1. Branch Related Variables Needle Related Variables
Linking Certain Physical Characteristics with Postharvest Needle Abscission Resistance in Balsam Fir
Mason T. MacDonald, Rajasekaran R. Lada, R. Scott Veitch
Results
Introduction
Balsam fir is the most popular Christmas tree species used in Atlantic Canada, with over 3 million trees harvested each year contributing approximately $72 million to the economy. However, postharvest needle abscission poses a major problem and may result in low consumer satisfaction and a shift in preference towards artificial trees.
Several parameters, including needle retention, were significantly different between NAR classes. Outside of expected differences in needle retention, only break strength, branch diameter, fresh weight, and needle density were significantly different between NAR classifications.
One major factor affecting needle retention is diversity in seedling populations. Individual trees differ greatly in needle drop. Previous research has allowed classification of balsam genotypes based on needle abscission resistance (NAR). The objective of this research is to determine if any
Balsam fir tree with close view of branch
biophysical characteristics are associated with the differing NAR classes.
Methods
NAR Classes
Low (complete abscission in under 20 days postharvest).
Moderate (complete abscission in 21 to 40 days postharvest).
High (complete abscission in over 41 days postharvest).
Experimental Design
The experiment followed a completely randomized design. The explanatory factor was NAR classification. A total of 45 branches were randomly selected (15 from each NAR class). Response variables are listed below. ANOVA was completed for each set of data, to determine if there were any differences in the various response variables between different NAR classes.
A comparison of low and high NAR genotypes finds that high NAR genotypes have a 9.1% smaller diameter, 25.0% lower initial mass, 33.2% lower needle break strength, 32.4% lower needle density, and 91.0% longer needle retention than low NAR clones.
Conclusion
It may be concluded that needle break strength, branch diameter, needle density, and fresh weight all differ significantly between balsam fir genotypes depending on their NAR. This has potential application for producers, breeders in selecting longer needle retaining trees and consumers while selecting balsam fir for display as Christmas trees. For each, it is preferable to select trees with lower needle break strength, branch diameter, needle density, and fresh weight.
Branch Related Variables
Needle Related Variables
Diameter
Needle Retention Duration
Length
Angle of Attachment
Mass
Needle Density
Internode Distance
Needle Length
Fragrance
Relative Water Content
Flushing
Break Strength
Xylem Pressure Potential
Needle Percentage
Acknowledgements