Fedorkov, A. 2012. Variation in the Leader Shoot Elongation Patterns in Larix Species and Provenances in the North-West of Russia. Baltic Forestry 18(1): 119-124.

A phenological study of seven Russian larch (Larix Miller) provenances was performed in a field trial located in the Komi Republic (north-west Russia) (61°39'N, 50°41'E, alt. 160 m a.s.l) at the age of five years. The provenance origin had a significant (p<0.001) effect on the leader shoot growth characteristics. The average undamaged leader shoot length was 27 cm and varied considerably over the provenances: 38 cm for Plesetsk and 14 cm for Yakutia. The average growth rate was 5.2 mm day-1 and means varied from 8.5 mm day-1 for Plesetsk and to 3.4 mm day-1 for Yakutia provenances. The earliest time for onset and cessation of shoot elongation was for Yakutia provenance and the latest one for Ufa provenance. The range of these provenances was 28 days for start and 46 days for cessation of the growth. The onset of growth correlated positively with the latitude and longitude of the provenance origin but negatively with annual elongation. A positive correlation was observed between rate of shoot elongation and annual shoot growth.

Key wordscessation of growth, onset of growth, phenology, Russian larch, shoot length.