- Author: Lynn M. Sosnoskie
A drive around parts of the San Joaquin Valley revealed some fields with Palmer amaranth (Amaranthus palmeri) rising above the crop canopy (See image below).
A male Palmer amaranth in a corn field in Merced County
Palmer amaranth is a tall (growing up to 10 feet in height), dioecious (male and female flowers develop on separate plants), summer annual that grows rapidly and produces significant amounts of seed (upwards of 400,000-1,000,000 per female plant). The species is extremely competitive with many crops, including corn and cotton. In the United States, Palmer...