Farm Diversification

Erucic acid is a long chain fatty acid and this confers particular properties as a lubricant in high temperature and high pressure applications.  After the oil is extracted from the seed, erucic acid is converted in a chemical process to erucimide for commercial use. 

It is used for a variety of specialist applications, including as an industrial lubricant, with a particular application as a lubricant in the petroleum oil industry, and as a printing ink in photocopier applications.  Most importantly it is used as a slip agent for polythene and has achieved Generally Recognised As Safe (GRAS) status for use with polythene which comes into contact with foodstuffs.  A thin layer of erucimide is widely used with polythene bags, providing a large market for erucimide. 

The extremely high costs of registering alternative products for use with food makes this an attractive outlet for erucimide.

HEAR varieties have the advantage of having similar agronomic requirements to double low rapeseed.  The land used needs to be of sufficient quality for general cropping and fertiliser and agrochemical inputs follow the same pattern as for double low rapeseed. 

Both winter and spring sown HEAR varieties have been grown commercially, but current cultivation in the UK is restricted to winter HEAR due to higher yields and therefore better economic performance.  There are several winter varieties available and information on these is updated annually in the SAC/HGCA North UK Oilseed rape variety leaflet.  Current varieties include Maplus, Hearty, Marcant and Helico.  Some HEAR varieties which have been available for a number of seasons, such as Hearty, had very poor resistance to the disease light leaf spot which is the principle foliar disease in the north of the UK .   Newer varieties such as Marcant and Helico have better resistance to light leaf spot.  Insufficient trialling of HEAR varieties within the official trialling system have taken place to enable direct comparison with conventional varieties of oilseed rape.  Based on limited data, HEAR varieties still appear to offer slightly less yield than the top yielding conventional double low types, although performance of the newer HEAR varieties has improved.

Growers should be aware of the potential of volunteers from HEAR varieties to contaminate future crops of oilseed rape grown in the field.  If sufficient numbers of HEAR plants become established in conventional double low rapeseed crop and maturity coincides with the harvest of the crop to give a significant presence of HEAR seed in the harvested sample this could potentially result in raising levels of erucic acid above the contracted maximum.  In practice few cases of erucic acid contamination above the contractual level have occurred, but growers should take steps to minimise volunteer numbers of HEAR in non rapeseed parts of the rotation. 

HEAR commands a premium over conventional oilseed rape, frequently in the order of £30/tonne. 

A premium is necessary to compensate for any reduction in yield compared to conventional varieties and to cover any costs associated with control of volunteers.