Find out the horticulture projects the USDA Application Technology Research Unit is working on

The origin of the proverb “necessity is the mother of invention” is traced as far back as Plato. And since that ancient philosopher’s time, the thought that need might drive ingenuity has largely been proven. But what happens when what’s been invented has adequately addressed the need? What spurs invention then?

A visit to the Application Technology Research Unit on The Ohio State University campus in Wooster, Ohio, offers an answer. Within the labs, halls and machine shops, there is one driving force behind the innovations being developed for the green industry. Here, efficiency is the mother of invention.

“All of our research follows that mission,” explains ATRU Research Leader James Altland. “How can we make production more profitable and more efficient for U.S. growers?”

The ATRU is the applied technology arm of the USDA’s Agricultural Research Service. Its home in the Department of Food, Agricultural and Biological Engineering building in Wooster allows the team to work closely with OSU’s agricultural programs and students.

The heart of the ATRU is a hangar-like lab space behind a long row of massive, rolling garage doors. The area is crowded with machines the team can use to fabricate prototypes of their ever-evolving agricultural solutions. Everything they need to invent and iterate is on site, including a full-size wind tunnel.

There is an atmosphere of creative collaboration that seems to drive the resident researchers here — so much so that the solutions built for one application or industry can quickly shift to another. An ATRU breakthrough for nurseries, for instance, can easily find its way into the greenhouse space.

“We start with that in mind,” explains Altland. “We might start with an orchard or nursery crop, but we consider how it might be applied to greenhouse or shrub nurseries, for instance. When we demonstrate this work, other growers will say they want to try it with their crops. It’s an easy process, then, to transfer it to other cropping systems. That’s been very successful for us.”

The case of the intelligent spray system

One of the more successful innovations to come out of the ATRU was developed under the leadership of Heping Zhu. His research with the USDA focuses on pesticide applications and the ecological and enterprise issues entangled in the chemical management of pests in commercial crops.

Spray application of chemicals has been an important part of his research since the 1990s, when he developed a program that predicted spray drift to aid research faced with constraints in field experimentation.

It was only natural that Zhu turn his eye toward “air blast” pesticide spray technology, which had met the needs of growers and remained relatively unchanged for 80 years. The problem was air blast solutions were indiscriminate, continuously spraying regardless of plant or tree size or the gaps between them in the field.

So, Zhu and his team sought a solution to apply sprayed pesticides far more accurately, with a goal of cuttting down on waste and drift while also maximizing outcomes.

The solution his team created was the intelligent spray system. Guided by laser imaging, the system can map canopy density of nursery crops, arbors or orchards as the air blast unit is pulled through the rows. That data is fed into a program that controls an array of sprayers that can apply chemical pesticides based on canopy need, in real time, and mitigate overspray where there is no need to apply.

The system did not require the manufacture of an entirely new type of air blast sprayer. It was instead developed as a unit that could be used to retrofit air blast sprayers already in use and make them smarter.

The project was commercialized in 2019 by Smart Apply, Inc. and attracted the attention of John Deere, which saw the potential and purchased the company in 2023. Since hitting the market, Zhu says there have been nearly a thousand units sold, with 120 of those sold by John Deere in 2025, beating the 100-unit sales goal for the year. Considering the full unit costs around $43,000, it was a feat in an uncertain economy.

Because of the price tag, the technology is particularly attractive to big growers, says Zhu. “They can reduce pesticide use from 80% to 30% during the growing season,” he says. “So, they can pay for the investment in less than a year.”

John Deere touts that along with a 50% reduction in water and chemicals used, the system can also reduce airborne drift by 87% and chemical runoff by 93%. So, the solution is good for the bottom line and reduces the ecological impacts of pesticides.

Still, the solution remains slightly out of reach for smaller growers. But maybe not for long.

“One of our major goals is to have this research and this technology adopted,” says Altland. “If it’s just a theoretical exercise, it’s not helpful. We are constantly aiming to bring the cost down and be readily adopted.”

Iterations of innovation put tech in reach

The intelligent spray system is a big investment, partly due to high-tech components and programming that make it so powerful. But ATRU researchers are always asking how they can make innovations more accessible to more growers.

To tackle affordability issues for precision variable rate spraying systems, ATRU researcher Hongyoung Jeon wondered if the same type of functionality could be achieved with more affordable stereoscopic vision cameras and software to extrapolate the imaging data.

The biggest benefit to the approach was that the cameras were already in wide commercial use for applications like facial recognition and warehouse inventory management, though not for agriculture. He and his team chose to work with the Intel RealSense camera, which retails for about $440, a significant savings from industrial laser imaging systems used on the intelligent spray units that can run upward of $10,000.

Aside from the camera, Jeon and his team have built a prototype by hand. That includes the on-board GPS unit, the program and computer that handles the image processing, as well as the controller that crunches the data to determine how much spray to emit through nozzles mounted to a standard tow-behind air blast sprayer. Again, the system is a retrofit.

In the field, the performance is similar to that of the John Deere system. Videos from field trials show the prototype being towed through a nursery and directing spray only where plant material is detected. The difference is that it is much smaller and far more affordable.

“The way it looks now, it’s about a $6,000 upgrade on top of a sprayer,” Jeon says. “And everything is retail cost, so the production cost will be lower.”

While the cost is significantly lower for small and medium-size growers, there are some trade-offs. While laser imaging can provide minute detail up to 90 feet on either side of the sprayer, stereo vision cameras provide lower resolution data to an accuracy of about 20 feet.

However, Jeon’s prototype carries its own power, meaning it can be decoupled from small tractors easily compared to the intelligent spray system, which requires power from the tractor.

From the nursery to the watering boom

The intelligent spray system began its life as an upgrade from the necessity of air-powered field sprayers, but the tech has also come in from the cold to boost the power of greenhouse boom irrigation. Using the laser visioning system and ATRU nozzle research, it’s possible that intelligent spray could become the next big breakthrough since boom watering was widely adopted by the greenhouse industry in the 1990s. That is, if growers buy in.

“We converted this system for greenhouses about five or six years ago,” Zhu says. “It’s still pretty hard for growers to accept this technology.”

The power of the intelligent spray system for greenhouses is that when fitted to water booms, it ensures that nozzles that aren’t above plants aren’t using water. That means a far more efficient use of water when operating watering booms over plants that require specific spacing, or when mixing a variety of plants on greenhouse floors or benches that have unique spacing needs.

“We place the lidar sensor in the middle of the boom and then scan everything under the boom and spray only when it sees plants,” Zhu explains. “And it’s just with one sensor.”

Just like the outdoor application, the system does not require a new boom installation. An existing boom and the existing nozzles of choice can be used. Zhu notes that the system was field-tested with Casa Verde Growers in Ohio and is currently installed at an experimental greenhouse in Columbus, Ohio, where it is used for research and demonstration.

Zhu says that unlike field sprayers that are only used for pesticides, greenhouse booms can be used for irrigation, nutrient delivery and pesticides.

That’s critical, considering fertilizer and pest control are expensive to waste if they’re being sprayed on empty space on a greenhouse floor rather than valuable plants. While the savings might seem incremental, the application of the tech in nursery settings shows that it can add up quickly.

To increase efficiency even further, Zhu and his team have developed an intelligent in-line mixing system. The industry-agnostic solution (which was also developed in nursery settings) eliminates the need for growers to pre-mix chemicals or nutrients into tanks that may leave them with waste once the application is completed.

Zhu’s system keeps chemicals and water separate and applies chemicals into the line only when they are needed based on sensor data.

When he first demonstrated the technology, he says, chemical companies cried foul. They explained that labels require very specific EPA-approved mixing ratios, and not using those ratios can put growers in legal jeopardy. Unfazed, Zhu gave the technology to growers to test and found that in-line mixing was just as effective and left far less waste product, saving on both chemical cost and water use.

Potentially related to pesticide application innovations like Zhu’s, the EPA released a draft Pesticide Registration Notice in January “establishing new criteria for label notifications that add an application method to a pesticide label,” such as in-line mixing of previously tank-mixed chemicals. An upcoming global summit will likely change label rules in 30 other countries as well.

And there is even more technology the ATRU team hopes to add to watering booms. In the summer of 2025, the on-site wind tunnel was put to good use as the team worked with OSU graduate student Matthew Herkins in a study designed to “develop an optimized electrostatic pesticide nozzle for boom sprayers to enhance the spray canopy deposition and minimize the spray drift potential,” per his June 2025 article published in the journal Agronomy.

Electrostatic nozzles essentially create a positive charge in emitted droplets that are attracted to negatively charged plant material. The charged droplets not only coat the top and sides of the leaves but also the undersides. However, this requires droplet size to be incredibly fine so that the attraction can overcome the force of gravity.

Because of that, outdoor applications of electrostatic-charged spray are not feasible, considering a stiff breeze could disperse droplets. But even in a greenhouse, exhaust fans create some air movement, increasing the potential for drift that could affect employees or sensitive plants.

Herkins’ article found that crops with uniform canopies (common in many ornamental varieties) allow for consistent boom height above plants. Those conditions, with the right nozzle (the TX-VK18 had best results), saw that electrostatic charging significantly increased droplet deposition on plant material.

That increased deposition can lead to less drift and therefore increased penetration of nutrient solutions or pesticides.

Combine all that tech and integrate it into modern greenhouse control systems, and the greenhouse of the future looks powerful. Not only will it be far more efficient in both resource and labor use, but it will also become increasingly friendly to the ecosystem.

Private/public partnerships are crucial

Altland stresses that the ATRU work would be largely academic with limited practical use if it weren’t for growers helping develop and test new tech and private companies willing to commercialize the solutions.

“We do a lot of our research on-farm, with the growers,” Altland says. “They are a great conduit for spreading the word. And they keep very careful track of how much they’re spending on pesticides and labor and give us great feedback.”

The intelligent spray system is a perfect example of those kinds of partnerships. Had there not been growers to allow testing in their nurseries and orchards, there would not have been a company willing to bring the tech to market.

“We have an Office of Technology Transfer that handles the intellectual property and the legal framework,” Altland explains. “So, we can take this technology to companies and transfer the rights to have it commercialized.”

He encourages growers who want to contribute to the research to visit the ATRU website. The site lists all the projects, from lidar nursery tech that can count and map the size and growth of trees to get an accurate field inventory to autonomous robot platforms designed to navigate greenhouses without additional infrastructure.

All the projects will need to be field-tested. And the requirements for participation are relatively simple.

“Proximity is a useful thing. We can work more readily with growers who are a little closer,” Altland says. “But we have worked with growers as far away as California and Oregon. But we have a national mandate. We work with all growers in the United States. And we’re looking for places where we can demonstrate our projects and refine the technology. It’s an iterative process. We need someone with patience and the willingness to make this technology better.”

What’s not required? Necessity. Because in the modern world of growing, efficiency is what will help build a better future.

Growers interested in working with the ATRU can click here or contact Dr. James Altland directly for information at james.altland@usda.gov.

Patrick Alan Coleman is editor of Greenhouse Management magazine. Contact him at pcoleman@gie.net.