Grafting fraser fir [Abies fraseri (Pursh) Poir.] scions onto rootstocks of turkish fir (Abies bornmuelleriana Mattf.) is a strategy used by some Christmas tree growers in the southern Appalachian Mountains of North Carolina to reduce losses by phytophthora root rot caused by Phytophthora cinnamomi Rands. This study compared the traditional time of grafting (April) with eight summer/early fall grafting dates from mid-July through mid-October. Shade and irrigation treatments were also superimposed on the grafting dates. To ensure optimal grafting success, grafting should be performed in the late winter/early spring (April) when scions are dormant and the rootstocks are becoming active. April graft success was 95% but when grafting fresh scions in summer/fall, graft success decreased from 52% in July to 0% in October. Shade improved summer graft success (52% with, 38% without). Irrigation did not significantly affect graft success or subsequent growth. In a supplemental storage study, grafting of stored scion material in summer/early fall was not successful (less than 1%).
Success and subsequent growth of fraser fir [Abies fraseri (Pursh) Poir.] cleft grafts were studied in relation to origin and type of scion material in the tree crown. First- and second-order shoots (current-year) were collected from five zones in the crown, ranging from top to bottom, and grafted to 5-year-old fraser fir transplants in April. Success rates were similar for first- and second-order scions, whereas budbreak and subsequent growth were best for first-order scions. In general, results were best for first-order scions taken from the upper crown. Plagiotropism of grafts was similar for all crown zones and shoot types.