World-changing ideas require the confluence of timing, vision and determination. In the years following World War II, those three factors came together at the University of Kentucky in the person of Emery Emmert.

A horticulture professor in the College of Agriculture, Emmert focused on improvements in produce production using the new plastics that were developed during the war.

“He developed two of the three primary practices that feed probably between 1.5 and 2 billion people a year in the world,” said Robert Anderson, University of Kentucky Cooperative Extension professor in horticulture. “He worked, at the time, with two or three other people, one from Cornell and one from New York state…. And these guys got together in the ‘50s and pretty much laid out what we call plasticulture.”

One of the results of Emmert’s research was the creation of the field greenhouse. The simple structure was built from lightweight wood and clear Mylar sheeting. Today it may not sound that technologically advanced, but in the early 1950s it was a revolutionary concept that would change the face of agriculture worldwide.

The field greenhouse is known by many names. To vegetable growers it is a high tunnel. At container nurseries, it’s called an over-wintering Quonset, and bedding growers call it a cold frame. But no matter the name, the technology has been used by growers around the globe to lengthen their growing seasons, protect their crops and increase their yields.

Oddly enough, Emmert’s field greenhouse didn’t catch on at first in the United States. However, Europeans and, ultimately, Asians quickly latched onto the technology.

“I guess the main reason is that the U.S. was all connected and an interstate highway system was being built. So in the U.S., if we needed winter produce, a truck simply came from Florida to Kentucky and that’s all that was necessary,” Anderson said. “But in Europe in the 1950s you couldn’t do that. And the same is true in Asia. There was no transportation. And even if there was transportation, it wasn’t to a subtropical winter climate.”

European growers were looking for a way to feed the population under the constraints of the time. Europe was faced with post-war political instability, the relatively small countries had limited growing zones within their borders, and importation laws made trade between the regions more difficult. Many Asian countries were facing the same problems. But with Emmert’s field greenhouses, European and Asian farmers found they could extend both their growing seasons and their yields. Protecting their crops from damaging rains proved to be a big advantage. Without mud splashing on the leaves, and wind- and rain-borne debris on the fruit, there were fewer incidences of foliar disease and crop loss.

Anderson said that he has traveled in South Korea and parts of Europe where it’s possible to look across fields and see row after row of high tunnels. It has become an inherent part of the agricultural methodology in those regions of the world.

In the United States, 50 years after their creation, growers are beginning to take advantage of the opportunities that high tunnels provide. Today’s consumer is showing an interest in sustainability, in supporting local farming economies through farmers’ markets and in organic produce. For growers of a certain size, the high tunnel can help them take advantage of these consumer trends and potentially increase their income.

“I’d say the main reason someone would have a high tunnel is if they do want to produce fruits and vegetables – primarily vegetables – and they want to sell in the local market,” Anderson said. “But if you’re thinking, ‘Well, I’m going to ship to Michigan or I’m going to ship tomatoes to Florida,’ it’s unlikely that high tunnels will be part of that scheme.”

Some technological advances have also made high tunnels more attractive to American farmers. Today’s tunnels are built from metal hoops, which make them easier and fairly inexpensive to build. Anderson said an unheated structure would run about $2 a square foot. Like most equipment, there is a range in the options that are offered, with some tunnels providing additional frost protection from an insulating layer of air between two layers of plastic. Growers also have the option of heating the structures, which allows for earlier planting in the spring and an extended harvest in the fall. The effect of Emmert’s work experimenting with using plastic in agriculture has had positive repercussions for half a century. Anderson said that most of the produce that the world eats is the result of plasticulture methods.

Emmert thought of his work as a mission to feed people, “which was in many ways what agriculture was about in the 1960s, 1970s, 1980s. Feeding the world, saving people, taking care of people around the world – that was his (Emmert’s) goal with all this,” Anderson said. “For me, to see all those high tunnels I saw in Korea – and I know there’s 10 times that in China – I was just so pleased to see it and know there was this connection with somebody who was here (at UK) 50 years ago.”