number of internodal buds formed, the length of the internode on which these 

 are located, and the number of buds that actually develop into branches coming 

 out from the internode. 



The data does not support a change in branch numbers developing from 

 internodal buds as a result of fertilizer application. A developed branch to 

 bud ratio on the 300 balsam fir trees in 1965 growth prior to fertilizing was 

 .92, and .85-.90 is a reasonable working range and expectation as to actual 

 initial branch development. Fertilized trees did not show any marked variation 

 from this in 1966— a drop to .86, but then the twenty control trees were .84 

 during that period also. 



The data on internodal bud development were tested as to the effect of 

 treatment on internodal bud change. The treatments did cause significant changes 

 for 1967 and 1966 as against 1965 in internodal bud formation. There was a 

 significant increase in the number of internodal buds produced in 1966 as 

 a result of the application of Comp. low and high, and N low. In 1967, N low 

 did not maintain a significant difference although complete (NPK) fertilizers 

 did significantly increase bud development. The conclusion is that Comp. low 

 and high fertilizers were effective in spurring bud formation. 



Since it was previously established that complete (NPK) and N low fer- 

 tilizer accelerated leader growth, some kind of relationship between leader 

 growth (or length of internode) and the internodal bud needs to be established. 

 Ten internodal buds are more than six, but if they are spread over twice the 

 internodal length, the tree form is not improved. This relationship can be 

 measured and evaluated by a ratio. The ratio is the number of internodal buds 

 developed per inch of leader growth, or buds per inch on the internode. 1965 

 data prior to fertilizer application indicate that balsam fir developed an average 

 of 12.05 internodal buds, from which 11.12 branches were produced, on an 

 average 1965 leader growth of 9.25 inches— a bud per inch of internode ratio of 

 1.30. This ratio was maintained for the two years after fertilizer treatments 

 during which accelerated leader growth took place, (ratio 1.47), a point of 

 major practical importance. Since the complete (NPK) fertilizers do the job of 

 developing internodal buds and maintain this ratio in the second year 

 (Table 4) there is strong argument for growers to consider fertilizing with low 

 levels of complete fertilizers and to be less concerned with long leaders. Inter- 

 nodal budding and subsequent branching should offset the leader growth in 

 producing a tree of good form. The results are presented in greater detail in 

 Table 4. 



In the statistical analysis of data the complete fertilizers and N low effected 

 a significant first year positive change in internodal branching compared to the 

 control. When 1967 internodal bud formation was compared to that of 1966 

 and 1965, the improvement in performance was significantly greater for the 

 complete (NPK) fertilizers than that of the control, indicating a carryover in 

 treatment effect into the second year after treatment. 



3. Effect of Fertilizers on Needle Color 



The investigators relied on field comparisons of needle color using 



17 



