Thoughts on Corn Planting Dates
As the end of March approaches, the anticipation of the start of another
planting season is mounting among the faithful patrons of the Chat n Chew
Café. Even the excitement of NCAA basketball doesnt hold a candle
to the enthusiasm of the speculation about who will be the first to actually
put corn in the ground instead of just pulling the planter around the
neighborhood and agitating those trying to be patient about the whole thing.
Can you plant too early? Yes. Can you plant too late? Yes. Do you always
know ahead of time when the right time was to plant? Not always.
What are the risks and benefits to early planting of corn?
Benefits of Early Planted Corn.
- More days available to plant compared to starting later.
- More days available to develop the crop compared to later planted
- Pollination occurs earlier in the summer when temperatures and soil
moisture are typically more favorable for growth and development.
- The shorter plant height of early-planted corn improves the
standability of the crop nearer to harvest.
- Maturity occurs earlier in the season and grain dry down occurs more
quickly due to the relatively warmer temperatures.
Risks of Early Planted Corn.
Typically cool soils from late March through mid-April often result in
lengthy germination and emergence periods, as well as lengthy periods for early
seedling development until the crop is established. It is not uncommon for
emergence to take from two to three weeks after planting to occur, rather than
a more desirable five to seven days. Uneven soil temperatures within the seed
zone may result in uneven germination and emergence, causing potential yield
losses of eight to ten percent.
Successful establishment of the plants permanent root systems
(nodal roots) may also be delayed when soil temperatures are sub-optimal for
root development. Until a plants permanent root system is established,
the young seedling is very susceptible to damage to the kernel or mesocotyl.
Such lengthy periods for early crop growth and development increase the young
seedlings exposure to disease, insect and weather (especially frost)
stresses. Plant death or stunting from such stresses can result in potential
yield loss when ensuing stands of corn are less than optimum.
Hedging Your Bets.
- Within reason, avoid planting extensive acreages when soil
temperatures are not conducive to rapid germination, emergence and early
seedling development. The definition of conducive basically means
average soil temperatures consistently greater than 50 degrees F. For central
Indiana, such soil temperatures typically occur beginning about the third week
- Within reason, avoid tilling or planting when soil moisture
conditions are ripe for the creation of soil compaction. Root
development, especially depth of rooting, can be dramatically restricted when
compacted tillage layers exist and lessen the crops ability to tolerate
drier soil conditions later in the summer.
- For early plantings, plant your best quality seed with the greatest
seedling vigor ratings. Save poorer quality seed lots and/or hybrids with
lesser seedling vigor ratings for later plantings when temperatures should be
more favorable for germination, emergence and early seedling development.
- For early plantings, consider using one of several available
planter-box seed treatments to obtain additional protection from soil-borne
insects during the critical early development stages. If a portion of your
purchased seed corn is pretreated with Gaucho" or Prescribe" insecticides, use
those seed lots first in your planting schedule and plant your normally treated
information about corn, take a look at the Corn Growers Guidebook on the World
Wide Web at http://www.kingcorn.org
It is the policy of the Purdue
Agronomy Department that all persons shall have equal opportunity and
access to its programs and facilities without regard to race, color, sex,
religion, national origin, age, or disability. Purdue University is an Affirmative Action
employer. This material may be available in alternative formats.
© 2001, Purdue University
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