Chad Lee Grain Crops Extension Univ. of Kentucky, Grain Crops Extension © 2008
Soil temperature Soil moisture Seeding depth Seed spacing 2 Univ. of Kentucky, Grain Crops Extension © 2008
Planting too early or too late can reduce yields Univ. of Kentucky, Grain Crops Extension ©
50 O F at a 2-inch depth for three or four days is excellent. Soil temperature at 50 O F at 7:00 am or 55 O F at 1:00 pm 4
Univ. of Kentucky, Grain Crops Extension © TownCoordinancesDate of Last Spring Occurrence of 32° F a,b (°)MedianEarly10%90%Late Owensboro 37.77N 87.11W 4/103/213/254/245/05 Paducah 37.08N 88.62W 4/083/073/224/184/23 Lexington 38.03N 84.44W 4/183/264/045/035/10 Princeton 37.09N 87.89W 4/103/213/264/213/26
Univ. of Kentucky, Grain Crops Extension © 2008 Planting Date: April 1 – May 1 (central and western KY) April 15 – May 15 (eastern KY) 6
Average Planting Date Corn Yield (Bu/Acre)* (6 -Yr Avg.) ( ) Avg. Loss (Bu/A) April April May May June *Average of 2 hybrids (Bt & Non-Bt) Univ. of Kentucky, Grain Crops Extension © J. Herbek and R. Bessin
Average Planting Date Corn Yield (Bu/A) ( ) Bt Hybrid Advantage (Bu/A) Non-Bt HybridBt Hybrid April April May May June Univ. of Kentucky, Grain Crops Extension © Herbek and Bessin
Average Planting Date Corn Yield (Bu/Acre)* (6 -Yr Avg.) ( ) Avg. Loss (Bu/A) April April May May June *Average of 2 hybrids (Bt & Non-Bt) Univ. of Kentucky, Grain Crops Extension © J. Herbek and R. Bessin
Optimum Corn Yields: mid-late April Yields declined: after May 1 Early May: Critical planting date for yield. In 3 of 6 years, yields declined. Other 3 years, had no yield loss. Univ. of Kentucky, Grain Crops Extension © Lexington, KY: Optimum planting for corn: May Herbek and Bessin
Princeton Lexington May April Univ. of Kentucky, Grain Crops Extension © 2008
Princeton Lexington Owensboro? May April Univ. of Kentucky, Grain Crops Extension © 2008
13 PlantingHendersonPrinceton DateAug 31 GDD Mar. 1, Apr. 5, Apr. 20, About 2700 to 3000 GDD’s needed for blacklayer. TownCoordinancesDate of Last Spring Occurrence of 32° F a,b (°)MedianEarly10%90%Late Owensboro 37.77N 87.11W 4/103/213/254/245/05 Paducah 37.08N 88.62W 4/083/073/224/184/23 Lexington 38.03N 84.44W 4/183/264/045/035/10 Princeton 37.09N 87.89W 4/103/213/264/215/26
Univ. of Kentucky, Grain Crops Extension © Hybrid Maturity (GDD) Planting Kentucky Location Date Date to Reach Black Layer Mayfield 3/15 7/288/88/20 4/1 8/18/138/24 4/15 8/68/188/30 5/1 8/148/269/8 5/15 8/239/49/19 6/1 9/59/2010/11 Bowling Green 3/15 7/278/78/19 4/1 7/318/128/23 4/15 8/58/178/29 5/1 8/128/249/5 5/15 8/219/29/16 6/1 9/39/1810/7 Henderson 3/15 7/278/88/20 4/1 8/18/138/24 4/15 8/68/188/30 5/1 8/148/259/7 5/15 8/239/49/19 6/1 9/59/2010/9
Planting Date 1 WAP2 WAP3 WAP4 WAP Mar 1, Mar 14, Apr 1, Apr 15, Apr 20, Univ. of Kentucky, Grain Crops Extension © About 100 GDD’s needed for complete emergence. About 200 GDD’s needed for V2 (two fully emerged leaves).
Univ. of Kentucky, Grain Crops Extension © TownCoordinancesDate of Last Spring Occurrence of 32° F a,b (°)MedianEarly10%90%Late Owensboro 37.77N 87.11W 4/103/213/254/245/05 Paducah 37.08N 88.62W 4/083/073/224/184/23 Lexington 38.03N 84.44W 4/183/264/045/035/10 Princeton 37.09N 87.89W 4/103/213/264/215/26
Univ. of Kentucky, Grain Crops Extension © 2008 1 ½ to 2 inches (into moisture) Tips to Reduce Planter Performance Effects on Corn Yield AGF Greg La Barge Extension Agent, Ohio State University Extension Dr. Peter Thomison Extension Specialist, Corn Production 17
Univ. of Kentucky, Grain Crops Extension ©
Univ. of Kentucky, Grain Crops Extension ©
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Univ. of Kentucky, Grain Crops Extension © Low areas High Areas
Univ. of Kentucky, Grain Crops Extension © Tillage (only when necessary) Deep ripping – only to alleviate compaction, conduct when soil is dry to improve cracking of the compacted layer Avoid the moldboard plow – quickest way to destroy soil structure and organic matter Exception: incorporate manure Use chisel plow or field cultivator, avoid powdering the soil surface
Univ. of Kentucky, Grain Crops Extension © Tillage – compaction concern Most likely to compact soil when tillage is conducted one day before soil is dry enough No-tillage – typically recovers from compaction quicker than tilled soils Compaction can and does occur in no-till, still need to be cautious
Univ. of Kentucky, Grain Crops Extension © Organic Matter and Soil Compaction G. Schwab
Spacing Between Rows (inches) Plant Population (plants/acre) Spacing Within Rows (inches) 3030, , Univ. of Kentucky, Grain Crops Extension © Variability up to 2 inches does not hurt yields. Variability above 2 inches will reduce yields. R.L. Nielsen
Spacing Between Rows (inches) Plant Population (plants/acre) Spacing Within Rows (inches) Allowable Within Row Spacing (inches) 3030, , Univ. of Kentucky, Grain Crops Extension © Variability up to 2 inches does not hurt yields. Variability above 2 inches will reduce yields. R.L. Nielsen
Univ. of Kentucky, Grain Crops Extension © mph 7.0 mph 3 locations in Ontario, Canada 2 years 28,900 seeds/acre * Sig. Difference between speeds Tollenaar et al Agron. J. 96: * * * * * * * * *
Univ. of Kentucky, Grain Crops Extension © Lauer and Rankin Agron. J. 96: (inches) 30,000 plants/acre Wisconsin 30,000 plants/acre Wisconsin
Univ. of Kentucky, Grain Crops Extension © Mg/ha = 120 bu/acre Liua et al Agron. J. 96: ,300 plants/acre Ontario 28,300 plants/acre Ontario inches
Liu et al., Crop Sci. 44: (2004). 4-inch deviation (doubles) 7-inch deviation (triples) 2-leaf delay4-leaf delay1-inch deviation 31 Univ. of Kentucky, Grain Crops Extension © 2008
Liu et al., Crop Sci. 44: (2004). 32 Univ. of Kentucky, Grain Crops Extension © 2008
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ECBSWCBBCWFAWCRW YieldGard CB YieldGard RW YieldGard Plus Herculex ++ - Herculex RW Herculex Xtra ++ Agrisure CB Agrisure RW Agrisure CB/RW R. Bessin, Univ. of Kentucky, Grain Crops Extension © 2008
WWWGFBSCMBCWCRW Gaucho Prescribe Cruiser Ex Pak Cruiser EP CRW Poncho Poncho R. Bessin, Univ. of Kentucky, Grain Crops Extension © 2008