SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/282941
36 SportsTurf | April 2014 www.sportsturfonline.com B ackpack and hand-held sprayers consist of a tank to hold the spray mix, a pump to provide pressure, and a spray wand with one or more noz- zles to deliver the spray solution in the desired spray pattern. Most backpack sprayers hold 4-6 gallons of spray mix, and hand-held sprayers usually hold 1-3 gallons. The small size, transportability, and ease of use make the sprayer a versatile tool. Backpack and hand-held sprayers are good for small acreages, spot spraying, and hard to reach lo- cations. Proper application of pesticides is only possible with an ac- curately calibrated sprayer. Calibration is the process of meas- uring and adjusting output of application equipment in order to apply the correct amount of active ingredient per unit area. Failure to care for and correctly calibrate spray equipment can result in misapplication of pesticides, repeat applications, dam- aged plants, excess cost, and environmental contamination. PRE-CALIBRATION CHECKLIST Proper maintenance and preparation of spray equipment will minimize application mistakes and prolong the life of your sprayer. Follow the guidelines below before making a pesticide application. • Fill the sprayer tank ½ full of clean water. Use only clean water. Do not add pesticides until the sprayer has been checked for leaks, is in good operating condition, and has been cali- brated. • Inspect the sprayer to be sure all components are in good working order and are undamaged. Pay special attention to the pump, spray wand, strainers, and hoses. Check that there are no obstructions or leaks in the sprayer. Fix any leaks before cal- ibration or making a pesticide application. If the sprayer has a pressure gauge, check it for accuracy. If the sprayer has a pres- sure regulator, follow manufacturer recommendations for peri- odic cleaning and inspection. • Be sure your spray tips are the correct type and size for the spray application you want to make. The spray tip is perhaps the most important, yet most neglected, component of the sprayer. It is critical to use the appropriate nozzle tip for the in- tended pest target and turfgrass conditions. The spray tip de- termines the spray pattern and droplet size. For single nozzle band applications, it is recommended to use even-flat-fan or flood-jet types. For spot applications, hollow or solid-cone noz- zles, even-flat-fan, or flood-jet types will work well. • Remove, clean, and replace (if necessary) the screen be- hind the spray tip. Clean the spray tip and screen in soapy water with a soft brush. Remove any deposits from the nozzle opening with a toothpick or compressed air. Never use a knife or metallic object to clean tips as it will ruin them. Never try to unclog a tip by blowing through it with your mouth. • With the spray tip removed, and in a place away from wells and water supplies, pressurize the sprayer and flush the system with plenty of water to remove any particles or debris. • Reassemble the nozzle and pressurize the sprayer to check the tip for a uniform spray pattern. This can be done by spray- ing water on a paved or bare surface and watching for streaks as the spray dries. Wet streaks that occur directly under the nozzle may result from damaged or worn spray tips, low operating pressure, or holding the wand too close to the ground. Clogged tips may produce streaks anywhere in the spray pattern of the affected nozzle. If a spray tip has an improper spray pattern, re- BACKPACK AND HAND-HELD SPRAYER CALIBRATION Field Science Photo courtesy of Michael Goatley, Jr., Ph.D.