Size Matters with Yield Loss from Weeds

Yield losses from competing weeds is a matter of timing and size. Weeds that emerge with the crop are most competitive because the weeds tend to grow faster than the crop they are planted in. This is very true for Giant Ragweed. Picture 1 shows a 8 inch weed in a soybean field. Picture 2 shows a 15 inch weed in the same soybean field. The 8 inch weed has already reduced yield by 5-6% and the 15 inch has reduced yield by 10% plus even when they are removed at this stage based on research from across the midwest. Put a priority on weed control in these fields over the next few days.