–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Whorl stage feeding
Much of the sorghum in north central and south central Kansas will soon be, or is already at, the whorl stage. That usually causes much concern if there are larvae feeding in the whorls, resulting in many “ragged” looking plants (see pic). However, please remember that these worms cause highly visible defoliation but that does not translate into later problems with plant growth and development, or yield. The larvae sampled this week in pre-whorl stage sorghum are mostly corn earworms (80%) with a few fall armyworms (20%) and were about half grown, so this feeding will continue for another 5-10 days. This is of interest because the adult corn earworm moths, when they begin ovipositing in approximately 2-3 weeks, will probably do so in soybeans where pod feeding by the larvae can have a direct effect on yield.
