branching, trees with rapidly growing leaders can appear sparse or "spindly", 

 and as a result, cultural practices such as root pruning and tip pruning of the 

 leaders are resorted to in order to produce a "full" tree. The ideal Christmas 

 tree, from a management standpoint, results by maintaining both rapid leader 

 growth and good internodal branch development, thus producing a "full" 

 tree in the shortest possible time. 



B. Results of Treatments 



1 . Leader Growth Change 



During the year prior to fertilizing, leaders on control trees grew an 

 average of 8.96 inches (1965). This increased to 10.69 inches in 1966 and 

 12.60 inches in 1967. Increase in leader growth on unfertilized trees of this 

 size is to be expected under normal weather conditions probably as a function 

 of age. Control trees therefore accelerated leader growth 1.73 inches in 1966 and 

 3.64 inches in 1967, as compared to 1965. Comparisons were made of the effect 

 of various fertilizers on growth acceleration with the control as a standard. 

 Some growth acceleration over the 1965 experience took place in all cases, 

 regardless of treatment. An overview of the result can best be gained by 

 reference to Figure 2. 



First year results indicated that there were significant 1 treatment effects on 

 mean leader growth acceleration. Among some of the greater accelerators 

 were low levels of N and both levels of complete (NPK) compared to N high 

 and treatments such as Ca low, Mg high, P low and S low that were producing 

 less leader growth acceleration. 



In 1967, the effect of fertilizer treatments on leader growth were consistent 

 with results observed in 1966. In addition, the trees receiving complete (NPK) 

 treatments (both levels) and N low were significantly greater in leader growth 

 than the control trees. Some of the treatments were experiencing a holdover in 

 negative leader growth effect as compared to the control trees. When 1967 

 growth was compared to that of 1966, five treatments had a significantly lower 

 gain over their own 1966 base as compared to the control trees. These treat- 

 ments were N high, P low, K high, Ca high and S high. 



Overall conclusions are that complete (NPK) fertilizers and low levels of 

 nitrogen accelerate leader growth; that results in this respect are more pro- 

 nounced in the second year, particularly with the complete treatment. Some 

 fertilizers reduce leader growth-high levels of N fall in this category. 



2. Internodal Bud and Branch Development 



The greater the number of branches developing between whorls (the 

 internodal length on the main stem) the better the tree form. The inter- 

 relationships among three variables concerned with internodal branching are 

 what really determine the overall effect on tree form. These variables are the 



"Significant" is used to mean statistically significant at the 0.05 level. Analysis of variance 

 was the statistical method initially employed. Pre-planned orthogonal tests with one degree 

 of freedom were then used to test the difference among individual treatments. 



13 



