Iowa's corn crop has tasseled, but it isn't as far along in development as it is in an average year. That's what the weekly Iowa Crops & Weather report issued by USDA on August 19 indicates. Based on statewide surveys as of August 18, the report shows less than half of Iowa's corn and soybean crop is in good-to-excellent condition.
Rain fell in some areas of Iowa during the week ending August 18, but many areas remain quite dry. And corn in those driest parts of the state, especially on fields with lighter soils, is starting to show some firing. Cooler than normal weather the past four weeks has helped Iowa corn and soybean crops withstand dryness and lack of rain--but the weather forecast for this week and next week is for "hot and dry."
"What happens with the weather this week and next week is going to be very important," says Roger Elmore, Iowa State University Extension corn agronomist. "The kernels on the ears are filling now, and kernel weights could end up being reduced if the plants don't have adequate moisture." Corn in Iowa came through pollination pretty good, although the late planted corn is just now pollinating. But kernel fill during these last two weeks of August and in early September will make a difference in yield.
A key consideration is Iowa's corn crop this year isn't as deep-rooted as corn was last year
The state pulled out of a drought earlier this year and farmers had to fight flooding and delayed planting in the spring. Then things got dry again, and also cooler than normal, during July and August. Some analysts are expecting better yields in 2013 than last year's drought-reduced crop produced, but it's still unclear how much better. And depending on weather during the next two weeks—August 19 to September 2 or so—yield potential may end up getting hurt if most of Iowa continues hot and dry.