Grower Know-How: Calibration Is ‘Super Critical’ To Superior Sprayer Function
August 23, 2022 Proper sprayer calibration and nozzle size go hand in hand.
Officials with four sprayer companies offer their thoughts on the two topics and other issues:
What should growers know about calibration?
Tim Schaal, CEO, Airtec Sprayers: “Accurate calibration can only be achieved by having an operator who pays attention while he is spraying. Speed, pump pressure, and nozzle size all play a critical role in determining accurate spray calibration. If any of those three items are incorrect during the process, the calibrated output will not be accurate. The desired gallons per acre can be achieved at multiple speeds, pressures, and nozzle size, making it important to determine those variables based on the desired level of coverage. For example, you can go faster with a bigger tip size to get a higher output, but depending on the thickness of the canopy, it might be more desirable to go slower with a smaller nozzle size to allow for leaf movement and canopy penetration. However, when doing dormant sprays when there is not much leaf canopy, it might be OK to go faster.”
Nick Fleitz, Agronomist, Pentair-Hypro: “Modern sprayers continually become more advanced, but it is still good to periodically perform a manual calibration to make sure all equipment is working as intended. This will ensure that you are applying correct doses to your crops for effective pest management and avoid any costly over-application scenarios. I like to see a manual calibration done once a year to ensure all instrumentation is reading correctly.”
Wayne Riddle, Agriculture Sales Manager, Slimline Manufacturing: “Calibration means confirming sprayer output but also includes sprayer inspection and adjusting the sprayer settings to match the crop and environmental conditions. It is important to confirm the sprayer is functioning correctly, each nozzle is delivering the desired rate and spray quality, and the desired rate is applied to the crop.”
What should growers consider when choosing the ideal nozzle type and size?
Steve Booher, Founder, Smart-Apply: “First, select nozzles designed for air blast sprayers. Choose a size based on the speed and rate of application. Select the proper spray pressure to achieve the proper droplet size, which is critical to achieve the proper deposition onto the foliage. Finally, calibration is super critical. While it’s easy to overlook, calibration of your sprayer setup and nozzles is key.”
Schaal: “Spray nozzles and size should be selected based on several factors, including the desired amount of material per acre (low, medium, or high volumes), the operating speed of the tractor, and the desired atomization size of the spray particle. Spray particle size greatly impacts the amount of coverage, as too small of a particle leads to excess drift, and too large of a particle leads to lack of coverage. You want to select a spray tip that can run at a high enough water pressure point to atomize correctly in the air stream created by the sprayer to create maximum coverage while eliminating waste.”
Fleitz: “The first goal should be to ensure you have nozzles that are sized correctly for your applications. Even if you have everything else set perfectly, a nozzle of the wrong size will reduce the performance of your sprayer. The next step is to consider the material of nozzle to be used. Most often in orchard, vineyard, and fruit production this will be a ceramic nozzle as ceramics are the most durable and possess the most longevity for production systems that frequently spray and at high pressures. The next step is considering what levels of drift reduction, potential drift and droplet size you feel comfortable with. This is something that varies by the individual applicator, but I always encourage applicators to take steps in mitigating drift potential where possible. Spray nozzle selection will have the single largest influence on drift potential, therefore utilizing nozzles with some degree of drift reduction should be considered.”
Riddle: “Pesticides are very specific to target and timing. Multiple sets of nozzles are required for a spray season to match the shape, size, and density of the crop.”
What are the most important factors to consider when selecting a vineyard or orchard sprayer?
Schaal: “Achieving the desired level of spray coverage while also minimizing the inherent risk of spraying for the worker and the environment. This is done by selecting a sprayer that can be operated safely both during the filling and operation of the unit. The sprayer needs to be able to achieve a high level of canopy penetration, with the spray particles calibrated at the appropriate spray rates for gallons per acre, both low and high volumes depending on the application. This all needs to be done while achieving low chemical waste by creating minimal spray drift and particle runoff.”
Fleitz: “Technology and the expected return on investment. Application technology is an area in agricultural equipment that is receiving significant amounts of attention and investment by equipment manufacturers. Much of this new technology can pay dividends through reduced chemical usage, greater efficiency, and reduced operator fatigue.”
Booher: “First off, what you are growing dictates the sprayer you purchase. A mature, tall pecan tree requires a much larger sprayer than an apple or peach tree. You also need to consider air distribution and air flow as well as rate control, so you hit your target with the right droplet size and rate of application. There are so many variations of sprayers, baffles, and wings that it becomes really complicated fast.”
Riddle: “Tractor – matching power take-off (PTO) horsepower (HP) to sprayer-required PTO HP to the sprayer specifications. How much time you spend spraying without interruptions by having the right sprayer specs to suit your needs? What is your target? Contact or systemic spray?”
Which type of sprayer do you recommend?
Schaal: “A sprayer needs to have a high volume of air to achieve the necessary canopy penetration for spray particles to get inside the plant where pest and disease thrives. However, the air needs to be targeted toward the plant canopy in a way to minimize spray drift and waste while achieving the desired level of coverage. Most sprayer models on the market now are not able to achieve both objectives, leading to either a lack of coverage or good coverage with extremely high levels of spray drift and waste.”
Booher: “There are so many air blast sprayers on the market and so many variations between orchards and vineyards that there is no single sprayer that works for all. Growers need to do their research and select a sprayer that best fits their needs. Also, purchase your sprayer from a local dealer so that parts, services, and accessories are readily available. With all of the supply chain disruptions, local dealers are a must.”
Riddle: Spraying is all about best coverage with the most cost-effective method of doing so. It all depends on crop and size of orchard/vineyard and growers’ intention or target. Each grower will have a different tractor and needs. The tractor determines what sprayer you can pull and deliver the most efficient results. Proper selection can save a grower 20% on fuel and chemicals.”
What are some technological advancements in spray technology that will benefit growers in the future, if not already today?
Schaal: “There are several technological improvements that can help growers achieve better results right now. However, the most important improvement growers can make to their spray operations starts with selecting a sprayer designed specifically for the planting type and crop. This will help achieve maximum coverage while reducing costly waste to the environment and improve worker safety. I encourage growers to evaluate their entire spray program to make improvements to the spray filling process, the spray operating process, and the spray cleaning process. These are low-hanging fruit items that will improve the bottom line and effectiveness of their spray programs.”
Fleitz: My favorite new tech in sprayers are the various approaches we are seeing applied to reducing overall chemical applies as well as more precisely targeting crop canopies rather than spraying an entire field area. Technologies like air booms and canopy detection systems that target spray onto the crop canopy and nowhere else.”
Booher: “Air blast sprayers are becoming more advanced, and there are precision spray technologies like the Smart Apply Intelligent Spray Control System that are based on technology developed and tested by the USDA. The system uses LIDAR, which stands for Light Detection and Ranging, that uses light in the form of a pulsed laser to measure the distance to the tree or vine and density and size of the tree/vine. The system then automatically adjusts the amount of spray and droplet size delivered and also automatically adjusts the spray to the speed of the tractor. The average reduction in chemical use is 50%. With younger, less dense trees, the reduction in chemicals can be as much as 90%. The system also captures all of the data, such as the date and time spraying was done, size and maturity of the tees/vines sprayed, and amount of chemicals used, which is something growers never had before. Finally, the Smart Apply system is sold as a kit and works with virtually any air blast sprayer. That’s much more attractive than having to buy a new sprayer.”
Riddle: “Improved turbine technology. The use of rate controllers. Data management. Smart application systems with laser technology.”
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