ANNUAL REPORT, 1944-45 



49 



following conclusions can be drawn: (a) during the first six months of life, infants 

 need more calcium than they receive under current dietary practices; (b) the 

 child between two and five years of age would have his calcium needs satisfied 

 by approximately one cupful of milk in addition to an otherwise adequate diet 

 and (c) at the peak of the pubertal spurt the child would need approximately three 

 cupfuls of milk daily. Children previously undernourished in respect to calcium 

 would need somewhat more calcium to bring their bones to a stage of physio- 

 logical calcification. 



ASE IN YEARS 



DEPARTMENT OF HORTICULTURE 

 R. A. Van Meter in Charge 



Factors Influencing the Hardiness of Evergreens. (C. J. Gilgut, Waltham.) 

 The winter of 1944-45 was one in which there should have been little or no 

 winter injury to ornamental woody plants. There was abundant rain in the fall, 

 there was plenty of snow on the ground, and the temperature did not go exces- 

 sively low. Yet there was as much winter injury as in the winter of 1943-44 

 which was preceded by an unusually dry summer and fall and during which there 

 was almost no snow — conditions commonly stated as the cause of winter in- 

 jury. 



Although varying with individual plants, the injurj' in 1944-45, as in 1943-44, 

 was no more extensive on plants grown with fertilizers to produce an abundant 

 soft growth late in the season than on plants grown without fertilizer to produce 

 a moderate amount of growth with ample opportunity for it to harden before 

 winter. 



That winter injury is not avoided when plants are grown slowly without ferti- 

 lizers is shown well in a block of 128 arbor vitae {Thuja occidentaiis globosa) set 

 out 5 years ago. The plants received no other treatment than regular cultivation 

 to control weeds, and the amount of current seasonal growth was moderate. They 



