FLOWER FORMATION OF CELERIAC (APIUM-GRAVEOLENS L. VAR. RAPACEUM) - I - VERNALIZATION AND DEVERNALIZATION

The influence of temperature on flower formation of celeriac was studi ed in growth chamber experiments. After the different treatments, tran splants were planted in the field where the percentage of bolting, dia meter of tuber and the final leaf number of plants were recorded later . Celeriac has a qualitative vernalization requirement. There is a sho rt juvenile phase that ends at a minimum size of about 0,1 g fresh wei ght or 2 visible leaves. Inductive temperature range between 0 and 14 degrees C. At constant temperature of 5-8 degrees C flower induction t akes place after about 3 weeks. High temperature above 14 degrees C du ring or after cold periods cause strong devernalization effects. The e xperimental methods used here are discussed with respect to their suit ability to simulate temperature effects in the field.