Postproduction of potted miniature rose: Flower respiration and single flower longevity

Research was conducted to investigate the relationship between flower respi ration and flow er longevity as well as to assess the possibility of using miniature rose (Rosa hybrida L,) flower respiration as an indicator of pote ntial flower longevity. Using several miniature rose cultivars as a source of variation, four experiments were conducted throughout the year to study flower respiration and flower longevity under interior conditions. For plan ts under greenhouse as well as interior conditions, flower respiration was assessed on one flow er per plant, from end-of-production (sepals beginning to separate) up to 8 days after anthesis, Interior conditions were 21 +/- 1 degreesC and 50 +/- 5% relative humidity with a 12-hour photoperiod of 12 mu mol.m(-2.)s(-1) (photosynthetically active radiation), Flower respirati on was higher if the plants were produced during spring/summer as compared to fall/winter. 'Meidanclar' 'Schobitet', and 'Meilarco' miniature roses ha d higher flow er respiration rates than 'Meijikatar' and 'Meirutral'. These two cultivars with the lowest respiration rates showed much greater flow e r longevity if grown during spring/summer as compared to fall/winter. The t hree cultivars with the higher respiration rates did not show differences i n flower longevity between seasons. For plants under greenhouse or interior conditions, flower respiration was negatively correlated with longevity in spring/summer but a positive correlation between these parameters was foun d in fall/winter, During spring/summer, flower respiration rate appears to be a good indicator of potential metabolic rate, and flowers with lon respi ration rates last longer.