Effects of natural daylength and nutrition on the cessation of cambial activity in young plants of Picea abies : Dickenwachstum der Bäume

Wien

1981

S. 167-176

2 Abb., 1 Tab., 4 Lit. Ang.

Unselbständiges Werk

200004866

The cessation of activity in the cambial zone of Picea abies under natural conditions has been estimated over several years. To assess the effect of photoperiod, experiments in controlled environments were combined with investigations of plants grown under field conditions. A direct effect of photoperiod, with a critical night lenght different from the night length causing termination of shoot growht, is established. In Trondheim (63ü 25' N) cambial activity normally stops between 10th and 20th of September. Night lengths and light conditions under changing weather in August habe been studied in an attempt to estimate the approximate date of photoperiodical induction and the critical night length for cessation of cambial activity. It appears that other factors such as mineral nutrition and light intensity can have a modifying effect on the raction leading to termination of acitivty in the cambial region.