Succulents have continued to grow in popularity in recent years due to their diverse colors, forms, and suitability as houseplants. However, few if any scientific publications exist on how to optimize growth and promote flowering of the most popular genera. Therefore, the objectives of Expt. 1 were to 1) establish the critical photoperiod for flowering and 2) quantify the interaction of photoperiod and radiation intensity on growth and development of Echeveria. In Expt. 2, I wanted to 1) establish if a single paclobutrazol drench could prevent excessive stem elongation in a low light environment and 2) determine the duration of paclobutrazol drenches efficacy. Lastly, in Expt. 3 I quantified the interaction of radiation intensity and day and night temperature on growth and development of seven succulent genera and cultivars. In Expt. 1, DLI and photoperiod interacted to affect the growth index of Echeveria 'Apus', 'Canadian', 'Elegans Blue', and 'Jade Point', suggesting that day lengths ⁹́Æ13-h and DLIs of 5 mol℗ʺm⁰́₂2℗ʺd⁰́₂1 resulted in larger plants, but not higher quality plants compared to those grown under short photoperiods and DLIs of 12 mol℗ʺm⁰́₂2℗ʺd⁰́₂1. In Expt. 2 plants under low DLIs exhibited an increase in extension growth. However, plants treated with increasing rates of paclobutrazol resulted in reduced stem elongation, even under low DLIs. Lastly, in Expt. 3 growth index increased under moderate DLIs and cooler temperatures for some genera and moderate DLIs and high temperatures for others. These results greenhouse growers with information regarding how succulents respond to the environmental stimuli of photoperiod, temperature, and radiation intensity.
Read
