COMPARISON OF CYCLOPROPENE, 1-METHYLCYCLOPROPENE, AND 3,3-DIMETHYLCYCLOPROPENE AS ETHYLENE ANTAGONISTS IN PLANTS

A comparison has been made of cyclopropene (CP), 1-methylcyclopropene (1-MCP), and 3,3-dimethylcyclopropene (3,3-DMCP) in their ability to p rotect plants against ethylene. In bananas, both CP and 1-MCP are effe ctive around 0.5 nL L(-1), and 3,3-DMCP was effective at 1 mu L L(-1). Bananas treated with CP and 1-MCP again become sensitive to ethylene at 12 days and those treated with 3,3-DMCP at 7 days. Mature green tom atoes are protected by 5-7 nL L(-1) of 1-MPC for 8 days at 25 degrees C and tomatoes treated with 3,3-DMCP at 5-10 mu L L(-1) are protected for 5 days. Carnation flowers are protected with CP or 1-MCP after exp osure to 0.5 nL L(-1) for 24 hours and by 1 mu L L(-1) of 3,3-DMCP. Th e display life of Campanula flowers is increased from 3.3 to 5.4 days by 10 mu L L(-1) of 3,3-DMCP and to 9 days by 20 nL L(-1) of 1-MCP. Et hylene inhibition of pea seedlings is reduced by treatment with 1-MCP at 10 mu L L(-1) of ethylene but as ethylene is increased to 3000 mu L L(-1) growth inhibition increases. 3,3-DMCP treatment causes very lit tle reduction of the ethylene effect even at very low concentrations.