46 Journal of Agricultural Research voi. xxii, no. i 



disappeared; the July 14 stock slightly surpasses the April 24 lot; and 

 there is nothing to indicate that summer transplants are not fully the 

 equal of spring transplants, so far as growth after planting is concerned. 



CONCLUSIONS 



Transplanting western white pine seedlings at any time in the fall is 

 not a safe practice at Savenac Nursery, because the frosts of the following 

 late fall and early spring heave out the young plants. 



Results in the plantation thus far indicate that, where 1-2 stock is 

 grown, the transplanting season may be extended from a date as early 

 in spring as the ground can be worked until early July. The shock of 

 removal from the seed bed is greatest when the transplanting is done in 

 midsummer, on account of the high evaporating power of the air, the 

 low water content of the soil, and the greater top-heaviness of the plant 

 with its considerably increased transpiring surface. A particularly 

 sev^e shock was also suffered when transplanting was done at the time 

 of bud opening and before the rudimentary needle fascicles had reached 

 ■^^g-inch in length. Stock transplanted at either of these critical periods 

 lagged behind the other lots for at least two years in the transplant 

 bed. However, when they were planted in the field as 1-2 stock, the 

 plants survived as well as the others, with little, if any, inferiorit}'- in 

 growth on account of the considerable rearrangement of growth rates 

 following the planting. 



There are, nevertheless, other reasons which make transplanting at 

 Savenac Nursery safer in spring than in summer. June and July trans- 

 plants suffer more from drought the first season and, because of their 

 poor root development at the end of the growing season, are more subject 

 to frost heaving the following winter. The first disadvantage can be 

 met by proper irrigation, but the second can not readily be prevented. 



The safest practice, therefore, is to confine this work as much as 

 possible to April and early May. 



The foregoing conclusions apply to i -year-old seedlings which are to 

 remain two years in the transplant rows, 1-2 stock being the only age 

 class of white pine transplants at present grown at Savenac Nursery. 



Certain points brought out by this study may have an important 

 bearing upon the season for field planting. It is probable, for instance, 

 that subsequent lateral root development in the plantation may be 

 decisively influenced by the time of planting. 



