SEED YIELDS OF CANOLA AND VOLUNTEER BARLEY AS INFLUENCED BY THEIR RELATIVE TIMES OF EMERGENCE

A model based on the rectangular hyperbola was used to describe the effects of population density and relative time of emergence of volunteer barley (Hordeum vulgare L. 'Klondike') on seed yield of both canola (Brassica campestris L. 'Tobin') and volunteer barley. At a given density of volunteer barley, canola seed yield decreased, while volunteer barley seed yield increased, the earlier the volunteer barley emerged relative to the canola. The results suggest that it is more critical to control early emerging volunteer barley plants (and possibly other weeds) since they have a greater effect on canola yield and can contribute significantly more seed to the soil than later emerging plants.