Borage Culture on the Black Soil Zone of Alberta, Canada

Recently, borage (Borago officinalis L. Boraginaceae) has been the subject of increasing agricultural interest because of the potential market for gamma linolenic acid (GLA), an unusual fatty acid extracted from the oil seed. GLA is an omega-6 essential fatty acid which has been identified as having several beneficial properties. Increased interest in production of the crop in western Canada has brought about a need for adequate agronomic management practices since very little local research information was available. Field studies were conducted in central Alberta in 1998 and 1999 on a black Malmo silt loam soil to evaluate the effects of planting date and nitrogen fertility level on borage seed yield, harvest index, and seed oil GLA content. Plots from all possible combinations of two planting dates (early vs late) and four nitrogen fertility rates (0, 20, 40, and 80 kg N/ha) were established and arranged in a factorial randomized complete block design. Plots were harvested twice during each growing season. In general, early planting resulted in significantly higher seed yield, and harvest index. Nitrogen fertility level had no significant effect on seed yield; while increasing nitrogen fertility rate tended to decrease the harvest index. The no-response to nitrogen could be the result of a high initial soil nitrogen content. Results indicate that, under the conditions of the experiment, early seeding is recommended. Although 20 to 40 kg N/ha proved to produce higher yields, further studies are needed to clarify the effect of nitrogen fertilization on the performance of borage crop before any recommendation is to be made.