Fumigation film and drip tape inaugurated changes in agriculture that made it easier and far more efficient to grow food crops in difficult climates, and now artificial intelligence is bringing about advancements in weed and pest control, among other promising developments. To discuss innovations in agriculture and how they could also benefit home gardeners, joining me on the podcast this week is Dr. Nathan Boyd, a professor of horticulture and weed science at the University of Florida.
Nathan is the associate center director at the Institute of Food and Agricultural Sciences’ Gulf Coast Research and Education Center, and the president of EZ Ag Innovations. His research and extension program focus on the development of integrated weed management plans for vegetable, strawberry and ornamental crops. He emphasizes the incorporation of biological knowledge with chemical, physical, and cultural management tools. In 2022, the Florida Fruit & Vegetable Association presented Nathan Boyd with its Researcher of the Year Award.
Dr. Nathan Boyd is a horticulture and weed science professor at the University of Florida, the associate center director at the Institute of Food and Agricultural Sciences’ Gulf Coast Research and Education Center, and the president of EZ Ag Innovations.
I was introduced to Nathan through a student in my Online Gardening Academy™ who said, “Dr. Nathan Boyd is the weed guru, and you need to get in touch with him.” As gardeners, we are all constantly challenged by weeds, so I couldn’t pass up the opportunity to speak with a widely respected expert on combating weeds.
Get to Know Dr. Nathan Boyd
Nathan grew up in a small town in New Brunswick, Canada, the dairy capital of Canada. Many members of his family are dairy farmers, including his father, who is 89 years old and still an avid gardener.
All the kids helped in the garden. “My parents bought vegetables very rarely,” Nathan recalls. “We grew and processed and froze and canned things. So that’s probably where my interest in gardening began.”
When he went to school, he studied something completely different, he says. He pursued a Bachelor of Science in marine biology. But he says he couldn’t get away from agriculture, and he did a project on rotational grazing with beef cattle. He went on to earn a master’s in organic potato production and then, at the University of Manitoba, a Ph.D. in weed biology and weed ecology. From there, he did post-doc studies with the U.S. Department of Agriculture in Salinas, California, on organic vegetable production, working with Dr. Eric Brennan.
After he was through with all that schooling, Nathan got a job at the Nova Scotia Agricultural College in Canada, where he worked for seven years on weed control for low-bush blueberries.
Then 12 years ago, Nathan joined the University of Florida faculty, where he works on weed control in commercial agriculture.
Nathan currently works mostly on plasticulture — the use of plastic materials in agriculture.
“That’s how we grow most vegetables in Florida,” he says, “and the reason for that is it’s so efficient in terms of fertilizer use and water use, which is a big deal, and of course, is a major weed control option.”
The key crops he works on are strawberries, tomatoes, peppers and cucurbits, but he also works on everything down to herbs and unique Asian vegetables. And he works on weed control for crops that are typically grown in bare ground, such as cabbage, potatoes and green beans.
“All of my research is focused around commercial growers, and when I say commercial growers, that can be anywhere from 10 acres to thousands of acres,” Nathan says. “There’s a wide range there. But what we’re tasked with is helping growers be successful around us. And my work is focused on weed management and all types of weed management tools.”
Nathan says that in his lab they pride themselves on taking an understanding of weed biology and then incorporating that with novel technology.
“If you don’t understand the biology, then you’re not going to be successful in the management,” he says.
A significant portion of his program is developing AI-powered weed management tools. “We use AI to identify weeds, target them, and control them only where they occur,” he says.
He says his lab brings biology and technology together. “You are less effective if you only focus on the biology or if you only focus on the technology — you need an understanding of both.”
The vast majority of the lab’s work is in conventional agriculture, but they also work with a lot of organic growers.
Nathan notes that growing in Florida is a lot more difficult than growing in California, which he attributes to Florida’s hot, humid weather. “We struggle a lot with diseases and weed pressure too is very different,” he says.
Fumigation film allows the soil to retain fumigants that control pests and pathogens, and the film retains moisture and suppresses weeds. Drip tape under the film provides irrigation and fertilizer. Fumigation film and drip tape are both examples of plasticulture. (Courtesy of Nathan Boyd)
Plasticulture
“Plasticulture is widely adopted across the U.S. but especially in the Southeast commercial production, and there are very good reasons for that,” Nathan says.
Historically, a Florida farmer might have grown tomatoes on land for a number of years, then moved tomato production to another piece of land, and the original land would revert back to cattle land for a number of years before returning to tomato production.
But tomatoes were irrigated with furrow-irrigation, in which water is run down ditches, and then seeps into the soil from those ditches.
“As you can imagine, that’s a huge volume of water, and even though we are in a semi-tropical environment, water management’s very important in Florida,” he says.
Plasticulture also includes drip tape, which is installed under plastic films. To put the films in place, the beds are shaped when the soil is wet because the soil is sandy — “there’s no soil structure here,” Nathan points out.
Plasticulture replaced seepage irrigation and reduced water use. It also made fertigation a feasible solution to apply just the amount of fertilizer that is needed.
“You can apply just enough water that the plant needs through that drip tape, and the fertilizer is also applied through the drip tape,” he says. “And because we’re growing on sands, our soils don’t hold fertilizer very well. So if you can apply a little bit twice a day versus trying to put as much as the plant needs for the whole season in the bed, you’re a lot more efficient. “
For the most part, the fields are also fumigated, and the plastic film holds the fumigate in the beds.
“Then when it comes to weed control — with the exception of purple and yellow nutsedge — the only place the weeds can emerge is in between the beds or in the planting hole,” Nathan says. “So you’ve really reduced the amount of effort you need to control weeds.”
Nutsedge can puncture the plastic, so it comes up everywhere. There is yellow nutsedge and purple nutsedge. Purple nutsedge only grows so far north, but in Florida, it is the dominant of the two species. “It actually prefers to grow under plastic,” Nathan says. “They can spread very rapidly and cause serious problems, not just with competition, which is what most people think. But weeds also affect crop quality. They affect the ability to see the crop, especially with strawberries.”
Plasticulture replaced seepage irrigation and reduced water use. It also made fertigation a feasible solution to apply just the amount of fertilizer that is needed. (Courtesy of Nathan Boyd)
Concerns with Plasticulture
“The downside of plasticulture is of course, what do you do with all that plastic?” Nathan says.
When the plastic is beyond its useful life and is pulled up, there is a lot of dirt on it, which makes recycling the plastic a challenge.
Nathan’s lab is part of a group with members across the nation who are evaluating using bacteria to break down plastic. If successful, it would be a huge move forward to biodegradable plastic, he says.
The plastic used in experimenting with bacteria is a cellulose, Nathan says. “So it’s completely broken down by the bacteria.”
He has trialed various biodegradable plastic products over the years that just never worked in Florida’s climate. “You need a plastic that’s flexible, that can stretch, that can handle the environment that we have here,” he says. “There’s a lot of variables, and there’s just been a lot of products that didn’t work. I’m seeing products now that we put out last year that worked really well, and within a month or two, you can’t find anything just by eye once you incorporate them [with bacteria].”
When fumigation film is past is useful life, it creates a lot of plastic garbage. But biodegradable products may be on the horizon. (Courtesy of Nathan Boyd)
Plasticulture Isn’t Always Economical
Cabbage is typically not grown using plasticulture. Research has shown that cabbage crops grown using plasticulture have high yields and better quality, Nathan says, but a good cabbage crop can be grown without plasticulture — and growers choose simplicity.
“If something’s less complicated — and they don’t have to worry about disposing of the plastic — and they can make it work, then they’re going to go with that option,” he says.
Sweetcorn, likewise, can be grown easily without using plasticulture.
Nathan says it’s not a matter of “You can’t grow it with plastic.” Rather, it’s a matter of growers evaluating the costs and the benefits.
Drip irrigation, which is another example of plasticulture, is clearly beneficial, but the infrastructure is expensive to implement. When farmers can have a successful crop without it, they will skip the expense.
One determining factor before using plastic film is whether the soil will be fumigated. Fumigation controls weeds, soil-borne pathogens and nematodes. For a crop like cabbage, farmers don’t fumigate the soil, so they don’t need plastic to keep fumigant in.
Farmers only use plasticulture when the benefits outweigh of costs. If a crop performs just fine on bare ground, a farmer won’t spend the time and effort on plasticulture. (Courtesy of Nathan Boyd)
Fumigation
Due to urbanization and development pressure, farms don’t have all the land they once had for long crop rotation, Nathan points out. Less frequent crop rotation means more pest pressure to contend with.
“The end result is more intensive production on a smaller land base. And that’s part of the reason for the need for fumigants,” he says.
He says people have the perception that when fumigants are put in soil, they kill everything. But that’s not the case. “It buys you a little bit of time,” he says. “That’s all it does. It buys you time.”
Though not considered a fumigate, brassicas such as broccoli are used in a fumigate-like way.
“Lettuce growers rotate with broccoli, and they do harvest and sell the broccoli, but that’s not why they grow the broccoli,” Nathan explains. “When you chop broccoli and incorporate it into your soil, it releases a compound that functions very much like a fumigant in killing certain pathogens.”
A fumigant called dimethyl disulfide is basically the same compound that is released by brassicas when those brassicas are incorporated into the soil. “You can actually use brassicas as a way to help control certain Verticillium or other diseases that are soil-borne,” Nathan says.
AI in Agriculture
“AI is the next revolution in agriculture, and we’re just at the beginning of it,” Nathan says. “And when we emerge on the other side, agriculture’s never going to be the same again. And it’s because we can do things with AI that we could only dream of doing before.”
For example, his lab works to predict the time of weed emergence so growers know when to treat for weeds. Modeling weed emergence involves a lot of work, including having people go out in trucks for a week to drive around counting weeds and collecting data. It’s inefficient, Nathan says.
“But with AI, we’ve developed machines that we can deploy that basically can help us achieve that goal,” he adds.
Properly trained AI can identify weeds across a wide range of conditions. AI will record where a weed occurs, when and what growth stage it is at. AI can also model more environmental variables than Nathan can normally account for.
AI can also be used to only apply herbicide where a weed is, rather than broadcasting it, and also to apply the correct herbicide: one that works on broadleaf weeds or one that works on grasses or nutsedge.
“You use a fraction of the amount of herbicide,” Nathan says.
It’s good for farmers because they save money and good for the environment because there are less herbicides being put out into the environment.
AI can also be used to identify the best time to cultivate a field, and AI is likewise being researched for applying insecticides and fungicides.
“In the next five, 10 years, you’re going to see a lot of really cool tools and things that’ll emerge for everything from the home gardener to the large growers,” Nathan says.
There is ground-based and drone-based AI equipment. Nathan’s lab only works on ground-based equipment, which he says provides better images and does not run into prohibitions against using aerial drones. The lab also designs systems that can be operated from a cellphone for the sake of simplicity.
AI can identify weeds, track when they emerge and what the weather conditions were, and apply herbicides only where they are needed. (Courtesy of Nathan Boyd)
Why Corn Gluten Didn’t Catch On
Corn gluten was touted as an organic preemergent weed control, but it didn’t catch on.
Nathan explains that corn gluten fell out of favor because for it to work, its application has to coincide with the right amount of moisture. “I don’t think a lot of people understood that relationship, and if you just go out and throw it out and there’s not moisture, then it won’t do anything,” he says
“When it’s not understood how to use it most effectively and then someone tries it and it doesn’t work, they don’t try it again. That happens a lot. Then they tell everyone else it doesn’t work.”
Corn gluten, especially for organic growing, has a role, Nathan says, but he adds that it’s very narrow in its application time and in the environment in which it works. “And that’s a bit of a problem.”
Weed Control
Allowing weeds to emerge, then killing them, followed by planting in your crop, will overcome weed pressure and create optimum conditions for the growth of your crop. Your crop will grow to have a closed canopy that prevents weeds from receiving light and overtaking your crop.
Nathan advises managing weeds at the right stage. “A lot of crops, you may not notice the weed until it’s bigger,” he says, “and it’s a lot more disturbing to your crop to remove it. And, of course, the key issue is don’t let them go to seed.”
For organic weed control in a home garden, Nathan recommends cutting weeds with a hoe rather than using an organic spray that may not kill the weeds and may damage the crop.
Low-growing crops like strawberries can be hard to see to harvest when competing with weeds. (Courtesy of Nathan Boyd)
If you haven’t listened to my conversation with Dr. Nathan Boyd on the plasticulture, AI and more innovations in agriculture, you can do so now by clicking the Play button on the green bar near the top of this post.
What innovations in agriculture don’t get enough attention? Let us know your experience in the comments below.
Links & Resources
Some product links in this guide are affiliate links. See full disclosure below.
Episode 006: Weedless Gardening with Lee Reich
Episode 155: Managing Weeds Organically: Rodale Institute’s Latest Research, Prevention and Control
joegardener Online Gardening Academy™: Popular courses on gardening fundamentals; managing pests, diseases & weeds; seed starting and more.
joegardener Online Gardening Academy Organic Vegetable Gardening: My new premium online course. The course is designed to be a comprehensive guide to starting, growing, nurturing and harvesting your favorite vegetables, no matter what you love to eat, no matter where you live, no matter your level of gardening experience.
joegardener Online Gardening Academy Master Seed Starting: Everything you need to know to start your own plants from seed — indoors and out.
joegardener Online Gardening Academy Beginning Gardener Fundamentals: Essential principles to know to create a thriving garden.
joegardener Online Gardening Academy Growing Epic Tomatoes: Learn how to grow epic tomatoes with Joe Lamp’l and Craig LeHoullier.
joegardener Online Gardening Academy Master Pests, Diseases & Weeds: Learn the proactive steps to take to manage pests, diseases and weeds for a more successful garden with a lot less frustration. Just $47 for lifetime access!
joegardener Online Gardening Academy Perfect Soil Recipe Master Class: Learn how to create the perfect soil environment for thriving plants.
Earthbound Expeditions: Discover South Africa with Joe Lamp’l
Dr. Nathan Boyd at the Gulf Coast Research and Education Center
Milorganite® – Our podcast episode sponsor and Brand Partner of joegardener.com
Heirloom Roses – Our podcast episode sponsor and Brand Partner – Enter code JOE20 at checkout for 20% off all roses until 12/31/24.
Pure Protect Deer Repellent by Heirloom Roses – Our podcast episode sponsor and Brand Partner of joegardener.com
Dramm – Our podcast episode sponsor and Brand Partner of joegardener.com
Farmers Defense – Our podcast episode sponsor and Brand Partner of joegardener.com
Disclosure: Some product links in this guide are affiliate links, which means we get a commission if you purchase. However, none of the prices of these resources have been increased to compensate us, and compensation is not an influencing factor on their inclusion here. The selection of all items featured in this post and podcast was based solely on merit and in no way influenced by any affiliate or financial incentive, or contractual relationship. At the time of this writing, Joe Lamp’l has professional relationships with the following companies who may have products included in this post and podcast: Corona Tools, Milorganite, Soil3, Greenhouse Megastore, Territorial Seed Company, Earth’s Ally, Proven Winners ColorChoice, Farmer’s Defense, Heirloom Roses and Dramm. These companies are either Brand Partners of joegardener.com and/or advertise on our website. However, we receive no additional compensation from the sales or promotion of their product through this guide. The inclusion of any products mentioned within this post is entirely independent and exclusive of any relationship.
