North Dakota State University
NDSU Extension Service

Survey of Weeds in North Dakota - 2000

ER-83, May 2003
R. K. Zollinger, NDSU Extension Weed Specialist

^a Acres infested was obtained by multiplying weed frequency by crop acres which was 9.8 million (m) for HRS wheat and 2.5 m for barley in 1978 and 9.9 m for HRS wheat and 1.7 m for barley.

^b Percent yield loss caused by weed competition was based on weed density and competition data from the literature as follows: green and yellow foxtail (assumed similar), wild oat, wild mustard, and wild buckwheat (Nalewaja 1972), field bindweed (Gigax 1978), and Canada thistle (Hodgson 1968). Total % yield loss is based on all acres.

^c Grain loss based on average North Dakota production of 29.8 bu/A for HRS wheat and 46 bu/A for barley in 1978 and 26.3 bu/A for HRS wheat and 46 bu/A for barley in 1979. Losses from weed competition in barley were only available for wild oat where loss in barley was about 25% less than in HRS wheat for wild oat plants (Bell and Nalewaja 1968). The losses in barley from all weeds were assumed at 25% less than in HRS wheat.

^a Acres infested was obtained by multiplying weed frequency by crop acres which was 6.4 million for HRS wheat, 2.9 m for durum wheat, 1.8 m for barley, and 1.25 m for canola in 2000 (NDAS 2002).

^b Percent yield loss caused by weed competition was based on weed density and competition data from the literature:

HRS wheat, durum wheat and barley: green and yellow foxtail (assumed similar), wild oat, wild mustard, and wild buckwheat (Nalewaja 1972), kochia (Dahl 1984), Canada thistle and perennial sowthistle (perennial sowthistle assumed 50% less than Canada thistle) (Donald 1990, Hodgson 1968), field bindweed (Gigax 1978), common milkweed (Yenish et al. 1997), and common sunflower, common ragweed, common cocklebur (assumed similar) (Gillespie 1982).

Canola: wild oat, Canada thistle, quackgrass, perennial sowthistle, and volunteer cereal (Canola Grower Manual). Total % yield loss is based on all acres.

^c Grain loss based on average North Dakota production of 36.5 bu/A for HRS wheat, 27 bu/A for durum wheat, 55 bu/A for barley, and 1,320 lbs/A for canola in 2000 (NDAS 2002). Losses from weed competition in barley were only available for wild oat where loss in barley was about 25% less than in HRS wheat for wild oat plants (Bell and Nalewaja 1968). The losses in barley from all weeds were assumed at 25% less than in HRS wheat.
 

Table 132 (continued).

^a Acres infested was obtained by multiplying weed frequency by crop acres which was 1.85 million for soybean, 0.525 m for dry beans, and 1.27 m for sunflower in 2000 (NDAS 2002).

^b Percent yield loss caused by weed competition was based on weed density and competition data from the literature:

Soybean and dry beans (assume equal yield reduction even though dry beans are less competitive than soybean and would result in a greater % yield loss): green and yellow foxtail (assume similar), wild oat, volunteer cereal (assume similar), pigweed, common ragweed (assume similar), wild mustard, volunteer canola (assume similar), common cocklebur (Stoller et al. 1987), common lambsquarters (Crook and Renner 1990), biennial wormwood (Nelson 1992), sunflower (Auwater 1978), nightshade (Blackshaw 1991), quackgrass (Young et al. 1982).

Sunflower: green and yellow foxtail (assume similar), wild oat, volunteer cereals (assume similar), wild mustard, volunteer canola (assume similar), kochia (Blamey et al. 1997). Total % yield loss is based on all acres.

^c Grain loss based on average North Dakota production of 34 bu/A for soybean, 1,450 lbs/A for dry beans, and 1,374 lbs/A for sunflower in 2000 (NDAS 2002).

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EB-83, May 2003

NDSU Extension Service, North Dakota State University of Agriculture and Applied Science, and U.S. Department of Agriculture cooperating. Sharon D. Anderson, Director, Fargo, North Dakota. Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. We offer our programs and facilities to all persons regardless of race, color, national origin, religion, sex, disability, age, Vietnam era veterans status, or sexual orientation; and are an equal opportunity employer. This publication will be made available in alternative format upon request to people with disabilities (701) 231-7881. North Dakota State University NDSU Extension Service