DES MOINES, Iowa (AP) — For drivers in Midwestern farm country, the growing season brings a special danger on the roads: tall corn that can obscure other vehicles until it’s too late. The plant’s broad leaves and thick stalks can stand up to 12 feet high, forming a wall of foliage that turns rural roads into long, narrow corridors of green, yellow and brown. Many intersections have no stop signs.

The peril is especially pervasive in Iowa, the nation’s top corn producer, where crops cover more than 90 percent of the land. At least five people have been killed so far this season in crashes blamed on corn.

Authorities issue warnings, but they can do little more than plead with drivers to use caution. The problem is also widespread across Illinois, Nebraska, Minnesota and Indiana.