Issue No. 9, Article 12/May 25, 2007
Can You Identify This Problem?
In a field south of Pleasant Plains where we were making stand counts on May 18, we found an unusual symptom in some plants. Most of the plants in question were individual ones, with normal plants on both sides, but some were in small groupsof two or three plants in the row, and some plants seemed to show less severe symptoms of the same problem. In a line of four particular plants, the first one seemed to show an intermediate amount of the symptom--its leaves were not as narrow as the two plants following it, but they were narrower than those of the fourth, and normal, plant.
"Mystery disorder" observed in a field in Sangamon County on May 18. The plant on the right is normal.
The lower two or three leaves seem normal in size on affected plants. The leaves above this are not curled up, but they have very little area; the leaf blades are barely wider than the midrib. They seem to be emerging from the whorl at about the normal rate. We did see some typical stinkbug damage on other plants in this study, with stunting and ragged holes from a stinkbug "sting" that had occurred perhaps two weeks earlier. The study was planted on April 18, and plants are at V5-V6. There are four different hybrids in this trial; we did not determine if symptoms like this occurred in only one hybrid, but we do not think so. We have the same study at Urbana and have not seen this problem at that location.
What is affecting these plants? Will they grow out of it, or will they yield nothing?--Emerson Nafziger