Tank mixing herbicides is an essential step to control certain weeds
in corn. The recommendation is to use at least two modes of action
to reduce the risk of herbicide resistance developing. There are
also new herbicide groups that make control of broadleaf weeds
like volunteer canola and wild buckwheat a lot easier. Avoid
certain group 2 and group 4 herbicides as their growth inhibiting
characteristics can be detrimental to corn development.
Managing risk
Crop rotations are always a key management area for crop success.
Avoid growing corn the year following canola. Canola doesn’t promote
the development of mycorrhiza, an organism essential for phosphate
uptake, in the soil. Corn has a high phosphate demand so there can
be subtle yield differences based on rotation management.
Protecting the investment
It’s all about the “N”
The application standard of N (nitrogen) ranges from one to one and
a half pounds of N per bushel of grain, or an average of one and a
quarter pounds per bushel as a guide. The key is to understand the
growing area and realistic yield performance. Yield targets must
take this into account as well as past performance.
Studies over the last 10 years are finding that the early maturing
hybrids are staying healthier longer. There is now a higher demand
for nitrogen uptake after tassel. A new standard is being set with
research showing that corn now requires 65 percent of its nitrogen
before tasseling and 35 percent later in the season. Delayed
release nitrogen fertilizers should be considered as they are well
suited to corn production and the late season demand.
Following 4R nutrient stewardship management guidelines of
right source, right time, right amount and right place, growers
and agronomists need to find the balance of fall anhydrous, front-
loading prior to planting, in-crop application prior to tasseling as
well as manure management.
One of the more serious issues for western Canadian corn growers
is the European corn borer. Most of the corn hybrids in Canada
include protection against this insect.
Two modes of action have been developed for corn hybrids and
the refuge requirement has been reduced to five percent. Based
on CFIA guidelines on packaging the refuge requirement is now
included directly in the bag with the treated seed so growers may
see “Refuge in bag” (or RIB) when purchasing their corn seed.
A little high maintenance but worth it
With the continually improving and early maturing hybrids, more
western Canadian growers are looking to add corn to their rotation.
There is certainly a lot to consider. Successful corn production
requires strong genetics, seed treatments and warm soil to begin,
early weed control and ongoing, substantial, well-timed applications
of fertilizer. It is a high input crop but there are very few crops in
Western Canada that are yielding hundreds of bushels per acre.
O
Prepare your field for success
Corn seedling emergence is very dependent on heat accumulation. By conditioning soils,
removing previous crop residues and planting into warm, moist soil, crop establishment
is sped up and target plant populations are more readily achieved.
Ready your planters
Corn requires precise placement and spacing to maximize yield. Each plant that doesn’t
emerge, or emerges more than 48 hours after another plant, is lost yield potential.
Growers should ensure planters are calibrated and set up according to each seed lot,
in addition to inspecting and replacing worn parts, and test the planter to ensure seed
is placed properly and uniformly.
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