Weather raises concerns about septoria, freeze damage, timing of corn planting
According to Jill Scheidt, agronomy specialist with University of Missouri Extension in Barton County, septoria has been found on wheat in southwest Missouri.
Septoria begins as light yellow flecks or streaks; expanding into yellow to reddish-brown, irregularly shaped blotches. Dark brown specks may be scattered within the centers of mature lesions.
“Yield losses are seen when the flag leaf is present and a fungicide may be economical when the wheat is in or past the flag leaf stage,” Scheidt said. “Most wheat is jointing now.”
With temperatures possibly dropping below 32 degrees Fahrenheit, there is concern for damage of the wheat head.
According to Bill Wiebold, MU state specialist, wheat is the most sensitive to freezing temperatures when the heads are coming out and flowers are beginning to form.
“To check for freeze damage, wait three days after the low temperature occurs, cut the stem open and locate the forming wheat head. It is normally white or a pale green or yellow color,” Scheidt said. “If the head inside the stem has turned a brown color, freeze damage is likely to have occurred.”
According to MU State Specialist Peter Scharf, the recent rains may have taken nitrogen deeper into the soil profile, so any farmer planning to take credit for last year’s leftover nitrogen should proceed with caution. Fields may need normal amounts of nitrogen as opposed to lower than normal amounts of nitrogen.
According to Wiebold and Brent Myers, MU state specialists, producers should not be overly worried about planting corn in late April. Significant yield losses in corn are not seen until planting after the first of June.
“Potential yield losses occur slowly in corn planted during May and potential yield losses increase in corn planted in June due to non-ideal weather conditions occurring in July and August,” Scheidt said.
Myers and Wiebold say data indicates switching out of corn may not be wise even if planting is delayed until the end of May.