516 



L. ZUFA 



sand and white pine humus. Single plots, containing 21 cuttings, were 

 planted in 4 replications. 



VARIATION IN ROOTING WITHIN AND BETWEEN POPULATIONS 



The within population variation in rooting was studied on cuttings 

 planted in rooting beds in May 1968. The cuttings were taken from 

 several trees from 5- and 10-year-old populations of P. strobus and 

 from 2-, 5- and 15-year-old populations of P. griffithii x strobus. 

 Twenty-six cuttings from all except the 2-year-old tree were planted in 

 2 replications. 



The between population variation in rooting was studied on two 

 populations of P. griffithii x strobus. Each population was represented 

 by two 5-year-old trees. Again, 26 cuttings were taken from each tree 

 and planted in 2 replications in rooting beds in May 1968. 



Variation of rooting ability of cuttings obtained from P. strobus 

 and P. griffithii x strobus ortets was determined for the 5 -year-old 

 populations just described. 



RESULTS 



The December, January and March collection dates showed no signifi- 

 cant differences in rooting of cuttings. Needle fascicles collected and 

 planted in January and March rooted significantly better than those 

 planted in December (Table 1) . 



Table 1. Rooting of P. strobus and P. griffithii x strobus 

 propagules collected at different times: ortets 5 and 15 years 

 old 









Month of collection 









December 



January 



March 



Propagule 

 type 



No. 

 rooted 



rooted 



No. 

 rooted 



rooted 



No. 

 rooted 



q. 







rooted 



Cuttings 



Needle fascicles 



7 

 5 



23.3 

 16.7 



6 



12 



20.0 

 40.0 



8 

 11 



26.7 

 36.2 



Cuttings: 



Needle 

 fascicles : 



X 2 = 

 X 2 = 



0.96 

 10.19** 



d.f. = 2 

 a d.f. = 2 









significant at the 1% level 



Significant differences in rooting appeared between the propagules 

 taken from trees of different age. Although rooting decreased with age, 

 no difference was observed with propagules taken from trees 10 years of 

 age or younger (Tables 2, 3, 4). 



