Farm News, IA
08-31-07
Iowa crops remain under water
By Kristin Danley-Greiner, Farm News staff writer
Pockets of significant flooding has occurred across parts of the state in years
past, but no one has seen flooding as widespread as last week’s ordeal since the
“Floods of 1993.”î While the flooding has gone down in Iowa’s history books, it
has had a seasonal influence on many crop fields, too.
Harry Hillaker, state climatologist with the Iowa Department of Agriculture and
Land Stewardship (IDALS), said that 1993 was indeed the last “big flood yearî for
major flooding across the state.”
“There has been localized flooding almost every year in late summer, but
certainly in August, there has been much more widespread rainfall than we
typically see,”î he said. “We set a new monthly record for rainfall.”î
As of last Friday, the state had received an average of 8.62 inches of rain in
August, with the last record set in August 1993 at 8.24 inches. That record was
buoyed by some rainfall accrued in a mere 12- to 24-hour period, with places
such as Lake Rathbun in southern Iowa seeing more than 12 inches fall in the
overnight from one massive storm.
“This has been more of a somewhat isolated situation this year compared to
1993 when it was very saturated before that summer ever got started,Ӕ Hillaker
said. “But with the heat wave going across the U.S., we’ve been on the very
northern edge of that area and very hot weather amounts to a frontal boundary
where temperatures change fairly rapidly and different air masses have been
right across Iowa or close to us, which is a preferred area for thunderstorms to
develop.”
Hillaker noted that the weather pattern that ended up deluging the state with rain
had started out in Minnesota and central Wisconsin before gradually moving
southward through Iowa.
“Then it ended up being nearly stationary over the state,î” he said. “You tend to
get plenty of lightening and heavy rain with the thunderstorms in August.î”
Unfortunately, all that heavy rain flooded basements, communities and crop
fields. Iowa Gov. Chet Culver had requested some of the counties be declared
federal disaster areas and many crop fields are too far gone. It’s too late in the
growing game to replant and those crops that weren’t flooded out may still face
problems. Dr. David Wright with the Iowa Soybean Association said that all of the
rainfall experienced definitely would reduce yields.
“Soybean plants are now struggling to fill seed at the top of the plant,î” he said. “It
is quite likely that some pods at the top of the plant will abort entirely. This is a
problem for soybean producers, because the heat from previous weeks aborted
pods in the middle of the plant. Adequate moisture during this stage would
normally add some yield by increasing seed size. However, excess moisture, like
farmers have experienced, will reduce yield.î
Soybean disease has been an issue even before the storms rolled through,
particularly sudden death syndrome, which can be found throughout the
stateóeven in fields where it has never been seen before, Wright said.
’’White mold is also very prevalent in eastern Iowa. Both of these diseases will
continue to be a problem this year with no remediation possible for this year,î
Wright said.
Mindy Williamson with the Iowa Corn Growers Association said that the
association had heard of pockets of damage from growers.
’’We have growers where their corn looks great, but just one field over doesn’t,î
she said. ’’Depending on where you are, from those that I have talked to, they
would much rather see the rain now than in a month or two when we are trying to
harvest.î
Joel DeJong, a crops field specialist with Iowa State University Extension
based out of northern Iowa, said that are some areas that have received
’’extremely high amounts of rain, leaving water standing and saturated surface
soils.î
’’But, much of northwestern Iowa had drained all the subsoil moisture this year,
so this recharge is neededówe just wish it didn’t come all at once,î he said.
’’Cherokee had some basement flooding due to a heavy rapid rain that was
compounded by electricity that went off, so sump pumps were not working,
compounding the problem. There has been some areas receiving damage from
hail, and some corn acres have gone down due to wind. I think the heavy rains
have also caused some soybean fields to lodge, too.î
Palle Pedersen, soybean Extension agronomist at ISU, said that plants in
standing water wouldn’t survive longómaybe 72 hours at the most. If they make
it, they may have to deal with phomopsis and rotten beans.
’’This will have a huge impact if the soybean crop is standing in water,î Pedersen
said. ’’Many fields are still in R5, so a lot of yield hasn’t been made.î
Roger Elmore, corn specialist with ISU Extension, said that corn should see
little impact from the floods if the plants were in short-term, shallow waters.
’’If the plants are standing in water long, expect increases in root and stalk
diseases resulting in lodging later on,î he said. ’’If ears are below the surface for
long, expect ear rots, kernel rots, etc., and ruined grain. Harvest will be delayed
and painstaking if flooded fields are deemed to be worth harvesting. If the plants
are killed by this, and a long period of flooding could do this, expect 20 to 30
percent yield reductions—assuming no lodging or anything else occurs.î
Mick Lane with the ISA said that wet soils in many of the fields, combined with
heat and high humidity, could result in spread of some of the diseases now being
reported in the fields.
’’These include downy mildew, frog eye leaf spot, Fusarium wilt, sudden death
syndrome (SDS) and bacterial blight. In addition to these diseases, conditions in
recent days have been conducive to development of white mold (Sclerotinia),î he
said.
Keith Sexton, a producer from Rockwell City, reported clear fields in his area last
weekend with a rainfall total of 10 inches as of last Friday.
’’The crops on my farm are still looking fine. There’s some ponding in other fields,
particularly those by creeks and streams,î he said. ’’I’ve never seen anything like
this in August. Some of the plant roots are standing in mush, which means the
plants won’t stand up in sustained winds. When it comes time to harvest, there’ll
be wet spots out there that farmers can’t see and they’ll get stuck. My
grandfather used to ‘Never turn down rain in July and August,’ but I think some
farmers would right now.î
Kristin Danley Greiner can be reached at ksdg13@msn.com