Shattercane,Sorghum Bicolor(L.) Moench Ssp.Drummondii(Nees ex Steud.) De Wet ex Davidse—Black Sheep of the Family

Abstract

Look at a field of almost any grain and the top of the crop will be almost as tabletop flat as the ground below. Modern genetics produce almost perfectly uniform crop varieties and hybrids with identical, “cookie-cutter” individual plants. But one crop stubbornly refuses to cooperate with breeders. Look at a field of mature hybrid grain sorghum [Sorghum bicolor(L.) Moench ssp.bicolor] and you will see rugged individualists sticking up above the fruited plain of sameness like grain elevators towering over a small Midwestern town. These “off type” sorghum plants can be mutants, or the result of the random outcrossing of parent plants in seed production fields from the pollen of volunteer plants from a previous year's crop, nearby grain, or forage sorghums. They may also come from crosses with weedy types growing nearby such as johnsongrass [Sorghum halepense(L.) Pers.] or the dreaded shattercane [Sorghum bicolor(L.) Moench ssp.drummondii(Nees ex Steud.) de Wet ex Davidse] (Clark and Rosenow 1992). Just what is shattercane? Where did this “black sheep” of theSorghumclan come from? And why is it such a widespread weed today?