Abstract
There is a paucity of information on the role of ethylene in onion bulb dormancy, and the available literature is conflicting. Onion cv. SS1 bulbs were treated with 1
μl
l
−1 1-MCP for 24
h at 20
°C and then stored at 4, 12 or 20
°C. Sprout growth was reduced in onions treated with 1-MCP and stored at 4 or 12
°C, but not when stored at 20
°C. Greater concentrations of sucrose, glucose and fructose were measured in 1-MCP treated bulbs stored at 12
°C as compared with untreated bulbs. Dry weight was also maintained in onions treated with 1-MCP. Abscisic acid (ABA) concentration before storage has previously been shown to be correlated with storage life, but there were no differences in the ABA concentration between 1-MCP treated and untreated bulbs. It appeared that 1-MCP reduced the rate of carbon utilisation. The mechanism by which this occurred is unknown although it is unlikely to be mediated by ABA.