Stress, Anthesis—Silk Interval and Corn Yield Potential

Forecast daily high temperatures every day this week hover just below 100 degrees. Across Iowa corn ranges from the 10th leaf stage (V10) to tasseling and silking (VT and R1). As of July 1st, the USDA reports that 16 percent of Iowa’s corn was silking; that\u27s nearly 2 weeks ahead of normal. Unfortunately, dry surface and subsoil moisture conditions prevail (see June 26, 2012, Drought Monitor). In the USDA report linked above, 73 percent of Iowa\u27s subsoil moisture was reported as either short or very short compared to 2 percent last year. Crop water use ranged between 0.2 and 0.4 inches per day in central Iowa the last few days (see Soil Moisture Conditions and Crop Water Use, ICM News, for more information on this). With the majority of Iowa’s corn pollinating in the next week to 10 days, this combination of events does not lead to optimism among Iowa’s corn agronomists