314 



TOURNAI, OF FORESTRY 



I and concluding during the week of July 2 to July 9. An exception 

 occurs in the case of the three-year white pines. The period of greatest 

 height growth for this grade ceased close to June 18. 



After the period of maximum height growth has ceased in the case 

 of the four-year white pines and red pines, this growth still continues 

 to some extent. However, the growth occurring after the middle of 

 July was in all probability not in the length of the terminal shoot, but 

 in the elongation of the needles. This is more prominent in the case of 

 the four-year white pines than with the red pines. With the latter there 

 is scarcely any increase, even in the length of the needles, after the 

 middle of July. 



The temperature and rainfall of the season of 1915 were exceedingly 

 favorable for growth. 



Tables 3 and 4 show for the last five years, for the months of April, 

 May, June, and July, the rainfall and the mean temperatures. The 

 normal values are for the last 25 years. 



Month , 



1911 



April 2.05 



May 2.24 



June 3.59 



July 2.53 



Table 3. — Rainfall 



Precipitation in inches 



1912 

 2.97 

 3.58 

 1.37 

 2.64 



1913 

 1.49 



3-15 

 2.00 



1-59 



1914 

 4-35 

 3-63 

 4.75 

 1.89 



1915 

 0.5s 

 2.44 



3-94 

 6.18 



Table 4. — Temperature 



Temperature in degrees Fahr. 



Month r 



1911 1912 1913 1914 1915 



April 44 44 48 42 51 



Mav 64 58 55 59 52 



June 66 63 65 66 64 



July 73 71 70 70 69 



Normal 



2.99 



3-43 

 3.88 



3-75 



Normal 



44.2 

 57.0 



66.2 

 70.6 



Excess or deficiency 

 for 191 5 with 

 normal 

 —1.74 

 —0.99 

 -j-0.06 

 +2.43 



Excess or deficiency 



for 1 91 5 with 



normal 



+7.0 



—5-4 

 —2.6 

 —1.4 



The rainfall in 191 5 exceeded the normal in every month except Alay. 

 The data shows a deficiency for April. But .43 inch of the total .55 

 inch fell after the i6th, Avhen the planting was done. This gave par- 

 ticularly favorable conditions for the stock to establish itself. 



Although the rainfall during May was one inch below normal, never- 

 theless the amount was well distributed and was sufficient for good 

 growth, and there was no time at which a scarcity of moisture was felt. 

 There was sufficient to start the stock on its period of maximum rate 

 of height growth, which continued through June and into the first of 

 July. From this study, results show that this period occurs during 

 Tune, and there was at no time so little moisture as to retard it. 



