Christmas Science 10: Making Christmas Trees Last Longer

In the run up to Christmas, Communicate Science offers you 20 Christmas Science Facts. We'll post one every day until the 25th December.

Making Christmas Trees last Longer
Following on from yesterday's look at Christmas Trees, the news from Canada is that scientists have discovered a way to double the lifespan of Christmas trees in homes and prevent needles from dropping too early.

The work, by scientists at Universite Laval, Quebec in collaboration with Nova Scotia Agricultural College was published recently in the scientific journal Trees.

Working on balsam fir, the scientists confirmed that the plant hormone ethylene is responsible for needle loss by placing the tree branches in containers of water inside a growth chamber. After ten days, the branches began to produce ethylene and after a further three days, the needles began to drop.

It took 40 days before the branches were completely bare.

To test that the needle loss was in fact due to the ethylene, the researchers used two chemical compounds that interfere with this hormone: 1-MCP and AVG. After exposing the branches to one of these two products, the needle retention period rose to 73 and 87 days, respectively.

"By Day 40, the branches that had been treated were still green, tender, and fresh-looking, while the untreated branches had lost virtually all their needles," explained Steeve Pépin, co-author of the study and professor at the Faculty of Agriculture and Food Sciences at Université Laval.

"Since 1-MCP is a gas, it would be feasible to release it into the trucks used to ship the trees," suggests Pépin. This would be particularly useful for the export market.

Consumers also stand to benefit from this discovery since it would be possible to dissolve AVG in the water added to the tree stand, which would prolong the tree's lifespan indoors. "What is really encouraging is that we managed to double the needle retention period of the branches," notes Steeve Pépin. "However, we still have to prove that we can transpose these findings to the entire tree," he concluded.