older plantations where the amount and kind of fertilizer required is guided by 

 soil and foliar analysis in the laboratory. 



The increased growth in the trees is recorded by means of dendrometer bands, 

 and by measurement of current height growth. 



FROST DAMAGE 



Frost studies are important because of the sometimes extensive mortality to 

 new plantations and damage to growth in older plantations. Experimental techniques 

 have been established for the application of frosts of various degrees to small trees 

 in the field. Studies on the course of frost resistance of several species are being 

 conducted. Rapid procedures to measure the extent of frost damage by electrical 

 resistance have proved valuable. Additional studies have shown reliable methods 

 for the identification of previous frost damage in older trees. 



NURSERY AND PLANTING STUDIES 



The investigation of artificial methods of soil acidification have provided 

 information on the value and safety of several methods. Application of sulphur to 

 the soil has shown benefit although final assessment of the success of the trees 

 after leaving the nursery has not been completed. Other work is concerned with 

 the problems of nursery seedling production and inventory, and with the effects 

 of different methods of planting and site preparation on the subsequent performance 

 of a plantation. 



Forest Tree Breeding 



Breeding work with white pines, aspen poplars and hard pines was continued. 

 A project in spruce breeding was initiated with the objective of developing spruce 

 of superior quality for planting in northern Ontario. 



WHITE PINE 



Resistance to blister rust and weevil, and satisfactory growth rate and growth 

 form continue to be the main objective of this project. Second generation blister 

 rust resistant white pines are now beginning to flower and are being crossed to 

 determine which trees combine best in respect to rust resistance. Exploratory cross- 

 ing of white pines at the interspecific level indicated that Macedonian and Hima- 

 layan white pines are the most promising sources of rust resistance for crosses with 

 native white pine. 



Promising results from tests indicate that certain strains and types of white 

 pine are resistant to white pine weevil, 



ASPEN POPLARS 



The production of aspen-like hybrids, suitable for growing in southern Ontario, 

 having good growth rate and growth form, good wood and ease of vegetative 

 propagation are the main aims of this project. 



Emphasis in the project has gradually changed from extensive testing of large 

 quantities of average material to intensive testing of the most desirable types. 

 Rooting ability of some hybrids reached over 90 per cent in 1963. 



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