Palmer amaranth is the fast-growing weed more commonly known as pigweed and it is invading Texas cotton fields. If cotton growers don’t control it, yield loss could be as much as 40 percent.

Pigweed, which can grow as tall as 10 feet and overtake crops, is spreading aggressively in the High Plains this year after becoming resistant to the herbicide that once easily eradicated it, according to the Associated Press.

Eradication gets harder if the pigweed goes to seed. A female plant can have as many as 600,000 seeds that are carried by water. The above-average rainfall received in the High Plains since May has helped pigweed spread to other fields.

Different herbicides throughout the growing season may be the key to combat the weed.