The first full week of May was pretty "normal" across Iowa, compared with long-term averages. Sporadic thunderstorms and fluctuating temperatures were the norm. Cornfields that were planted in early April are emerging, with the largest corn in Iowa about V1 stage.
Freezing temperatures in some areas have taken a toll on aboveground corn tissue, and occasionally, the frost was severe enough to kill underground plant parts. If growing points have been killed, or if unemerged coleoptiles are damaged so that the corn cannot emerge, stand losses may warrant replanting of fields or parts of fields. Elwynn Taylor and Mahdi Al-Kaisi have an article on page 77 that addresses the current frost damage situation.
This article originally appeared on page 80 of the IC-494 (9) -- May 9, 2005 issue.