Vliv fotoperiodického režmu na jarovisaci ozimé pšenice

Abstract

1. Photoperiodic experiments with the effect of short day during vernalization of winter wheat under field conditions have shown that the short day enhances development if applied during vernalization. Short day applied after vernalization prolonged the development. 2. At low intensity artificial illumination and under optimal vernalization temperatures vernalization proceeds the faster the longer the illumination. On increasing illumination intensity differences between the effect of short and long day are obliterated. Vernalization in the dark takes place only if saccharides are added. 3. It is assumed that even in green plants the accumulation of a certain amount of ergastic material, particularly saccharides, represents one of the conditions of vernalization. This accumulation may be achieved by longer illumination (under conditions of vernalization temperature and low illumination intensity), i.e. by a direct photosynthetic effect, or else by short day (under field conditions) causing a specific, photoperiodically controlled growth reaction which inhibits growth. When vernalization proceeds in the dark saccharides must be supplied.