http://www.ag.ohio-state.edu/~corn/ |
|
January 24 - February 7, 2000
C.O.R.N. 2000-3
In This Issue:
A)
Management Tips for Optimizing Corn Yields and
Profits in 2000
Despite severe drought in the East and
flooding in localized areas during the 1999 growing season, grain surpluses and
record production in other parts of the Corn Belt have sharply reduced commodity
prices. This forces growers to critically evaluate inputs for next yearıs crop
production. The following is a list of proven production practices and reminders
to help corn growers increase their net income. Most of these involve cultural
practices that can be changed without increasing the cash cost of production but
require a higher level of management. Low or no-cost crop production
considerations coupled with superior management skills can help crop producers
survive this period of economic stress.
1. CHOOSE HIGH YIELDING, ADAPTED HYBRIDS.
Corn acreage, soil type, tillage
practices, desired harvest moisture, and pest problems determine the need for
such traits as drydown rate, disease resistance, early plant vigor, etc. End
uses of corn should also be considered. The most important factors for hybrid
selection are maturity and yield potential/stability.
Other characteristics for consideration
are stalk quality, drydown, and disease resistance. Pick hybrids that have
produced consistently high yields across a number of locations and years.
Hybrids of similar maturity may vary in yield potential by as much as 30 to 40
bushels per acre. Choosing a hybrid because it possesses a particular trait does
not ensure high yields; instead, look for yield stability across environments.
Consult results of state, company, and county performance trials before
purchasing hybrids.
Because weather conditions are unpredictable, the
most reliable way to select superior hybrids is to consider performance during
the past one to two years over a wide range of locations and climatic
conditions. When using University performance trials, choose some of the highest
yielding hybrids from the two year, several location average.
2. PLANT HYBRIDS OF DIFFERENT
MATURITIES to reduce damage from diseases and environmental stress at different
growth stages (improving the odds of successful pollination) and to spread out
harvest time and workload. Consider spreading hybrid maturity selections between
early-, mid- , and full-season hybrids-for example, a 25-50-25 maturity
planting, with 25% in early- to mid-season, 50% in mid- to full-season, and 25%
in full-season. Planting a range of hybrid maturities is probably the simplest
and most effective way to diversify and broaden hybrid genetic backgrounds.
3. COMPLETE PLANTING BY MAY 10: If soil
conditions are dry, begin planting before the optimum date. (The recommended
time for planting corn in northern Ohio is April 15 to May 10 and in southern
Ohio, April 10 to May 10). Avoid early planting on poorly drained soils or those
prone to ponding. Yield reductions resulting from "mudding the seed
in" may be much greater than those resulting from a slight planting delay.
Growers with the equipment capability should plant more than half of their corn
acres prior to the optimum planting date. This will allow all the corn acres to
be planted prior to the ideal calendar date. During the two or three weeks of
optimal corn planting time, there is on the average about one out of three days
when field work can occur. This emphasizes the need to begin planting as soon as
field conditions will allow, even though the calendar date may be before the
optimal date. As a guide, soil temperature is not as reliable as is calendar
date for making the decision on when to begin to plant corn. Earlier maturity in
the fall with more time for field drying, earlier plant emergence and ground
cover in the growing season, as well as better stalk quality, are all advantages
of planting early.
4. PLANT FULL-SEASON HYBRIDS FIRST,
then alternately plant early-season and mid-season hybrids, to take full
advantage of maturity ranges. Full-season hybrids generally show greater yield
reduction when planting is delayed compared with short -to mid-season hybrids.
In areas with longer growing seasons, consider planting some acreage to early
hybrids first to have new corn for the early market. Planting early hybrids
first, followed by mid season, and lastly the full season hybrids spreads the
pollination interval for all the corn acres over a longer time period and may be
a good strategy for some drought prone areas.
5. ADJUST SEEDING DEPTH ACCORDING TO
SOIL CONDITIONS: Plant between 1 1/2 to 2 inches deep to provide for frost
protection and adequate root development. In April, when soils are usually moist
and evaporation rate is low, seed should be planted shallower - no deeper than 1
1/2 inches. As the season progresses and evaporation rates increase, deeper
planting is advised. When soils are warm and dry, corn may be planted up to 2
inches on non-crusting soils. Consider seed press wheels or seed firmers to
ensure good seed-soil contact.
Risks associated with shallower
planting depths are the possibility of poor development of the permanent root
system under hot, dry conditions and shoot uptake of soil applied herbicides.
Seeding depth should be monitored periodically during the planting operation and
adjusted for varying soil conditions. Irregular planting depths contribute to
uneven plant emergence that can reduce yields.
6. ADJUST SEEDING RATES ON A FIELD-
BY-FIELD BASIS using the yield potential of a site to determine the appropriate
plant population. Higher seeding rates are recommended for sites with high yield
potential, high soil fertility levels and water holding capacity. On soils that
typically average yields of 160 bushels per acre or more, final stands of
28-30,000 plants per acre or more may be required to maximize yields. High plant
populations are also warranted when irrigation is used to maximize crop
performance.
Lower seeding rates are preferable when
droughty soils or late planting(after June 1) limit yield potential. On soils
that average 120 bushels per acre or less, final stands of 20,000 to 22,000
plants per acre may be adequate for optimal yields. Under drought stress
conditions, high plant populations do not cause significant yield reduction.
Planting rate or population can be cut to lower seed costs but this approach
typically costs more than it saves. When planting occurs in cold soils, the
seeding rate should be 15% higher than the desired harvest population. Follow
seed company recommendations to adjust the population for specific hybrids.
7. IMPROVE STAND ESTABLISHMENT:
Uneven plant spacing and emergence can
reduce yield potential. Seed should be spaced as uniformly as possible within
the row to ensure maximum yields and optimal crop performance - regardless of
plant population and planting date. Corn plants next to a gap in the row may
produce a larger ear or additional ears compensating to some extent for missing
plants. Although missing plants cause greater yield losses than doubles, under
stress conditions such as this past yearıs drought, crowding may result in
barren plants, ears too small to be harvested, stalk lodging and ear disease
problems. Reduced plant stands will yield better if plants are spaced uniformly
than if there are large gaps in the row.
8. PERFORM TILLAGE OPERATIONS ONLY WHEN
NECESSARY AND UNDER THE PROPER SOIL CONDITIONS.
Deep tillage should only be used when a
compacted zone has been identified and soil is relatively dry. Late summer and
fall are the best times of year for deep tillage. Avoid working wet soil and
reduce secondary tillage passes. Perform secondary tillage operations only when
necessary to prepare an adequate seedbed. Shallow compaction created by
excessive secondary tillage can reduce crop yields. Cloddy seed beds and soil
compaction contribute to uneven stands.
9. TAKE ADVANTAGE OF ROTATIONAL
BENEFITS:
Corn grown following soybeans will
typically yield 10-15% higher than corn grown following corn. Rotation benefits
are most pronounced following legumes such as soybean or alfalfa, especially in
reduced tillage systems on poorly drained soils.
Benefits from growing corn in rotation
with soybeans include 1)better weed control in both crops, 2) the opportunity to
rotate herbicides as crops are rotated (making it is less likely that certain
weed species will develop resistance), 3) less opportunity for an increase in
insect pests and diseases (Cash costs are reduced because rootworm insecticide
is not needed for first year corn), and 4) lower fertilizer nitrogen use is
possible without lowering corn yields.
10. DETERMINE HARVEST DATES BY CROP
MATURITY, NOT BY THE CALENDAR.
Plan to harvest fields with potential
lodging or harvest loss problems (such as stalk rot or deer damage) first. The
ideal kernel moisture level at which to harvest for dry grain storage is 25
percent.
Monitoring harvest losses is an
important part of the harvesting process. Ear corn losses from in front of the
combine (preharvest losses) should be subtracted from the total harvest loss
estimate. The loss of one normal-sized ear per 100 feet of row translates into a
loss of more than one bushel per acre. Most harvest losses occur at the
gathering unit.
Approximately 80% of the total machine
loss is caused by corn never getting into the combine. Drought-induced stalk
lodging and insect problems reduce the yield potential of many corn fields if
harvesting is delayed much beyond maturity. Estimates of harvest losses based on
long-term average data at Purdue University indicate that losses increase by 1
to 2% for each week of harvest delay. Ear damage by corn borers and other
insects may also increase the potential for grain quality problems caused by ear
molds. Dry shelled corn to 13 to 14%.
Readers can subscribe electronically to this newsletter by sending an e-mail message
to: corn-out-on@postoffice.ag.ohio-state.edu.
A successful subscription message will receive by an automatic reply from the listserv.
Contact your local Ohio State University Extension Office or e-mail
Past versions of C.O.R.N. can be found on the World Wide Web at: http:/www.ag.ohio-state.edu/~corn/archive/
C.O.R.N. is a summary of crop observations, related information, and appropriate recommendations for Ohio Crop Producers and Industry. C.O.R.N. is produced by the Ohio State University Extension Agronomy Team, State Specialists at The Ohio State University and Ohio Agricultural Research and Development Center. C.O.R.N. Questions are directed to State Specialists, Extension Associates, and Agents associated with Ohio State University Extension and the Ohio Agricultural Research and Development Center at The Ohio State University.
Contributors to C.O.R.N. include: State Specialists: Pat Lipps & Anne Dorrance (Plant Pathology), Hal Willson (Entomology), Peter Thomison (Corn Production), Jay Johnson (Fertility), Jim Beuerlein (Soybeans & Small Grain), Mark Loux (Weed Science), Jeff Stachler (Weed Science); District Specialists: Curtis Young (IPM), Ed Lentz (Agronomy) Jim Jasinski (IPM); Extension Agents: Mike Estadt (Pickaway), Tom Krill (Van Wert), Roger Bender (Shelby), Dave Jones (Allen), John Barker (Knox), Steve Bartels (Butler), Larry Lotz (Fayette), Ray Wells (Ross), Clark Hutson (Seneca), Barry Ward (Marion), Dennis Baker (Darke), John Hixson (Union), Bruce Clevenger (Defiance), Gary Wilson (Hancock), Greg La Barge (Fulton), Howard Siegrist (Licking) and Steve Prochaska (Crawford).
Editor: Greg LaBarge Web Editor: Nathan Watermeier
Information presented above and where trade names are used, they are supplied with the understanding that no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Keith L. Smith, Director, Ohio State University Extension.
TDD # 1 (800) 589-8292 (Ohio only) or (614) 292-1868
| C.O.R.N. | Newsletter | Archive | Search | Questions? | Ohioline | Publications |