Bales Versus Polybags in Cold and Frozen Overwinter Storage of Nursery Stock

Abstract

Fall lifted white spruce, white pine, and red pine were stored overwinter 1969–70 at Orono Nursery, Ontario. Frozen (−4 °C) and cold (1.5 °C) storage conditions; bales and polyethylene bags were compared. The trees were planted in the spring at three locations, both 'early' (May 5–8) and 'late' (May 26–28). This report is based on survival, height, and terminal shoot measurements to the end of the second season.Storage of white spruce was successful, the polybag was the better container, and frozen storage the better condition. White pine stored moderately successfully, and red pine storage was a failure.When planted late, fresh stock gave poor growth rates in all species. Reasonable extension of the planting season with frozen overwinter-stored stock appeared promising with white spruce. In white pine and red pine, however, late planting, even of stored stock, showed poor growth.

Provisional guidelines for fall lifting for frozen overwinter storage of nursery stock

“…85% (Mullin and Parker 1974) and 92% (Mullin and Bunting 1972). This may be partly due to the quality of the stock as the top-root ratio (Table 1) was well above the maximum of the working range given for 3-0 white spruce in Ontario nurseries; 2.5 to 4.5:l (Armson and Carman 1961), and was in the "top-heavy" class of Stoeckeler and Jones (1957).…”

“…Previous work has shown that white pine and red pine may be intermediate, and in that order (Mullin and Parker 1974;Mullin 1974a over a period of time such as "below 40°F for 20-30 days" (Nyland 1974b3, might be expressed in a simple formula. A negative degree-hardeningdays, D-H-D (from degree-days, Zasada 1973) with a basis of 50°F (Nyland 1974b), was prepared daily of the differences between 50°F and the daily minimum for soil temperature at 15 cm depth.…”

Lifting and Overwinter Storage of White Pine in Southern Ontario

“…In Ontario frozen storage (-3OC) has generally been conThe success of overwinter storage of white pine (Pinus strobus L.) varies with lifting date and storage temperature (Mullin and Parker 1974). Lifting as late as possible in the fall has been considered one way to improve success (Williams and Rambo 1967, Mullin and Parker 1974, Nyland 1974a).…”

“…Lifting as late as possible in the fall has been considered one way to improve success (Williams and Rambo 1967, Mullin and Parker 1974, Nyland 1974a). However, earlier lifting is sometimes necessary to avoid freeze-up.…”

“…1983a including white pine (Mullin and Hutchison 1978b). However, differences in DHD requirements for white pine between nurseries (Mullin and Parker 1976, Mullin and Hutchison 19786) (Mullin and Parker 1974, 1976, Mullin and Hutchison 1978b, owing to the incidence of mold in cold (1 -4OC) storage (Wilner and Vaartaja 1958, Nyland 1974band Venn 1980, 1981. However, mold tends to be less of a problem with stock lifted late in the fall.…”