Top Crop Manager

Early planting corn working

But recognition still slow for some.

November 12, 2007  By Top Crop Manager

32aIn a season so fraught with weather and growing extremes, proponents of early
planting corn are standing by what they have been saying. Namely, that when
the conditions present themselves, get into the fields and get planting.

It may be overstating the obvious to some, but for a significant number of
growers the trend is only slowly gaining popularity. With each spring's arrival,
the same words are spoken with increasing frequency: plant according to conditions,
not the calendar. But traditions are hard to overcome and talk around the coffee
shop can instill some hesitation over concerns of a late spring frost.

Yet science is beginning to indicate there is a benefit in adhering to the
conditions, in spite of weather anomalies. Clare Kinlin, Syngenta Seeds' field
agronomist for Central Ontario, is one proponent of early planting in corn,
even where weather is the humbling influence as it was during the 2004 growing
season. As well, he has heard precautionary words from growers concerned with
waiting for optimal conditions. "You'd be surprised how many guys say,
'It's too cold, I'm going to wait until it warms up a little bit'," says
Kinlin, acknowledging the difficulties of planting corn, with spreading manure
or spraying a pre-plant herbicide, all within a limited window of opportunity.
"But in Ontario, we get 10 days to plant corn and if a grower wants to
waste the first five of them waiting for it to warm up, that's his choice."


Kinlin planted four plots at a seed dealer's farm near Listowel, Ontario. Each
was planted on different dates, specifically, May 1, May 4, May 17 and May 28.
Asked if there is a difference in yield comparing early to late planting, Kinlin
estimates there to be roughly a four bushel per acre difference for every 10
days. But the difference in quality is the greatest factor, at least in plots
he has seen in 2004. "If you're looking at 10 days, probably the biggest
advantages will be improved test weight and you'll have better dry-down,"
says Kinlin. "If growers are pushing the heat unit window, they have to
get that stuff in earlier."

Two points worth considering
A pair of additional observations that Kinlin makes is in working the soil and
fears concerning a killing spring frost. In working the soil: he suggests it
is best to open up only as much of the land as can be planted in a day. "Once
you open that land up and it rains, it takes forever to dry," he says,
noting the challenges as more growers juggle several tasks, all while trying
to push the limits on April planting.

As for worries of a late spring frost: so long as conditions have allowed for
adequate planting, there is no sense in worrying, says Kinlin. "If you
get a frost on the first of June, it doesn't matter because all of the corn
is going to be ruined," he concedes. At that point, whether it is five
leaf corn planted on May 1 or eight to 10 leaf corn planted on April 12 is irrelevant.

Kinlin also stresses that prior to an early frost, corn plants continue to
develop roots and metabolize in the ground. As long as oxygen is present, the
plant will grow, however slowly, even in cool conditions.

Dr. Bill Deen is another proponent of early planting in corn. At the FarmSmart
Expo at the Elora Research Station in July 2004, Deen, an assistant professor
at the University of Guelph, made his case for the trend framed against what
had been, up to that time, an abysmal growing season. He told growers that corn
planted in late April to the first week of May was already tasselling. Since
then, he has discussed the early planting practice with one grower who is convinced
his earliest planted corn is his best. "They're of the opinion now that
if it's April 20, and the ground is fit to go, they're planting," says

Weather is the great determinant
The proviso to this issue, of course, is the weather. It has to provide that
window of opportunity to work the soil and allow for optimum planting, without
compaction concerns. But Deen cites a pair of added issues which has given the
cause an extra push. One is the improved vigour of corn seed. Although much
of his perspective comes from anecdotal evidence, there seems to be more of
it with each passing year. One grower he knows is a long-time advocate of early
planting but in 2003, he accidentally planted his seed too deep. By Deen's estimate,
the seed sat in the ground for nearly four weeks, yet still provided an adequate
yield. "It's my impression that seed vigour is better, and enables us to
consider planting earlier," he says.

Early planting also can lead to early silking dates, which in turn lead to
a longer grain-filling period, further enhancing photosynthesis by taking advantage
of longer day-lengths and warmer temperatures.

The second of two issues is planting depth. As Deen mentioned at the FarmSmart
Expo, emergence is one of the key factors in the early advancement of the crop.
And planting depth is closely linked. "If you go too deep, you can run
into significant problems, especially if conditions turn cooler," says
Deen. "As much as possible, you still want that rapid, even emergence,
and if you plant early, planting depth becomes a more critical decision."


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