From experiments with successive dates of sowing, different raising temperatures and different growing conditions the following facts emerged: with increasing raising temperature, crop weight increased by delayed bolting; extra light during the seedling stage, or short day during the seedling stage, delayed bolting, but did not always increase crop weight; after the raising period, high temperature stimulated bolting and increased crop weight.
Low temperature (5°C) during germination or in the seedling stage promoted bolting and flowering; in short days, vernalization accelerated bolting considerably; in long days, it depended on the age of the plant at the time of vernalization. Interruption of seed vernalization by normal temperature delayed bolting. The effect of seed vernalization, if applied for a limited period, could be nullified by high temperature (35°C) immediately after vernalization.
In unvernalized plants grown at 35°C bolting was accelerated. Increasing day length promoted early bolting. The only flower-promoting action of short days had been observed when short days preceded vernalization.
Low light intensity promoted or inhibited bolting, according to other factors.
|Qualification||Doctor of Philosophy|
|Award date||1 Jul 1964|
|Place of Publication||Wageningen|
|Publication status||Published - 1964|
- cichorium endivia
- plant development