Seeding date and nitrogen fertilization effects on the performance of borage (Borago officinalis L.)
2002
El Hafid, R. | Blade, S.F. | Hoyano, Y.
Recently, borage (Borago officinalis L.) 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 seed. GLA is an omega-6 essential fatty acid which has been identified as having several beneficial therapeutic effects such as treatment of atopic eczema, diabetes, cyclic mastalgia, heart disease, arthritis, and multiple sclerosis. Increased interest in production of the crop in western Canada brought about a need for suitable agronomic management practices because very little research information is available for this area. 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 total above-ground biomass (TDW), grain yield, harvest index, and seed oil GLA content. All possible combinations of two planting dates (early vs. late) and four nitrogen fertility rates (0, 20, 40, and 80 kg N ha-1) were established. The plots were arranged in a randomized complete block design. Plots were harvested twice during each growing season. In general, early planting resulted in significantly higher TDW, grain yield, and harvest index. Nitrogen fertility level had no significant effect on TDW and grain yield, whereas increasing nitrogen fertility rate tended to decrease the harvest index in 1999. The lack of response to nitrogen could be caused by a high initial soil nitrogen content. Under the conditions of the experiment, early seeding is recommended. Further studies are needed to clarify the effect of nitrogen fertilization on the performance of borage crop before any recommendation can be made.
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