Influence of seeding date and seeding rate on cow cockle, a new medicinal and industrial crop

There has been keen interest in the development of cow cockle (Vaccaria hispanica (Mill.) Rauschert) as a medicinal and industrial crop in North America. However, very limited agronomic information exists regarding the cultivation of cow cockle as a crop. The objective of this study was to determine how seeding date and rate affected stand establishment, seed yield, and seed weight of cow cockle at various sites across western Canada. Field experiments were conducted at three locations across western Canada from 2006 to 2010 to evaluate the effects of seeding date (early May, mid May, early June, mid June) and seeding rate (50, 100, 200, 400, 800, and 1600 seeds m(-2)) on cow cockle stand establishment, seed yield, and thousand seed weight (TSW). Delayed seeding had an inconsistent effect on plant stand establishment, but resulted in significant declines in seed yield and TSW in nearly all site-years. Plant stand establishment increased linearly with increasing seeding rate. A significant curvilinear increase in seed yield occurred with increasing seeding rate, while TSW declined significantly at increased seeding rates. The results of this study clearly show that seeding at an optimum rate of 400 seeds m(-2) as early as practical in the growing season will maximize seed yield and TSW in cow cockle crops. (C) 2013 Elsevier B.V. All rights reserved.