It should come as no surprise that the week of July 23 was a hot one in all of Iowa. We effectively gained an extra day and a half of heat compared with long-term averages in all parts of Iowa. Mind you that as corn and soybean are in the fill stage, degree days themselves aren't as important as they were in the leadup to pollination. Now we look at stresses on plants, and we do have variable moisture and accompanying heat stress in many parts of Iowa. Continued moisture stress, coupled with excessive heat (over the low to mid-90s), can now cause the abortion of some seeds that have set and also may reduce the accumulation of dry matter in seeds, causing reduced test weight. As long as moisture is adequate, the plants can do fairly well, but extended stress adds to losses. Of course, barring the availability of irrigation equipment, there is little now that a producer can do except wait for welcome rains and a bit cooler weather.
May 1 through July 30, 2006 Accumulated Base: 50 Ã‚Â°F Degree Days
This article originally appeared on page 220 of the IC-496(22) -- July 31, 2006 issue.