Effects of Different Durations and Timing of Far-red-deficient Environments on Chrysanthemum Growth

Abstract

The effect on plant height and internode length of `Iridon' chrysanthemum by far-red-deficient environments for two different durations was evaluated. Far-red deficiency was achieved by placing plants under double-walled polycarbonate panels filled with 6% (w/v) copper sulfate (CuSO4) solution. Controls were polycarbonate panels without CuSO4 solution. The plants were divided at random into four groups. One group was exposed all day to the CuSO4-filtered (ADCu) environment and another to all-day clear (ADCl) environment. Another set of plants were grown under CuSO4 filters and moved under clear filters 1 h before sunset each day (EODCl), while the last set of plants were grown under clear panels and moved under CuSO4 panels 1 h before sunset each day (EODCu). Plants moved at the end of the day were moved back to their original chambers after dark each night. The experiment was replicated. Overall change in plant height and average internode lengths were measured. The results were compared to ADCl (control). A 31% reduction in plant height was observed for EODCl, 42% reduction for ADCu, and 25% reduction for EODCu. Average internode length was reduced 11% for EODCl, 14% for EODCu, and 33% for ADCu.