Role of environmental factors and plant growth regulators on the floral transition of Exacum Styer group

Exacum Styer Group exhibit many outstanding characteristics that make this crop suitable as a new flowering pot, bedding or cut flower crop. One requirement for a new crop's commercial success is a reliable system to predict or control flower initiation and development. Therefore, this study focuses on evaluating the role of environmental factors on the transition from vegetative to reproductive growth. Light treatments, based on a combination of shade nets and supplemental lights were designed to deliver between 1152 moles and 5211 moles of light over a 36 week period. Visual inspection of plants occurred daily with the dates of first visible bud and anthesis recorded from each individual within all populations (i.e., genetically related seedlings). Average number of days to visible bud and average number of days to anthesis for individual populations ranged from 170-218, and 237-280, respectively. Average number of days to anthesis for individual treatments were as follows: Treatment 1 (ambient light + 65% shade) 272 days; Treatment 2 (ambient light + 35% shade) 278 days; Treatment 3 (ambient light) 273 days; Treatment 4 (ambient light + supplemental light) 238 days. Analysis of variance results indicate significant effects (P