Table 2.1-7.

Table 2.1-7. Yield reduction from various weed species in corn and soybeans.
  Percent corn yield reduction¹   Percent soybean yield reduction¹
1 2 4 6 8 10 1 2 4 6 8 10
Weeds per 100 feet of row Weeds per 100 feet of row
¹Interference data are from Stoller et al., 1985, Reviews of Weed Science; E. L. Knake and F. W. Slife, 1962, Weeds 10:26; and E. L. Werner and W. S. Curran, 1995, Proc. NEWSS 49:23.
² Dash (—) signifies that no data were available.
Cocklebur 4 8 16 28 34 40   1 2 4 6 8 10
Pigweed or lambsquarters 12 25 50 100 125 150 2 4 6 10 15 20
Shattercane (5–8/clump) 6 12 25 50 75 100 2 5 8 11 14 17
Giant foxtail 15 30 60 85 175 400 15 25 80 300 400 600
Velvetleaf 10 15 20 30 40 50 1 3 6 10 13 16
Smartweed —² — — — — — 2 4 6 10 15 20
Yellow nutsedge 400 800 — — — — — — — — — —
Volunteer corn — — — — — — 1 2 3 4 5 6