Can Science Produce a Longer Lasting Christmas Tree?

One of Dr. Raj Lada's post-doc students at the Christmas Tree Research Center in Bible Hill, Nova Scotia, conducts an experiment.

Photographs by Nick Pearce

There’s nothing like the site of a tacky, plastic Christmas tree to make a Christmas tree farmer cringe. But Americans don’t seem to mind trading off fragrant pitch and resin for PVC.

Of the American households that put up a tree, more than 80 percent put up a fake one, about double the number from 25 years ago, according to Gallup. What’s worse—if you’re a Christmas tree farmer, that is—is that fake trees easily last a decade or more, so for each one purchased today, that’s 10 or more real trees that won’t be sold in the years to come.

LED lighting had the most positive effect on needle drop by far; the frequency of light produced by red and white LED bulbs was the most beneficial.

A group of Christmas tree farmers in Canada is fighting back, however, staking their hopes on a new and improved variety of balsam fir developed at the Christmas Tree Research Center in Bible Hill, Nova Scotia. And this Christmas, plant scientists at this Dalhousie University institution—the only such facility in the world—are unveiling the fruits of their labor: the SMART Balsam.

Unlike most food crops and ornamental plants, which have been bred for centuries to improve the qualities that humans care about (like bigger flowers and sweeter fruit), relatively little breeding work has been done on Christmas trees until now.

“Christmas tree breeding has not been very advanced in the past,” says Dr. Raj Lada, director of the Christmas Tree Research Center. “Our goal was to generate the perfect tree—what we call a SMART tree—and provide the plant material to Nova Scotia growers.”

It Starts With a Christmas Favorite

Balsam firs, known for their deep green needles and delicious fragrance, are a Nova Scotia specialty and one of the top-selling Christmas trees in Canada. They also make up a large portion of the 1.7 million Christmas trees Canada exports annually, many of which end up in American living rooms; some are shipped as far as Bangkok and Dubai.

The problem is that balsam firs, like all of the species used for Christmas trees (and like any wild plant species, for that matter), are irregular in form. Some grow shorter and fatter than others; some are taller and thinner; some are dense, while others are sparse; some have straight, evenly distributed branches, some are rather deformed-looking; and some start shedding needles shortly after they are cut, while others stay fresh and green through the new year without littering all over your carpet.

The SMART Balsam has none of these irregularities, because it is a clone. “Most growers plant their trees from seeds, usually obtained from cones where there is no controlled pollination, which means the genetics of every seedling are unique, so each tree behaves differently,” Lada explains.

SMART is an acronym for a mouthful of plant science jargon: senescence modulated abscission regulated technology. To put it more simply, says Lada, SMART trees are everything you ever wanted in a Christmas tree: picture-perfect architecture, strong aroma, blue-green color, and excellent needle retention.

These trees are also smart in a business sense. Once the trees are commercially available, the Christmas Tree Council of Nova Scotia, a local growers group, plans to roll out a marketing campaign geared for the millennial set, whom they’re thinking are likely choose a good-looking tree with a catchy-looking label that reads “SMART” over a deformed-looking no-name brand. They’re also hoping would-be Christmas tree shoppers will even fork over a few extra bucks for it—and be seduced away from the artificial tree aisle by the promise of a hipper live tree, produced by tech-savvy scientists.

The anti-GMO crowd can rest assured knowing that the SMART Balsam is not a product of genetic engineering, says Lada, though he and his team employed the latest tricks in genomics science to produce it, along with old-fashioned breeding techniques.

Here’s how:

Making a Christmas Tree SMART

First, thousands of balsam firs were screened for the ideal traits (form, needle retention, fragrance, etc). Then, the genetic markers for these traits were identified through transcriptomics analysis—a technique that allows researchers to understand how different genes are expressed in differing environmental conditions. Armed with this information, the team used traditional hybridization methods to create enhanced balsam fir varieties with the desired traits, and then cloned them to ensure that every tree would be identical.

Cloning in this case is less frankensteinian then it sounds—it’s akin to a gardener “taking cuttings,” and is the way that any camellia or rosemary bush in your yard would have been propagated.

Dr. Raj Lada, the director of the Christmas Tree Research Center in Bible Hill, Nova Scotia.

Dr. Raj Lada, the director of the Christmas Tree Research Center in Bible Hill, Nova Scotia.

The biggest feat in all this, says Lada, was to identify the genes responsible for needle drop, the trait of live trees that consumers find most irksome. It’s not just one gene that’s responsible for needle drop, he says, there are many, and the trick was to learn how the genetics of needle drop interact with other variables, ranging from external conditions, like temperature and humidity to biological factors, such as photosynthetic and hormonal processes.  

“This was the first time that such a complex set of relationships have been investigated for a single physiological dysfunction in Christmas trees—in this case post-harvest needle loss.” says Lada. “It is such a complex process, it’s not just a single factor.”

Balsam firs typically hold their needles for six or seven weeks after being cut, while the SMART tree holds onto the them for three months or more. Lada sees this as a huge boon to growers, as Christmas trees destined for export are cut as early as the first week of October in Nova Scotia.

Don’t expect to erect one in your living room any time soon, though. Growers in Nova Scotia will plant the first SMART trees in the coming year, and it will be at least five years before they mature to Christmas tree size and make their retail debut.  

Do the Lights on Your Tree Matter?

One unexpected discovery to come out of the research was the finding that LED Christmas lights have a highly beneficial effect on needle retention. Because photosynthesis, which continues even after a Christmas tree is cut, helps the needles stay fresh and attached to the tree, the team evaluated the impact of a variety of lighting schemes, including LEDs, incandescent bulbs, and the fluorescent lights common in stores where many Christmas trees are sold, as well as the impact of darkness from when the trees are being shipped. LED lighting produced the best results by far, but Lada found that the frequency of light produced by red and white LED bulbs was the most beneficial.

“The red and white spectrums are the ones that are utilized by the tree at a chloroplast level, allowing it to synthesize carbohydrates and sugars,” says Lada. “And that provides the tree with energy to preserve the needles for a longer period.”

That’s good news for the planet, as LED Christmas lights use 80 to 90 percent less energy than the old-fashioned incandescent light strands. That benefit is not exclusive to SMART trees, however—any Christmas tree will last longer with LED lights. And unfortunately, SMART trees may turn out to be less eco-friendly than their no-name competitors.

One of Lada’s hopes was that he could unlock the genetics of pest and disease resistance in balsam firs, in order to provide growers with more robust trees that would require less pesticides. But it turned out that breeding for genetic resistance to needle drop ran counter to breeding for pest resistance. So far, it appears that those traits are incompatible on a genetic level, though Lada intends to keep trying. “It’s taking longer than we expected to come out with a tree that will be eco-friendly, so growers don’t have to apply as much agrochemicals,” he says. That will have to wait until SMART balsam version 2.0.

 

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Can Science Produce a Longer Lasting Christmas Tree?