VEGETATIVE PROPAGATION EXPERIMENTS IN' WHITE PINE 521 



Table 9. Variation of percentage rooting of P. griffithii x 

 strobus cuttings obtained from 2 populations of 5 -year-old 

 ortets: Mav collection 



Population No. of cuttings No. rooted % rooted 



1 52 



2 52 32 61.1 



X 2 = 46.2*** a d.f. = 1 



*** Significant at the .1% level 



Table 10. Rooting of ?. szrc'cus and P. griffithii x strobus 

 cuttings obtained from ortets 5 years old: May collection 



Ortet species No. rooted % rooted 



?. szrc'z:^ 24 12.6 



?. griffithii 



x strc'bus 68 35.8 



X 2 - 11.12** 3 d.f. = 1 



Significant at the 1% level 



DISCUSSION 



Some of these experiments confirmed results obtained in other studies; 

 for example, the information on rooting by using various rooting media 

 (Nienstaedt, et al . , 1958) and on age influence in rooting (Delisle, 

 1954). In the P. strobus tests, rooting ability did not decrease up to 

 an age Of 10 years. This should allow enough time to test for blister 

 rust resistance prior and parallel to vegetative propagation. 



We did not find differences in the rooting of cuttings and needle 

 fascicles (Table 5) . This means that the rooting of needle fascicles 

 would be advantageous as it offers possibilities for rapid mass propaga- 

 tion. However, it seems that only the needles with fascicular buds are 

 able to develop into a normal plant. The induction of fascicular buds 

 by pruning the terminals should not present any problem. Hoff and 

 McDonald (1968) successfully rooted needles with fascicular buds. If 

 the rooting of such fascicles with buds is as easy as the rooting of 

 those without buds, then this method would become a very valuable means 

 of vegetative propagation in white pines. Roots developed on needle 

 fascicles are shown in Fig. 3. 



