Plasticulture opens doors on the farm

ROCK SPRINGS, Pa. – The idea of Pennsylvania-grown bananas may sound like a joke, but it’s a definite possibility if farmers use a simple approach evaluated by Penn State scientists.
Plasticulture – broadly defined as the use of polypropylene and polyethylene in farming – is making a tremendous difference on farms in silage bags, bale wraps, row covers, drip irrigation tape, plastic plant trays and mulch, aquaculture tanks, protective seedling sleeves and hydroponic supplies.
One of the most up-and-coming aspects of plasticulture – high tunnels – is revolutionizing crop availability and yields.
It’s cold outside. The tunnels have come on strong in the past few years, according to Mike Orzolek, a Penn State vegetable crop specialist. Orzolek is also the director of the university’s Center for Plasticulture.
During the cool fall and winter months, he works in the Penn State research plots without a coat.
Inside the high tunnels at the research farm near Rock Springs, Pa., he can pick strawberries, raspberries, cherries, tomatoes, onions and gladioluses.
The temperature inside a high tunnel – plastic sheeting stretched over a metal hoop frame – can be 20 to 30 degrees warmer than the outside temperature, thanks to the plastic’s insulation properties.
It’s likely he’s picking fruits and flowers with better quality, higher yields, a longer growing season and less insect or disease damage – a step above what’s seen in open field situations, according to Bill Lamont, a Penn State horticulturist.
Controlling the environment is what it’s all about, he said. And it’s all because of the plastic.
Short history. Plasticulture started at the University of Kentucky in the 1950s, and spread to the commercial industry in the 1960s. Experiments started with double-layer polyethylene greenhouses, then spread to low tunnels, plastic mulch and more.
Researchers continue to look into the benefits of multi-colored mulches, according to Jodi Fleck-Arnold, a plastics engineer for Pliant Corp. in Schaumberg, Ill.
The color wheel. “Black is still the workhorse of the industry, but using the right colored film mulch makes a big difference,” she said.
Blue, green, red, silver and black plastics all have different properties that warm the soil, block light, increase yields or enhance crop colors.
For example, silver plastics reflect light and confuse aphids, helping growers control insects. Blue plastics transform the wavelength of light and affect plants’ root structures. Red plastics can make tomatoes redder.
Other colors help grow a plant that’s tall and thin or short and fat, Fleck-Arnold said.
“And all blacks aren’t the same. A trash bag isn’t the same as high-tech ag film,” she said.
Around the world. Plasticulture has changed the way the world grows food, Lamont said.
China is the biggest user of plasticulture products, and in gardens at the South Pole and in Africa, researchers have been able to grow lettuce, tomatoes and cucumbers to provide fresh vegetables where they’ve never been before.
At Penn State, the scientists say it’s not uncommon for them to use less water, less herbicides and insecticides and use less inputs and get double or triple the normal yield.
They’ve grown a ton of peppers on an acre, and 10,000-12,000 muskmelons on an acre.
They’ve never had blight on tomatoes grown inside the tunnels and have found those fruits and vegetables grown under plastic have a longer shipping and shelf life.
Other applications. Also at the Penn State farm, researchers are growing a variety of crops in the tunnels.
They’re growing sweet cherries that are bigger, have less splitting from the rain and virtually no bird damage. Yields are bigger, yet the trees – grown ‘indoors,’ under plastic –