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Corn Seed Size
Corn producers have debated
the effect of seed size and shape on yield for years, yet research
has consistently shown that seed quality has a far greater affect
on plant emergence and crop performance than any differences in the
size of seed planted. That's why every Mycogen Seeds' corn conditioning
plant has undergone major renovations in recent years. New and gentler
equipment with gentle seed handling properties has been installed
to eliminate seed damage from the conditioning process. Seed is harvested
utilizing sweet corn harvesting and husking equipment which maintains
germination quality. The result from all of these efforts has been
the best quality seed ever produced by Mycogen Seeds. This emphasis
on quality is showing up in farmers' fields across the country regardless
of the size or shape of Mycogen® brand seed corn planted.
As early as 1937, Nebraska
researchers found that kernels taken from the base, tip and middle
of open-pollinated ears didn't differ in plant development or grain
yield. In the 1970s, researchers evaluated large and small seed from
single-cross hybrids with equal warm germination percentages; these
tests compared performance under three different planting dates (soil
temperatures) and three seeding depths. No difference in emergence
rate was seen as a result of seed size differences. The only observed
difference was that plants from larger seed had greater early season
plant height when compared to those from the smaller seed.
The size seed of corn is
controlled by the genetics of the parent plant. Seed size also can
be affected by the production year environment (temperature, moisture
and soil fertility), and the physiology of the parent lines.
The development of seed
on the ear begins with kernels at the base of the ear being fertilized
first and then continuing to the tip. Weather experienced by the plant
during pollination largely determines the size and shape of the seed.
Seed on a single ear can fall into 3 different size/shape categories,
with larger, round seed coming from the base, small rounds from the
tip and flat seeds from the center. No parent line will produce seed
all of one size or shape. However, some parent lines have a tendency
to produce larger seed sizes while others produce mainly smaller seed.
The introduction of plateless
planters has given corn growers the ability to plant seed corn of
any size or shape combination, without changing planter plates and
still ensuring proper planting rates. As a result, plant breeders
have been able to concentrate more of their efforts on producing the
best possible genetics for performance without worrying as much as
in the past about seed size and percent of "market-acceptable"
seed produced by each line.
Trials conducted at Iowa
State University, North Carolina State University and University of
Nebraska indicate that performance differences between various kernel
sizes are more likely due to stand establishment factors than to subsequent
growth factors.
The result of all of the
studies: quality difference can significantly affect emergence and
yield; seed size/shape has no measurable effect. As long as corn seed
is of good quality, and is planted in a manner that allows it to germinate
and emerge, there appears to be no reason for preferring one seed
size to another.
Buy and plant the corn
hybrids that you believe offer the greatest value in terms of genetic
potential, seed quality and price. Seed size or shape should be a
factor only as a preference between hybrids if genetic potential,
seed quality and price are the same.
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