A decision-support system for real-time management of Easter lily (Lilium longiflorum Thunb.) scheduling and height--I. System description
Abstract A decision-support system was developed for recommending night and day temperature settings to control the timing and height of Easter lily ( Lilium longiflorum Thunb.). Existing biological models and qualitative rules were combined into an overall model of the response of plant development rate to temperature. A process control algorithm was used to determine appropriate height control actions based on a graphical control chart of plant height over time. A knowledge-based system checked the feasibility of output from the development and height control models and generated a text report. This model was implemented on a personal computer in a program called “The Greenhouse CARE System” and has been linked directly with an environmental computer to control greenhouse temperatures. A companion article describes validation of this model.
Observations on the Relationship Between Degree-day Summations and Timing of Easter Lilies

The timing of the crop is probably the most important thing that Easter lily (Lilium longiforum thunb) forcers must accomplish, and the variable date of Easter complicates scheduling (6, 12). The influence of bulb maturity and treatments prior to being placed in the greenhouse, often not under the grower’s control, makes forcing a challenge (2, 11, 17). Several methods are used to monitor progress of the crop, but adjusting temperatures is the actual means of controlling the rate of growth and development. Measurements of time and temperature, expressed as heat units or degree-days, are used to monitor the growth and development of many crops (1, 13, 21) and to predict with a high level of precision certain stages of their development. Degree-days or heat units offer little advantage over time alone as indicators of crop progress under conditions where temperature can be controlled to eliminate or minimize variations. Variations in greenhouse temperatures, greater during daytime hours than at night, especially in southern U.S. locations, are largely responsible for timing problems with Easter lilies. Heat unit summations may be reliable indicators where such variations occur. There are apparently no reports of attempts to use heat units or degree-days to monitor Easter lily shoot development.
High-Performance Liquid Chromatographic (HPLC) and HPLC-Mass Spectrometric (MS) Analysis of the Degradation of the Luteinizing Hormone-Releasing Hormone (LH-RH) Antagonist RS-26306 in Aqueous Solution
The kinetics of the degradation of an LH-RH antagonist, RS-26306,1, in aqueous solution from pH 1 to pH 11 were studied by reverse-phase HPLC. The pH–rate profiles at 50, 60, and 80°C were U-shaped with the rate law of kobs = kHaH + kw + kOHaOH. The predicted 25°C shelf life at the pH of maximum stability, pH ∼5, is greater than 10 years. The products from the degradation were analyzed by HPLC-MS using thermospray ionization. Below pH 3, the primary product, 2, forms from the acid-catalyzed deamidation of the C-terminal amide. Above pH 7, epimerization of the individual amino acids is the principal reaction. Between pH 4 and pH 6, intramolecular serine-catalyzed peptide hydrolysis becomes important, yielding a tripeptide, 3, and a heptapeptide, 4. At the pH of maximum stability all three pathways for degradation are observed.