STUDIES OF ABSCISIC ACID AND CYTOKININS IN FICUS BENJAMINA DURING PRODUCTION, ACCLIMATIZATION, AND IN A SIMULATED INTERIOR ENVIRONMENT

Foliage plants comprise a major portion of the floriculture industry. Interior conditions in both the home and commercial settings usually have low irradiance levels. Foliage plants, typically exhibit leaf yellowing and defoliation under the low light intensities of interior environments. Growers have developed a process called acclimatization which attempts to adapt plants to interior conditions. In this process, plants are grown under low light levels for a certain period of time prior to sale. This process requires many weeks and results in plants of greatly reduced visual quality.; One of the most extensively used plants in interiorscapes that is commonly put through the acclimatization process is Ficus benjamina L., weeping fig. This plant exhibits significant leaf abscission during the acclimatization process and in interior environments.; This research examines the role of three plant hormones in the defoliation of Ficus benjamina. A system was developed to separate and quantitate endogenous zeatin and zeatin riboside via high performance liquid chromatography (HPLC) and abscisic acid by HPLC and gas-liquid chromatography (GLC). These hormones were monitored in roots, new leaves, and mature leaves of Ficus benjamina during production acclimatization, and in an interior environment.; Abscisic acid does not appear to have a direct role in Ficus benjamina leaf yellowing and abscission. The two major cytokinins, zeatin and zeatin riboside, on the other hand, may be directly involved in the durability and survival of Ficus benjamina leaves under low irradiance interior situations. Acclimatized plants contain higher cytokinin levels than non-acclimatized plants, stay green longer, drop fewer leaves, and show a better chance of survival than non-acclimatized plants in a low irradiance interior environment. Acclimatized plants continue to have higher cytokinin levels than non-acclimatized plants after 3 months in an interior environment, and even when watering frequency is less than optimal.