In HDC project FV 395, Richard Colgan at the University of Greenwich worked with Produce World over three seasons (2011-13) to investigate ways of keeping broccoli fresh for longer.
The research found that azoxystrobin, when applied as a fungicide near the end of crop life, delayed the onset of senescence. Its effect depended on the health of the crop and varied with the season.
Ethylene in stores, mainly from forklift trucks, hastened senescence of broccoli. Conversely, ethylene scrubbing improved shelf life. It also reduced the decline in Vitamin C content in storage. Variety matters - Ironman responded much better than Parthenon to ethylene scrubbing.
There is usually more commercial advantage from aiming for prolonged storage under reduced ethylene when the crop is not stressed in the field, is cut relatively immature and is of a small beaded variety. Brassicas other than broccoli can also benefit.
Ethylene can be scrubbed using 1-MCP (SmartFreshTM), as in the Greenwich study, but also using ultraviolet light extractors or cells containing ozone or potassium permanganate. Costs vary. Growers are likely to need specialist advice before modifying storage to include ethylene scrubbing. Those who can provide this service include, Greentech Consult, Freshpod, Nutricycle and Phoenix Retail Services.
Horticultural Development Company
For details on all HDC activity, visit www.hdc.org.uk