By Jim Fawcett, ISU Extension field agronomist
I never thought I'd live to see a storm that rivals the 1998 storm that had 100 mph winds in a 20-mile swath over 100 miles long, but the storm Monday morning, July 11 apparently had straight line winds of up to 120 mph in a swath of 20 miles or so wide and traveled from south of Ames up through Tama, Benton, Linn and Jones counties and into Dubuque County. There is likely over 100,000 acres of corn that is flattened, in addition to thousands of trees snapped off, grain bins blown over and farm buildings destroyed.
The good news is it looks like the vast majority of the corn is flat because of root lodging and not green snap. I've looked at fields from Martelle in Jones County over through Vinton to Toledo, and every flattened field I looked at had very little green snap. With the 1998 storm there was a tremendous amount of green snap, which resulted in large yield losses. The 1998 storm occurred on June 29, so much more of the corn was in the more vulnerable V10-V12 stage when stalks are more brittle. Most of the corn is in the V14-V18 stage now, so less subject to green snap. The heavy downpours that occurred at the same time may have also helped by saturating the topsoil and allowing roots to shift rather than breaking stalks.
Crop Storm Meeting
There will be a crop storm damage meeting Thursday, July 14 at 3 p.m. at the John Olson farm site, 2.5 miles south of Vinton at the intersection of Highway 218 and 63rd Street, northwest corner. There will be signs. The meeting will cover what to expect from recent storm damage to crops, management decisions, livestock feed options and Farm Service Agency programs. Speakers at the meeting will be Jim Fawcett, ISU Extension field agronomist, Jim Jensen, ISU Extension management specialist, Denise Schwab, ISU beef program specialist and Pat Derdzinski, Benton County Farm Service Agency director.
There is also a lot of seed corn affected in the storm damage area. In general, the lodging is not as extensive in the seed fields, because the corn is shorter, but unfortunately there are many seed fields where the lodging is great enough so that it is difficult to impossible to walk through the fields. This means they cannot be detasseled, so they are a total loss. Many seed fields may be disked up.
The main thing to do at this point is check with your insurance to see if wind damage is covered. Many policies do not cover wind, or if they do it is only covered if there is green snap.
Jim Fawcett is an Iowa State University Extension field agronomist serving eastern Iowa. He can be reached at 319-337-2145 or by emailing firstname.lastname@example.org.