There's Still Time!
niform stands of corn are
important for achieving full yield potential from those bags of expensive seed
corn that you buy and plant. Uneven
plant-to-plant spacing and/or emergence can reduce yield potential by seven to
15 bushels per acre, with little hope of ever recovering that difference by
the end of the growing season.
Be sure to inspect your planter now while
theres still time to replace worn parts and make adjustments. If you
dont have the time or skills, then make arrangements for your dealer to
service your planter. Here are some tips and guidelines for planter maintenance
items. More specific help is available from your friendly, neighborhood planter
After planting is completed...
Hopefully, you already completed these items shortly
after you finished planting last spring. Put them on your "to-do" list for the
end of the coming planting season.
- One of the most important strategies for avoiding
excessive "weathering" of your planter is to protect the planter from the
elements in the off-season. Ideally, store the planter indoors. If this is not
possible, then at least store it under cover outside.
- Thoroughly lubricate all chains and bearings.
Clean disc openers and coulters; apply rust preventive "paint" to avoid rust
buildup. If practical, remove the planter chains and soak in oil until the next
Take advantage of spring fever (or cabin fever!)
during the winter and go over your planter with the proverbial fine-toothed
comb. A precursor to this activity is to locate the planters operations
manual and browse through it to refresh yourself on important pre-season
- Check and replace all worn out parts.
- Ensure that coulters and disc openers are aligned
accurately to ensure accurate furrow opening and seed placement.
- On Case planters, replace any worn seals and
check the trueness of fit of the seed drum to ensure uniform air pressure and
accurate seed metering.
- Adjust or replace worn disc openers. Worn openers
cut "W"-shaped furrows rather than "V" and may interfere with accurate seed
positioning and seed firming. Adjust the shims of the openers so that bottoms
of the openers just touch. Replace the openers when it is no longer possible to
adjust their closeness.
- Replace worn planter chains or rusty, stiff chain
links. Less than smooth operation of planter chains decreases seeding accuracy.
- Inflate tires to their proper air pressure. Under-
or over-inflated drive tires influence the accuracy of the planter transmission
settings for seed drop.
- Clean seed tubes and monitor sensors. Seed
treatment residues interfere with accuracy of monitor sensors. Mouse nests have
a bit of influence on uniformity of seed drop through the seed tubes.
- Check the bottom of each seed tube for wear that
changes the shape of the tube opening and influences the final trajectory of
the seed dropping from the seed tubes.
- For finger-pickup type planters, check the
finger-pickup backplates for rust buildup and seed treatment residues.
Excessive buildup of either rust or seed treatment residues may cause jerky
movement of the finger mechanism. Excessive rust buildup can also scarify or
damage the corn kernels, resulting in decreased seed quality the moment you
plant the seed. Also,
- Check for worn down dimples on the
backplates. If worn down, more double seed drops will occur.
- Check and adjust the tension on the fingers.
Misadjusted finger pressure directly affects the ability of the unit to
accurately singulate seed.
- Check the condition of seed conveyor belt. Age
and lengthy exposure to seed treatment residues results in brittleness that
interferes with the smooth travel of the belt. Remember that perfect
singulation by the seed metering unit may be offset by interference with the
seeds travel to the furrow.
- Finally, CALIBRATE THE PLANTER!
All the maintenance in the world is for naught if you
head to the field without calibrating the planter. Difference among seed lots
can influence planter calibration. Obviously, using a single planter for both
corn and soybean planting influences calibration. Time spent calibrating a
planter is time well spent.
- For pneumatic planters (air or vacuum), calculate
the seed weight for each seed lot you will be seeding. Do this by simply
dividing the number of seeds per bag by the weight of the bag. Both values are
listed either on the seed tag or on the bag itself. For example, an 80,000 seed
bag divided by 50 lbs equals 1600 seeds per lb. From the operations manual,
identify the correct pressure (air or vacuum) for the calculated seed weight.
Finally, identify the correct seed disc (or drum) for the calculated seed
weight. Do this for each seed lot you have purchased and record the results
somewhere that will be easily accessible during planting.
- From the planters operations manual,
identify the correct transmission setting for your desired seeding rate.
- Calibrate actual seed drop with the planter
transmission settings and the planter monitor readouts. Do the calibration at
normal planting speeds and seeding rates under as close to field conditions as
possible (not simply down the farm lane!). One trick to simplify locating seed
in the furrow without a lot of digging is to temporarily tie up the closing
wheels on one or more units during the calibration operation.
- While youre at it, calibrate any pesticide
and fertilizer planter attachments at same time. Application rates can easily
change from year to year.
- Check that the planter toolbar is parallel to the
soil surface when the planter is in the ground and running. The consequences of
not being parallel with the ground affect disc opener depth, press wheel
efficiency, and the adequacy of seed to soil contact.
A little attention and tender loving care paid to
your planter now will pay big dividends later in terms of more uniform stands
of corn and higher grain yields. The beauty of this advice is that most of the
maintenance and adjustments necessary for bringing a planter into shape are
relatively inexpensive, while the potential returns in yield can be quite
For other information about corn, take a
look at the Corn Growers Guidebook on the World Wide Web at
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Agronomy Department that all persons shall have equal opportunity and
access to its programs and facilities without regard to race, color, sex,
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employer. This material may be available in alternative formats.
© 2000, Purdue University
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