The record low temperatures last Monday, May 2, have caused significant damage to corn plants and early-planted soybeans in Iowa. It also affected a few of the sentinel plots in which plants emerged early. Plants in seven plots emerged before the freeze, and we were able to protect some by covering them with plastic sheets. Our collaborators at the West Central Coop at Jefferson protected their sentinel plot with hay. However, two plots were frozen and were immediately replanted last week.
To prepare for frost, farm managers in some locations had planted a second plot a bit later to provide a backup. Soybeans emerged last week after the freeze at many of our locations. All plots will look much better after a week of warm weather.
We have a change in plot location to announce. The plot listed for Carroll County was actually planted in Greene County near Jefferson. We are still set to have the earliest flowering soybeans in the state, and the plots should function as planned in monitoring disease movement if soybean rust reaches Iowa this growing season.
Covering sentinel plots at Iowa State University Curtiss Research Farm (S. S. Navi).
This article originally appeared on page 73 of the IC-494 (9) -- May 9, 2005 issue.