05-21-2009 Sorghum halepense
Johnsongrass was introduced to the United States in the early 1800’s as a potential forage crop, or hay. Seeds were introduced from Turkey in the 1830’s, and planted in a southern river bottom plantation by a man named Johnson – the plant flourished and spread across the south.
By the late 1800’s it was widely planted in the United States. The United State Department of Agriculture started an organized control program for Johnsongrass in 1900. Johnsongrass is now considered a serious weed pest in all annual agricultural crops, orchards, vineyards, ditches, roadsides, and fence rows. Lands infested with Johnsongrass can produce seven tons of rhizomes per acre, and ten bushels of seed per acre. Under conditions of stress, Johnsongrass produces hydrocyanic acid, which is toxic to grazing livestock. It is mentioned as one of the top ten worst weeds in the world.