Non-stop Knowledge: Intensive Hydroponics at CEAC

Non-stop Knowledge: Intensive Hydroponics at CEAC

Non-stop Knowledge: Intensive Hydroponics at CEAC

Don’t expect an easy Hydroponics 101 at University of Arizona’s Controlled Environment Agriculture Center (CEAC). Here, the intensive crop production courses manage to cram an entire semester’s worth of knowledge in one week.

“The seed you buy has the genetic potential to produce good plants. It’s your challenge to put the appropriate environment around that seed to bring out the best in it,” says Dr. Gene Giacomelli, Director of the University of Arizona’s Controlled Environment Agriculture Center (CEAC) in Tucson. “From day one when you put moisture on that seed and it starts growing, genetics say it will be a good plant, but it’s up to you to grow it to its greatest potential—and that calls for a learned interdisciplinary approach.”

One way to achieve that is through an intensive hydroponic greenhouse crop production course sponsored by the CEAC, in which an entire semester’s worth of knowledge is crammed into one week.  In these courses, Dr. Stacy Tollefson focuses on red vine fruiting crops (tomatoes) and Myles Lewis centers in on floating greens (lettuce).

“These are the basic starter crops for hydroponic farmers; the money makers,” says Tollefson, a member of the USDA Hydroponic Task Force. (True novices start with lettuce because growing concepts are easier to grasp and production times are shorter.)

“There are many ways to grow these crops successfully, but done correctly, you’ll get greater yield and improved quality—like the 70 pounds of tomatoes per plant we get in our greenhouses; some of the highest yields in the country, in fact,” Giacomelli says with pride.


Non-stop Knowledge Intensive Hydroponics at CEAC3


The intensive combo courses, which already ran in January and June and are scheduled again for this fall, combine classroom lecture and Power Point presentations in the mornings and afternoons filled with hands-on activities in the greenhouse. The non-stop knowledge is geared for all levels of attendees. “From Mr. and Mrs. Smith who are backyard greenhouse hobbyists to PhD holders who just need a single sector of information, I give out 15 years of knowledge in a couple of days,” says Lewis. “We want to make sure everyone leaves at the same level of learning.”

Tollefson’s tomato training begins with an introduction to plant needs and hydroponic systems, and then takes off with crop layout, scheduling, and maintenance procedures to steer plants to success. Sessions on greenhouse basics, pollination, and pest protection are also included.

“There’s no one overriding secret,” Tollefson acknowledges. “You just need a grounded education to know what you’re doing instead of just throwing something against the wall and hoping it sticks. In my book, nutrition/fertilizer and pest management are huge. You’ve got to know what to feed your plants … and pest management from spider mites to white flies. [They] will take you down every time if you can’t handle them.”


“I don’t care what system you buy, whether its NFT or deep flow, or what greenhouse you buy or even make yourself. I just want you to be informed about how to grow and have the ability to grow successfully.”


Lewis says that while every situation is different, there are a couple of secrets for hydroponic lettuce that are common.

“Temperature control of your nutrient solution is important. Lettuce is a cool-weather crop, so we want to give it cold feet. I don’t want to equate it to tricking the plant, but that’s more or less what you’re doing. And keeping an eye on solution temperature, say between 19 and 22˚C, helps keep water-borne diseases like pythium in check.

“In combination with that is air flow—both horizontal and overhead—which often gets overlooked. Air flow control isn’t a silver bullet but an important tool in the arsenal to manage physiological disorders like tip burn. So, air flow and temperature are two key areas for me.”


Non-stop Knowledge Intensive Hydroponics at CEAC


Looking at the lettuce syllabus, you see there is no salesroom approach in the course content.

“At the end of the day,” says Lewis, “I don’t care what system you buy, whether its NFT or deep flow, or what greenhouse you buy or even make yourself. I just want you to be informed about how to grow and have the ability to grow successfully.”

The entire mission of CEAC and both the instructors points to a promising future of growing food hydroponically. “The range of hydroponic crops will expand in the future to handle more product,” says Lewis. “I’d like to see hydroponic growing enter residents in the form of an appliance, a dishwasher-sized gadget with lights, a pump, water, and a cooling device in a closed environment, a veritable salad maker right next to the refrigerator. You won’t feed the world this way, but you could feed one family at a time with in-house salad green production.”

Tolleson envisions the future of hydroponic growing will be found more frequently in new areas—urban sites or arid deserts—because of shipping costs, transport time, and freshness factors. “We know we can grow this way in extreme environments and while it’s not being done that much now, as the world population continues to increase, we’re going to have to look at that more closely.”


Non-stop Knowledge Intensive Hydroponics at CEAC


As a member of the USDA’s Aquaponic and Hydroponic Task Force that turned its research report over to the National Organic Standards Board nearly a year ago, Tollefson is waiting to see what final recommendations will be made concerning hydroponic systems and the possibility of organic certification.

“It’s a loaded topic,” she says. “A sub-committee preliminary vote was made to not certify liquid organic systems like aquaponics and raft systems, but it hasn’t gone to the full board yet. Some discussion was held concerning the regulation of container growing and organic solid amendments in the media versus organic media via a drip line, but for the moment, the decision was made to not decide and it’s all on hold still. At the next meeting, there may be a new proposal for rules involving container growing and striving for a vote on the liquid systems issue, but I haven’t seen any definite agenda items yet on those subjects.”


Another round of CEAC Hydroponic Greenhouse Intensive Courses for both lettuce and tomato will be presented in September 2017 at a yet-to-be-determined date. For further details, contact Austin Smith at or phone 1-520-626-9566.


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