In grade change, trees with spring lateral treatments developed significant 

 improvement over those treated in the fall. Whether overall grade or its com- 

 ponents (symmetry, density or taper) were examined, spring treated trees 

 rated higher than control (with one exception-spring shearing, in the symmetry 

 rating), and the fall lateral treatment trees no better and mostly lower than the 

 control. 



Spring clipped trees showed greater grade improvement over spring sheared 

 trees in crown symmetry and crown taper but the result in overall grade 

 improvement was not significantly different between the two treatments. 

 Perhaps the lack of differentiation is caused in part by the experimental 

 method. In the experiment, the first year shearing was applied to a tree 

 whether it needed the shearing or not, as long as the random selection indicated 

 that shearing was the technique to use on that tree. The general results suggest 

 that if a tree needs an initial shearing to improve its form, this should be done 

 in the spring, and that subsequent spring clipping will prove effective in producing 

 a tree of quality form. 



3. Fertilizer Treatment 



The effect of fertilizers on growth are indicated by the associated 

 Growers' Plots experiment described in Section II of this publication. Cultural 

 work had been underway for two years on the Main Plots when a limited number 

 of fertilizers were applied (quantities listed in Table 1) in the spring of the 

 third year so as to test the effect on tree color. The color was recorded by 

 use of Munsell color charts in the fall of 1966. Significant changes favorable 

 in relation to what is desirable for commercial Christmas tree culture did occur 

 in hue, value and chroma. 



Hue notation indicates where the color stands within the spectrum of red, 

 yellow, green, blue and purple. Complete (NPK) and nitrogen (N) fertilizing 

 resulted in a significant hue change toward the blue range in trees so treated, 

 compared to control trees and trees treated with potassium (K) and phosphorus 

 (P). The latter showed no significant difference in hue. 



Chroma, which is the purity or intensity of a color, or departure from 

 neutral, was significantly higher in the control trees, and those treated with 

 K and P. The NPK and N trees showed less color intensity (more neutral shades). 

 The approach toward gray is not considered a disadvantage in balsam fir 

 Christmas trees, provided the hue moves toward blue and the value moves toward 

 the darker part of the range. 



Value is the relative lightness or darkness of a color. The NPK and N group 

 of trees possessed the darkest value (an improvement for balsam fir Christmas 

 tree purposes). The K and P treated trees were in a middle group with the 

 control trees in the lightest of the three significantly different groups. 



The overall conclusion supports the more detailed findings of the Growers' 

 Plots work; namely, that fertilizing with complete (NPK) or nitrogen (N) 

 fertilizer brings significant improvement in tree color in the year in which 

 it is applied when applied in dosages as suggested. The dosages on the Main 

 Plots, incidentally, were intermediate in volume between the two levels used in 



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