Competition Between Kochia and Sugarbeets

In a 2-year study, kochia [ Kochia scoparia (L.) Schrad.] competed with sugarbeets ( Beta vulgaris L.) for various periods after emergence. Kochia then was removed and plants that emerged subsequently were controlled by hand-weeding. Yield of sugarbeet roots was reduced when kochia competed for more than 5 or 6 weeks. Kochia that competed with sugarbeets for the entire season reduced yields more than 95%. In another study, kochia was controlled by frequent hand-weeding for different periods after sugarbeet emergence. When kochia was controlled initially for 3 to 4 weeks, yield of sugarbeets was not reduced. Some kochia emerged following the 3 to 4 weeks of hand-weeding. However, competition from sugarbeets reduced the weight of this kochia at harvest by 59 and 92%.