WEED THRESHOLD INFORMATION FOR CORN

% Yield Reduction
WEEDS 1 2 4 6 8 10
(Number of weeds/100 ft of row)
C. Cocklebur or G. Ragweed 4 8 16 28 34 40
Redroot Pigweed or C. 12 25 50 100 125 150
Shattercane (2-3/clump) 6 12 25 50 75 100
Giant Foxtail (5-8/clump) 10 20 50 100 150 200

Source: Univ. of Illinois Field Crop Scouting Manual

NOTE: All effects are additive. If more than one weed exists, add the effects of each yield reduction to get total yield reduction.

ligule, leaf blade and leaf sheath


Table of Contents | Top

Corn, Soybean, Wheat, and Alfalfa Field GuideBulletin 827