As financial and environmental pressure continues to mount on farmers to reduce chemical inputs, the marketplace is responding with a host of sophisticated products aimed at better targeting crop protectants. At the same time, the demand for more precise sprayer capabilities opens sales and service opportunities for equipment dealers ranging from new OEM equipment sales to retrofit projects on existing spraying equipment.

Also, new technology on both sides of the Atlantic for horticultural crops shows even more precision on the horizon that eventually will be felt on row-crop farms in the U.S. and Europe.

Variable-Rate Sprayers

In the U.S., farmers are clamoring for more precision from their spray rigs, and many are spending $12,000-$20,000 to move from conventional spray booms with fixed nozzle output to sophisticated systems providing individual nozzle control.

Tony Stueve, says OEM sprayer manufacturers account for 40-50% of current sales for the PinPoint individual nozzle control system by Capstan Ag Systems. “We’ve been the major supplier of pulse-width-modulation (PWM) individual nozzle control for variable-rate application since 2012, but Raven and TeeJet now have systems similar to ours,” he says.

“Technology, which can yield 15-20% savings in chemical use through reduction of overlap sprays and under-application, is also available to retrofit existing sprayers.”

Digitally-controlled PWM systems, which maintain constant operating pressure, regardless of field speed, use solenoid-operated nozzles pulsed in varying duty cycles. Pentair/Hypro, however, offers similar precision section control with its individually operated ball valve nozzles on its Pro-StopE system.

Unlike the PWM systems that operate at a constant pressure, Pentair uses variable rate and pressure in its system to accomplish similar VR results through fast-acting on-and-off nozzle valves, says Pentair’s John Lang.

Sprayer manufacturers say future improvements to VR sprayers likely will include enhanced in-field, on-the-go record keeping for proof of regulatory compliance and improved data capture for making farm management decisions.

Sniper Sprayers

While VR sprayers are coming of age on farms across North America, an even more precise sprayer system is being developed by Cambridge Consultants (CC) in the U.K.

“We created a sprayer to apply chemicals only where they’re needed,” says Tom Fry of CC. “The idea was to achieve the same precision as an ink-jet print head — but at over half a meter rather than just a few millimeters.”

Using a fast-acting valve set in a swivel head to provide precise control of droplet size, CC is using machine vision through a camera mounted on a spray boom to identify targets according to shape, size and color. Signals from the camera are processed through algorithms in a microprocessor that calculates field speed, distance to target, air resistance and spray trajectory. It then signals the control module with a prescription to pinpoint the target with the crop protectant.

“The technology can target a specific leaf or insect even when the sprayer is moving at speeds of more than 25 mph,” he explains.

Through the intense targeting and precise delivery, CC says chemical use has been cut by more than 90% in some of their studies.

Lasers in the Orchard

Agricultural Research Service engineers have developed a VR tree sprayer that has reduced pesticide use up to 68%, with an average cost savings of $230 per acre in ornamental nurseries.

The sprayer uses laser guidance to synchronize application rates to tree structures according to size, shape and foliage density. Researchers at Ohio State, Oregon State and the University of Tennessee who evaluated the machine say savings of more than $230 per acre can be achieved when it is used in orchards and on other high value food crops.

Air Flow at the Boom

While it doesn’t use computer technology, K-B Agritech’s Pattern Master is helping improve spray coverage by reducing wind shear caused by a sprayer’s boom moving at field speeds.

Kurt Kamin, co-owner of K-B Agritech, says a sprayer moving at 12 mph ground speed — even in a dead calm — will create a high pressure area in front of the boom, so there may be a relative wind of 15-16 mph moving over the boom and flowing back to hit the spray pattern.

“That shear is turbulence and it will affect the accuracy of your spray delivery,” he says.

The Pattern Master is a patented aluminum plate shaped somewhat like an airfoil with a brush on the bottom mounted ahead of the sprayer nozzles. The device deflects pressure-related turbulence, allowing the spray to land where it is intended and not drift away, he explains.

April 2016 Issue Contents