Palmer amaranth

Palmer amaranth may be the most aggressive pigweed species with respect to growth rate and competitive ability. Palmer amaranth or Palmer pigweed in particular is highly competitive. It will outgrow cotton and is much more efficient. Growers of crops have not been able to provide adequate moisture to offset temperatures staying above 85 F with 112 F heat indices. In these conditions, many herbicides break down over time and Palmer pigweed will keep thrusting. It can grow from 2-5 inches in three days or less. In only a few weeks, it can grow from 12 to 18 in compared to cotton at 5 to 8 in.