US yields are increasing by over 2 bu/acre/year due to genetic and agronomic improvements. Here are management practices used by NCGA national contest winners, many of which can be applied to all corn production fields.
High-Yield Corn ProductionThis presentation summarizes management practicesused by NCGA national contest winners, many ofwhich can be applied to all corn production fields.
Corn Yield TrendsUS yields are increasing byover 2 bu/acre/year due togenetic and agronomicimprovements.• Hybrid Yield Potential• Transgenic insect resistance• Drought tolerance• High plant density tolerance• Early season stress tolerance Average corn grain yield in the US• Insecticide seed treatments compared to average of winners (1st, 2nd and 3rd place) of the NCGA national corn• Herbicides that improve weed yield contest in 2002 to 2011*. control * Yields have increased by over six• Higher plant populations bu/acre per year for irrigated classes and• Foliar fungicides by almost 3.5 bu/acre per year for non- irrigated classes.
Hybrid SelectionTo achieve highest possibleyields, growers should select ahybrid with: • Top-end yield potential • Full maturity for the field • Good emergence under stress • Drought tolerance • Disease resistance Seed brand planted by NCGA national corn yield contest winners with yields over 300 bu/acre and 350 • Insect resistance bu/acre in 2007 to 2011. • Good standability Your DuPont Pioneer sales pro-46 contest winners in the last fessional can help you select top5 years have had yields over hybrids for your area with specific300 bu/acre, with a majority insect-resistant traits and otherusing Pioneer® brand hybrids. traits best suited for each field.
Crop Rotation & Soil FertilityMost contest winnersplanted a crop other thancorn the year previous tothe contest (see graph).Add at least the level ofP and K that will beremoved by the crop.• A 250 bu/acre corn crop removes about 108 lbs of P2O5 and 68 lbs of K20 per acre.Soil pH should be at 6.2 Crop rotation used by winners of the NCGAor above for growing national corn yield contest in 2007 to 2011.corn.
Nitrogen (N) Rates & Application TimingCorn grain removes approximatelyone pound of N per bu harvested,and stover production requires ahalf-pound for each bu of grainproduced.• Fertilizer does not need to be the only source of N, take credit for previous legume crop, manure, soil organic matter, and N in irrigation water. Be sure that N is not limiting at key Timing of nitrogen application by corn development stages. winners of the NCGA national corn • N uptake by the corn plant peaks yield contest in 2007-2011. between V12 and VT (tasseling). • N requirement is high beginning at V6 and extending through the early dent stage. • Contest winners largely avoided fall N and applied pre-plant or at planting. • Most contest winners also side-dressed N.
Starter, Micronutrients and ManureStarter fertilizer was appliedby over half of contestwinners to ensure thatseedling plants hadsufficient soil nutrients in theroot zone for optimum earlygrowth and development.Nearly half of contestwinners appliedmicronutrients – primarilyzinc, boron and sulfur.About one-third of contest Use of starter, micronutrients andwinners applied manure to manure by NCGA national corn yieldtheir fields, which supplies contest winners in 2007 to 2011.N, P and K to the crop in asteady form.
Planting DateWinning contest plots are usuallyplanted as early as practicalfor their geography. • Lengthens the growing season. • Moves pollination and initial ear-fill earlier. When pollination is completed in June or early July, heat and moisture stress effects may be reduced.When planting early, stand Good stand establishment is a aestablishment is a primary primary concern when planting early.concern. • Seedling diseases have increased in recent years due to earlier planting and higher levels of corn residue left on the soil surface. o DuPont Pioneer provides a stress emergence score as well as a premium seed treatment on all Pioneer® brand hybrids.
Planting Rate & Row WidthGenetic improvement of corn hybridsfor superior stress tolerance hascontributed to increased yields.Higher population has increasedyield per unit area by optimizing yieldcomponents: ears per acre, kernelsper ear and weight per kernel.Contest winners overwhelminglychose 30-inch rows for their contestplots, with a small number using 20- Corn research plot in 30-inch rows.inch rows and some using twin rowson 30-inch centers.• Research results on narrow and twin rows have shown advantages averaging 1-2% in the central Corn Belt and about 4% in Minnesota and the Dakotas.
Foliar Fungicide UseA 2012 DuPont Pioneersummary showed that in475 DuPont Pioneer on-farm and university studiesconducted from 2007 to2011 a positive yieldresponse to fungicideapplication occurred 80%of the time, with an averageyield response of 7.0bu/acre. • More growers are Foliar fungicide application by NCGA national treating their corn corn yield contest winners in 2007 to 2011. acres with a foliar fungicide.
Weed ControlIn 2011, all winners used hybrids withthe Roundup Ready® Corn 2 gene intheir contest plots.• Glyphosate was not typically the only herbicide used.• 75% of winners used 3 or more active ingredients in their herbicide program. This allowed growers to: o Control weeds early o Widen the window of control o Include multiple modes-of-action to manage resistant weeds and/or prevent resistance development.A pre-emergence followed by post-emergence herbicide program is likely tobe the most reliable and effective.
Other Practices and ConclusionsIn the last 5 contest years, insecticide seed treatments were usedby the vast majority of contest winners. • Some used other practices such as multiple deep tillage trips; planter calibration; soil and plant-applied insecticides; and “non-traditional” products such as root enhancers, growth regulators, and growth promoters. • It may be difficult to evaluate the effect of individual treatments when several are applied to a single plot. This complicates identifying useful products for the future, even if improved yields are obtained in the plot.Hybrid selection, crop rotation, nitrogen fertility, plant population,planting date and foliar fungicides are criticalfactors in achieving highest corn yields. • Growers using these practices are rapidly accelerating corn yields in contest plots as well as on production acres.