Efficacy of new inhibitors of ethylene perception in improvement of display life of kalanchoe (Kalanchoe blossfeldiana Poelln.) flowers

1-Hexylcyclopropene (1-HCP) and 1-octylcyclopropene (1-OCP) are potent ethylene inhibitors. Pre-treatment of Kalancho blossfeldiana Poelln. cultivar Alexandra flowers with these compounds delayed inrolling and extended the display life of flowers. 1-OCP was most effective at concentrations of 200 and 500 nl l(-1) while 1-HCP was effective at 1000 and 2000 nl(-1) being five to ten fold higher than the concentration of 1-methylcyclopropene (1-MCP) (200 nl l(-1)) used as standard/control. 1-OCP however, prolonged the display life of individual flowers to almost 10 days and was significantly better than 200 nl l(-1) 1-MCP. The effectiveness of 1-HCP and 1-OCP was a function of time and temperature. At short (0.5 h) exposure times, the flowers were highly sensitive to ethylene that translated to a commensurate decrease in display life. Exposure time of 2 h for both 1-HCP and 1-OCP was sufficient and any longer treatments did not have any additional effect. Apparently, treatment temperature did not have an influence on the performance of 1-HCP and was depicted by lack of significance on display life at all temperature levels (5, 10, 15, 20 degreesC). 1-OCP was effective at 15 and 20 degreesC while lower temperatures reduced its performance. Reasons for differences in effects of these compounds are discussed. (C) 2003 Elsevier B.V. All rights reserved.