Poplars 



New materials were restricted to a few clones of Populus alba . P. 

 treinula and P. canescens from Switzerland and Yugoslavia. Hybridization was 

 centered on the production of second-generation hybrids between P, alba and aspens, 

 using several first-generation hybrids In our collection. The fungus- causing die- 

 back on aspen hybrids was as damaging to our materials as it was last year. 



A large plantation was established in the spring and two smaller ones 

 in the fall. A cross of our P. alba with a P. alba from Spain yielded some mate- 

 rials with better rooting ability from stem cuttings than either parent, indica- 

 ting the action of complementary genes. 



^- Hard Pines 



The development of new types, resistant to European shoot moth and 

 superior in form and growth rate, continued to be the objective. A collection of 

 scions of red pine was received from its range limit in south-western Wisconsin. 

 A new collection of scions from plus trees, was undertaken last fall and grafted 

 early this year. Several new co-operative experiments, involving hard pines, and 

 resistance to shoot moth, were started at St. Williams and Turkey Point. Much 

 material for this purpose was received from Petawawa and set out at Turkey Point. 

 A series of grafting experiments with red pine were started last fall. This 

 species shows poor results in greenhouse winter grafting and needs further study. 



Wlilte Cedar 

 The production of linproved types of this species and of western red 

 cedar, hardy in southern Ontario, is the aim. The deep snow of 1959-60 blanketed 

 the western red cedar seedlings and prevented a good freezing test. Instead, the 

 seedlings were heavily culled in the beds, in respect to size and possible winter 

 damage. It was found that the hardy western red cedar, received previously from 

 Rochester, are most probably hybrids with Thuja standishii from Japan, which may 

 account for their hardiness. . ■,. . 



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