Cash Crop
Sunday, December 09, 2001
Copyright © Las Vegas Review-Journal
North Las Vegas greenhouse home to hydroponic beefsteak tomatoes
By MATTHEW CROWLEY
DONREY WASHINGTON BUREAU
Blistering summer heat might make some wonder if any agriculture can happen in Las Vegas. Nevertheless, abundant sun -- and an electricity generating plant that was built as part of a push for more efficient power plants -- has helped make beefsteak tomatoes a cash crop for a North Las Vegas greenhouse.
In the Sunco greenhouse in North Las Vegas, yard after yard of tomato plants hang from lines in the ceiling. The greenhouse is a big-time operation, with 117,000 plants covering 500,000 square feet, producing an annual yield of 3.8 million pounds of tomatoes, or about 7 million fruits. In all, said Ken Gerhart, Sunco's president and site manager, the greenhouse generates annual sales between $2.5 million and $3 million.
Oddly, the Sunco greenhouse emerged from a 1970s push for more efficient power plants.
A federal law adopted after the 1973 oil embargo required that at least 5 percent of the energy from new congeneration plants be used for commercial, industrial or space-heating purposes.
Instead of releasing hot water into the atmosphere as steam, Sunco's 50-megawatt congeneration power plant, built in 1994, uses the hot water produced by the plant to heat the greenhouse.
That means humidity is a little higher inside the greenhouse than outside, but Gerhart says this is natural.
"We're trying to grow plants, not people," he said with a laugh.
Hydroponics, from the Greek, means putting water to work. So, it's through water that the tomatoes thrive. Instead of needing nutrient-rich soil, the tomatoes at the greenhouse rest in perlite, a porous volcanic rock, and receive doses of nutrient-rich solution. Operations both big (large greenhouse operations such as Sunco's) and small (hobbyist farmers) have used hydroponics to produce tomatoes, cucumbers, strawberries and herbs.
Sunco and its greenhouse switched owners this fall when a subsidiary of Black Hills Corp. of Rapid City, S.D., completed a previously announced agreement to buy a 273-megawatt, gas-fired, cogeneration plant in North Las Vegas from Houston-based Enron Corp.
On Sept. 7, Black Hills said it sold a 50 percent interest in the existing plant to an unidentified party. Nevada Power has a contract to buy electricity from that existing unit through 2024. Black Hills will sell the remaining power from that unit on the competitive market.
Las Vegas has a critical ingredient for good tomato growth, Gerhart said: sunshine; tomatoes are a light-needy plant. Gerhart said control makes the operation work; every climate element is controlled. Whitewashed panels in the ceiling, opened and closed by computers, help control the passage of sunlight. Computerized sensors throughout the greenhouse sense temperature and add humidity as a mist. As the mist evaporates, the air cools, helping keep the temperature between 76 and 80 degrees.
Computers also control irrigation, deciding when to feed the plants their water-and-nutrient mix. Water distribution runs roughly in inverse proportion to light intensity, Gerhart said. When light's high, the system distributes more water, when light intensity is low, it distributes less. Gerhart said each plant uses about three-fourths of a gallon of water daily for irrigation and cooling, distributed in up to 70 daily irrigations.
"With hydroponics, you can itemize watering and nutrition," said Patricia Rorabaugh, a lecturer in the Plant Science Department at the University of Arizona.
On its Web site, the University of Arizona said hydroponic-controlled environment agriculture works well in the desert because it allows high-density maximum crop yield and production where no suitable soil exists, and it's virtually indifferent to ambient temperature and seasonality. Furthermore, by taking the crops out of soil, hydroponics helps avoid soil-related diseases, pests and salinity imbalances.
Douglas Peckenpaugh, editor of The Growing Edge, a Corvalis, Ore.-based agriculture magazine, said greenhouse hydroponics allow for year-round production, uninhibited by weather, and produces consistently flavorful tomatoes that other methods cannot.
Sometimes, he said, nonhydroponic tomatoes trucked into markets, such as Las Vegas, from other regions, get taken from soil early and are ripened with ethylene gas. Such gas-ripened tomatoes miss the residual flavor-producing sugars tomatoes left to ripen on the vine have, he said. Also, said Rorabaugh, the ethylene gas method ripens tomatoes from the outside in, not the other way around as happens in nature. Hydroponics lets tomatoes ripen on the vine and retain their sugars and flavor.
People will pay for flavor, the University of Arizona Web page asserts:
"When consumers are willing to pay double or triple standard prices for a great tasting, blemish free product, buyers and sellers alike can smile at the possibilities," the site said.
Insects help the plants grow and fight off disease. Bumblebees pollinate the plants, Gerhart said, landing on flowers and rubbing pollen off their legs. The Sunco greenhouse has 50 hives, of 50 bees each. Gerhart said bumblebees work well because they're mellow, unlikely to bother greenhouse workers unless provoked. They're also homebodies of a sort, unlikely to leave the greenhouse and stray toward other, far-away pollen sources. The hives stay active for about 14 weeks before they're frozen and replaced by new hives and new bees, Gerhart said.
Tiny, stingerless wasps, about the size of the dot of an "i" someone can make with a felt-tip pen, battle tomato plants' chief rival, whitefly, Gerhart said. The wasps eat the whitefly larvae and lay their own eggs in them. By using 100,000 wasps weekly, Gerhart said, the greenhouse can control a major pest without pesticides.
It takes the Sunco plants 85 days to go from seed to harvestable fruit, he said. Harvest begins in mid-October and continues through mid-June when old plants come down, new plants go in and the cycle resumes. When the harvest is at its peak, Gerhart said, the staff swells to 40 workers.
Tomato growing is a way of life for Gerhart. It's something he grew up with; his father and grandfather ran greenhouses in northern Ohio. And it's something he does all the time, taking his beeper home with him and tapping into office computer databases after hours on days he works. He and Sunco colleague Karen Seefeldt combine to monitor the greenhouse 24/7.
Gerhart said he thrives in the desert, just like his crop.
"I'd rather shovel sand than snow," he said.
