From WILL - Ag Notes -

Palmer Amaranth Untreatable 10 Days after Emergence

University of Illinois Weed Scientist Aaron Hager is urging farmers to diligently control a new weed species in the state. Palmer amaranth plants reached a 4-inch height less than 10 days after emergence. Palmer is very hard to control after it is taller than four inches. You can read more from Aaron Hager on the weed in The Bulletin.

photo comparing the growth rate of waterhemp vs palmer amaranth
This greenhouse demonstration compares the growth rate of  palmer amaranth compared to waterhemp at 4 days post emergence and 16 days. Palmer becomes nearly untreatable after reaching a height of 4 inches, usually less than 10 days after emergence.
Categories: Agriculture