The computer simulation model ROSESIM is based on `Royalty' rose (Rosa hybrida L.) growth response to 15 unique treatment combinations of photosynthetic photon flux (PPF), day temperature (DT), and night temperature (NT) under constant growth chamber conditions. Environmental factors are assumed constant over an entire day, but set points may vary over the duration of the crop. Anticipated values for factors may be read from an ASCII file, allowing a variety of strategies to be modeled and compared.
A Valentine's Day crop senario compared 2 management strategies for crop development time and flower quality:  constant 24/17.1 DT/NT for the entire crop, or  15 days warm 30/20C DT/NT to promote bud break, 10 days 20/15C DT/NT to promote stem caliper and leaf size, 10 days 25/18C DT/NT to promote bud development, and remaining time to flower 20/15C DT/NT to enhance flower size and color. PPF was increased gradually over crop time as would occur naturally for Dec. to Feb. Strategy  had longer stems (63 vs. 50 cm), similar stem and leaf dry weights, but less flower bud dry weight (1.0 vs. 1.6 g), while flowering 2 days earlier (41 vs. 43 days after pinch). c:\pm4\ash94h.pm 4