Corn is starting to tassel in portions of the Northern Plains, which means pollination is beginning. That is the most critical time period in corn for yield potential. University of Minnesota Extension corn agronomist Jeff Coulter says the pollination process is quick, lasting about ten days. “The two weeks before the tassels emerge and the two weeks after are most important. At that time, kernel set is being determined.” Coulter says the warmer temperatures are unlikely to have a negative effect on corn fields. The likelihood of heat stress starts to increase when the temperature exceeds 86 degrees with dry soil or 92 degrees with adequate soil moisture. Listen to the interview.