to pick up contaminated material, bleach, and hydrated lime available.

Fires

  • If a fire occurs involving pesticides, call 911 or your local fire department and keep people and animals away from the fire.

Fires involving pesticides can be very dangerous. Burning pesticides may release toxic fumes that are poisonous to firefighters, bystanders, and animals or contaminate the environment. Pressurized containers can explode. Pesticides can spill out of containers damaged by the fire. Runoff from fighting a fire can contaminate a larger area.

For more information on practices to reduce the potential of fires and on dealing with fires involving pesticides, see the BCMA Pesticide Wise website: http://www.al.gov.bc.ca/pesticides/g_5.htm

Poisoning

  • Call the Poison Control Centre at 1-800-567-8911 or 911 immediately if you suspect poisoning and follow their instructions.

Poison Control Centres are open 24 hours a day. They give first aid information and treatments for poisoning. Have the information from the pesticide label available.

Symptoms of Pesticide Poisoning

Read pesticide labels for poisoning symptoms of the pesticides that you are using. Effects from pesticide poisoning vary from person to person and are often hard to recognize. Some symptoms of pesticide poisoning are headache, tiredness, nausea, dizziness, irritation of the skin or nose or throat, blurred vision, tiny pupils, trembling, perspiration, difficult breathing, vomiting, and unconsciousness. Call your doctor, the Poison Control Centre or 911 immediately if you suspect poisoning and follow their instructions.

First Aid

  • In the case of a medical emergency contact your doctor or call 911.

Make sure you, and other people on the farm, know what to do in case of an emergency. Consider taking First Aid and Cardio Pulmonary Resuscitation courses. For course training information contact your local St. John Ambulance office or visit http://www.sja.ca/English/Pages/default.aspx.

Spills

  • Protect yourself.

  • Keep bystanders away.

  • Contain the spill. Surround and cover with absorbent material.

  • Clean up the spill.

  • If you need help call the Provincial Emergency number at 1-800-663-3456.

  • All spills greater than 5 kg or 5 L must be reported to the Provincial Emergency Program at 1-800-663-3456.

Should a spill of chemicals occur, the spiller is the responsible party and they must stop, contain, and minimize the effects of a spill. They must also immediately report spills of greater than 5 kg or 5 litres to the Provincial Emergency Program by telephoning 1-800-663-3456. Ministry of Environment staff will assist you with your requirements for the cleanup of the material, the hazards of the chemical, and the appropriate actions to take.

Human Health

For further information on pesticide safety and potential impacts to human health please take a B.C. Pesticide Applicator Course.

TOXICITY

Pesticides can be toxic to humans. The degree of toxicity (LD50) is determined by feeding (oral LD50) or through application to the skin (dermal LD50) of the active ingredient to animals such as rats and rabbits. The lower the LD50, the more poisonous the pesticide's active ingredient. The LD50 value ratings, outlined below, are based on short term toxicity of the pesticide's active ingredient.

 

Toxicity Oral LD50 (mg/kg) Dermal LD50
(mg/kg)

Very Toxic

0 to 50

0 to 200

Moderately toxic

51 to 500

201 to 1,000

Slightly toxic

over 500

over 1,000

 

Note that most formulated products dilute the amount of active ingredients and that these active ingredients are further diluted when mixed in a spray solution in the spray tank.

Check product Material Safety Data Sheets (MSDS), available upon request from chemical suppliers and online, for specific LD50 values. The oral and dermal toxicities of pesticides recommended in this guide are listed in the table after the Spray Schedules.

Exposure

Pesticides can enter your body through the skin (dermally), the mouth (orally), the nose (inhalation), or the eyes. The skin is the most common route of poisoning for pesticide applicators. Skin contact may occur from a splash, spill or drift. The skin is most likely to get contaminated when mixing and loading pesticides. Personal protective equipment (PPE) such as respirators, face shields and coveralls help to minimize pesticide exposure. Product specific PPE is required to meet margins of safety determined by Health Canada. Make sure you read the label so you know what equipment and other precautions are required to protect yourself.

Hazard

The hazard of using a pesticide depends on both its toxicity and the amount of exposure. You can reduce hazards by choosing pesticides with low toxicity and by reducing exposure. Wear protective gear and follow the safety guidelines outlined on the product label.

Hazard Shapes and Symbols

Shapes and symbols on pesticide labels indicate how harmful a pesticide can be. The shapes indicate how hazardous the product is. The symbols inside the shapes tell you the type of hazard. If symbols are not displayed on the product label, the pesticide has very low hazard rating.

Personal Protective Equipment (PPE)

Wear protective clothing and equipment to minimize exposure to pesticides. Requirements outlined on the pesticide product label have been set by Health Canada to provide a margin of safety to protect your health. Remember to wear PPE during mixing and loading, application, and clean-up. Always wear long pants, a long sleeved shirt and socks. You may also need to wear coveralls, a chemical resistant spray suit, eye or face protection, a respirator, waterproof apron, waterproof pants and jacket. The equipment you need to wear depends on the pesticide applied and the type of application equipment used. Therefore, follow the safety and PPE precautions on the pesticide label.

Contact AgSafe (formerly FARSHA) for information on properly fitting your respirator and other farm/worker safety information.

Re-Entry Intervals of Pesticides

Re-Entry Interval (REI) is the amount of time after a pesticide has been applied when access to the treated area must be restricted.  This time allows for the breakdown of pesticide residues to levels that do not pose a risk to health.  REI information is listed on the product label. WorkSafe BC (WCB) regulations also apply to many farms, and require a minimum of 24 hours for slightly toxic pesticides and 48 hours for moderately or very toxic pesticides before re-entry, regardless of the activity to be performed on the farm.

The REI listed in the tables below indicate the number of hours (h) or days that you or your workers must wait after spraying before the treated area can be entered without wearing PPE. Some pesticide labels indicate a re-entry period or a range of re-entry periods for different activities. When the label and WCB both recommend re-entry times, follow the longest duration whether it is on the pesticide label or a WCB requirement. The following tables list both the label and WCB re-entry periods. Refer to product labels for more detail, including PPE needed to enter treated blocks before the re-entry interval is over. When there are no re-entry times on a pesticide label, follow WorkSafe BC (WCB) re-entry periods. Use spray application record sheets to keep up-to-date records of spray applications and re-entry intervals (www.al.gov.bc.ca/treefrt/pestdis/pests.htm). Orchardists that have employees must post a sign at entry points to the orchard to tell workers when they can safely enter the field. Contact AgSafe if you would like appropriate signs.

Pre-Harvest Interval and Harvesting Restrictions

Pre-harvest interval (PHI) is the time between the last application of a pesticide and the crop harvest. It is important to follow the PHI on a given product to prevent unsafe levels of pesticide residue on food crops. Orchardists must wait for the PHI (days-to-harvest) to pass before harvesting their crops in order to avoid causing risk to consumers and illegal pesticide residues on crops. The PHI, usually given in number of days, are listed on the product label.

Transport, Storage, Use and Disposal Guidelines

For further information on transport, storage, use and disposal of pesticides take a B.C. Pesticide Applicator Course. More information on these topics is also available from the BCMA page - Safety Precautions

Transporting Pesticides

  • Never transport pesticides with food, feed, fertilizer, clothing, or household goods.

  • Never transport pesticides in the passenger section of any vehicle.

  • Lock up the pesticides if you leave your vehicle. Do not leave pesticides unattended in the open box of your truck.

  • You cannot transport certain dangerous goods unless you use shipping documents, special labels, and vehicle signs. Ask your pesticide dealer if the product you have purchased requires special transport procedures. Growers are usually exempt from this when they are transporting less than 500 kg of pesticide.

Storing Pesticides & Shelf Life

Pesticides vary in their stability and response to storage conditions. Try to purchase only quantities of pesticides that you will use up in one growing season. However, under proper storage conditions, you can use most pesticides after at least one year of storage. For more information on pesticide storage, consult the online publication On-farm Pesticide Storage and Handling Facility or visit the BCMA web page Storage and Shelf Life.

Follow these guidelines for storage:

  • Commercial (agriculture, horticulture or industrial) and Restricted pesticides must be kept in a locked storage facility that is vented to the outside and has a warning sign posted on the door. 

  • Pesticides must be stored in their original container with the original label.  If a label is illegible or missing, label the container with the trade name, active ingredient, quantity in the container and PCP number.

  • Never keep pesticides near livestock, food, feed, seed, wells, water supplies, or in your home.

  • Pesticide storage must be 30.5 metres (100 feet) from any well.

  • Store dry/powdered pesticides above liquid pesticides. 

  • Keep herbicides separate from other pesticides.

  • Return pesticides to storage when not in use.

  • Keep a list of the pesticides in storage.

  • Protect the pesticides from extreme temperatures. Some liquid pesticides are destroyed by freezing. Temperatures should not exceed 40 °C.

  • Close containers when not in use.

  • Appropriately dispose of unwanted, unmarked and damaged containers.

  • Keep containers above floor level to protect from dampness and flooding.

  • Post emergency contact numbers on the outside of the pesticide storage facility or near-by.

  • Keep a fire extinguisher, broom and shovel, absorptive material, and protective clothing near-by, in case of emergencies.

  • Pesticides kept in temporary sites or in facilities away from the primary storage facility have the same storage requirements as the primary storage facility.

Mixing and Loading Pesticides

  • Read and follow all label directions.

  • Wear the label-recommended protective clothing and equipment.

  • Choose a mixing and loading site away from people, livestock, pets, wells, and water bodies.

  • Measure accurately and double check your math.

  • Do not rip open paper pesticide bags. Slit them open with a sharp knife.

  • Mix pesticides in still or low wind conditions. Stand up-wind of the pesticide.

  • Hold the container below eye level when measuring or adding pesticide into the spray equipment.

  • Only use mixing equipment for pesticides and return it to locked storage when not in use.

  • Triple rinse pesticide containers as soon as they are empty. Rinse measuring and mixing equipment. Put rinse water into the sprayer.

  • Use clean water. In general the pH of the water should be from 5.0 to 7.0. Some products are very sensitive to pH. Check with the label for specific recommendations.

  • Prevent overflow. Don’t leave the tank unattended.

  • Prevent contaminating the water supply by leaving at least a 15 cm air gap between the end of the filler hose and the water in the spray tank. You can also use a backflow preventer valve or a nurse tank.

Applying Pesticides

  • Read and follow label directions.

  • Use calibrated application equipment.

  • Use the label or production guide rate.

  • Have fresh water and emergency supplies on hand.

  • Make sure the area to be treated is clear of people and animals and be aware of neighbour activities adjacent to your orchard.

  • Don’t work alone when handling very toxic pesticides.

  • To prevent accidental damage of your crop use separate equipment for applying herbicides.

  • Cover or remove animal food and water containers near the treatment area.

  • Wear gloves to replace or clean plugged nozzles. Do not blow out a plugged nozzle or screen with your mouth. Use a soft brush or toothpick.

  • Shut off the spray nozzles when you turn at the end of rows.

  • Use and maintain the tractor speed chosen during calibration.

  • Prevent pesticides from contaminating non-target areas by developing a drift management plan.

Maintain good communication with your neighbours and respect your boundaries. Leave an unsprayed buffer around lakes, streams, ditches, and wells. Check the pesticide label for the widths of buffer zones. Spray when the wind is blowing away (down wind) from sensitive areas. To minimize drift, you should:

  • Spray only when winds are less than 5-8 km/hr but not when it is dead calm or when the air temperature increases with height and causes inversion conditions. There is usually less wind in the early morning and late evening.

  • Do not spray when temperatures are greater than 30° C.

  • Use a drift control agent.

  • Shut off sections of the spray boom that are not needed.

  • Use drift guards or other specialty nozzles that reduce drift.

  • Use boom sprayers with as low pressure as possible, the correct nozzles, large volumes of water, and set the boom as near to the ground as possible to get uniform coverage.

  • Wash your hands before eating, drinking, smoking, or using the toilet.

  • If necessary, post warning signs to keep people out of treated areas.

Note: Pesticides must be registered for chemigation before they can be applied through irrigation systems. Therefore, only apply pesticides through the irrigation system when the label has instructions for chemigation. If chemigation is used, followthe guidelines described in the online publication  Chemigation Guidelines for BC.

After Applying Pesticides

  • Clean equipment away from water supply and bodies of water.

  • Remove and clean protective clothing and equipment.

  • Shower.

  • Keep records of every application including pesticides, fertilizers and growth regulators (see the Grower Records form under the Resources Chapter).

Disposal of Unwanted Pesticides

  • Calculate the amount of pesticide needed for the application, so that none is left over.

  • Do not re-spray an area to get rid of leftover spray.

  • Apply leftover spray according to label directions on another site or crop listed on the label. Do not put unwanted pesticides into sewers, down drains, or on the land.

  • Keep your pesticides safely stored until you can appropriately dispose of them.

  • For more detailed information on the disposal of unwanted pesticides and containers visit the B.C. Ministry of Agriculture web page Pesticide and Container Disposal.

Disposal of Containers

  • Drain the container into the spray tank for at least 30 seconds or shake out the bag into the spray tank.

  • Triple or pressure rinse drums, glass bottles, plastic and metal containers. Single rinse plastic and paper bags.

  • Put the rinse water into the spray tank.

  • Drain and dry the container, remove and discard the cap and pamphlet, then crush, puncture or damage empty containers so they cannot be re-used.

  • Return the containers to your pesticide storage until you can take them back to the supplier, to a public landfill or to a collection site. Do not burn pesticide containers. Burning containers is an offense under the Environmental Management Act and can result in fines or court action.

  • A list of container collection sites can be found at: www.croplife.ca/web/english/stewardship/empty_container_view.cfm?province=BC

  • The Environmental Management Act controls the introduction of waste into the environment that will cause pollution. It is important for orchardists to dispose of their waste in compliance with this Act and the related regulations under this Act such as the Open Burning Smoke Control Regulation, the Agricultural Waste Control Regulation, the Hazardous Waste Regulation and the Spill Reporting Regulation. The disposal of several waste products from farm operations are controlled by these regulations in order to protect people and the environment. These include the disposal of empty pesticide containers, pesticides and pesticide contaminated waste water as well as the burning of waste materials.

Pesticide Application Equipment

Using pesticides requires accuracy and caution. To accomplish this, growers should use proper equipment, maintained in good condition and calibrated regularly.

Tree Row Volume Spraying

Tree Row Volume (TRV) is a measurement of the volume of trunk, limbs and leaves in a hectare or acre of trees. Research in the Okanagan and elsewhere has shown conclusively that adjusting the volume of spray mixture applied for tree size prevents over application. For example, excessive pesticide, nutrient or thinning sprays may result in residues that exceed allowable levels, leaf and fruit burning, over thinning and unnecessary loss of beneficial insects and mites. To use TRV, an adjustment in sprayer calibration (i.e. change nozzles, pressure, travel speed) will be required to apply the calculated volume of spray mixture.

Older plantings with larger trees, on which most of the production guide recommendations are based, had roughly a 5.5 m x 3.6 m (18 ft x 12 ft) spacing that resulted in a foliage volume of approximately 24,000 cubic metres/ha (350,000 cubic feet/acre). Calculate TRV as follows:

TRV = area of hectare (or acre) x tree height x tree width
                   row width

= 10,000 sq m x 3.6 m x 3.6 m      = 43,560 sq ft x 12 ft x 12 ft
     5.5 m                                                   18 ft

= 24,000 cubic metres                        = 350,000 cubic feet

Because new plantings are between 20 and 75% of the foliage volumes of the older trees, reduce spray mixture volumes to match foliage volume of the smaller trees. For example, a 3.4 m x 1.2 m (11‑ft x 4 ft) planting has the following Tree Row Volume:

TRV = 10,000 sq m x 2.3 m x 1.2 m   = 43,560 sq ft x 7.5 ft x 4 ft       
                3.4 m                                            11 ft

TRV = 8200 cubic metres                  = 119,000 cu feet

To calculate the % reductions in TRV use the formulas:

= TRV smaller trees           = TRV smaller trees
     24,000 cu m                     350,000 cu ft

= 8200 cu m x 100%           = 119,000 cu ft x 100%
  24,000 cu m                          350,000 cu ft

  = 34%                                  = 34%

These results indicate that if you commonly apply 560 L/ha (50 gal/acre) in a semi standard 5.5 m x 3.6 m(18 ft x 12 ft) planting, you would apply 34% of 560 L or 190 L/ha (17 gal/acre) in the 2.3 m x 1.2 m (11‑ft x 4 ft) high density planting. Due to low humidity in the Interior of B.C., it is suggested that 190 L/ha (17 gal/acre) is the minimum water volume used in mature spindle plantings. For situations such as spray thinning where 2240 L/ha (200 gal/acre) or more is applied, 34% of that volume (760L/ha) (68 gal/acre) would be used, which will maintain the same chemical concentration. It is important not to reduce the concentration of the chemical because this will reduce the effectiveness of the chemical.

For immature trees, use the same method of calculating Tree Row Volume. To reduce spray volume, use fewer and smaller nozzles, increase tractor ground speed and reduce pressure. For most sprayers, do not to go below 100 psi as spray droplet size changes too dramatically.

Because tree canopies change through the growing season due to growth and increased foliage density, the Tree Row Volume that was initially calculated for the beginning of the season should be increased by 10% to 20% (i.e., from 34% to 44% with a 10% increase) as the growth increases throughout the season. Therefore in the example above, the spray volume of 190 L/ha (17 gal/acre) would be increased to 246 L/ha (22 gal/acre).

Blow-through is another problem in high density plantings with our existing PTO driven sprayers. There are actual pesticide losses because the spray mix droplets and air are going so fast that they go around leaves instead of hitting a leaf. Therefore as much as it is practical with present equipment, it is important to reduce air speed so more spray hits the tree and leaves. To achieve this, various options are available for sprayers: smaller fans, two speed sprayer gear boxes and fans that allow adjustment of blade tilt to reduce or increase air speed. In addition, reduce air speed by reducing tractor engine speed. Slow speed in a given gear, or use a higher gear and lower engine speed to achieve the same ground speed and reduce fan speed.

Cutting Off Nozzles

Most of the time, with most sprayers, for proper calibration and TRV considerations, you must reduce the number of nozzles to fit the spray pattern with the tree size. Just cutting off the top nozzles used for spraying 560 L (50 gal) or 2250 L (200 gal) in old trees will not necessarily give the proper spray volume for high density trees. It is important to calculate TRV for the high density planting and use that water volume in the calculation for the sprayer calibration.

Alternate Row Spraying

Some growers are using alternate row spraying when they cannot reduce blow-through adequately. This can work well for 3.6 m (12 ft) rows and narrower spacing if the spray penetrates and swirls through the row well. The next time a spray is applied, start in the panel next to where spraying began the first time to obtain good control and coverage in most high density plantings. Sometimes where uniformity of application is essential, such as spray thinning and perhaps for codling moth control, spray every row.

Sprayer Use

Mixing Chemicals

Partially fill the sprayer tank with water before adding chemicals. If you are combining spray materials, always add wettable powders before emulsifiable concentrates or crop oils. Keep the agitator running to keep the spray properly mixed. Without agitation, wettable powders may settle out.

For best results, premix wettable powders before adding to the spray tank. Make a slurry of wettable powder and water and then pour it into the spray tank. Always follow manufacturers’ directions when mixing chemicals.

Maintenance and Operation of Air-Blast Sprayers

Good control of orchard pests and diseases requires proper maintenance and operation of spray equipment. If you are not familiar with air-blast sprayers, you should download a copy of the handbook Airblast 101 - A Handbook of Best Practices for Airblast Spraying developed by the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). You can also download the factsheets Adjusting, Maintaining and Cleaning Airblast Sprayers and Six Elements of Effective Spraying in Orchards and Vineyards produced by OMAFRA. Or visit the BCMA web site Pesticide Application Equipment .

Make sure you know the capabilities and short-comings of your sprayer so that you can use it to the best advantage. Your horticultural advisor is equipped to test your air-blast sprayer and advise you regarding its operation.

Evaluate whether a tower air manifold is appropriate for your operation.  In some situations these manifolds can more accurately direct applications and minimize drift.

Attention to the following points will help to improve spray success:

  1. Do not spray in the wind. No sprayer will do as good a job in a wind as it will under calm conditions. Do not spray in dead calm due to the possibility of air inversions.

  2. Travel between 1.5 and 3 km per hour (25-50 m per minute). The speed of travel is governed by density of foliage, tree size and spacing, and by sprayer efficiency. The speed must be slow enough to permit the spray-laden airstream to penetrate through the foliage.

  3. Keep the fan blades clean. Dirty blades cannot pump air efficiently.

  4. Be sure the fan is operated at the correct speed. A drop in fan speed means a drop in air velocity and volume.

  5. Use an accurate pressure gauge and read it frequently. The gauge should be mounted where it can be seen readily from the tractor seat.

  6. Select suitable nozzles for the job. For low-volume air-blast spraying 550-850 L/ha (220-345L/acre), the nozzle disk orifices should be between 1.2 mm and 2.4 mm in diameter and the swirl plates should have two openings not greater than 1.6 mm in diameter. For high-volume spraying, the nozzle dimensions are not as critical. To avoid excessive deposits in the lower portion of the trees, use smaller disks in the lower part of the nozzle boom than in the upper part. When spraying small trees, you can reduce waste of spray material by blanking off some of the upper nozzles.

  7. Calibrate the sprayer. Before putting spray material in the tank, calibrate nozzle output and tractor speed accurately so you know exactly what area you can cover with a tank of spray mixture. If the tank covers 0.64 ha, put enough chemical in the tank to treat 0.64 ha.

  8. Keep your sprayer clean. Flush out the tank, pump, strainers and nozzles thoroughly after each day’s spraying.

  9. Air shear nozzles – To obtain adequate spray droplet break-up with air-shear nozzles, the air velocity must be at least 250 km/hr.

Sprayers Classified According to Volume of Spray Mixture Per Hectare

ULTRA LOW VOLUME

The term “ultra low volume” is used when the total volume of spray applied per hectare is 5.5 L or less (2.2 L/acre) and the material is undiluted.

LOW VOLUME

In low-volume spraying the spray chemical is diluted, but the mixture is applied at a rate that will give no run-off from leaves and fruit. It is often referred to as “concentrate” spraying. The usual range is 550 - 850 L of spray mixture per hectare (220-345 L/acre), but may be as low as 110 - 175‑L/ha (45-70 L/acre).

MEDIUM VOLUME

In medium-volume spraying there is considerable running together of the spray droplets but little actual run-off of spray mixture from leaves and fruit. It’s often referred to as “semi-concentrate” spraying. The usual range is from 1100-2200 L spray mixture per hectare.

HIGH VOLUME

High-volume spraying is characterized by a running together of the spray droplets to thoroughly wet all parts of the trees. It always results in considerable run-off of the spray mixture. This method is often referred to as “dilute” spraying. Application rates up to 5600 L per hectare (2270 L/acre) are common.

Orchard Weed Sprayers

Orchard weed sprayers have special features that distinguish them from other sprayers.

  1. Low pressure. To minimize spray drift, the pump pressure of herbicide sprayers should not exceed 280 kilopascals (kPa) or 40 lbs pressure per square inch (psi).

  2. Boom features. To spray under branches in the tree row, orchard weed sprayers use a single boom with 2 - 4 nozzles. The end nozzle should have a special off-centre nozzle tip, or be a swivel nozzle directed at an angle to provide coverage of vegetation in the tree row. The boom should be hinged at the tractor end to prevent breakage when the boom strikes branches or tree trunks and the boom height should be easily adjustable to accommodate spraying of vegetation of different heights.

Other features of orchard weed sprayers are common to any other chemical spraying equipment.

Sprayer Cleaning

Immediately after use, flush out the sprayer with soapy water and rinse with clean water.

Some herbicides are particularly hard on roller pumps. Take special care to rinse out those pumps after the use of these herbicides. After cleaning the system thoroughly, it is a good practice to add a small amount of oil (not diesel or stove oil) to the system to maintain the roller pump in good condition.

Special Precautions

  1. It is most important to ensure that the area treated is equal to the area used for calculating the rate. For example, if you calculate the rate for a granular application for 1.8 x 1.8 m around the tree, but only treat a 1.2 x 1.2 m area, the calculated amount of herbicide covers 1.44 m2 instead of 3.24 m2. You end up applying more than double the rate.

  2. Uniform application is important to assure both crop safety and the desired weed control. For example, if you halve the travel speed at the end of rows of a sprayer calibrated at 3.2 km/hr, you will apply twice the amount of chemical at the slower speed.

  3. Do not use a herbicide sprayer for applying other pesticides or liquid fertilizers.

  4. Do not apply herbicides by hand gun as their high operating pressures can cause drift and uneven application. Spray drift may injure tree foliage and fruit, and may be a hazard to the applicator, e.g., paraquat (Gramoxone).

  5. Portable spinning disc applicators (e.g. Herbi) apply chemicals in ultra low volumes of water. Droplet sizes are small and the spray is prone to drift even in situations of low wind or updrafts in hot, calm weather.

Weed Sprayer Calibration

It is important to properly calibrate sprayers in order to deliver and apply spray material accurately and uniformly. Not only does proper calibration ensure reliable pest control, but also minimizes the risks of crop injury, excessive chemical residues and environmental contamination. Tractor speed, row width, nozzles and pump pressure combined with tree row volume calculation, will determine the volume of spray mixture applied per hectare or acre. Using properly calibrated sprayers and Tree Row Volume can result in substantial savings in chemical costs. BCGAP integrated fruit production guidelines require each grower complete an annual sprayer calibration check list (see below) before each spray season to ensure the sprayer(s) is in good working order and properly calibrated.

There are at least two good reasons why herbicide spraying equipment calibration is of utmost importance: (1) excessive rates can result in damage to trees; and (2) low rates can result in lack of control, wasting expensive time and chemicals. Calibration of weed sprayers is covered in the Pesticide Applicator Course for Agricultural Producers available from B.C. Ministry of Environment.

Sprayer Calibration Check List

The guidelines require that (1) growers maintain their sprayers in good working order and (2) that they must check sprayers annually for correct calibration. This will ensure application of the correct chemical rate, spray coverage and compliance with the  guidelines.

The following check list will aid in preparing your sprayer for the upcoming season. Have you owner’s manual handy to check manufacturer’s specifications where required. Replace any defective parts immediately, and seek advice where difficulties arise in completing the check list or checking the calibration.

Be careful when working around equipment while the tractor is running.

Engage the hand or foot brake when off the tractor and ensure transmission is in neutral.

Sprayer part/ function What to check for: OK Date repaired

1. Hoses

  • splits and cracks, especially where hoses pass through or around objects

 

 

  • leaks at connections

 

 

2. Filters

  • leaks, damaged seals and filter elements, blocked filter

 

 

3. Tank

 

  • leaks due to cracks, punctures or other damage

 

 

  • venting system is clear

 

 

  • tank sits firmly in its mount

 

 

  • securing straps are correctly adjusted

 

 

  • intake lines are secured; no leaks, cracks or creases

 

 

  • mixing basket is intact (no cracks, holes) and clean

 

 

4. Agitation system

 

  • agitation system works properly.

 

 

  • if mechanical agitation system, make sure that maximum adjustment is available on the packing gland

 

 

  • the other end of agitation shaft is supported properly

 

 

  • the bearings are not worn

 

 

  • the paddles are turning and in the correct positions

 

 

5. Tires and Wheels

 

  • tires have no cuts and have correct tire pressure

 

 

  • wheel nuts are all present and tight

 

 

  • wheel bearings are tight

 

 

6. Controls

 

  • intact control circuitry (electronic, hydraulic or air) for correct operation

 

 

  • pressure control valves operate smoothly and properly

 

 

  • shut-off valves operate properly (tank shut-off valves, nozzle controls)

 

 

7. Pressure Gauge

 

  • gauge reads ‘zero’ when sprayer not in operation

 

 

  • gauge contains proper level of fluid

 

 

  • needle does not jump around when sprayer running

 

 

8. Nozzles

  • nozzles are not worn, corroded or plugged (a gauge is available to check the output of nozzles)

 

 

9. Hitch, PTO

  • hitch and safety chain are correctly positioned and intact

 

 

  • all grease points lubricated

 

 

  • PTO correctly connected and cover attached

 

 

10. Calibration

  • sprayer accurately calibrated following the instructions below

 

 

 

Mark off the distance to cover one acre or one hectare in a level area of your orchard. You can calculate this distance as follows:

One acre:

a) Multiply row width ______ft X row length ______ft = _______sq ft

b) Divide 43560 by value (a) = _________, the number of rows you must travel to cover one acre.

c) Multiply value (b) by row length to get the distance (feet) you must travel to cover one acre.

For example: an orchard is planted with row width 12 feet, row length 600 feet.

  1. 12 ft X 600 ft = 7200 sq. ft

  2. 43560 divided by 7200 = 6.05 = the number of rows to travel to cover one acre

  3. 6.05 X 600 ft  = 3630 ft, the distance to travel to cover one acre

One hectare: 

a) Multiply row width ______m X row length ______m = _______sq m

b) Divide 10 000 by value (a) = _________, the number of rows you must travel to cover one hectare.

c) Multiply value (b) by row length to get the distance (metres) you must travel to cover one hectare.

 

For example: the above orchard measured in metric is planted with row width 3.7 m and row length 183 m.

  1. 3.7 m X 183 m = 677.1 sq m

  2. 10 000 divided by 677.1 = 14.7 = the number of rows to travel to cover one hectare

  3. 14.7 X 183 m  = 2690 m, the distance to travel to cover one hectare

 

Once inspection of the sprayer is complete and necessary repairs made, fill the sprayer tank and spray the test acre or hectare at the speed, RPMs, etc. at which the sprayer was previously calibrated. Compare the volume of spray actually delivered to the volume for which the sprayer is calibrated. Adjust the sprayer controls and re-test until the calibrated and test spray volume outputs are within 5% of each other (i.e. +/- 5 L/100 L).

 

Checked by:________________________     Date checked: ___________________________

 

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Environmental Precautions

For further information on environmental precautions and pesticides take a B.C. Pesticide Applicator Course.

Buffer Zones

Buffer Zones are strips of land between the area being treated and a sensitive environment or habitat that must not be exposed to pesticides (see figure below). The purpose of the buffer zone is to protect sensitive areas from pesticide drift through air, soil or water. Many pesticide labels now have buffer zone information and will tell you what sensitive areas must be protected and the size of the buffer zone.

Protecting Fish and Other Wildlife

Exposure to trace amounts of some pesticides may kill birds, fish or aquatic organisms which are important food sources for fish. Destroying the vegetation along fish-bearing water harms fish by removing food and shelter. Protect fish and wildlife from pesticide poisoning by following label precautions and safety guidelines in this publication.

Fish and fish habitats are protected by the Fisheries Act. This Act prohibits the addition of deleterious substances into water inhabited by fish and prohibits the harmful alteration, disruption or destruction of fish habitat. Deleterious substances can include, but are not limited to, fuels, solvents, lubricants and pesticides. This Act applies to creeks, rivers, and lakes on your own property as well as on public land.

The Migratory Birds Convention Act prohibits the deposit of any substance that may be harmful to migratory birds (for example some pesticides) in water or other areas that they frequent.  If you know your pesticide application is in the vicinity of areas frequented by migratory birds be informed of the potential risks associated with your product choice and take the appropriate precautions during the application.

Many labels have specific buffer requirements to prevent surface water contamination. Read the label to ensure you are taking the appropriate precautions. It is also important to know the risks associated with the pesticide products you use. For example, products such as endosulfan and diazinon are highly toxicity to birds and many aquatic organisms including fish.

There are many species in the southern interior of B.C. that are unique in Canada. The Species at Risk Act is federal legislation that protects Canadian species of wildlife from becoming extinct or extirpated. If you have species such as, but not limited to, the Great Basin Spadefoot Toad, Yellow Breasted Chat, Western Screech Owl, Tiger Salamander and many snake species contact the Ministry of Environment (250-490-8200) for best management practices. A list brochures on endangered species and ecosystems is posted on the Ministry web site. Another useful site for information on endangered species is Species @ Risk .

Protecting Bees and Beneficial Insects

Many pesticides, particularly insecticides, are toxic to honeybees, wild bees, and beneficial insects. Protect these insects from pesticide poisoning by:

  • Considering impacts to beneficial insects when choosing pest control options (See table on page 15-9, read the label and/or consult with a crop advisor).

  • Telling nearby beekeepers about your spray program.

  • Not applying pesticides near hives.

  • Not applying pesticides toxic to bees when plants are in bloom.

  • Select formulations least harmful to bees. Microencapsulated formulations are very hazardous; wettable powders are more hazardous than EC and liquid formulations; granulars are least hazardous to bees.

  • Reducing drift.

  • Timing applications carefully. Consider the pest and beneficial insect’s life cycles to ensure efficacy against targeted pests and minimal impacts to beneficial insects. Evening sprays are less hazardous than morning sprays. Both are safer than midday.

More information on bee poisoning is presented in the Varieties and Pollination section of the Horticulture chapter.

Protecting Groundwater

Groundwater is the source of water for wells and springs thus it is essential that groundwater be protected from contaminants. It may not be possible to clean contaminated groundwater after it is polluted and if it is, the costs and resources required will likely be extreme. The best solution to groundwater contamination is prevention.

Avoid spills, drift, run off and properly dispose of unwanted pesticides and empty containers. Never store pesticides near wells or pump houses and guard against leaking containers.

Groundwater contamination is most likely to occur where soils are gravelly or sandy, the water table is close to the soil surface, there is high rainfall or extensive irrigation, or the pesticide is injected or incorporated into the soil. Pesticides that are persistent in the soil, are weakly absorbed and leach quickly, or are highly soluble have a higher potential to contaminate groundwater. Some labels have specific use precautions addressing this issue. Always read the label and know what potential risks are associated with your orchard and the products you choose.

Well construction, maintenance and location can be factors in contamination. Maintain proper seals between pump and pump base, as well as seals between well casings. Further information can be obtained by contacting local Health Authorities.

Legislation

The purposes of legislation is to prevent unacceptable risk to people and the environment and to ensure a safe food supply for consumers. These laws provide a margin of safety to people on or near the orchard such as orchardists and their family, farm workers and neighbors. Consumer safety and confidence is supported by specific laws that prohibit the sale of fruit with pesticide residues above established safety limits. Other standards promoted by these laws are safe drinking water and the protection of fish and migratory birds. These laws reflect societal values and considerations for the health and safety of you, your community, your customers and your environment.

Breaking the laws can result in substantial fines, court action and administrative penalties.

The following list is meant to give a brief overview of some of the laws and regulations that may apply to pesticide users in B.C. agricultural settings.

Federal: Provincial:

•     Fisheries Act

•     Food & Drugs Act

•     Migratory Birds Convention Act

•     Pest Control Products Act

•     Pesticide Residue Compensation Act

•     Species at Risk Act

•     Transportation of Dangerous Goods Act

•     Drinking Water Protection Act

•     Environmental Management Act

•     Health Act

•     Integrated Pest Management Act

•     Workers’ Compensation Act

Municipal: The Community Charter gives local governments the ability to make pesticide by-laws.

Pest Control Products Act and Regulations

Only pesticides registered by the Pest Management Regulatory Agency (PMRA) of Health Canada can be used or sold in B.C. The label is a legal document. The user is required to use the pesticide in a manner that is consistent with label directions. Using pesticides from other countries is against the law unless you have a Pesticide Own Use Import permit. You must only use pesticides against pests and on crops listed on the label. Using pesticides for uses not on the label is against the law. The PMRA takes random crop samples during the growing season to check for residues of unregistered pesticides.

Occasionally additional uses for pesticides are allowed under the User Requested Minor Use Label Expansion program (URMULE) which may not appear on the label. This guide includes these minor uses as much as possible.

The PMRA classifies pesticides as Domestic, Commercial (may also be labeled more specifically as Agriculture, Horticulture or Industrial) or Restricted on the labels. Restricted products are more hazardous and have specific restrictions and precautions on the label.

For further information on this Act and Regulation visit Health Canada web site at http://www.hc-sc.gc.ca/cps-spc/pest/index-eng.php

The Food and Drugs Act

All domestic and foreign produced foods must be free of harmful residues of pesticides. Health Canada sets the maximum residue levels (MRL) for pesticides applied to crops in Canada and for similar crop products imported into Canada. Established Canadian MRLs are posted on the Health Canada web site Maximum Residue Limits for Pesticides.  The Canadian Food Inspection Agency (CFIA) takes random samples of crops to test for pesticide residues at the time of sale. The CFIA can seize any crop in which pesticide residues exceed the MRL for that crop. It is important that you follow the recommended rates, pre-harvest intervals and the number of applications allowed per season in this Guide and on the label to avoid exceeding the MRLs. In some cases buyers or processors will not accept fruit treated with certain materials. Check with your buyer, processor or packer so that the marketability of your crop is not affected. If you are exporting your fruit ensure that you know the requirements of the importing country.

British Columbia Laws

Provincial legislation regulates worker safety, drinking water safety, the sale, use and disposal of pesticides in B.C. Farmers must comply with several provincial acts and regulations that have rules about pesticides. For a summary of the main provincial pesticide rules farmers need to comply with, please see the Ministry of Agriculture and Lands Website at: www.al.gov.bc.ca/pesticides/i_4.htm.