Carry-over effect of gibberellins (GA_4/7) and ringing on female flowering in Norway spruce (Picea abies (L) Karst) seedlings

Abstract

Summary -The second year after treatment effect of gibberellins (GA 4/7 ) and ringing on increased female flowering was observed in 13-year-old full-sibs of Norway spruce. This carry-over effect was exhibited independently by GA 4/7 and ringing. GA 4/7 significantly increased and ringing sig-

Control of the first flowering in forest trees

“…Staghorn sumac normally does not flower until 4-5 yrs of age. Growth regulators used alone were also effective in promoting precocious flowering in Larix decidua (Hoist 1962) and, combined with girdling, forced flowering in P. abies (Bonnet-Masimbert 1987, Chalupka 1996. Hoekstra & Mergen (1957) significantly increased flowering in 7-yr-old Pinus elliottii seedlings that had no history of flowering, with girdling, wire strangulation, root pruning, and fertilization treatments.…”

Variability of morphological features, bud burst and flowering of Norway spruce (Picea abies [L.] Karst.) in the seed orchard of the Bielsk Forest District

“…Stimulation of tree flowering can be another factor with a positive influence on cone and seed production within seed orchards. In Poland, the methods of flowering stimulation were described by Chałupka (1985Chałupka ( , 1987Chałupka ( , 1991Chałupka ( , 1997. On the other hand, however, the results then obtained were not definite enough to support fully reliable methodolo-gy for stimulation of Norway spruce flowering.…”

New insights in seed orchards pollen contamination, study case in an advanced breeding program

“…Mechanical and chemical treatments have been used to increase flowering. Hormonal treatments (e.g., gibberellins) have been studied frequently (Bleymüller 1976;Chalupka 1979Chalupka , 1981Chalupka , 1997Dunberg 1980;Luukkanen 1980;Bonnet-Masimbert 1987) and are recommended when reproductive induction and synchrony are fundamental prerequisites for the production of seeds (Kang 2001). Recently, Almqvist (2008) reported that although practical use of GA4/7 in Norway spruce seed orchards does not always have a clear positive effect, the treatment is still a cheap and highly profitable way of increasing the cone production.…”