The Real Christmas Tree Board

Three experiments were conducted to determine the effect of pyroligneous acid (PA) on balsam fir Christmas trees. Experiment 1 compared PA applied via the xylem as a Christmas tree stand additive to a foliar spray. PA was ineffective when fed via the xylem, but 1% and 4% foliar sprays significantly delayed abscission. Experiment 2 was conducted to confirm the effect of foliar sprayed PA on needle retention but did not have the same success as Experiment 1. There was no significant effect on needle retention in Experiment 2. Finally, Experiment 3 examined changes to certain phytochemicals and other characteristics after a PA spray. Though PA did not improve needle retention, there were significant increases in chlorophyll a, chlorophyll b, and flavonoids. These changes were associated with a decrease in membrane injury. Overall, PA was beneficial to balsam fir through increases in beneficially phytochemicals and membrane stability. However, such increases did not consistently translate to improved needle retention. It is recommended that PA be explored further as a foliar spray using different surfactant agents that may help PA permeate into balsam fir needles.