date:Apr 12, 2013
indicates that leaves have been damaged. Damaged leaves will likely turn black within a few days, then become bleached. If the flag leaf is killed, that tiller wont produce much, if any, grain. Damage to lower leaves will not have such a drastic effect. Even if the flag leaf on the most advanced tillers is lost, less developed tillers can still come on and produce grain at this point in the season.
Ice in the stems. If there was ice in the stems below the first node the morning of the freeze,