Minnesota Crop News > 2001-2008 Archives
August 4, 2004
Corn Lodging – What Can We Expect?
Dale R. Hicks, Department of Agronomy and Plant Genetics, University of Minnesota
The extreme winds that occurred in southern Minnesota
on August 3rd caused corn to lodge badly. Lodged plants
will likely yield lower and make harvesting more difficult.
Will the corn straighten up?
Some stalk straightening will occur, but plants will not
completely stand erect. Most of the straightening will
occur within the next 2 to 4 days. After that, the plants
will not grow upright anymore. Most of the straightening
will occur near or above the ear position. The plant will
be goose necked. And, ears on goose necked plants will
be closer to the ground and higher-than-normal harvest
losses may occur. Slower harvest speeds will help to reduce
the harvest losses. Lodged plants (and usually in a twisted
mass) also increase combine operator fatigue during harvest.
Effect on Pollination
While most of the corn in the affected area is pollinated,
some may not be, especially in low areas that have been
wet and slow to shoot tassels. The amount of pollen is
not likely to be a limiting factor, but some silks may
not catch pollen because they are physically hidden below
other silks when the plant and ear are leaning over. This
may not reduce the number of kernels per ear substantially,
but lower kernel number per ear will reduce the yield potential.
The missing kernels will be on the lower side of the ear,
facing the ground.
Effect on Yield
Grain yields will be affected because of poor sunlight
interception. When plants are leaning, leaves are 'stacked'
on top of each other. The top layer of leaves gets good
sunlight, but the leaves farther down are shaded and are
less efficient in photosynthesis. With normally standing
plants, more of the leaves intercept sunlight, or the solar
energy penetrates to a lower level in the corn canopy and
is captured by more leaves.
Often in field situations, wind lodging results in different
degrees of plant leaning. When some of the plants are standing
or lodged to a lesser degree than other plants, the leaf
canopy is more ‘rough’ and light can penetrate
to lower levels in the canopy. Some plants that are standing
more erect will have more of their leaves at light saturation
levels, and will increase yields because there is more
solar energy to fill grain on those plants. This minimizes
the effect on yield, but will not completely compensate
for the lower yields of severely lodged plants.
A University of Wisconsin study simulated plant lodging
at various growth stages and found that younger plants
straightened more with less effect on yield than did plants
that lodged at the pollination stage. In that study, plants
lodged at the pollination stage yielded 13 to 31% lower.
All plants were lodged in that study; the effect on yield
should be less if there is differential lodging as compared
with all plants lying over.
Lodging is a stress on the corn plant. With reduced photosynthesis,
plants will move plant sugars to the ear from stalk storage
earlier than normal. As a result, weak stalks occur and
stalk rots will invade the lower stalk at an earlier calendar
date. Weak stalks that are leaning because of wind lodging
may break over sooner, which will also add to the preharvest
Corn plants that are wind lodged will straighten some
and will do so in the next few days. Grain yield will be
reduced; the reduction will depend on the percentage of
plants lodged. Harvest losses could be higher, but minimized
with slower combine speeds. Harvesting may take longer
and be more stressful (in addition to the personal stress
caused by lower yields).