During the spring and early summer of 1976 over 4000 grafts were made at the Red Rock Research Centre, both on potted rootstock (2+1) and field-grown stock (2+2). These materials represented 136 ortets from throughout the Prince George Selection Unit, an area of approximately 6400 square kilometers located south and east of the city of Prince George. In the spring of 1977 nearly 1200 of these ramets (10 per clone) were planted out in a breeding arboretum at the Red Rock Reserve. Both the number of flowers and the frequency of flowering ramets were assessed in June, 1978.
At the beginning of the 3rd growing,season (2 full years after grafting and 1 full year after outplanting) over 41% of the clones (56) exhibited female flowering. Response varied from a single flower on one ramet to over 30 flowers and 10 flowering ramets per clone. Almost 20% of the clones produced staminate strobili but over 2/3 of the flowering ramets were clearly stressed (poor growth). Judging from observations noted on older clonal materials, pollen production will become almost nil on healthy grafts for at least the first 5-8 years of establishment.
Interestingly, a large difference in flowering response existed for ramets established on potted rootstock and field grown rootstock. Only 11% of those ramets on potted stock flowered; over 62% of the field grown stock supported flowering ramets (female). Furthermore, field grown stock supported more flowers per flowering ramet (2.0 vs 1.6) than did potted stock. Generally speaking, the grafts established on field grown stock were larger and more vigorous than those on potted rootstock. It is also worthy of note that nearly 91 percent of the flowering scions were either dominant or very nearly so relative to the remaining rootstock branches.
[Abstract contains full text of memo.]
BC Forest Service - Research Division. 1978. Early Flowering in Lodgepole Pine Grafts. British Columbia Ministry of Forests, Lands, Natural Resource Operations and Rural Development. Research Memo (FLNRORD). RM32
Topic: FLNRORD Research Program
Keywords: FLNRORD, Research Memo, British Columbia
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