BEHAVIOUR OF MINIATURE HYDRANGEA MACROPHYLLA (QUALITY AND DURATION OF FORCING) AFTER VARIOUS COLD TREATMENTS BEFORE FORCING
Our experiments have two aims :
- research of a minimum duration of cold treatment to break the dormancy ;
- consequences on the quality of plants and the forcing duration of two cultivars : 'Rosita' (pink) and 'Adria' (blue).
After cultivation, pot plants with their leaves are placed into cold storage rooms during november. In 1986/1987, two durations of cold treatment (+ 2°C) were applied : four and six weeks.
The forcing in our greenhouses (+ 18°C) started on december the fifteenth.
In our conditions of experiment, the results show that the optimum duration of cold treatment is four weeks for the two cultivars.