Borage (Borago officinalis) is indigenous to Britain and has been grown throughout the UK for a number of years as a high value, specialty oil crop. The oil is one of the main arable sources of gamma linolenic acid (GLA), and is primarily grown as a dietary supplement in health foods, but may also be used in cosmetics and pharmaceuticals.
Borage is a spring sown oilseed crop that can act as a useful break crop in arable rotations. In the late 1990’s there was possibly 2,000-3,000 ha being grown, but competition from imports and overproduction led to a fall in market prices leading to a reduction in planting. The current crop area in the UK is estimated at around 700 ha. Average seed yields range anywhere from 0.2 – 1t/ha, but as the plant only loosely holds the seeds a large proportion of the potential yield is lost due to shedding. In Northern Europe average yields of around 0.6t/ha can be achieved where conditions are favourable.
The crop should be swathed once the most forward flowers begin to shed, which is generally around late July. It should then be combined about a week after swathing, however harvesting can be difficult due to seed losses from shedding.
The crops nutrient requirements are fairly low, with a nitrogen requirement of up to 60 kg/ha, which should be applied to the seedbed. Maintenance applications of phosphate and potash should be made to the seedbed along with the nitrogen.