Summary

A study of 66 progenies from late flushing and open pollinated trees within 12 bavarian stands (Moulalis 1971) gave also some results in respect of summer shoot formation in dependance of bud break. In 1969 and 1970, when plants were four or five years old, there were evident differences in the percentage of individuals which had flushed respectively which had formed second shoots at certain observation days (May 8, 1969 and May 20, 1970 resp. July 26, 1969 and August 10, 1970). These differences obviously depended on weather conditions during springtime and on different provenance (lower or higher elevation). Under normal conditions in 1969 all progenies had flushed early and rather simultaneously, and showed more and earlier summer shoot formation than 1970 under infavourable conditions. In 1970, when bud break had been generally delayed and provenances from lower elevations had flushed markedly earlier than those from higher elevations, there was later and less summer shoot formation respectively no formation at all within the progenies descending from higher elevation.

The results of this study seem to proof, that genetical flushing behaviour is connected with ability to develop summer shoots, both being modified equally by weather conditions during springtime (i. e. early or late flushing in a certain year is followed by early or late summer shoot formation). Provenances of higher elevation, which have normally a reduced summer shoot formation, are much more modified by unfavourable conditions than those from lower elevation. Late formation of second shoots can be dangerous, because poor lignification promotes damages by early frost.