Wheat Crop Developing Nicely

April 16, 1999
After a rather uneventful fall and winter, the Illinois wheat crop is developing normally during relatively good weather in most parts of the state this spring. Reports from the southern extremity of the state indicate that the wheat crop is in the Feekes growth stage 7 or 8; stage 8 is the emergence of the tip of the flag leaf, and it usually occurs when plants are about 15 inches tall or so, though this varies somewhat with temperature and moisture. Growth stage 9 is when the flag (uppermost) leaf is fully emerged from the leaf sheath below it; this is the point at which you should be able to feel the head pushing up into the flag leaf sheath from below. It is important to watch the flag leaf and the leaf below it for signs of disease and insect damage. These two leaves provide the majority of the sugars that fill the grain after flowering, and thus their health is often directly related to yield potential.

At this point, though temperatures have cooled from earlier in April, the wheat crop is on track to head at or slightly earlier than the normal time. Normally, wheat heads about the end of April in the southern extremity of the state, and then progresses steadily northward, with heading about May 12 or so at Urbana and at the end of May or the first days of June at the northern border. Weather conditions at flowering, which takes place several days after heads emerge, are critical in determining yield prospects. Wet weather at flowering, especially if temperatures are warm, usually means the development of head and leaf diseases that represent a real threat to the crop.--Emerson D. Nafziger

Author: Emerson Nafziger