IF YOU WAIT TO CONTROL WEEDS IN SOYBEANS, YOU CAN LOSE BIG
Early-season weed interference in soybeans can cost you both yield and revenue. Research by Dr. Peter Sikkema at the University of Guelph’s Ridgetown Campus shows just how significant those losses can be and why timing weed control right from the start is so important.
Make the first pass your best pass with Authority® Supreme herbicide
Dr. Sikkema’s research demonstrates that the weed control strategy with the highest return in soybeans is a two-pass program that starts with a broad-spectrum soil-applied herbicide.
Authority® Supreme herbicide brings a powerful Group 14 + 15 combination for outstanding early-season control of both broadleaf and grassy weeds, including tough, resistant species in both herbicide-tolerant and Identity-Preserved (IP) soybeans. It delivers the extended residual activity needed to keep fields clean through the critical weed-free period, setting you up for stronger yields and a greater ROI.
1 107 fields in Southwestern Ontario were included in the trials and the average yield loss due to weed interference with no weed control was 35%. With some fields having extremely low weed pressure and showing 0% yield loss and other fields with very high weed pressure, causing 88% yield loss. 2 Seven experiments conducted from 2017 to 2019 showed a 3.3 bushel/acre yield loss from relying on a total post-emergence weed control program. This resulted in a $45 per acre loss based on soybean prices during that same time period. 3 In 107 trials conducted from 2007-2021 there was an average of 35% yield loss due to weed interference. The 2025 average projected soybean price in Ontario was $13.97 per bushel for a gross value of $688 per acre. Based on a 35% yield loss due to weed interference, that adds up to 17.3 bushels per acre or $242 per acre. Using an effective two-pass weed control program of a soil-applied herbicide followed by a post-emergence herbicide would cost $61 based on 2025 average input costs, which results in a 397% return on investment.
