Decade of technology revolution helping PCAs do a better job

Farmers have been driving tractors for generations by starting the engine, gripping the steering wheel, and engaging the transmission.

Those same farmers have also been spraying crop protection products for generations by mixing water and chemicals in a spray tank, then pressurizing the tank, thus forcing the mixture through a nozzle on the end of a pipe.

Nothing really complicated about those operations. However, those two simple production practices are changing dramatically in today's high-tech farming.

Satellite GPS technology has taken the farmer's hands off the steering wheel — and computers, pulsators and air induction are making dramatic changes in how material comes out of sprayer nozzles.

A farmer who awakened from a 10-year deep sleep and listened to Ken Giles, University of California, Davis biological and agriculture engineer and Ted Sheely, Kings County, Calif. farmer at the recent technology session at the California Association of Pest Control Advisers (CAPCA) annual conference, he would have thought he was listening to men from outer space.

A decade ago satellite guided tractors would have seemed like fodder for a sci-fi novel. However, Sheely estimates that in the decade since he bought his and other early-day visionaries bought their first GPS tractor guidance systems, 100 percent of growers on the West Side of the San Joaquin Valley have purchased similar GPS systems.

Many of them saw this revolutionary guidance system using aerial maps to guide tractors at Sheely's farm, where for almost a decade he turned his spread into a giant prove-it, real life laboratory for GPS technology.

He did not stop there and has been a pioneer in variable rate technology using crop aerial maps coupled with computer manipulated meter systems and GPS tractor guidance to put in different amounts of crop production products based on mapped areas of fields.

He estimates that 80 percent to 90 percent of the farmers applying gypsum in his area are using the variable rate technology developed on his farm. Fifty percent of the cotton plant growth regulators in his area are now applied variable rate and about 5 percent are involved in the latest VR technique, applying cotton defoliants at rates dictated by aerial plant mapping. “And all those numbers are increasing,” he said.

A decade ago, percentages were zero.

It has been rapidly adopted because it saves time and money just like the technology available now to achieve the three key critical aspects of agricultural spraying, according to Giles. They are off-site protection, efficacy and productivity.

“We no longer have to go out and spray the world” to protect crops, Giles told PCAs at the CAPCA technology session in Reno, Nev.

In California you could not spray the world if you wanted to.

There are too many environmentally sensitive areas for that. Buffer zones are virtually out of the question in California because there are too many people, water bodies, sensitive adjacent crops, buildings and the like.

Yet successful farming continues to flourish in the state because technology is providing the ability to create buffers to keep pesticides and other crop production chemistry away from where it does not belong.

There is probably a greater array of new and coming technology for spraying crops than in the GPS/variable rate technology, which is also a key element of Giles' work in improving application technology.

Ultrasonic air blast sprayers that automatically spray trees and turn off where there are no trees offer dramatic savings, according to Giles' trials.

“Some trials have shown 50 percent to 70 percent savings in the use of chemicals,” he said. Just as significantly as reducing the amount of material sprayed on the ground and not the trees is the reduction in material that runs off orchards, especially during dormant sprays.

It is so significant, grants are available from the state for farmers to purchase ultrasonic sprayers. However, technological advancement does not stop there as Giles and his colleagues try to improve on the technology with imaging plants for sprayers to select weeds using “leaf specific” agriculture.

This uses near-infrared technology to distinguish weeds from crops. It can separate nightshade from a tomato plant with almost 100 percent accuracy. That is magic, since nightshade and tomatoes are the same species of plant.

Giles and his peers at UC Davis can also use precise micro-maps that allow the use of non-selective herbicide to control weeds like nutsedge in cotton much like a hand hoe crew would, but with more accuracy.

Giles said the time is coming when pulsating nozzles can be used to control spray rate and droplet size rather than doing it with flow rates and pressure.

He has also melded the GPS/VR/Computer systems to control and monitor individual nozzles across large booms. He can plug into that computer weather data, as well as location of environmentally sensitive areas.

He also is working with inducing air into a nozzle to reduce drift-tendency small droplets.

All of this high technology still requires the use of some old standard tools. Sheely says all the GPS/Mapping/VR technology cannot replace good old fashioned soil sampling and petiole analysis.

Giles is learning that in the world of finite spray applications, splashing is an issue and adjuvants and drift agents are needed to make sure the infra-detected nightshade is sprayed without splashing on the nearby tomato plant.

Giles and Sheely said all this new technology will not replace the PCA, but it will allow him or her to do a better job.

“Precision ag is a tool box a farmer and his PCA can use as little or as much as they want. It will allow them to do a better, more efficient job of farming,” Sheely noted.

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