Shearing shapes a tree by cutting two years of lateral-terminal growth from 

 each branch which has at least three years of growth on it. For example, in the 

 schematic diagram (Figure 1), only N and N-l primary lateral-terminal growth 

 would be sheared from whorl N-3 during the year N, and the younger whorls 

 above left untouched (older whorls below would be sheared as was the N-3 

 whorl). 



It was originally thought that shearing two years growth from available 

 primary lateral terminals would be followed annually. However, the effect of 

 shearing the first year was analogous to the commercial practice of "shaping" a 

 tree the first time, obtaining a more symmetrical form. It became apparent that 

 a similar treatment in a subsequent year was not needed, and in fact would leave 

 a tree looking decimated. Therefore, beginning in the spring of 1965, shearing 

 assumed a form similar to the original definition of clipping; that is, primary 

 lateral terminals were cut to the base of the previous year's growth. 



Fertilizer was applied around a tree in a circular band extending 8 inches 

 from the stem out to the "drip line" of the crown. N,P, and K applications were 

 computed as "moderate" levels based on known experience and resulted in 

 roughly equivalent weights for each element. The N-P-K or "complete" fertilizer 

 was a total composite. The amount applied per tree is indicated in Table 1 . 



Main Plots — Fertilizer Dosages 



Annual measurements and observations of treatment trees included total 

 height change, number of "good" or usable whorls from the standpoint of 

 developing a Christmas tree, numbers of lateral tips in the top three whorls (in 

 the 0, -1 and -2 years with 1963 being zero, with measurement of tips developed 

 in new whorls thereafter), number of branches which developed in the new 

 whorls, internodal lengths and crown diameter. 



An overall grading of the tree as a Christmas tree was also made on a scale 

 from 1 (very poor) to 7 (excellent) at the beginning and end of the experiment. 

 Needle color of each tree was recorded (Munsell system) at these times, but was 

 not a criterion in arriving at tree grade in this study. 



Data were analysed by use of analysis of variance (see Table 2). In the 

 heading, the table also contains the objective and partially subjective criteria 

 used in evaluating the various cultural practices at the end of the three year 

 study. When the terms "significant" or "significantly" are used in this writing, 

 they are used in the statistical sense on the 0.05 level. 



