PRODUCTION POTENTIAL OF BORAGO OFFICINALIS L.

Seed of Borago officinalis L. (borage) is a rich plant source of gamma-linolenic acid (GLA), a prostaglandin precursor. Although interest exists in commercial production of the seed, cultural requirements have not been developed and production is limited by abscission of mature seeds. Field studies were conducted in Lafayette, Indiana, USA in 1985 to assess the seed production potential of borage and to determine the effect of plant spacings and harvest timing on seed yield and growth. Plant spacings included 23, 30, 46, or 91 cm within row (between row spacing: 91 cm) and between row spacings of 30, 46, 61, or 91 cm (within row spacing: 30 cm). Three plants/plot were harvested 17, 21, 44, and 66 days after anthesis and sampled for fresh and dry weight. Total fresh and dry weight at all row spacings generally increased from 17 to 44 days after anthesis and then declined. Shattered seeds were harvested in 3 consecutive nondestructive (ND) harvests plus 1 destructive (D) harvest. Spacings generally did not significantly affect seed yield at any single ND harvest. A within row spacing of 30 cm resulted in the highest season total yield of 753.5 kg ha^-1. Seed yield averaged across within row spacings increased from 74.6 kg ha^-1 at 51 days after anthesis to 129.4 kg ha^-1 at 71 days after anthesis. The highest calculated yield of GLA (7.2 kg ha^-1) was produced at 71 days after anthesis. Multiple ND harvests increased seed yield above a single D harvest. Seed yield might be increased by a combination of ND and D harvest methods.