Early Root and Shoot Competition between Spring Cereal Cultivars and Wild Mustard (Brassica kaber)

The use of more competitive species and cultivars in small grain cereal production may help to develop production systems that require less herbicide. this study was designed to identify root and shoot characteristics of cereal seedlings that would allow distinguishing the more competitive (me) cultivars from the less competitive (lc) ones. two growth cabinet trials were conducted using four crops: two-row barley, six-row barley, oat, and wheat. a total of twelve cultivars (six classified a priori as me and six classified a priori as lc) were grown with and without wild mustard. the inhibitory effects of the mecultivars on wild mustard growth were not systematically larger than those ofthe lc cultivars at 3 weeks after emergence. oat was found to be more competitive than two-row and six-row barley. wild mustard adversely affected the above-ground growth of two-row barley and oat but had no effect on below-ground growth; shoot competition may precede root competition. for two-row barley, oat, and wheat competing with wild mustardgrowth of mc cultivars was superior to that of lc cultivars. only mc oat and wheat cultivars produced more above-and below-ground growth than lc cultivars while exerting a greater competitive effect on wild mustard growth.. these results suggest that it may be possible to select oat and wheat cultivars for greater competitive ability against wild mustard based on root and shoot characteristics.