and Silviculture Section of the Timber Branch and has as its objective the procure- 

 ment of information for the scientific advancement of the artificial regeneration 

 program. The work is developed by experiments at the nuseries, on the planting 

 sites, and in the older plantations. The unit consists of three research foresters, 

 one of whom is currently on educational leave-of-absence. 



Nursery Studies 



Several long-term studies are presently being conducted in the nurseries. At 

 Orono nursery, an experiment to study the effects of various mthods of acidifying 

 the soil is in the third year. At the Kemptville nursery a study of several tech- 

 niques to reduce the losses of young seedlings due to frost heaving is in advanced 

 stage. Experimental stock from two nurseries, Kemptville and Fort William, is 

 being planted in a series of tests across the province to compare the planting 

 success of trees of different age-classes. 



Forest Fertilization 



The series of experiments with the use of fertilizers (based on soil and foliar 

 analyses) on less thrifty plantations, was continued in 1961. The work was done 

 in jack pine (Pinus Banksiana) plantations to supplement earlier work which 

 had been confined to red pine (P. resinosa Ait) plantations. 



Further work was done also on the study of the use of fertilizers at the time 

 of planting to achieve greater survival and growth of the newly established trees. 



Frost Damage 



Laboratory and greenhouse studies were continued of the rates and degrees 

 of dehardening of plant tissue in relation to frost damage and kill. This is a 

 serious problem in some areas each year, and it may be possible to avoid serious 

 damage by changes in nursery or planting techniques. Some laboratory and green- 

 house work is being conducted on the use of hormones in nursery and planting 

 operations. 



Forest Tree Breeding 



Breeding work with white pine, aspen poplars, hard pines and white cedar 

 was continued. Work with chestnut was reduced to a maintenance basis. 



White Pine 



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

 growth rate were the main objectives in breeding. This project was started by the 

 Research Branch in 1946. 



Scions of nine clones and two populations of Pinus albicaulis were the main 

 acquisitions, besides a few clones of P. flexilis, P. monticola, P. koraiensis and 

 P. strobus. 



Selections from seedling populations screened for resistance to blister rust 

 comprised 59 clones. 



A total of 86 interspecific and intraspecific crosses were made yielding 4,033 

 full seeds. 



Three kinds of interspecific crosses were made, namely six crosses of P. 

 monticola x griffithii, two crosses of P. armandi x albicaulis and 30 crosses of 

 P. koraiensis x albicaulis. 



The range-wide five-station provenance test of white pine initiated in 1957 

 was outplanted. One outplanting was established at Turkey Point with a total of 

 6,292 trees. Another outplanting, with the same 13 provenances, was established 

 in Ganaraska Forest and comprised 4,212 trees. 



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