Inhibition of Flower Bud Formation inBetula platyphyllaandBetula pendulaby Gibberellin (GA₃) Application

Experimental investigation on weather cues for mast seeding of Fagus crenata

“…The receptivity for floral induction in F. crenata may occur during the decisive period, i.e., between 21 April and 20 May. A number of experiments on the promotion and inhibition of floral initiation by gibberellin application have also indicated that floral initiation is dependent upon a specific time period (Junttila and Jensen 1988;Yoshino 2000). In some temperate conifers and hardwoods, this receptive period for floral initiation may occur before the vegetative bud burst and early shoot elongation (Owens and Colangeli 1989) or during later shoot elongation (Greenwood et al 1991;Yoshino 2000).…”

“…A number of experiments on the promotion and inhibition of floral initiation by gibberellin application have also indicated that floral initiation is dependent upon a specific time period (Junttila and Jensen 1988;Yoshino 2000). In some temperate conifers and hardwoods, this receptive period for floral initiation may occur before the vegetative bud burst and early shoot elongation (Owens and Colangeli 1989) or during later shoot elongation (Greenwood et al 1991;Yoshino 2000). Assuming that F. crenata behaves similarly, the receptive period for floral initiation may be from late April to mid or late May because bud burst and cessation of shoot elongation in F. crenata occur between late April and early May and from mid to late May, respectively (Maruyama 1979;Tomita and Seiwa 2004).…”

“…Such an effect of weather on female and male inflorescence initiation may be closely related to the time of floral initiation. In some northern temperate conifers, such as Pinus, Tsuga, Thuja, and Chamaecyparis (Owens 1995), and hardwoods, such as Alnus, Betula, and Quercus (Merkle et al 1980;Caesar and Macdonald 1984;Yoshino 2000), female inflorescences may be initiated later than male inflorescences, and this may be why the receptive period for initiation differs between female and male inflorescences. However, the timing of female and male inflorescence initiation in F. crenata is similar (Hashizume 1983;Mikami and Kitakami 1983).…”

Long‐term fluctuations and mechanisms of seed production of riparian tree canopy species

“…Because the flower buds of broadleaf trees form in the early summer of the previous year (Lester, 1963;Merkle et al, 1980;Taniguchi et al, 2002;Yoshino, 2000Yoshino, , 2003, the average temperature and precipitation from May to August of the previous year were used.…”

“…Many trees that flower in spring tend to have flower buds that differentiate in June or July of the year before flowering (Taniguchi et al, 2002;Yoshino, 2000Yoshino, , 2003. The amount of seedfall of F. platypoda was not significantly correlated with weather in May-August in the year before flowering (Table 2), suggesting that the amount of seedfall was not affected by weather at the time of flower bud differentiation.…”