Paul Wenger, California Farm Bureau President and Modesto Farmer AS A LICENSED Pest Control Operator and Qualified Applicator since 1984, I’ve seen a lot of changes in our agricultural industry, especially in the area of pest and disease control. The products and crop protection materials we use today are much more targeted to the pests, diseases and weeds than when I started my pest control business. Most of the products we apply today are much safer for the applicator as well as the environment. Crop protection materials are necessary to provide the highest quality food and fiber crops for the consumers who rely upon them.
What hasn’t changed in the past 32 years that I’ve been a pest control operator, is the need to do the very best we can and to do our job in the safest way possible. Repetition of any job or activity can lull a person into taking shortcuts or not paying as much attention to detail as they should. Spray Safe was developed for that very reason. The California Farm Bureau is proud to participate in Spray Safe events, so we can continue our California tradition of producing the highest quality, most wholesome food, with the safest working conditions in the world.
APPLICATOR ALERTS
As farmers and equipment operators,
✔ Spray S
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kes Sense
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Events - p .2 Mixing Sy stems Re gs - p. 3 ✔ Schoo l Notifica tion Regs - p. 4 ✔ Worke r Protect ion Stand ards - p. 5 ✔ Safety and UAS Spraying - p. 6 ✔ Boots on the G round - p .8 ✔ CAPC A ED 201 7 Calend ar - p. 9 ✔ Aerial Applicatio n Dynam ics - p. 10 ✔ Closed
That’s why Spray Safe continues to be such a successful program. It’s important to remember that no matter how long we’ve been doing something, we can always learn how to do it better and safer. Spraying Safely: it’s the right thing to do.
EDUCATION & TRAINING 2017 OFFERS VALUABLE OPPORTUNITIES FOR EDUCATION AND TRAINING For a Spray Safe event near you, see page 2. For more than 40 CAPCA ED seminars covering important training in crop protection, see page 9.
DECEMBER 2016 VOL. 1, NO. 3
IN THIS
we must work together to be sure each of us are doing the best job we can and in the safest, most responsible manner. I appreciate it when my employees ask questions, because they often make me aware of a situation that needs to be fixed, which I had not seen or known about. The watchful eye and willingness to ask questions, makes me a better farmer. As neighbors and fellow pesticide applicators, we are not in completion with each other when it comes to safety and doing the best job we can. If there’s a problem, it effects our entire agricultural industry. That’s why we need to look out for each other, ask questions and get the answers needed if in doubt about a particular situation or job. And most importantly, share what we’ve learned with others.
APPLICATOR ALERTS
Spray Safe: It Makes Sense for All of Us
SPRAY SAFE
CAPCA EDITORIAL STAFF
Ruthann Anderson - Editor
Joyce Basan - Deputy Editor Dee Strowbridge - Membership/Conference Sylvia Stark - Advertising Sales Manager Lien Banh - Office Manager Mindy DeRohan - CAPCA ED Manager Ariana Zamora - So. CA Representative Jacqueline Tabarez - No. CA Representative Rachel Kihlthau - Executive Assistant Graphic Design - Rosemary N. Southward southwardr@comcast.net PURPOSE California Association of Pest Control Advisers (CAPCA) is a non-profit voluntary mutual benefit association. CAPCA’s purpose is to serve as the leader in the evolution of the pest management industry through the communication of reliable information. CAPCA is dedicated to the professional development and enhancement of our members’ education and stewardship which includes legislative, regulatory, continuing education and public outreach activities. PUBLISHING INFORMATION Applicator Alerts is published by the California Association of Pest Control Advisers (CAPCA), 2300 River Plaza Dr., Suite 120, Sacramento, California 95833. Web: www.capca.com, (916) 928‑1625. POSTMASTER: send address change to CAPCA. CAPCA has endeavored to include appropriate and accurate statements, but disclaims any and all warranties and/or responsibility for the statements or articles submitted to Applicator Alerts that may have additionally been edited for style, content and space prior to publication. Views expressed are those of the authors and do not necessarily represent CAPCA policies, or positions or endorsements. Editorial content of this publication is educational and informational in nature. No part of this publication, including images, may be reproduced without prior written permission from the publisher. Contact CAPCA at (916) 928‑1625 for reprint authorization. PRINTING: Sundance Press Tucson, Arizona
FIND US ON LINKEDIN: https://www.linkedin.com/company/californiaassociation-of-pest-control-advisers-capca-
SAVE THE DATES
FOR THESE 2017 SPRAY SAFE EVENTS: Yuba-Sutter Spray Safe
Wednesday, January 18, 2017 Yuba-Sutter Fairgrounds, Franklin Hall Yuba City, CA 95991 8:30 a.m. – 1:00 p.m. Admission - Free Lunch provided Info: Claudia Street, Yuba-Sutter Farm Bureau (530) 673-6550
Yolo County Spray Safe
Wednesday, February 1, 2017 Yolo County Fairgrounds, Waite Hall Woodland, CA 95776 7:45 a.m. – 1:00 p.m. Admission - $10 Pre-registration; $15 at-the-door (Lunch is not guaranteed if you do not register in advance) Info: Gretchen Schauer, Yolo Co. Farm Bureau (530) 662-6316
Kern County Spray Safe
Friday, February 3, 2017 Kern County Fairgrounds Bakersfield, CA 93307 9:00 a.m. – 1:00 p.m. (Trade Show 7:00 a.m. – 9:00 a.m.) Admission – Free Lunch provided Info: Jeff Rasmussen (661) 978-8076 or Terra Laverty (661) 742-3842
San Joaquin Spray Safe
Thursday, February 23, 2017 Robert Cabral Ag Center Stockton, CA 95206 Registration 7:30 a.m.; meeting 8:00 a.m. Admission - Free Lunch provided Info: Larry Fisk (209) 814-4406 or Dennis Duda (209) 983-4294
Santa Barbara County Spray Safe
Tuesday, March 7, 2017 Santa Barbara County Fair Grounds Santa Maria, CA 7:00 a.m. – 2:00 p.m. CE hours will be offered Admission - Free Lunch provided DPR speaker scheduled breakout sessions Held in English and translated/broadcasted into Spanish Info: Teri, Santa Barbara Farm Bureau (805) 688-7479 or Lotti Martin, SB Ag Comm office (805) 934-6200
Ken Everett, Environmental Program Manager, DPR THE CALIFORNIA DEPARTMENT of Pesticide Regulation (DPR) was the first regulatory agency to require closed chemical transfer systems (closed system) in the United States. In 1977, DPR started requiring closed systems for pesticides that displayed the signal word “Danger.” Over time, DPR and its enforcement partners, the County Agricultural Commissioners, noticed issues with the regulations. Some of those issues included:
A major change to the regulation (Title 3 California Code of Regulations [CCR] Section 6746) was making it more performance-based rather than prescriptive-based. This means that the system has to move the product (from its original container to the application equipment) without deteriorating, leaking or breaking and without hazardous chemical exposure to the mixer/loader. How this is accomplished is up to the designer of the system.
• Manufacturers and growers were having difficulty meeting the rinsing requirement.
Another change to the Closed Mixing System regulations is the introduction of the “two-tiered” container rinsing requirement. A Tier I pesticide requires that the Closed Mixing System rinse the container and extract the rinsate while still attached to the Closed Mixing System. A Tier II pesticide allows for the container to be removed from the Closed Mixing System for rinsing, and the rinsate hand-poured into the tank.
• Many pesticides are classified as “danger” pesticides because of hazards that a closed system would not protect against (i.e. oral ingestion). • For a period of time there were no manufacturers of closed systems, so new systems and replacement parts were not available. • Systems were too expensive for small growers. • Systems were often very complicated. • Many of the systemic poisoning organophosphates (i.e. Phosdrin) and chlorinated hydrocarbon (i.e. heptachlor) that the closed system regulation was developed for were no longer registered for use in California. • The hazards with some pesticides now in use stems more from direct contact action (i.e. corrosion of skin/ eyes) than from systemic activity (i.e. poisoning). On January 1, 2016, DPR implemented the new Closed Mixing Systems Regulations that were designed to make compliance with the regulation easier without compromising safety.
The “Precautionary Statements” on the pesticide label determine which rinsing requirement (Tier I or II), that must be followed.
• Labels that specify that a certain type of Closed Mixing System are required to use that specific Closed Mixing System. • Labels that do not have such declarations in the Precautionary Statements but have a label requirement for a closed system must use a Tier II system. • Statements of “Skin contact can cause rash” or “Skin contact can cause irritation” do not require a Tier I or II Closed Mixing System. To learn more about the Closed Mixing System regulations see DPR’s links below or contact your County Agricultural Commissioner for more information. Ken Everett is the Manager at DPR Enforcement Branch Northern Regional Office in West Sacramento. Website Links http://www.cdpr.ca.gov/docs/legbills/ calcode/030302.htm#a6746 http://www.cdpr.ca.gov/docs/whs/ ind_hygiene_eng_cont.htm
• The Precautionary Statement “Fatal if absorbed through skin” requires a Tier I Closed Mixing System. • Precautionary statements like “May be fatal if absorbed through skin,” or “Corrosive, causes skin damage” require a Tier II Closed Mixing System. • Labels that don’t have the typical precautionary statements, such as “If this product gets on your skin it will be fatal to you,” or “Skin contact is fatal” require a Tier I Closed Mixing System.
County Agricultural Commissioner: https://www.cdfa.ca.gov/exec/county/ countymap/
• Labels that state “Skin contact may be fatal or will damage skin (for example burns, blisters or causes skin injury),” require a Tier II system. 3
SPRAY SAFE
UPDATE: California’s Closed Mixing Systems Regulations
SPRAY SAFE
School Notification Draft Regulations Ruben J. Arroyo, Kern County Agricultural Commissioner SOMETIME IN LATE 2017 a notification of pesticide use near schools regulation package will be implemented. Normally when this happens I am commonly asked the same two questions by many people: “Ruben, what am I going to have to do in order to meet the regulation?” and “Why are they doing this?”
▸ Under the current education code (35294.4) schools may enact procedures for responding to the release of a pesticide within ¼ mile of a school.
Well, there is quite a bit of detail to the requirements but here is my simplified version of answering these questions as they pertain to the current draft form of this package.
● Individual schools or day care facilities, along with the growers and the Commissioner can develop an alternative agreement, to which all three parties must consent, that provides equal or greater protection than the proposed regulation.
“Ruben, what am I going to have to do in order to meet the regulation?” • Stop all use of pesticides that are applied by air, sprinkler, air blast, fumigation, and dust formulations, between the hours of 6am and 6pm within ¼ mile of a school or day care. (Based on current draft regulations. The final regulations may vary.) • If your pesticide doesn’t fall into the above categories and you would like to apply pesticides during those hours then the grower will be required to do two things - notify the school or day care annually of their intent to apply pesticides to the site and give them 48 hour notification of each specific application. “Why are they doing this?”
There are also two other important provisions of this regulation package:
● Individual schools or day care facilities may choose to waive their right to receive application notification. Many more questions will be asked and I will continue to do my best to answer all of them. Please call me or your local Agricultural Commissioner for anything that requires some explaining! (661) 868-6300
http://www.cdpr.ca.gov/docs/pressrls/2016/161019.htm
● To provide an extra measure of protection to schools from the risk of short-term pesticide exposure. ▸ Since 2005, 4 incidents of agricultural drift have occurred onto schools grounds. ▸ Since 2009 there have been 0 incidents of agricultural drift onto school grounds.
Supporting CAPCA Since 2006
▸ In Kern County we prohibit the use of restricted materials within ¼ mile of schools while school is in session or during a school sanctioned event. ● The regulation would also provide advance notification when certain pesticides are applied, thus increasing communication between growers and schools or child daycare facilities, and help them in responding to inquiries and potential incidents. ▸ Current Regulation allows for the local Commissioner to use permit conditions for pesticides that are used within ¼ mile of a school. Kern County requires that growers contact schools and document on the notice of intent prior to any use of a restricted material. 4
a Insecticides a Soil Treatments a Fungicides a Water Treatments a Herbicides a Bio-Insecticides 1.888.273.3088 | biosafesystems.com
EPA’s Revised Rule
Workers and handlers must be trained annually
Pesticide Safety Training for Workers and Handlers
Notification
Hazard Communication
Minimum Age Requirements Display of Pesticide Safety Information
Decontamination
Exemptions Drift Related Requirements & Application Exclusion Zone
Employers must maintain records of worker and handler training for two years Adds additional topics to worker and handler training (reducing take home exposure, exclusion zones, minimum age, respirator use, etc.)
Requires posting on all outdoor applications when REI’s are greater than 48 hours Requires employers to provide pesticide specific hazard information (SDS) at the central location as well as application specific information. Pesticide Application and Hazard Information must be maintained for two years and be made available to workers, medical personnel, or “designated representatives” if requested Notice of pesticide applications and completed applications must be given to the property operator and include: the date, start time, end time, location, product name, EPA#, active ingredient, and REI. Requires all early entry workers and handlers to be at least 18 years old Requires pesticide safety information to be displayed at a central location and decontamination sites • All permanent decontamination facilities; and • All decontamination facilities servicing 11 or more workers. Requires employers to provide 1 gallon of water per worker and 3 gallons of water per handler/early entry worker (measured at the start of their work period) for decontamination Employers must provide water at all mixing and loading sites for ocular decontamination (when label requires protective eyewear or using a closed system) from a system capable of delivering 0.4 gallons/minute for 15 minutes or from six gallons of water able to flow gently for about 15 minutes (retains 1-‐pint rule for other handlers not at the mix/load site). Eliminates the exception for employees directly supervised by Certified Crop Advisors. Retains nursery and greenhouse requirements but changes the term “entry restricted area” to “exclusion zone” and requires new application exclusion zones of up to 100 ft. around application equipment for outdoor production.
Impact on California (CA)
New revisions will change worker training requirements to annually. Handlers are already required to be trained annually. Add requirement for worker training record keeping. Handler training record keeping is already required. CA already has most proposed topics in PSIS services however those topics would need to be modified in regulation as part of the training requirements. •
Qualified trainers must be present during entire training and their qualifications recorded on the training records (1/17) Training Topic Changes (1/18)
• Posting signs will be required for REI’s greater than 48 hours CA already requires SDSs to be maintained. However, now SDSs will be required to be displayed at the central location as part of the Application Specific Information. CA already requires record keeping for two years, now will need to make available to “designated representatives” upon request. Notice of pesticide applications and completed applications must be given to the property operator and in CA will now include: the start time and end time along with other information already required in CA. Will require CA to revise our current handler age requirements to apply to all handling situations and adopt early entry worker age requirement. Will require PSISs to be displayed at all permanent decontamination facilities and all decontamination facilities serving 11 or more workers.
In CA sufficient water must be available for routine and emergency washing or decontamination. CA will now require the new minimum decontamination water requirements be available at the beginning of each work day. Need to add these new minimum requirements for ocular decontamination at mix/load sites.
CA must delete these exemptions as well. Will require CA to adopt new “exclusion zones” – for more information on Application Exclusion Zone (AEZ) got to https://www.epa.gov/sites/production/files/2016-‐ 04/documents/aez-‐qa-‐factsheet.pdf
Implementation – First round of required changes expected to be in place January 2, 2017. Second round of required changes (relating to new training topics) expected to be in place January 2018. DPR’s revised 3 CCR incorporating the 2017 changes are online at http://www.cdpr.ca.gov/docs/legbills/rulepkgs/16-‐001/16-‐001.htm
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UPDATES O THE WORKER Protection PROTECTION STANDARDS Updates to Tthe Worker Standards
APPLICATOR SPRAY ALERTS SAFE
Worker Safety Implications from Aerial Spraying by UAS
Brad Anderson, Yamaha Motor Corporation, USA UNMANNED AERIAL SYSTEMS (UAS), or drones as they are commonly referred to, are aircrafts that do not have a pilot aboard. These aerial platforms are operated by a remote control transmitter and are controlled by a pilot in command (PIC) with assistance from a visual observer. UAS’s are beginning to establish a footprint in our everyday lives through many different industries, including the field of agriculture. The adoption of UAS’s in the field of agriculture has the potential to create a significant impact and alter the landscape of how crops are farmed; including the spraying of crops with crop protection products. For the past 20 years, countries such as Japan and Korea have been using UAS’s for agricultural aerial applications, or crop dusting, of crop protection products on a variety
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of different crops. Their usage has expanded and in Japan alone, there are over 2,000 UAS platforms operating annually, spraying a variety of crops. Within the past year, aerial applications from UAS platforms have also begun to be utilized in the United States, with first commercial applications happening earlier this year in California. While UAS platforms are much smaller and do not carry the payload or have the efficiencies of manned aerial applications, they still have significant advantages in situational applications. Typical applications involving a UAS are much different than applications performed by manned aircraft, as they are often in smaller areas since they can operate in tighter spacing due to the smaller size and slower speed of the aircraft. A significant benefit for the adoption of UAS platforms in aerial
applications is the potential for an improvement in worker safety. Since the operator remotely operates the unit, they are able to be further away from the application materials as they are dispensed. As a result, there is potential for the worker exposure for field workers to be decreased. While the PIC and visual observer are both in the treated area, they are able to position themselves and maintain a safe distance to limit their exposure to chemicals at the point of application as well as from potential drift. Another perceived benefit for UAS applications is the potential for decreased physical strain on field workers. One type of application that has shown promise is utilizing UAS platforms as a substitute where backpack spraying is currently utilized. Removing a 50-pound backpack from a worker while
walking up and down difficult terrain should help keep workers in better physical condition, and possibly limit potential workers comp issues. Often times it becomes strenuous on field workers to scale hillsides while carrying a backpack filled with chemicals, compared to a PIC and visual observer carrying just a transmitter. There are currently no laws specific to aerial applications from a UAS, as a result all UAS aerial applications must follow the laws and regulations governing manned
aerial applications. All UAS aerial applicators must have at least an apprentice pilot license administered by DPR, while also maintaining a commercially rated and current FAA pilot license and medical certificate. In addition, any UAS company performing aerial spray applications must also possess a Part 137 certificate from the FAA that allows them to dispense economic poisons and employ one person with a DPR Qualified Applicators License (QAL). Finally, the UAS pilot performing a spray application is considered the applicator and must also file all the
usage reports with the county. While UAS’s are still a very new and developing tool within agricultural applications, they appear to potentially offer some advantages. The advantages can be numerous and even include safer alternatives in certain situational aspects for field workers. The use of UAS is an introduction to an entirely new tool for most agricultural organizations, but it is one that could benefit everyone within the industry.
SAVE THE DATES AVOCADO / PSHB SEMINARS January 25, 2017 Museum of Ventura County 100 E. Main St., Ventura, CA 93001 January 26, 2017 Temecula Conference Center 41000 Main St., Temecula, CA 92590 Watch our website for more information:
https://capcaed.com/ For more information, contact Ariana Zamora at ariana@capca.com or (805) 704-3255
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Boots on the Ground: Q&A with John Roncoroni, Farm Advisor & PCA APPLICATOR ALERTS (AA): The field of spray technology is continually changing to address spray drift issues and to improve application efficiency. Perhaps most notably is the choices available in spray nozzles, yet this can be an area that is overlooked. Why is nozzle choice so important to overall performance in application? JOHN RONCORONI (JR): There are many factors involved in a successful application, but an herbicide application will not be successful unless the herbicide gets to the part of the plant where it works. Nozzle selection can affect the rate and coverage of the herbicide which in turn will affect the overall performance of the application. AA: Droplet size and drift are very connected so what should every applicator keep in mind when addressing the range and coverage during spraying? JR: Droplet size is a double edged sword. Smaller droplets will usually mean better coverage. This is important when using contact herbicides, or when spraying grasses or small weeds. Larger droplets will usually mean better drift control. Larger droplets are good when using systemic herbicides like glyphosate or when spraying large broadleaf plants.
AA: What are the benefits of the air induction nozzles? JR: All flat fan nozzles spray a range of droplet sizes. Airinduction nozzles produce a larger proportion of large droplets and fewer smaller droplets, or ‘fines’ than standard flat fan nozzles. One thing that is important for growers to remember is that especially with the second generation air induction nozzles it is necessary to increase the sprayer pressure - often 80 psi - to achieve the desired droplet size mix and pattern. AA: How do surfactants effect disposition of the material being sprayed? JR: I am not an engineer and surfactant chemistry is complex, but surfactants serve two very important purposes: 1. Reduce the surface tension of the water. Without surfactant the water/herbicide combination will tend to sit like a ball on the leaf with very little of it touching the leaf. Surfactants flatten out the ball so there is more area touching the leaf; and 2. Help the herbicide get into the leaf. Plants have a waxy cuticle layer to keep the plant from losing water and dying. Surfactants help the water/herbicide combination get through this layer AA: When it comes to spray drift and safety, what are the main things you consider? JR: I think that means plant safety, there are a few things. First- the weather especially wind. There are some days when you just shouldn’t
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spray. Those are usually easy to determine - it’s the days that are, let’s say, “iffy.” You would spray at a later date but today is better for a number of reasons - be careful on those days. Wind direction - if you are going to spray, it is better to have the wind blowing back on to your field than on to your neighbors. Sprayer speed - there will be more drift when you go faster. Nozzle orifice opening - especially with standard flat fan nozzles - an 02 will produce more ‘driftable droplets’ than an 04. AA: Can you give an overview of the tool/resource available on UC IPM’s website for investigating herbicide injury symptoms? JR: Dr. Kassim Al-Khatib has put together a great tool for herbicide drift symptoms and a primer on causes of drift and ways to reduce it (see http://herbicidesymptoms. ipm.ucanr.edu/ ). The biggest part of the site is devoted to diagnosing herbicide symptoms. Using pictures from many sources, including other UC scientists, you can often determine the cause of herbicide symptoms. You can choose specific symptoms on one or several crop and ornamental plants. Or you can choose a specific herbicide or herbicide family and look at that symptom on one or several different plants.
Mark your calendars now for these valuable training events. January 19, 2017 – Fresno – CAPCA ED January 24, 2017 – Yuba City – CAPCA ED January 26, 2017 – Tracy – CAPCA ED February 28, 2017 – Chico – CAPCA ED March 2, 2017 – Santa Ana – CAPCA ED March 14, 2017 – San Ramon – CAPCA ED March 21, 2017 – Redlands – CAPCA ED March 23, 2017 – Modesto – CAPCA ED March 23, 2017 – San Luis Obispo – CAPCA ED March 29, 2017 – Exeter – CCA Nutrient Management April 11, 2017 – Escondido – OFAC April 26, 2017 – Carson – CAPCA ED April 27, 2017 – Simi Valley – CAPCA ED May 3, 2017 – San Jose – CAPCA ED May 23-24, 2017 – Temecula – CAPCA Spring Summit June 13, 2017 – Palm Desert – CAPCA ED June 22, 2017 – Sacramento – CAPCA ED June 28, 2017 – Oxnard – OFAC July 11, 2017 – Lodi – CCA Nutrient Management July 26, 2017 – Fresno – Nutrient Management August 2, 2017 – San Mateo – CAPCA ED August 2, 2017 – Ontario – CAPCA ED August 10, 2017 – Tulare – OFAC August 15, 2017 – Carlsbad – CAPCA ED August 17, 2017 – Simi Valley – CAPCA ED August 24, 2017 – San Luis Obispo – CAPCA ED September 12, 2017 – San Jose – CAPCA ED September 13, 2017 – Santa Paula – CAPCA ED September 14, 2017 – Bakersfield – CAPCA ED September 21, 2017 – Modesto – CAPCA ED September 27, 2017 – Chico – CAPCA ED October 15-17, 2017 – Reno, NV – CAPCA Conference November 1, 2017 – Sacramento – CAPCA ED November 9, 2017 – Tulare – CAPCA ED November 14, 2017 – Napa – CAPCA ED November 15, 2017 – Modesto – CCA Nutrient Management November 15, 2017 – Arcadia – CAPCA ED November 16, 2017 – Santa Ana – CAPCA ED November 29, 2017 – Bakersfield – Nutrient Management November 30, 2017 – Gilroy – Nutrient Management December 14, 2017 – Calistoga - OFAC
CAPCA ED 2017 SAVE THE DATES
CAPCA ED – 2017 Schedule
Watch our website for registration information: https://capcaed.com/ For additional information contact: Mindy DeRohan, CAPCA ED Manager mindy@capca.com / (916) 928-1625 x207 Ariana Zamora, So. CA CAPCA ED Coordinator ariana@capca.com / (805) 704-3255 Jackie Tabarez, No. CA CAPCA ED Coordinator jackie@capca.com / (916) 928-1625 x205
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Aerial Application Dynamics Made Simple Terry Gage, President, California Agricultural Aircraft Association AERIAL APPLICATION is a useful tool for making quick and effective applications of seed, fertilizer and crop protection/enhancement products. With this application method, there are many different forces at work that impact droplet size and spray deposition. In this article, we will explore some of the key components of aerial application spray dynamics and how flight and other variables impact droplet size and efficacy. Understanding the Forces of Flight The shape of the wing forces air to move faster over the top of the wing creating a low pressure area above and a high pressure area below. This creates lift.
Airflow coming over the wing creates quite a bit of turbulence that will break up the spray droplets in an unpredictable pattern. To mitigate this, we drop our booms out of this turbulence.
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In ground application systems, higher pressure creates smaller droplets. Does this hold true in aerial application? Let’s revisit the airflow over the wing again. Modern ag airplanes travel across the target field from 120mph – 150mph. Wind shear has a significant impact on droplet size as this force can cause droplets to shatter. The Spray Drift Task force did various studies to evaluate how nozzle orientation impacted droplet size.
What these tests determined is that spray droplets from a straight back nozzle at higher pressures increases the exit velocity which maintains the droplet size, while nozzles that released the spray in other orientations caused the droplets to break up creating finer droplets due to wind shear. There are other physical properties that impact droplet size: Dynamic Surface Tension – Force that hold droplets together and Viscosity – Amount a liquid is able to give before breaking. Tank mixes are extremely important when making aerial applications as these forces can increase and decrease droplet size. Why Do We Care About Droplet Size? Drift and Coverage We know that droplets below 200 microns take longer to fall to the ground and are more likely to travel beyond the intended target. Efficacy is impacted if the product doesn’t hit the target plant and/or if enough of the product does not make the intended target. Speaking of coverage, what does this mean to you? Some think coverage is amount of water used in an application. Coverage can also be the amount of material that hits the intended target and gets utilized. Are these two definitions the same? Not exactly. When you reduce a 500 micron droplet into 250 micron droplets, how many do you get? Two 250 micron droplets? No, as droplets have volume cutting a 500 micron droplet down to a 250 micron droplet results in eight 250 micron droplets as shown below.
Increasing the amount of water from 10 gallons per acre to 20 or more gallons per acre increases the overall amount of spray but dilutes the amount of active ingredient (AI). Does this increase efficacy? Not if enough of the AI hits the intended target whether that be plant or insect. Wouldn’t our efficacy be increased if more AI hit the intended target? Of course! So instead of focusing on gallons per acre, we really should focus on droplet size. In
our example of cutting a 500 micron droplet in half, we end up with eight 250 micron droplets allowing for better contact on the intended target. As you can see, aerial spray dynamics are quite complex. Fortunately, there is significant scientific work completed by numerous Biological and Ag Engineering departments in Illinois, Kansas and Texas and by many other aerial deposition researchers around the world. Their continuing analysis drives development of new technology and modeling to determine droplet size and drift minimization. Today’s ag pilots use nozzle technology, deposition analysis and several models to determine the best equipment set up to deliver needed commodity inputs on target.
In Our Next Issue: Impor tant Informatio n and Updates o n Citrus Is sues, Including A sian Citrus Pysllid/Hu anglongbin g Watch for this impor tant feature in our March 2017 Applicator Aler ts publicatio n.
The Spanish translation for this k n issue of the Applicator Alerts a was provided by Th u! Newsletter the Kern County Agricultural Yo Commissioner’s office. We wish to extend our sincere appreciation to Agricultural Commissioner Ruben Arroyo and his staff for their support and assistance.
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APPLICATOR ALERTS DECEMBER 2016 / VOL . 1, NO. 3
In This Issue: Spray Safe Events Closed Mixing Systems Regs School Notification Regs Worker Protection Standards Safety & UAS Spraying Aerial Application Dynamics Boots on the Ground Q&A
CAPCA 2300 River Plaza Dr., Ste 120 Sacramento, CA 95833
PRSRT STD US Postage PAID Tucson, AZ Permit No. 271
APPLICATOR ALERTS