|
Effect of day and night temperature conditions on growth and development of plug seedlings of Impatiens wallerana ´Dazzler Pink´ and how to pevent stretch of plug seedlings during nursery period were investigated under environment controlling chamber. and then, the growth and flowering of different plug seedlings after transplanting was also investigated in greenhouse. The plug seedlings grown under 16 different day and night temperatures (DT/NT) regimes with ranging from 16 to 28℃ under 12 hrs photoperiod. Plant height and internode length were highly affected as day temperature and difference between day and night temperature (DIF) increased, especially responsed by DIF when DT is above 24℃. The number of nodes were influenced by DT x average daily temperature (ADT) and the number of branches increased under -DIF condition whereas decreased under +DIF condition. In contrast with the branching, leaf area increased as DIF increased from - to + value. Flower initiation was hastened as ADT decreased. however, the flowering was hastened as ADT increased, Fresh and dry weight (DW) of plug seedling increased as DT increased. Compactness index (DW/height) of plug seedlings increased as DT decreased, It was, therefore, found that optimum DT and NT for the high quality of seedling was 16-20℃ and 16-24℃, respectively. After transplanting, the flowering time of Impatiens was hastened in spite of less flower number as ADT increased wheres flowering was delayed in spite of more flower number as ADT decreased. It was concluded that the optimum temperature for the growth and development of Impatiens on the basis of best quality of plug seedling and flowering response was ranging from 16-20℃ DT and from 16-24℃ NT.
|